TW202429203A - Bake-sensitive underlayers to reduce dose to size of euv photoresist - Google Patents

Abstract

Provided are patterning structure underlayers deposited between a substrate and an imaging layer, the underlayers having chemically labile, activatable bonds useful in extreme ultraviolet lithography. Reactive moieties may be released from the underlayer’s activatable bonds in the presence of heat, oxidizing gases and/or inert gases into the imaging layer above.

Description

Baking sensitive underlayers to reduce EUV resist dosage

The present disclosure relates generally to the field of semiconductor processing, and more particularly to extreme ultraviolet (EUV) photoresist (PR) lithography techniques and materials.

As semiconductor manufacturing continues to advance, feature sizes continue to shrink, requiring new processing methods. One area where progress is being made is in patterning, for example using photoresists that are sensitive to lithographic radiation.

The prior art description provided here is for the purpose of generally presenting the background of the present disclosure. The work results of the inventors named in this case, the scope of the prior art paragraph so far, and the implementation forms that may not be qualified as prior art at the time of application are not explicitly or implicitly admitted as prior art against the content of the present disclosure.

Provided herein is a patterned structure bottom layer deposited between a substrate and an imaging layer, the bottom layer having chemically labile (activatable) bonds useful in EUV lithography. In the presence of heat, oxidizing gases and/or inert gases, reactive moieties can be released from the activatable bonds of the bottom layer into the imaging layer above. Their interaction within the imaging layer triggers the desired reaction, such as crosslinking, which has many benefits, including reducing dose size and increasing adhesion. The use of the bottom layer results in synergistic results when post-exposure baking is performed after EUV exposure. After development, scum and roughness can also be reduced. Various embodiments herein relate to bottom layers, methods for optimizing their use, patterned structures, and equipment for depositing bottom layers on substrates.

Thus, in a first aspect, the present invention comprises a method for optimizing the formation of a patterned structure. In some embodiments, the method comprises

Providing a substrate; selecting a carbon-containing underlayer including a plurality of activatable portions for deposition on the substrate, wherein the carbon-containing underlayer is selected to generate reactive species upon activation by heating, treatment with an oxidizing gas, treatment with an inert gas, or a combination thereof; depositing the selected carbon-containing underlayer on the substrate; and forming a film of a radiation-sensitive imaging layer on the selected underlayer; and whereby the interaction between the reactive species and the film reduces the amount of radiation used for effective photoresist exposure of the patterned structure.

In some embodiments, the activatable moieties include hydroxyl, carboxyl, peroxy, ^sp2 carbon, sp carbon, unsaturated carbon-containing bonds, allyl CH bonds, ether alpha CH bonds, vinyl CH bonds, aldehyde CH bonds, tertiary CH bonds, benzyl CH bonds, ketone alpha CH bonds, or combinations thereof.

In some embodiments, the carbon-containing base layer includes a carbon-doped film.

In some embodiments, the carbon-doped film is doped with halogens, metals, organometallic complexes, hydrogen, oxygen, or combinations thereof.

In some embodiments, the metal includes antimony, tin, bismuth, indium, tellurium, gold, platinum, palladium, nirconium, iridium, titanium, ruthenium, rhodium, silver, tungsten, or combinations thereof.

In some embodiments, the organometallic complex comprises an organometallic complex having an oxidizable metal-carbon bond.

In some embodiments, heating includes heating to a temperature of about 100°C to 250°C.

In some embodiments, the oxidizing gas includes chlorine, nitric oxide, nitrogen dioxide, carbon monoxide, carbon dioxide, hydrogen peroxide, ozone, oxygen, or a combination thereof.

In some embodiments, the oxidizing gas is supplied in an inert gas as an oxidizing gas mixture.

In some embodiments, the oxidizing gas is supplied in an amount of about 10% to about 100% of the oxidizing gas mixture.

In some embodiments, the inert gas includes helium, neon, argon, krypton, xenon, radon, nitrogen, or a combination thereof.

In some embodiments, the carbon-doped film is doped with a halogen, antimony, tin, bismuth, indium, or tellurium, and the activation comprises heating.

In some embodiments, the activatable moieties include ^sp2 carbon, sp2 carbon, unsaturated carbon-containing bonds, allyl CH bonds, ether α-position CH bonds, vinyl CH bonds, tertiary CH bonds, benzyl CH bonds, or combinations thereof; and the activation comprises heating and treatment with an oxidizing gas.

In a second aspect, the present invention includes a method for manufacturing a patterned structure. In some embodiments, the method includes providing a substrate; depositing a baked sensitive base layer on the substrate; forming a film of a radiation sensitive imaging layer on the baked sensitive base layer; Exposing the film to extreme ultraviolet radiation to produce a film comprising a plurality of exposed areas and a plurality of unexposed areas; baking the film comprising the exposed areas and the unexposed areas to activate the bake-sensitive base layer to produce reactive substances, wherein the reactive substances produced in the bake-sensitive base layer preferentially interact with the exposed areas to form exposed cross-linked areas; and developing the film comprising the exposed cross-linked areas and the unexposed areas; whereby the interaction between the reactive substances and the exposed areas reduces the amount of radiation used for effective photoresist exposure of the patterned structure; and wherein exposing the cross-linked areas increases the contrast between the exposed areas and the unexposed areas.

In a third aspect, the present invention includes a method for manufacturing a patterned structure. In some embodiments, the method includes providing a substrate; Depositing a bake-sensitive base layer on the substrate, the bake-sensitive base layer including a top base layer surface and a bottom base layer surface; Forming a film including a radiation-sensitive imaging layer on the top base layer surface of the bake-sensitive base layer; Baking the film to activate the bake-sensitive base layer to generate a reactive substance, wherein the reactive substance generated in the bake-sensitive base layer interacts with the film; and thereby, the interaction between the reactive substance and the film reduces the amount of radiation used for effective photoresist exposure of the patterned structure.

In a fourth aspect, the present invention includes a method for manufacturing a patterned structure. In some embodiments, the method includes providing a substrate; depositing a bake-sensitive base layer on the substrate; forming a film including a radiation-sensitive imaging layer on the bake-sensitive base layer; exposing the film to extreme ultraviolet radiation to produce an exposed film; and baking the exposed film to activate the bake-sensitive base layer to produce a reactive substance, wherein the reactive substance produced in the bake-sensitive base layer interacts with the exposed film; and whereby the interaction between the reactive substance and the exposed film reduces the amount of radiation used for effective photoresist exposure of the patterned structure.

In some embodiments, the baking includes heating, contacting the film with an inert gas, contacting the film with an oxidizing gas, or a combination thereof.

In some embodiments, the reactive species interacts with the exposed film to promote cross-linking of the exposed film.

In some embodiments, the reactive species is an oxygen-containing reactive species.

In some embodiments, the baking comprises heating to a temperature of about 75°C to 280°C.

In some embodiments, the oxidizing gas includes chlorine, nitric oxide, nitrogen dioxide, carbon monoxide, carbon dioxide, hydrogen peroxide, ozone, oxygen, or a combination thereof.

In some embodiments, the oxidizing gas is supplied in an inert gas as an oxidizing gas mixture.

In some embodiments, the oxidizing gas is supplied in an amount of about 10% to about 100% of the oxidizing gas mixture.

In some embodiments, the method further includes increasing adhesion between the substrate and the radiation-sensitive imaging layer due to the interaction of the reactive species with the exposed film.

In some embodiments, the inert gas includes helium, neon, argon, krypton, xenon, radon, nitrogen, or a combination thereof.

In some embodiments, the bake-sensitive base layer is a carbon-containing film or a silicon-containing film.

In some embodiments, the bake-sensitive underlayer is a carbon-containing film.

In some embodiments, the bake-sensitive base layer has a plurality of activatable moieties, and the activatable moieties include hydroxyl, carboxyl, peroxy, ^sp2 carbon, sp carbon, unsaturated carbon-containing bonds, allyl CH bonds, ether α-position CH bonds, vinyl CH bonds, aldehyde CH bonds, tertiary CH bonds, benzyl CH bonds, ketone α-position CH bonds, or combinations thereof.

In some embodiments, the bake-sensitive base layer includes a carbon-doped film or a silicon-doped film.

In some embodiments, the carbon-doped film is doped with halogens, metals, organometallic complexes, hydrogen, oxygen, or combinations thereof.

In some embodiments, the metal includes antimony, tin, bismuth, indium, tellurium, gold, platinum, palladium, nirconium, iridium, titanium, ruthenium, rhodium, silver, tungsten, or combinations thereof.

In some embodiments, the organometallic complex comprises an organometallic complex having an oxidizable metal-carbon bond.

In some embodiments, the organic metal complex having an oxidizable metal-carbon bond includes organic ruthenium, organic platinum, organic palladium, organic iridium, organic gold, organic benzenium, or organic rhodium.

In some embodiments, the silicon-containing doped film is doped with halogens, metals, carbon, hydrogen, oxygen, or a combination thereof.

In some embodiments, the bake sensitive underlayer has a thickness of no more than 60 nm.

In some embodiments, the reactive species includes peroxyl radicals, hydroperoxyl radicals, oxygen radicals, hydroxyl radicals, hydrogen radicals, formate radicals, iodine radicals, carbon dioxide, carbon monoxide, water, iodine, hydrogen iodide, antimony hydride, hydrogen telluride, bismuth hydride, formate anions, superoxide anions, or combinations thereof.

In some embodiments, the substrate is a partially fabricated semiconductor device film stack; the substrate further includes or is a hard mask, an amorphous carbon film, an amorphous carbon hydride film, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a silicon carbide film, a silicon boron nitride film, an amorphous silicon film, a polycrystalline silicon film, or a combination thereof; the radiation sensitive imaging layer includes a tin oxide-based photoresist or a tin oxide hydroxide-based photoresist; and the bake sensitive underlayer includes a vapor-deposited film of carbon hydride doped with oxygen (O), silicon (Si), nitrogen (N), tungsten (W), boron (B), iodine (I), chlorine (Cl), or a combination of any two or more thereof, wherein the film has a thickness of no more than 60 nm.

In some embodiments, the bake sensitive underlayer is vapor deposited on the substrate using a hydrocarbon precursor in the absence or presence of an oxo carbon precursor to provide a carbon-containing film; and optionally wherein the oxo carbon precursor is co-reacted with hydrogen ( _H2 ) or a hydrocarbon, and optionally further co-reacted with a silicon (Si) source dopant.

In some embodiments, the hydrocarbon precursor is an alkane, an alkene, or an alkyne.

In some embodiments, the bake-sensitive underlayer is formed in the presence of a nitrogen-containing precursor, a tungsten-containing precursor, a boron-containing precursor, an iodine-containing precursor, a chlorine-containing precursor, a bromine-containing precursor, a fluorine-containing precursor, a platinum-containing precursor, a ruthenium-containing precursor, an iridium-containing precursor, a gold-containing precursor, a palladium-containing precursor, or a In the case of a precursor containing rhodium, a precursor containing zirconium, a precursor containing antimony, a precursor containing indium, a precursor containing bismuth, a tellurium, a precursor containing tin, a precursor containing silver, a precursor containing titanium, or a combination thereof, vapor deposition is performed using the hydrocarbon precursor to provide a doped film.

In some embodiments, the doped film includes iodine, a combination of iodine and silicon, or a combination of iodine, silicon, and nitrogen.

In some embodiments, the bake sensitive underlayer is vapor deposited on the substrate using a silicon-containing precursor co-reacted with an oxidant, and wherein the silicon-containing precursor is optionally further co-reacted with a carbon (C) source dopant.

In some embodiments, the bake-sensitive base layer is vapor deposited on the substrate by plasma enhanced chemical vapor deposition, wherein the plasma enhanced chemical vapor deposition is used as a termination operation for vapor deposition on the substrate.

In some embodiments, the bake-sensitive underlayer is vapor deposited on the substrate by plasma enhanced chemical vapor deposition or atomic layer deposition.

In some embodiments, the method further includes modifying the bake-sensitive base layer to provide a roughened surface, and optionally exposing the bake-sensitive base layer or the roughened surface to an oxygen-containing plasma after deposition to provide an oxygen-containing surface.

In a fifth aspect, the present invention comprises a patterned structure. In some embodiments, the patterned structure comprises a radiation-sensitive imaging layer disposed above a substrate; and a bake-sensitive base layer disposed between the substrate and the radiation-sensitive imaging layer, the bake-sensitive base layer being configured to reduce the amount of radiation used for effective photoresist exposure of the radiation-sensitive imaging layer.

In some embodiments, the bake-sensitive base layer is a carbon-containing film or a silicon-containing film.

In some embodiments, the bake-sensitive underlayer is a carbon-containing film.

In some embodiments, the carbon-containing film comprises a hydroxyl group, a carboxyl group, a peroxide group, an ^sp2 carbon, an sp carbon, an unsaturated carbon-containing bond, an allyl CH bond, an ether α-position CH bond, a vinyl CH bond, an aldehyde CH bond, a tertiary CH bond, a benzyl CH bond, a ketone α-position CH bond, or a combination thereof.

In some embodiments, the bake-sensitive base layer is a carbon-doped film or a silicon-doped film.

In some embodiments, the carbon-doped film is doped with halogens, metals, organometallic complexes, hydrogen, oxygen, or combinations thereof.

In some embodiments, the metal is antimony, tin, bismuth, indium, tellurium, gold, platinum, palladium, nirconium, iridium, titanium, ruthenium, rhodium, silver, tungsten, or a combination thereof.

In some embodiments, the organometallic complex is an organometallic complex having an oxidizable metal-carbon bond.

In some embodiments, the organic metal complex having an oxidizable metal-carbon bond is organic ruthenium, organic platinum, organic palladium, organic iridium, organic gold, organic benzene or organic rhodium.

In some embodiments, the silicon-containing doped film is doped with halogens, metals, carbon, hydrogen, or a combination thereof.

In some embodiments, the carbon-doped film is doped at about 0.01 to 20 atomic %.

In some embodiments, the radiation-sensitive imaging layer includes an extreme ultraviolet-sensitive inorganic photoresist layer, a chemical vapor deposition film, a spin-on film, a tin oxide film, or a tin oxide hydroxide film.

In some embodiments, the substrate is or includes a hard mask, an amorphous carbon film, an amorphous carbon film doped with boron (B), an amorphous carbon film doped with tungsten (W), an amorphous carbon hydride film, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a silicon carbide film, a silicon boron nitride film, an amorphous silicon film, a polycrystalline silicon film, or a combination thereof.

In some embodiments, the bake sensitive underlayer has a thickness of about 2 to 60 nm.

In some embodiments, the bake sensitive underlayer has a density of about 0.7 to 2.9 g/cm ³ ; optionally, wherein the underlayer further provides higher etch selectivity; and optionally, wherein the underlayer further provides lower line edge and line width roughness and/or lower dose to size.

In a sixth aspect, the invention comprises a spin coating method. In some embodiments, the method comprises spin coating an organic metal imaging layer on a baked sensitive bottom layer on a substrate; wherein the baked sensitive bottom layer is configured to reduce the amount of radiation used for effective photoresist exposure of the organic metal imaging layer.

In some embodiments, the method further comprises exposing the organometallic imaging layer to extreme ultraviolet radiation.

In some embodiments, the method further comprises developing the organometallic imaging layer using a wet developing technique after exposing the organometallic imaging layer to extreme ultraviolet radiation.

In some embodiments, the wet development is performed using an alkaline developer, an ammonium-based ionic liquid, a glycol ether, an organic acid, a ketone, or an alcohol.

In some embodiments, the wet development is performed using tetramethylammonium hydroxide, propylene glycol methyl ether, propylene glycol methyl ether acetate, 2-heptanone, ethanol, or a combination thereof.

In some embodiments, the method further includes performing a post-coating bake at a temperature less than 250°C after spin coating.

In some embodiments, the method further includes performing a post-exposure bake at a temperature below 280°C.

In some embodiments, the method further includes performing a post-development bake at a temperature below 280°C.

In some embodiments, the bake-sensitive base layer is provided by plasma enhanced chemical vapor deposition or vapor deposition.

In some embodiments, the organometallic imaging layer includes organotin.

In some embodiments, the organic metal imaging layer comprises organic zirconium, organic antimony, organic zinc, organic uranium, organic zinc, organic tellurium, organic indium or a combination thereof.

In some embodiments, the method further includes providing a hard mask between the substrate and the bake-sensitive bottom layer.

In some embodiments, the hard mask is a grayable hard mask.

In some embodiments, the bake-sensitive base layer comprises hydrogenated carbon.

In some embodiments, the bake-sensitive underlayer comprises carbon hydride doped with oxygen (O), silicon (Si), nitrogen (N), tungsten (W), boron (B), iodine (I), chlorine (Cl), bromine (Br), fluorine (F), platinum, ruthenium, iridium, gold, palladium, rhodium, nibosium, antimony, indium, bismuth, tellurium, tin, silver, titanium, or any two or more thereof; and optionally, the carbon hydride doped with iodine is configured to improve the generation of secondary electrons after exposure to radiation.

In some embodiments, the bake sensitive underlayer has a density of about 0.7 to 2.9 g/cm ³ ; and optionally, wherein the bake sensitive underlayer further provides higher etch selectivity; and optionally, wherein the bake sensitive underlayer further provides lower line edge and line width roughness and/or lower dose size.

In a seventh aspect, the present invention includes a method. In some embodiments, the method includes providing a baking sensitive base layer on a substrate, the baking sensitive base layer being a vapor-deposited film of carbon hydride; spin-coating an organic tin imaging layer on the baking sensitive base layer; exposing the organic tin imaging layer to extreme ultraviolet radiation; and developing the organic tin imaging layer using a wet developing technique.

In some embodiments, the wet development is performed using an alkaline developer, an ammonium-based ionic liquid, a glycol ether, an organic acid, a ketone, or an alcohol.

In some embodiments, the wet development is performed using tetramethylammonium hydroxide, propylene glycol methyl ether, propylene glycol methyl ether acetate, 2-heptanone, ethanol, or a combination thereof.

In some embodiments, the method further comprises performing a post-coating bake at a temperature less than 250°C after spin coating.

In some embodiments, the method further comprises performing a post-exposure bake at a temperature less than 250°C after the exposure.

In some embodiments, the method further comprises performing a post-development bake at a temperature below 250°C after development.

In some embodiments, the bake-sensitive base layer is provided by plasma enhanced chemical vapor deposition.

In some embodiments, the method further includes providing an ashable hard mask between the substrate and the bottom layer after spin coating.

In some embodiments, the carbon-doped film is a carbon-doped organic metal complex film, and the carbon-doped organic metal complex film is formed by vapor deposition of a carbon-doped film precursor and an organic metal complex.

In some embodiments, the carbon-doped film is a carbon-doped organic metal complex film, and the carbon-doped organic metal complex film is formed by alternately depositing a carbon-doped film precursor and an organic metal complex.

In some embodiments, the carbon-doped film is a carbon-doped organic metal complex film, and the carbon-doped organic metal complex film is formed by immersing the bake-sensitive base layer in a solution of the organic metal complex.

In some embodiments, the organic metal complex-doped carbon-containing film includes an organic metal complex layer located above the bake-sensitive underlayer.

In some embodiments, the organic metal complex-doped carbon-containing film has the organic metal complex dispersed in the bake-sensitive underlayer.

In some embodiments, the carbon-containing film doped with an organic metal complex includes an organic metal complex layer located above the bake-sensitive base layer, and an organic metal complex dispersed in the bake-sensitive base layer.

In an eighth aspect, the present invention includes a method for manufacturing a patterned structure. In some embodiments, the method includes providing a substrate; depositing a doped baked sensitive bottom layer on the substrate, wherein the doped baked sensitive bottom layer is doped with a dopant comprising iodine, antimony, bismuth, tellurium, and combinations thereof; forming a film of a radiation sensitive imaging layer on the doped baked sensitive bottom layer; baking the film including exposed areas and unexposed areas to activate the doped baked sensitive bottom layer, thereby generating reactive substances, wherein the doped baked sensitive bottom layer is doped with a dopant comprising iodine, antimony, bismuth, tellurium, and combinations thereof; forming a film of a radiation sensitive imaging layer on the doped baked sensitive bottom layer; baking the film including exposed areas and unexposed areas to activate the doped baked sensitive bottom layer, thereby generating reactive substances, wherein the doped baked sensitive bottom layer is doped with a dopant comprising iodine, antimony, bismuth, tellurium, and combinations thereof; forming a film of a radiation sensitive imaging layer on the doped baked sensitive bottom layer; baking the film including exposed areas and unexposed areas to activate the doped baked sensitive bottom layer, thereby generating reactive substances, wherein the doped baked sensitive bottom layer is doped with a dopant comprising iodine, antimony, bismuth, tellurium, and combinations thereof; forming a film of a radiation sensitive imaging layer on the doped baked sensitive bottom layer; The reactive species generated in the baking sensitive bottom layer preferentially interacts with the exposed areas to form exposed cross-linked areas; and the film including the exposed cross-linked areas and the unexposed areas is developed; whereby the interaction between the reactive species and the exposed areas reduces the amount of radiation used for effective photoresist exposure of the patterned structure; and wherein exposing the cross-linked areas increases the contrast between the exposed areas and the unexposed areas.

In some embodiments, exposing the film to extreme ultraviolet radiation also activates the doped baked sensitive base layer, thereby generating reactive species.

In a ninth aspect, the present invention includes a method for manufacturing a patterned structure. In some embodiments, the method includes providing a substrate; depositing a doped baked sensitive bottom layer on the substrate, the baked sensitive bottom layer including a top bottom layer surface and a bottom bottom layer surface, wherein the doped baked sensitive bottom layer is doped with a dopant including antimony, bismuth, tellurium, and combinations thereof; vapor-depositing a dopant on the top bottom layer surface of the doped baked sensitive bottom layer; A film comprising a radiation sensitive imaging layer; and baking the film to release the dopant from the doped baked sensitive base layer to produce a dopant reactive species, wherein the produced dopant reactive species interacts with the film; and whereby the interaction between the dopant reactive species and the film reduces the amount of radiation used for effective photoresist of the patterned structure.

In some embodiments, vapor depositing a film comprising a radiation sensitive imaging layer on the top base layer surface of the doped baked sensitive base layer also produces a doping reactive species.

In a ninth aspect, the invention includes an apparatus for processing a substrate. In some embodiments, the apparatus includes a processing chamber including a substrate support; a processing gas source connected to the processing chamber and flow control hardware; substrate handling hardware connected to the processing chamber; and a controller having a processor and a memory, wherein the processor and the memory are communicatively connected to each other, the processor is operatively connected to at least the flow control hardware and the substrate handling hardware, and the memory stores computer executable instructions for performing the operations described in any method described herein.

These and other aspects are further discussed below with reference to the drawings.

Herein, reference is made in detail to specific embodiments of the present disclosure. Examples of specific embodiments are shown in the accompanying drawings. Although the present disclosure will be described in conjunction with these specific embodiments, it will be understood that this is not intended to limit the present disclosure to these specific embodiments. On the contrary, it is intended to encompass alternatives, modifications, and equivalents that may be included within the spirit and scope of the present disclosure. In the following description, many specific details are set forth to provide a thorough understanding of the present disclosure. The present disclosure may be implemented without some, or all of these specific details. In other cases, known processing operations are not described in detail to avoid unnecessarily obscuring the present disclosure. Definitions

"Acyloxy" or "alkanoyloxy" as used interchangeably herein refers to an acyl or alkanoyl group as defined herein attached to the parent molecular group via an oxygen group. In certain embodiments, the alkanoyloxy group is -OC(O)-Ak, wherein Ak is an alkyl group as defined herein. In some embodiments, the unsubstituted alkanoyloxy group is a _C2-7 alkanoyloxy group. Exemplary alkanoyloxy groups include acetyloxy.

"Aliphatic" refers to a hydrocarbon group having at least one carbon atom to 50 carbon atoms (C _1-50 ), such as 1 to 25 carbon atoms (C _1-25 ) or 1 to 10 carbon atoms (C _1-10 ), wherein the hydrocarbon includes alkanes (or alkyl), alkenes (or alkenyl), alkynes (or alkynyl), including cyclic forms thereof, and further including straight chain and branched chain arrangements, as well as all stereo and positional isomers. Aliphatic groups are unsubstituted or substituted, for example, with functional groups described herein. For example, aliphatic groups may be substituted with one or more substituents described herein for alkyl.

"Alkenyl" refers to an optionally substituted _C2-24 alkyl group having one or more double bonds. An alkenyl group can be cyclic (e.g., _C3-24 cycloalkenyl) or acyclic. An alkenyl group can also be substituted or unsubstituted. For example, an alkenyl group can be substituted with one or more substituents described herein for an alkyl group.

"Alkenylene" refers to a polyvalent (e.g., divalent) form of an alkenyl group that is an optionally substituted _C2-24 alkyl group having one or more double bonds. An alkenylene group may be cyclic (e.g., _C3-24 cycloalkenyl) or acyclic. An alkenylene group may be substituted or unsubstituted. For example, an alkenylene group may be substituted with one or more substituents described herein for an alkyl group. Exemplary, non-limiting alkenylene groups include -CH=CH- or -CH= _CHCH2- .

"Alkoxy" refers to -OR, where R is an optionally substituted alkyl group as described herein. Exemplary alkoxy groups include methoxy, ethoxy, butoxy, trihaloalkoxy (e.g., trifluoromethoxy), and the like. Alkoxy groups can be substituted or unsubstituted. For example, alkoxy groups can be substituted with one or more of the substituents described herein for alkyl groups. Exemplary unsubstituted alkoxy groups include _C1-3 , _C1-6 , _C1-12 , _C1-16 , _C1-18 , _C1-20 , or _C1-24 alkoxy groups.

"Alkyl" and the prefix "alk" refer to branched or unbranched saturated hydrocarbon groups of 1 to 24 carbon atoms, such as methyl (Me), ethyl (Et), n-propyl ( n -Pr), isopropyl ( i -Pr), cyclopropyl, n-butyl ( n -Bu), isobutyl ( i -Bu), dibutyl ( s -Bu), tertiary butyl ( t -Bu), cyclobutyl, n-pentyl, isopentyl, dipentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, eicosyl, tetracosyl, etc. Alkyl groups may be cyclic (e.g., _C3-24 cycloalkyl) or acyclic. Alkyl groups may be branched or unbranched. Alkyl groups may also be substituted or unsubstituted. For example, the alkyl group may include a halogen alkyl group, wherein the alkyl group is substituted with one or more halogen groups as described herein. In another example, the alkyl group may be substituted with one, two, three, or four substituents in the case of an alkyl group of two or more carbon atoms, wherein the substituents are independently selected from the group consisting of: (1) C _1-6 alkoxy (e.g., -O-Ak, wherein Ak is an optionally substituted C _1-6 alkyl group); (2) an amino group (e.g., -NR ^N1 R ^N2 , wherein each of R ^N1 and R ^N2 is independently H or an optionally substituted alkyl group, or R ^N1 and R ^N2 and the nitrogen atom to which it is attached together form a heterocyclic group); (3) aromatic groups; (4) aromatic alkoxy groups (e.g., -O-Lk-Ar, wherein Lk is a divalent optionally substituted alkyl group and Ar is an optionally substituted aromatic group); (5) aromatic acyl groups (e.g., C(O)-Ar, wherein Ar is an optionally substituted aromatic group); (6) cyano groups (e.g., -CN); (7) aldehyde groups (e.g., -C(O)H); (8) carboxyl groups (e.g., -CO ₂ H); (9) C _3-8 cycloalkyl groups (e.g., monovalent saturated or unsaturated non-aromatic cyclic C _3-8 alkyl); (10) halogen (e.g., F, Cl, Br or I); (11) heterocyclic group (e.g., 5, 6, or 7-membered ring containing one, two, three, or four non-carbon heteroatoms such as nitrogen, oxygen, phosphorus, sulfur or halogen, unless otherwise specified); (12) heterocyclic oxy group (e.g., -O-Het, wherein Het is a heterocyclic group as described herein); (13) heterocyclic acyl group (e.g., -C(O)-Het, wherein Het is a heterocyclic group as described herein); (14) hydroxyl group (e.g., -OH); (15) N-protected amine group; (16) nitro group (e.g., -NO ₂ ); (17) pendoxy group (e.g., =O); (18) -CO ₂ ^RA , wherein ^RA is selected from (a) C ( ₁₉ ) _{-C(O)NR B R C , wherein each of RB and RC is independently selected from the group consisting of (a) hydrogen, (b) C 1-6 alkyl, (c) C 4-18} ^aromatic _{group and} (d) (C _4-18 aromatic group)C _1-6 alkyl (e.g., -Lk ^{- Ar} , wherein Lk is a divalent optionally substituted ^alkyl group and Ar is an optionally substituted aromatic group); and (20) -NR ^G R ^H , wherein each of ^RG and ^RH is independently selected from the group consisting of (a) hydrogen, ( _b ) N _- protected amine group, (c) C _1-6 alkyl, (d) C The present invention also includes _{a group consisting of (i) (C 3-8 cycloalkyl} ) C _1-6 alkyl (e.g., _-Lk -Cy, wherein Lk is a _divalent optionally substituted alkyl group as described herein, and Cy is an optionally substituted cycloalkyl group), wherein in one embodiment _, no two groups are bonded to the nitrogen atom via _a carbonyl group. The alkyl group may be a primary, secondary, or tertiary alkyl group substituted with one or more substituents (e.g., one _or more halogens or alkoxy groups). In some embodiments, the unsubstituted alkyl is C _1-3 , C _1-6 , C _1-12 , C _1-16 , C _1-18 , C _1-20 or C _1-24 alkyl.

"Alkylene" refers to a polyvalent (e.g., divalent) form of an alkyl group as described herein. Exemplary alkylene groups include methylene, ethylene, propylene, butylene, and the like. In some embodiments, the alkylene group is C _1-3 , C _1-6 , C _1-12 , C _1-16 , C _1-18 , C _1-20 , C _1-24 , C _2-3 , C _2-6 , C _2-12 , C _2-16 , C _2-18 , C _2-20 , or C _2-24 alkylene. The alkylene group may be branched or unbranched. The alkylene group may also be substituted or unsubstituted. For example, the alkylene group may be substituted with one or more substituents described herein for the alkyl group.

"Alkynyl" refers to an optionally substituted _C2-24 alkyl group having one or more radicals. Alkynyl groups may be cyclic or acyclic, and are, for example, ethynyl, 1-propynyl, etc. Alkynyl groups may also be substituted or unsubstituted. For example, alkynyl groups may be substituted with one or more substituents described herein for alkyl groups.

"Alkenylene" refers to a polyvalent (e.g., divalent) form of an alkynyl group that is an optionally substituted _C2-24 alkyl group having one or more bonds. Alkenylene groups may be cyclic or acyclic. Alkenylene groups may be substituted or unsubstituted. For example, an alkynylene group may be substituted with one or more substituents described herein for an alkyl group. Exemplary, non-limiting alkynylene groups include -CH≡CH- or _-C≡CCH2- .

"Amine" refers to -NR ^N1 R ^N2 , wherein each of R ^N1 and R ^N2 is independently H or optionally substituted alkyl, or optionally substituted aryl, or R ^N1 and R ^N2 together with the nitrogen atom to which they are attached form a heterocyclic group as defined herein.

Unless otherwise indicated, "aromatic" refers to a cyclic, conjugated group or moiety of 5 to 15 ring atoms having a single ring (e.g., phenyl), or multiple fused rings at least one of which is aromatic (e.g., naphthyl, indolyl, or pyrazolopyridinyl); that is, at least one ring and any optional multiple fused rings have a continuous and unlocalized pi-electron system. In general, the number of out-of-plane pi electrons corresponds to Huckel's rule (4n+2). The point of attachment to the parent structure is usually through the aromatic portion of the fused ring system. Aromatic groups can be unsubstituted or substituted, for example, with groups as described herein for alkyl or aryl. Other substituents can include aliphatic, halogenated aliphatic, halogen, nitrate, cyano, sulfonate, sulfonyl, and the like.

"Aromatic group" refers to any group of carbon-based aromatic groups, including but not limited to phenyl, benzyl, anthracenyl, anthryl, benzocyclobutenyl, benzocyclooctenyl, biphenyl, The term "aromatic group" also includes heteroaryl groups, wherein the heteroaryl group is defined as a group comprising an aromatic radical having at _least one heteroatom within the aromatic ring. Examples of heteroatoms include, but are not limited to, nitrogen, oxygen, sulfur, and phosphorus. Similarly, the term "non-heteroaryl" is also included in the term "aromatic group" to define a group that includes aromatic groups, and the aromatic group does not contain heteroatoms. The aromatic group can be substituted or unsubstituted. The aryl group can be substituted with one, two, three, four or five substituents described herein for the alkyl group.

"Arylene" refers to a polyvalent (e.g., divalent) form of an aromatic group described herein. Exemplary arylene groups include phenylene, naphthylene, biphenylene, triphenylene, diphenyl ether, dihydroacenaphthene, anthracene, or phenanthrenyl. In some embodiments, the arylene group is C _4-18 , C _4-14 , C _4-12 , C _4-10 , C _6-18 , C _6-14 , C _6-12 , or C _6-10 arylene. The arylene group can be branched or unbranched. The arylene group can also be substituted or unsubstituted. For example, the arylene group can be substituted with one or more substituents described herein for an alkyl or aromatic group.

"Arylene" refers to a divalent form of an arylene group as described herein, wherein the arylene group is attached to an alkylene group or a heteroalkylene group as described herein. In some embodiments, arylene is -L-Ar-, -L-Ar-L-, or -Ar-L-, wherein Ar is an arylene group and each L is independently an optionally substituted alkylene group or an optionally substituted heteroalkylene group.

"Atomic layer deposition" (ALD) refers to a vapor phase deposition process in which a deposition cycle, and preferably a plurality of successive deposition cycles, is performed in a processing chamber (i.e., a deposition chamber). Typically during each cycle, a precursor is chemisorbed onto a deposition surface (i.e., a substrate assembly surface, or a previously deposited underlying surface, such as material from a previous ALD cycle) to form a monolayer or submonolayer that is not susceptible to reaction with additional precursors (i.e., a self-limiting reaction). Thereafter, if desired, a reactant (i.e., another precursor or a reactant gas) may be introduced into the processing chamber to convert the chemisorbed precursor into a desired material on the deposition surface. Typically, the reactant is capable of reacting with the chemically adsorbed precursor. In addition, a purge step may be utilized during each cycle to remove excess precursor from the processing chamber after the chemically adsorbed precursor is converted and/or to remove excess reactant and/or reaction byproducts from the processing chamber.

"Carbonyl" refers to a -C(O)- group, which may also be represented as a >C=O or -CO group.

"Carboxyl" refers to a -CO ₂ H group.

"Carboxyalkyl" means an alkyl group, as defined herein, substituted with one or more carboxy groups, as defined herein.

"Carboxyaromatic" means an aromatic group, as defined herein, substituted with one or more carboxy groups, as defined herein.

Unless otherwise specified, "cyclic anhydride" refers to a 3-, 4-, 5-, 6-, or 7-membered ring (e.g., a 5-, 6-, or 7-membered ring) having a -C(O)-O-C(O)- group in the ring. The term "cyclic anhydride" also includes bicyclic, tricyclic, and tetracyclic rings, wherein any of the above rings is combined with one, two, or three rings independently selected from the group consisting of an aromatic ring, a cyclohexane ring, a cyclohexene ring, a cyclopentane ring, a cyclopentene ring, and another monocyclic heterocyclic ring. Exemplary cyclic anhydride groups include free radicals formed by removing one or more hydrogens from succinic anhydride, glutaric anhydride, maleic anhydride, phthalic anhydride, isobutylene-1,3-dione, oxepanedione, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromelitic dianhydride, naphthalic anhydride, 1,2-cyclohexanedicarboxylic anhydride, and the like. Other exemplary cyclic anhydride groups include dioxo tetrahydrofuranyl, dioxo dihydroisobenzofuranyl, and the like. The cyclic anhydride group may also be substituted or unsubstituted. For example, the cyclic anhydride group may be substituted with one or more groups, including those described herein for heterocyclic groups.

Unless otherwise specified, "cycloalkenyl" refers to a monovalent unsaturated non-aromatic or aromatic cyclic alkyl radical having one or more double bonds and from three to eight carbons. Cycloalkenyls may also be substituted or unsubstituted. For example, a cycloalkenyl may be substituted with one or more groups including those described herein for alkyl.

Unless otherwise specified, "cycloalkyl" refers to a monovalent saturated or unsaturated, non-aromatic or aromatic cycloalkyl radical of from three to eight carbons, and examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclopentadienyl, cyclohexyl, cycloheptyl, bicyclo[2.2.1.]heptyl, and the like. Cycloalkyl groups may also be substituted or unsubstituted. For example, cycloalkyl groups may be substituted with one or more groups, including those described herein for alkyl groups.

"Halogen" means F, Cl, Br or I.

"Haloalkyl" means an alkyl group, as defined herein, substituted with one or more halogens.

"Heteroalkyl" refers to an alkyl group as defined herein containing one, two, three or four non-carbon heteroatoms (e.g., independently selected from the group consisting of nitrogen, oxygen, phosphorus, sulfur, selenium or halogen).

"Heteroalkylene" refers to a divalent form of an alkylene group as defined herein that contains one, two, three, or four non-carbon heteroatoms (e.g., independently selected from the group consisting of nitrogen, oxygen, phosphorus, sulfur, selenium, or a halogen). Heteroalkylene groups may be substituted or unsubstituted. For example, a heteroalkylene group may be substituted with one or more of the substituents described herein for an alkyl group.

Unless otherwise specified, "heterocyclic group" refers to a 3-, 4-, 5-, 6- or 7-membered ring (e.g., a 5-, 6- or 7-membered ring) containing one, two, three or four non-carbon heteroatoms (e.g., independently selected from the group consisting of nitrogen, oxygen, phosphorus, sulfur, selenium or halogen). A 3-membered ring has zero to one double bond, a 4- or 5-membered ring has zero to two double bonds, and a 6- or 7-membered ring has zero to three double bonds. The term "heterocyclic group" also includes bicyclic, tricyclic and tetracyclic groups, wherein any of the above heterocyclic groups is combined with one, two or three rings independently selected from the group consisting of an aromatic ring, a cyclohexane ring, a cyclohexene ring, a cyclopentane ring, a cyclopentene ring, and another monocyclic heterocyclic ring, such as indolyl, quinolyl, isoquinolyl, tetrahydroquinolyl, benzofuranyl, benzothienyl, etc. The heterocyclic group may be substituted or unsubstituted. For example, the heterocyclic group may be substituted with one or more substituents described herein for the alkyl group.

"Hydrogen" refers to a monovalent radical formed by removing a hydrogen atom from a hydrocarbon. Non-limiting unsubstituted alkyl groups include alkyl, alkenyl, alkynyl, and aryl groups as defined herein, wherein these groups include only carbon and hydrogen atoms. A alkyl group may be substituted or unsubstituted. For example, a alkyl group may be substituted with one or more of the substituents described herein for an alkyl group. In other embodiments, any alkyl or aryl group herein may be substituted with a alkyl group as defined herein.

"Hydroxy" refers to -OH.

"Hydroxyalkyl" refers to an alkyl group as defined herein substituted with one to three hydroxy groups, with the proviso that no single carbon atom of the alkyl group may have more than one hydroxy group attached thereto, examples of which are hydroxymethyl, dihydroxypropyl, and the like.

"Hydroxyaryl" refers to an aromatic group as defined herein substituted with one to three hydroxy groups, with the additional proviso that no more than one hydroxy group is attached to a single carbon atom of the aromatic group, examples of which are hydroxyphenyl, dihydroxyphenyl, and the like.

"Isocyanato" refers to -NCO.

"Oxygen anion radical" refers to the -O ^‒ radical.

"Oxo" refers to a =O group.

"Phosphino" refers to a trivalent or tetravalent phosphorus with a hydroxyl group. In some embodiments, the phosphino group is a -PR ^P ₃ group, wherein each ^RP is H, an optionally substituted alkyl group, or an optionally substituted aromatic group. The phosphino group may be substituted or unsubstituted. For example, the phosphino group may be substituted with one or more substituents described herein for the alkyl group.

"Selenol" refers to a -SeH group.

"Tellurol" refers to a -TeH group.

"Thioisocyanato" refers to -NCS.

"Thiol group" refers to a -SH group.

"Deposition" or "vapor phase deposition" refers to a process in which a metal layer is formed on one or more surfaces of a substrate from a vaporized precursor composition including one or more metal-containing compounds. The metal-containing compounds are vaporized and directed to and/or in contact with one or more surfaces of a substrate (i.e., a semiconductor substrate or semiconductor component) placed in a deposition chamber. Typically, the substrate is heated. The metal-containing compounds form a non-volatile, thin, uniform metal-containing layer on the surface of the substrate. One pass of the method is a cycle, and the process can be repeated as many cycles as needed to achieve the desired metal thickness.

"Etchant" refers to any compound used to remove material such as layers, byproducts or contaminants from a surface.

"Bakeout sensitivity" refers to the sensitivity to a specific temperature threshold plus a specific gas environment.

“Bake-Sensitive Underlayer” refers to an underlayer material that is sensitive to a specific temperature threshold plus a specific gas environment (i.e., oxidizing/reducing/inert, etc.), resulting in a chemical change that induces a DtS reduction that is beneficial to the imaging layer.

As used herein, the terms "top", "bottom", "upper", "lower", "above", and "below" are used to provide relative relationships between multiple structures. The use of these terms does not imply or require that a particular structure must be located at a particular location in a device.

The term "about" as used herein is understood to take into account minor increases and/or decreases beyond the recited values that do not significantly affect the expected function of the parameter beyond the recited values. In some cases, "about" includes +/-10% of any stated value. This term is used herein to modify any stated value, range of values, or endpoints of one or more ranges.

Extreme ultraviolet (EUV) lithography (typically at 13.5 nm wavelength) is considered to be a viable next generation lithography patterning technology. However, many technical barriers have delayed the widespread introduction and implementation of this technology. EUV photoresist (PR) is one of these barriers.

Known chemically amplified resists (CARs) offer an economical approach. However, organic polymer CARs produce line edge roughness (LER) and line width roughness (LWR), and have sensitivity and resolution limitations due to the random fluctuations of the polymer used. Recent research and development efforts have focused on the development of new EUV inorganic resist platforms. Such systems have several advantages over polymer-based CAR systems. These inorganic resists are typically based on metal oxides, including metal hydroxide oxides. The small metal oxide molecular size improves the final resolution of the patterning step, and metal oxide resists typically exhibit higher etch resistance than CARs, which can reduce the PR thickness to reduce the aspect ratio of the structure.

However, there are various challenges associated with inorganic PR. Spin-on carbon (SOC) hard mask materials are typically used in a hard mask film stack to which EUV PR is coated for patterning. But SOC has a soft carbon (C) rich film with poor etch resistance and LWR. Common hard mask materials such as silicon oxide (e.g., silicon dioxide, SiO2), silicon nitride, and ashable hard mask (AHM) can be used directly under the PR to obtain better etch selectivity and good LER and LWR. But delamination between EUV PR and hard mask materials, especially after wet development of EUV exposed PR, is a long-standing problem. Only about 20% of EUV photons are absorbed by a typical PR, which means that a large number of primary and secondary electrons are usually generated in the PR bottom layer. The dose to size (Dose to Dize, DtS) data show that in order to resolve the same critical line size, EUV inorganic PR deposited directly on common hard mask materials requires a higher dose than EUV inorganic PR on SOC.

As described herein, a thin underlayer film disposed directly below the EUV inorganic PR enables the film stack EUV inorganic PR to have improved performance. Specifically, a bake sensitive underlayer is an underlayer having a chemically labile or activatable portion. In some embodiments, the underlayer may be carbon-containing or silicon-containing. The activatable portion may be a component of the underlayer, added to the underlayer as a dopant, or may be a component of the underlayer and also originate from a dopant.

Sources of the carbon-containing film may include, but are not limited to, methane, acetylene, ethylene, propylene, propyne, propadiene, cyclopropene, butane, cyclohexane, benzene, and toluene.

In some embodiments, when the substrate is a carbon-containing substrate, it may have certain types of bonds that are susceptible to cleavage under appropriate conditions, which may include heat, oxidizing gases, or a combination of heat and oxidizing gases. Some examples of activatable C-H bonds include, but are not limited to, allylic C-H, ether alpha C-H, vinyl C-H, ketone alpha C-H, aldehyde alpha or on carbonyl carbon C-H, tertiary C-H, and benzyl C-H.

For such a carbonaceous substrate, the synergistic effect of the oxidizing gas results in the release of reactive moieties. These moieties can be reactive species including peroxyl radicals, hydroperoxyl radicals, oxygen radicals, hydroxyl radicals, hydrogen radicals, formate radicals, iodine radicals, carbon dioxide, carbon monoxide, water, iodine, hydrogen iodide, antimony hydride, hydrogen telluride, bismuth hydride, formate anions, superoxide anions, or combinations thereof.

Without wishing to be bound by theory, the reactive species (after release from the bake-sensitive underlayer having the activatable moiety) can diffuse into the imaging layer and cross-link the imaging layer material. This cross-linking results in a reduction in dose size.

For example, when the carbon-containing substrate is doped with a halogenide, an oxidizing gas may not be necessary because heat alone is sufficient to break the C-X bonds. For such substrates, the reactive species may include halogen radicals or anions.

In some embodiments, _the iodine doping source for the _carbon -containing substrate includes the precursor HI, _CH2I2 , _CH3I , _{ICH2CH2I , C2H4I} , _CF3I , or _{ICF2CF2I .}

In some embodiments, the bromine dopant source for _the carbon-containing substrate includes _the precursor HBr, _CH2Br2 , _CH3Br , _{BrCH2CH2Br , C2H4Br} , _CF3Br , or _{BrCF2CF2Br .}

In some embodiments, the chlorine doping source for the carbon-containing substrate includes the precursor HCl, _CH2Cl2 , _{CH3Cl , ClCH2CH2Cl , C2H4Cl , CF3Cl ,} or _{ClCF2CF2Cl .}

In some embodiments, the fluorine doping source for the carbon-containing substrate includes _the precursor HF, _{CH2F2 , CH3F} , _CF4 , _{FCH2CH2F , C2H4F} , _CF3F , or _{C2F6 .}

Similar to the example of the carbonaceous underlayer doped with halides, when the carbonaceous underlayer is doped with a metal or an organometallic complex, an oxidizing gas may not be necessary because heating alone is sufficient to break the C-M bonds.

In some embodiments, suitable metals include antimony, tin, bismuth, indium, tellurium, gold, platinum, palladium, zirconium, iridium, titanium, ruthenium, rhodium, silver, tungsten, or combinations thereof. The metal may be coated on the underlying layer as a thin layer or deposited with a precursor to the underlying layer.

In some embodiments, suitable organometallic complexes include organometallic complexes having oxidizable metal-carbon bonds, such as organorudium, organoplasmium, organopalladium, organoiridium, organogold, organobenium, or organorhodium.

The base layer doped with the organometallic complex can be produced by various techniques. In one embodiment, the base layer is first deposited on a substrate. Next, the base layer is soaked in the organometallic complex dissolved in a solution; and optionally heated. As a result of the soaking, the organometallic complex can be 1) deposited as a thin layer coating the base layer; 2) dispersed throughout the base layer; or 3) deposited as a thin layer and dispersed throughout the base layer.

In some embodiments, the solvent that can be used to dissolve the organometallic complex includes tetrahydrofuran, n-hexane, acetonitrile, ethanol, isopropanol or dimethyl sulfoxide. The soaking time can be about 20 seconds to about 5 minutes. During the soaking period, the solution can be optionally heated to a temperature of about 25° C. to about 150° C.

In some embodiments, suitable organic rhodium complexes include dicarbonyl(pentamethylcyclopentadienyl)rhodium(I).

Suitable organic zirconium complexes include bis(pentamethylcyclopentadienyl) zirconium and bis(cyclopentadienyl) zirconium.

Suitable organogold complexes include dimethyl(acetylacetonato)gold(III).

Suitable organic iridium complexes include (methylcyclopentadienyl)(1,5-cyclooctadiene) iridium(I) and 1-ethylcyclopentadienyl-1,3-cyclohexadiene iridium(I).

Suitable organic palladium complexes include allyl(cyclopentadienyl)palladium(II).

Suitable organic platinum complexes include (trimethyl)pentamethylcyclopentadienylplatinum(IV) and trimethyl(methylcyclopentadienyl)platinum(IV).

Suitable organic ruthenium complexes include those having cyclopentadienyl, cyclic unsaturated hydrocarbon, alkyl, alkenyl or β-diketone ligands.

The bottom layer may also be formed of a silicon-containing film. The silicon-containing film may be silicon oxide. In any embodiment, the silicon-containing film may be doped with halogens, metals, carbon, hydrogen or a combination thereof.

When heating is required, the heating may be performed at a susceptor temperature of about 75° C. to about 280° C. or to a temperature of about 75° C. to about 280° C. In some embodiments, two or more different temperatures may be used for different baking gas environments (i.e., a first bake in an oxidizing gas with heating; and a second bake in an inert gas (i.e., 100% N ₂ ) at a higher temperature than the first bake).

The duration of heating is variable and can be optimized for the selected substrate. In some embodiments, the duration can be from about 1 minute to about 10 minutes. In some embodiments, when two or more different temperatures are used, the first temperature can be maintained for a first duration of about 1 to about 5 minutes, and the second temperature can be maintained for a second duration of about 1 to about 10 minutes. The two durations can be the same length of time or different lengths of time.

The choice of oxidizing agent may vary and depend on the nature of the substrate selected. When an oxidizing agent is used, it may include chlorine, nitric oxide, nitrogen dioxide, carbon monoxide, carbon dioxide, hydrogen peroxide, ozone, oxygen, or a combination thereof.

The oxidizing agent may be delivered to the processing chamber in an inert gas. In addition, the bottom layer precursor may also be delivered in an inert gas. When the oxidizing gas is supplied as an oxidizing gas mixture (with an inert gas), the oxidizing gas may be supplied in an amount of about 10% to about 100% of the oxidizing gas mixture.

In certain embodiments, the inert gas is helium, neon, argon, krypton, xenon, radon, nitrogen, or a combination thereof.

In certain embodiments, the above-described underlayers may be utilized to optimize or fine-tune the production of patterned structures, as a dose size reduction may result based on the selection of an appropriate underlayer and treatment of the underlayer to release reactive species that promote crosslinking in the imaging layer. The treatment (baking or baking-type treatment) may be heating alone or with an oxidizing gas. Even when the treatment is a baking-type treatment only, beneficial effects may be measured without EUV exposure. The selection criteria for the underlayer will depend on the specific product or desired effect. In some embodiments, a doped underlayer may be selected. In some embodiments, a doped underlayer may be selected. For example, a halogenated doped bake-sensitive base layer may be selected when it is preferred to avoid the use of oxidizing agents because the halogenated doped bake-sensitive base layer can be activated in the presence of heat alone. In some embodiments, other dopants may be preferred to achieve the desired effect. In still other embodiments, doping may not be required to form a bake-sensitive base layer, where the material of the base layer itself already contains activatable bonds.

In certain embodiments, the above-described base layer can be used to prepare a patterned structure by subjecting it to EUV exposure and post-exposure baking. The reduction in dose size and/or the increase in adhesion is one of the beneficial effects obtained by the synergistic combination of these two lithography steps. The reduction in dose size is about 20% to about 60% compared to a non-baked sensitive base layer (a base layer lacking an activatable portion).

In certain embodiments, the above-described base layer may be used to prepare a patterned structure by subjecting it to EUV exposure, post-exposure baking, and development. In such methods, the active species generated from baking the sensitive base layer (during the PEB) will preferentially interact with the imaged EUV exposed areas compared to the unexposed areas. This means that the active species will not interact indiscriminately with the exposed and unexposed areas and will help increase the amount of cross-linking in the exposed areas of the imaged layer. This will produce additional chemical/material contrast in the imaged layer between the unexposed and exposed areas. The beneficial end result of this method is a reduction in pattern edge roughness and/or a reduction in scum.

Utilizing the above-described underlayer, the resulting multi-layer (e.g., dual-layer) hard mask solution has comparable or better DtS performance than EUV inorganic PR directly on the SOC stack. Moreover, the underlayer can also serve as an adhesion layer between the EUV inorganic PR and the hard mask, regardless of the film composition of the hard mask, thereby improving etch selectivity and LER/LWR performance. Surfaces other than hard mask can be used under the underlayer, wherein the underlayer can serve as an adhesion layer between the EUV PR and any practical substrate (e.g., hard mask, wafer, partially fabricated semiconductor device film stack, etc.).

As further described below, suitable base films may be deposited by chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), or other vapor deposition methods (e.g., by sputtering deposition, physical vapor deposition (PVD), including PVD co-sputtering). The base layer deposition process may be performed in either an etching tool (e.g., Kiyo® or Flex® available from Lam Research Corporation, Fremont, CA) or a deposition tool (e.g., Lam Striker®). In some embodiments, it may be integrated as a stop step in a hard mask deposition process. Different film compositions of the base layer can be selected depending on the film stack.

It should be understood that although the present disclosure is directed to lithographic patterning techniques and materials using EUV lithography as an example, it is also applicable to other next-generation lithography techniques. In addition to EUV (including the standard 13.5 nm EUV wavelength currently in use and under development), the radiation sources most relevant to this type of lithography are DUV (deep UV), which generally refers to the use of 248 nm or 193 nm excimer laser sources; X-ray, which is a form of EUV in the lower energy range that includes the X-ray range; and electron beams, which can cover a wide energy range. Such methods include those methods in which a substrate having exposed hydroxyl groups is contacted with a hydroxy-substituted tin terminator to form a hydroxy-terminated tin oxide (SnOx) film as an imaging/PR layer on the substrate surface. The specific method may depend on the specific materials and applications used in the semiconductor substrate and the final semiconductor device. Therefore, the methods described in this application are merely examples of methods and materials that can be used in the present technology.

FIG. 1 illustrates a process flow of one aspect of the present disclosure, namely, a method of manufacturing a patterned structure. The method 100 includes providing a substrate at 101. The substrate can be, for example, a hard mask, a film, a stack, a partially fabricated semiconductor device film stack, etc., fabricated in any suitable manner. In some embodiments, the substrate can include a hard mask disposed on a workpiece (e.g., a partially fabricated semiconductor device film stack). The hard mask located above the topmost layer of the film stack can have a variety of compositions, such as _SiO2 , silicon nitride, an ashable hard mask material, and can be formed by chemical vapor deposition, such as PECVD. In some embodiments, an ashable hard mask composed of an amorphous carbon film is desired. For example, the amorphous carbon film herein may be undoped or doped with boron (B) or tungsten (W). Suitable amorphous carbon films may have a composition including, for example, about 50 to 80 atomic % carbon (C), 10 to 20 atomic % hydrogen (H), and 5 to 40 atomic % B or W doping.

Other substrates may also be used. For example, the substrate may be or include amorphous carbon hydride, silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, silicon boronitride, amorphous silicon, polycrystalline silicon, or any combination of any of the above in any form (e.g., a bulk film, a thin film, another film, a stack, etc.).

At 103, a photoresist base layer is deposited on the substrate. The base layer is configured to increase adhesion between the substrate and a subsequently formed EUV-sensitive inorganic photoresist and reduce EUV dose for effective EUV exposure of the photoresist. The base layer may be or include a vapor-deposited film of hydrated carbon doped with O, silicon (Si), nitrogen (N), tungsten (W), boron (B), iodine (I), chlorine (Cl), or a combination of any of them (e.g., a combination of Si and O). In one embodiment, the film is deposited by introducing or delivering a hydrocarbon precursor (e.g., to provide carbon atoms) and a dopant precursor (e.g., to provide non-carbon atoms for doping). In another embodiment, the film is deposited by introducing or delivering a dopant-containing precursor (e.g., an iodine-containing precursor), wherein the dopant-containing precursor provides a doped film after deposition. In particular, hydrogenated carbon films doped with iodine can improve secondary electron generation after exposure to EUV radiation. Other non-limiting precursors and dopants used to provide such an underlayer are described herein.

The film may have a thickness of no more than about 60 nm. For example, the photoresist bottom layer may have a thickness of about 2 to 20 nm, such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, or 20 nm, and may optionally include about 0 to 30 atomic % O and/or about 20 to 50 atomic % hydrogen (H), 0 to 16 atomic % halogens such as iodine, fluorine, bromine, or chlorine, and/or 30 to 70 atomic % C. Other bottom layer properties are described herein.

In some embodiments, the base layer may be vapor-phase deposited on the substrate by PECVD or ALD using a hydrocarbon precursor, which may or may not contain carbon monoxide (CO) and/or carbon dioxide (CO ₂ ). In certain embodiments, vapor-phase deposition includes introducing or delivering a hydrocarbon precursor that does not contain CO and does not contain CO ₂ .

In some embodiments, the underlayer may be vapor-deposited on the substrate by PECVD or ALD using an oxocarbon precursor that co-reacts with hydrogen ( _H2 ) or a hydrocarbon. In variations of this embodiment, the oxocarbon precursor system may further co-react with a Si source dopant during deposition. In a particular embodiment, the oxocarbon precursor system may include CO or _CO2 . Without wishing to be limited by mechanism, the use of an oxocarbon precursor may include hydroxyl (-OH) groups or other oxygen-containing groups to the underlayer, which may provide a hydrophilic surface or a surface with a higher hydrophilicity (compared to an underlayer lacking, for example, -OH or oxygen-containing groups). In a non-limiting example, a hydrophilic surface may improve adhesion between the underlayer and the PR layer.

In other embodiments, a Si-containing precursor co-reacted with an oxidant (e.g., a carbon oxo-, an O-containing precursor, CO, or CO ₂ ) can be used and the bottom layer vapor-deposited on the substrate by PECVD or ALD. In a variation of this embodiment, the Si-containing precursor is further co-reacted with a C source dopant (e.g., a hydrocarbon precursor as described herein). Non-limiting Si-containing precursors are described herein, such as silanes, halogenated silanes, aminosilanes, alkoxysilanes, organosilanes, etc.

In some embodiments, the photoresist base layer may be vapor deposited on the substrate by PECVD, for example, by adjusting the flow of precursors into the PECVD processing chamber to achieve the desired composition of the base layer as a termination operation for vapor deposition on the substrate.

In other embodiments, the bottom layer can be vapor deposited on the substrate by PECVD to provide a hydrogenated carbon film. In some embodiments, the film is a low density film (e.g., 0.7-2.9 g/cm ³ ). In other embodiments, the undoped film (or the film before doping) has a density of less than about 1.5 g/cm ³ or a density of about 0.7-1.4 g/cm ^3. In still other embodiments, the doped film has a density of about 0.7-1.4 g/cm ³ .

The PECVD process may include any useful precursor or precursor combination. In one embodiment, the precursor is a hydrocarbon precursor (e.g., any of those described herein). Optionally, the doped hydrogenated carbon film is formed during PECVD by using a dopant-containing precursor (e.g., a nitrogen-containing precursor, a tungsten-containing precursor, a boron-containing precursor, and/or an iodine-containing precursor).

Deposition of the bottom layer may include the use of a plasma (e.g., in a PECVD process), including a transformer coupled plasma (TCP), an inductively coupled plasma (ICP), or a capacitively coupled plasma (CCP). In certain embodiments, deposition may use low TCP power (e.g., about 100 to 1000 W) with minimal bias (e.g., no bias) to provide a low density film. Of course, higher power plasmas may be employed, as described herein. In certain embodiments, the generation of a plasma (e.g., TCP or ICP) may be controlled by power in a continuous wave (CW) mode.

Deposition (e.g., using TCP or ICP power in CW mode) can include an applied bias (regardless of frequency) where the bias is pulsed at a duty cycle between about 1% and 99% (e.g., in a range of about 1 Hz to about 10 kHz, such as 10 to 2000 Hz). Additional pulse frequencies and duty cycles are described herein. In some embodiments, the applied pulsed bias can be provided to control ion energy. Non-limiting applied pulsed bias powers can be from about 10 to 1000 W, as well as other ranges described herein.

In yet other embodiments, the deposition system may include an applied CW bias. The CW bias may also be used to control ion energy. In some embodiments, the applied CW bias power may be from 10 to 1000 W (e.g., 10 to 500 W, 10 to 400 W, and other ranges described herein).

Still other conditions (e.g., useful for low density films) include using certain pressure conditions (e.g., such as 5 to 1000 mTorr, including 10 to 1000 mTorr, 10 to 500 mTorr, or 10 to 400 mTorr) and certain temperature conditions (e.g., such as about 0 to 100°C, including 0 to 50°C and 10 to 40°C).

Pulsed or continuous bias can be used to fine-tune the properties of the film. In one embodiment, a pulsed bias can provide a higher density film compared to a low density film prepared using a bias power of 0 W. In some cases, the higher density film can provide higher etch resistance compared to the low density film. In other cases, the higher density film can provide reduced undercut compared to the low density film prepared using a bias power of 0 W. Additional plasma conditions and processing are also described herein.

Referring again to FIG. 1 , at 105 , a radiation-sensitive imaging layer is formed on the base layer. For example, the imaging layer may include an EUV-sensitive inorganic photoresist. A suitable EUV-sensitive inorganic photoresist may be a metal oxide film, such as an EUV-sensitive tin oxide-based photoresist. Such photoresists (also referred to as imaging layers) and their compositions and uses are described, for example, in International Patent Application No. PCT/US2019/031618, filed on May 9, 2019, entitled “METHODS FOR MAKING EUV PATTERNABLE HARD MASKS,” Publication No. WO2019/217749, and in Patent Application No. 11, 2019, entitled “METHODS FOR MAKING HARD MASKS USEFUL IN NEXT GENERATION The international patent application No. PCT/US2019/060742 and publication No. WO2020/102085 of "LITHOGRAPHY" are introduced herein as references regarding the composition, deposition and patterning of metal-organic-based metal oxide films that can be directly photopatterned for forming EUV photoresist masks. As described therein, according to various embodiments, the EUV-sensitive inorganic photoresist can be a spin-on film or a vapor-deposited film.

2A-2C illustrate stages in the fabrication of a non-limiting patterned structure as described herein. The patterned structure shown in FIG2C has a hard mask 204 disposed on a substrate 202 (e.g., a wafer or a partially fabricated semiconductor device film stack). An imaging layer 208 is disposed over the hard mask 204. And, a bottom layer 206 is disposed between the hard mask 204 and the imaging layer 208. The bottom layer 206 can be configured to increase the adhesion between the hard mask and the imaging layer, and to reduce the amount of radiation to which the effective photoresist is exposed.

In the test structures according to the described embodiments, the DtS performance of EUV PR on amorphous carbon AHM with bottom layer as described herein was as good as or better than EUV PR on SOC, which in some cases reduced the required dose by 10% or more. In addition, no peeling of EUV PR from the hard mask double layer (amorphous carbon AHM with photoresist bottom layer) after development was observed.

The bottom layer 206 may also provide increased etch selectivity and/or reduced line edge and line width roughness (LER/LWR) in the structure. In a test structure according to the described embodiment, LER/LWR is improved by about 25% or more relative to EUV PR on AHM or SOC.

Referring again to Figures 2A to 2C, Figures 2A to 2B illustrate an embodiment of the fabrication of the structure of Figure 2C. For example, as described above with reference to Figure 1, Figure 2A shows a hard mask 204 disposed on a substrate 202, while Figure 2B shows a bottom layer 206 deposited on the hard mask 204.

The use of an underlayer within the stack can provide improved performance. In one instance, interaction between the underlayer and the imaging layer provides DtS reduction. As can be seen in FIG. 2D , the patterned structure includes a hard mask 214 disposed on a surface of a substrate 212, and an underlayer 216 disposed between an imaging layer 218 and the hard mask 214. Possible interactions include migration (or diffusion) of metal (M) atoms 218A from the imaging layer 218 into the underlayer 216; and/or migration (or diffusion) of hydrogen (H) atoms 216A from the underlayer 216 into the imaging layer 218. Without wishing to be bound by mechanism, such migration events may provide productive interactions between the base layer and the imaging layer, which may thereby help improve adhesion and/or DtS.

In addition, the composition of the base layer and the imaging layer can be designed to promote favorable reactions, thereby improving DtS. For example, as shown in Figure 2E, the imaging layer system can include a tin-based photoresist with radiation-cleavable ligands. After exposure to radiation (e.g., EUV), the ligands (R) are removed from the tin (Sn) center and Sn-H bonds are formed in its place. After the post-exposure bake (PEB) step, the Sn-H bonds participate in further heat-activated cross-linking reactions, thereby increasing the material property difference between the exposed photoresist and the unexposed photoresist.

Thus, in one instance, as shown in FIG. 2F , the bottom layer 226 may include a ligand (R ₁ ) that provides a releasable H atom upon exposure to EUV radiation to form _{a reacted ligand (R 1 *} ). Possible R ₁ groups include, for example, optionally substituted alkyl groups, and may be linear or branched. In the imaging layer 228, the EUV cleavable ligand R will provide an eliminated ligand R* and a reactive metal center Sn. The H atoms released from the bottom layer 226 may promote the formation of Sn-H bonds within the imaging layer 228, thereby reducing DtS. If the bottom layer also contains oxygen (O) atoms, these atoms can form MO bonds (e.g., Sn-O bonds) in the imaging layer, which can further reduce DtS. In addition, Sn atoms from the imaging layer 228 can diffuse into the bottom layer 226, allowing the generation of additional secondary electrons. Embodiment 1 : Dry deposition of the bottom layer

The bottom layer can be deposited using any useful means. In one instance, the deposition includes vapor phase deposition of a hydrocarbon precursor or a carbon-containing precursor (e.g., any of the precursors described herein). The deposition can include using a process gas (e.g., as a plasma or as an inert gas) during deposition, where non-limiting process gases include carbon monoxide (CO), helium (He), argon (Ar), krypton (Kr), neon (Ne), nitrogen ( _N2 ), and/or hydrogen ( _H2 ).

Deposition conditions include control of precursor flow rate, gas flow rate, process pressure, temperature (e.g., electrostatic chuck (ESC) temperature), plasma (e.g., TCP) power, bias power, and duty cycle (DC) within the process chamber. The precursor flow rate may be between about 1 and 100 standard cubic centimeters per minute (sccm). The gas flow rate may be between about 1 and 1600 sccm. The chamber pressure may be between about 5 and 1000 mTorr (e.g., 5 to 800 mTorr, 10 to 500 mTorr, 10 to 400 mTorr, 30 to 500 mTorr, 10 to 1000 mTorr, or 30 to 1000 mTorr). The ESC temperature may be between about 0-100°C (e.g., 0-50°C or 10-40°C). The power used to generate the plasma may be between about 10 and 3000W per station (e.g., 100-1000W, 200-1000W, 200-800W, or 200-500W). The RF frequency used to generate the plasma may be between about 0.3-600MHz (e.g., 13.56MHz, 60MHz, 27MHz, 2MHz, 400kHz, or a combination thereof). By using a pulsed plasma or a continuous wave (CW) plasma, the RF bias power may be between about 0-1000W. The processing chamber may be an ICP chamber or a CCP chamber. In some embodiments of the ICP chamber, the frequency of the top ICP generator and the bias generator are both 13.5 MHz. In some embodiments, depending on the bottom layer, the pressure can be about 10-400 mTorr, and the TCP power can be about 200-500 W.

Table 1 provides examples of non-limiting bottom layer treatment protocols. For Example 1, the hydrocarbon precursor is methane (CH ₄ ) and the other gas is He. For Example 2, the hydrocarbon precursor is CH ₄ and the treatment gas includes CO, H ₂ and He. [ Table 1 ] : Treatment Protocol Parameters Embodiment 1 Embodiment 2 CH ₄ flow rate 30 sccm 15 sccm CO flow rate 0 50 sccm _H2 flow rate 0 50 sccm He flow rate 660 sccm 185 sccm pressure 150 mTorr 30 mTorr ESC Temperature 20°C 20°C TCP Power 400 W 400 W Bias Mode --- --- Bias power 0 W 0 W

[ Table 2] : Etching resistance of the bottom layer Bottom layer Film composition (by XPS ) Relative etching rate for AHM C % O % AHM (HST) 100 0 1 Embodiment 1 99.0 1.0 2.8 Embodiment 2 96.4 3.6 3.3 Implementation 2 : Pulsed bias treatment for the deposition of the bottom layer

Further processing is developed to improve the etch resistance of the bottom layer. In particular, bias power is used to change the density of the bottom layer. For example, the deposition of the bottom layer can include a bias (regardless of frequency) that is pulsed at between about 1% and 99% DC (e.g., in the range of about 1 Hz to about 10 kHz). This bias can be provided at any useful power, such as about 10-500W.

It will be understood that a plasma pulse may involve a repetition of cycles, wherein each cycle may last for a duration T. Within a given cycle, the duration T includes the duration for the pulse ON time (the duration that the plasma is in the ON state), and the duration for the plasma OFF time (the duration that the plasma is in the OFF state). The pulse frequency will be understood to be 1/T. For example, for a plasma pulse cycle T = 100 µs, the frequency is 1/T = 1/100 µs or 10 kHz. The duty cycle or duty ratio is the fraction or percentage of a period T that the plasma is in the ON state, such that the duty cycle or duty ratio is the pulse ON time divided by T. For example, for a plasma pulse period T = 100 µs, if the pulse ON time is 70 µs (i.e., the duration of the plasma in the ON state in one period is 70 µs), and the pulse OFF time is 30 µs (so that the duration of the plasma in the OFF state in one period is 30 µs), then the duty cycle is 70%.

Other deposition conditions may include control of precursor flow rate, gas flow rate, process pressure, temperature (e.g., ESC temperature), flow rate, bias power, pulse frequency, DC and TCCT parameters in the process chamber. The precursor flow rate may be between about 1-100 sccm. The process gas flow rate may be between about 1-1600 sccm. The chamber pressure may be between about 5-1000 mTorr (e.g., 5-800 mTorr, 10-500 mTorr, 10-400 mTorr, 30-500 mTorr, 10-1000 mTorr, or 30-1000 mTorr). The ESC temperature may be between about 0-100°C (e.g., 0-50°C or 10-40°C). The power used to generate the plasma may be between about 10-3000W (e.g., 100-1000W, 200-1000W, 200-800W, or 200-500W). The RF frequency used to generate the plasma may be between about 0.3-600MHz (e.g., 13.56MHz, 60MHz, 27MHz, 2MHz, 400kHz, or a combination thereof). The RF bias power for pulsing the plasma between 1-100% of DC may be between about 10-1000W, where 100% represents CW (e.g., 1-99%). The RF bias power may be pulsed at a frequency below 5000Hz, such as about 10-2000Hz. The TCCT parameter may be from 0.1 to 1.5. In some non-limiting processes, the plasma exposure can include a high frequency (HF) RF component (e.g., typically between about 2-60 MHz) and a low frequency (LF) RF component (e.g., typically from about 100 kHz to 2 MHz). The processing chamber can be an ICP chamber or a CCP chamber.

Table 3 provides an example of a processing scheme for a non-limiting bottom layer formed by a pulsed bias treatment (Example 3). Various bottom layer films were formed using Example 3, where the bias power was 70W or 140W, and where the DC was varied between 10-50%. The pulsed bias treatment provides a film with increased density (e.g., a density greater than about 1.09 g/ ^cm3 ) compared to a film formed with a 0W bias. In this way, the density of the bottom layer can be fine-tuned by increasing the bias power. In some cases, a denser film can provide a lower etch rate, thereby providing improved etch resistance. [ Table 3] : Pulse Processing Scheme Parameters Embodiment 3 CH ₄ flow rate 30 sccm He flow rate 660 sccm pressure 150 mTorr ESC temperature 20°C TCP Power 400 W Bias power 70 W, 140 W Bias pulse frequency 100 Hz TCCT 1.4 DC % 10%, 20%, 30%, 40%, 50% Implementation 3 : Deposition of doped substrate

The bottom layer may include one or more dopants (e.g., non-carbon dopants when a hydrocarbon precursor is used). Dopants may be provided by using a hydrocarbon precursor (e.g., to provide carbon atoms) and a separate dopant precursor (e.g., to provide non-carbon atoms for doping). In another embodiment, dopants are provided by using a single dopant precursor that includes carbon atoms and impurity atoms. Non-limiting non-carbon impurity atoms include oxygen (O), silicon (Si), nitrogen (N), tungsten (W), boron (B), iodine (I), chlorine (Cl), or any combination of these. Other dopants and dopant precursors containing impurities are described herein.

In some cases, the use of dopants can improve etch resistance. Any of the processing schemes described herein can be modified to incorporate dopants into the underlying layer. For example, the deposition system can include the use of a doped precursor (e.g., any of those described herein), and the processing schemes described herein generally for the precursor (e.g., flow rate, pressure, temperature, plasma power, bias power, pulse frequency, duty cycle, TCCT, etc.) can be used for the doped precursor.

For example, the flow rate of the precursor (e.g., hydrocarbon precursor and/or dopant precursor) can be between about 1-100 sccm. The flow rate of the process gas can be between about 1-1600 sccm. The chamber pressure can be between about 5-1000 mTorr (e.g., 5-800 mTorr, 10-500 mTorr, 10-400 mTorr, 30-500 mTorr, 10-1000 mTorr, or 30-1000 mTorr). The ESC temperature can be between about 0-100°C (e.g., 0-50°C or 10-40°C). The power used to generate the plasma can be between about 10-3000W (e.g., 100-1000W, 200-1000W, 200-800W, or 200-500W). The RF frequency used to generate the plasma can be between about 0.3-600MHz (e.g., 13.56MHz, 60MHz, 27MHz, 2MHz, 400kHz, or a combination thereof). The RF bias power using a pulsed plasma of about 1-99% DC or a CW plasma (100% DC) can be between about 0-1000W. The RF bias power can be pulsed below 5000Hz, such as a frequency of about 10-2000 Hz. The TCCT parameter can be from 0.1 to 1.5. The processing chamber can be an ICP chamber or a CCP chamber.

In one embodiment, the dopant is nitrogen (N) or includes nitrogen (N) to provide a nitrogen-doped bottom layer. Non-limiting nitrogen-containing precursors may include any of the precursors described herein, such as nitrogen ( _N2 ), ammonia ( _NH3 ), _hydrazine ( _N2H4 ), amines, and aminosilanes. In one embodiment, the nitrogen-doped bottom layer is formed by co-flowing a hydrocarbon precursor and a nitrogen-containing precursor.

Table 4 provides examples of non-limiting treatment protocols for nitrogen-doped substrates. For Example 4, the hydrocarbon precursor is CH ₄ and the nitrogen-containing precursor is N ₂ . For Example 5, the hydrocarbon precursor is CH ₄ and the nitrogen-containing precursor is NH ₃ . [ Table 4] : Treatment protocols for nitrogen-doped substrates Parameters Example 4 (Using _N2 ) Example 5 (using NH ₃ ) CH ₄ flow rate 30 sccm 30 sccm _N2 flow rate 15 sccm 0 NH ₃ flow rate 0 15 sccm He flow rate 645 sccm 645 sccm pressure 150 mTorr 150 mTorr ESC temperature 20°C 20°C TCP Power 400 W 400 W Bias power 0 W 0 W TCCT 1.3 1.3

In certain embodiments, the nitrogen-doped underlayer may be characterized by the presence of NH bonds (e.g., having peaks at about 3500 to 3100 cm ^-1 and/or about 1635 cm ^-1 in a Fourier transform infrared (FTIR) spectrum) and/or C≡N bonds (e.g., having peaks at about 2260 to 2222 cm ^-1 , about 2244 cm ^-1 , and/or about 2183 cm ^-1 in a FTIR spectrum).

The etch rate of the doped bottom layer can be improved in some cases.

In another embodiment, the dopant is tungsten (W) or includes tungsten (W) to provide a tungsten-doped bottom layer. Non-limiting tungsten-containing precursors may include any of the precursors described herein, such as tungsten halides (e.g., WF ₆ , WCl ₆ or WCl ₅ ), tungsten carbonyls (e.g., W(CO) ₆ ), or others. In one embodiment, the tungsten-doped bottom layer is formed by co-flowing a hydrocarbon precursor and a tungsten-containing precursor.

In certain embodiments, the tungsten doped underlayer may be characterized by the presence of W-OH···H ₂ O bonds (e.g., having a peak at about 3500 to 3400 cm ^-1 in the FTIR spectrum), W=O bonds (e.g., having a peak at about 981 cm ^-1 in the FTIR spectrum), and/or WOW bonds (e.g., having peaks at about 837 cm ^-1 , 800 cm ^-1 and/or 702 cm ^-1 in the FTIR spectrum).

Table 5 provides examples of non-limiting treatment schemes for tungsten doped bottom layers. For each embodiment, the hydrocarbon precursor is CH ₄ . For embodiment 6, the tungsten-containing precursor is WF ₆ at a lower flow rate of 1 sccm. For embodiment 7, the tungsten-containing precursor is WF ₆ at a higher flow rate of 2 sccm. For embodiment 8, the tungsten-containing precursor is WF ₆ at a lower flow rate of 1 sccm but at a higher pressure of 50 mTorr. [ Table 5] : Treatment schemes for tungsten doped bottom layers Parameters Embodiment 1 Embodiment 6 Embodiment 7 Embodiment 8 CH ₄ flow rate 30 sccm 30 sccm 30 sccm 30 sccm WF ₆ Flow Rate 0 1 sccm 2 sccm 1 sccm He flow rate 658-659 sccm 658-659 sccm 658-659 sccm 659 sccm pressure 30 mTorr 30 mTorr 30 mTorr 50 mTorr ESC temperature 20°C 20°C 20°C 20°C TCP Power 400 W 400 W 400 W 400 W Bias power 0 W 0 W 0 W 0 W TCCT 0.2-1.2 0.2 to 1.2 0.2 to 1.2 0.2 to 1.2

The density of the doped bottom layer can be increased. Table 6 provides the refractive index (RI at 633 nm), deposition rate and density of these bottom layers. As further seen in Example 7, co-flow of hydrocarbon precursors with tungsten-containing dopant precursors increases density and RI compared to a baseline deposited without a dopant precursor. [ Table 6] : Properties of Tungsten Doped Bottom Layers Embodiment 1 Embodiment 6 Embodiment 7 Embodiment 8 RI @ 633 nm 1.575 1.546 1.711 1.530 Deposition rate (Å/min) 296.0 572.8 679.0 588.6 Density (g/cm ³ ) 1.08 2.07 2.83 1.93

In another example, the dopant is boron (B) or includes boron (B) to provide a boron-doped bottom layer. Non-limiting boron-containing precursors can include any of the precursors described herein, such as boron halides (e.g., BCl ₃ ), boranes (e.g., B ₂ H ₆ ), borates (e.g., B(OH) ₃ ) and organoboron compounds (e.g., B(CH ₃ ) ₃ ). In one case, the boron-doped bottom layer is formed by co-flowing a hydrocarbon precursor and a boron-containing precursor.

In certain embodiments, the boron-doped underlayer may be characterized by the presence of B···OH bonds (e.g., having a peak at about 3200 cm ^-1 in the FTIR spectrum), BO bonds (e.g., having a peak at about 1340 cm ^-1 in the FTIR spectrum), and/or BOH bonds (e.g., having a peak at about 1194 cm ^-1 in the FTIR spectrum).

Table 7 provides an example of a non-limiting boron-doped bottom layer treatment regimen. For Example 9, the hydrocarbon precursor was CH ₄ and the boron-containing precursor was BCl ₃ . For Example 10, the deposition conditions were the same as Example 9, but the film was further treated with H ₂ . In Table 7, the H ₂ treatment conditions include pressure = 5 mTorr; TCP = 300 W; bias power = 100 W; H ₂ flow rate = 200 sccm; treatment time = 1 second. [ Table 7] : Boron-doped bottom layer treatment regimen Parameters Embodiment 1 Embodiment 9 Embodiment 10 CH ₄ flow rate 30 sccm 30 sccm 30 sccm BCl ₃ flow rate 0 5 sccm 5 sccm He flow rate 655 sccm 655 sccm 655 sccm _H2 treatment No No Yes pressure 150 mTorr 150 mTorr 150 mTorr ESC temperature 20-24°C 20-24°C 20-24°C TCP Power 400 W 400 W 400 W Bias power 0 W 0 W 0 W TCCT 0.2-1.2 1.3 1.3

In certain embodiments, both the deposition rate and density of the doped bottom layer can be enhanced. Table 8 provides the RI at 633 nm, the deposition rate and the density of the bottom layer. As shown in Example 9, the co-flow of the hydrocarbon precursor and the boron-containing dopant precursor increased the deposition rate and increased the density compared to the baseline without the dopant precursor. [ Table 8] : Properties of the Boron-Doped Bottom Layer Embodiment 1 Embodiment 9 Embodiment 10 RI @ 633 nm 1.57 1.56 1.52 Deposition rate (Å/min) 287.0 403.0 543.0 Density (g/cm ³ ) 1.06 1.24 TBD

As described herein, doping precursors may be employed during deposition to provide a doped underlayer. In certain embodiments, the doped underlayer may have enhanced properties, such as improved etch resistance, etch rate, refractive index, deposition rate, and/or density. Embodiment 4 : Deposition of various hydrocarbon precursors

The bottom layer can be deposited using any useful precursor. For example, the precursor can include a hydrocarbon precursor having only carbon and hydrogen atoms. In another case, the precursor can be a doped hydrocarbon precursor having carbon atoms, hydrogen atoms, and non-carbon impurity atoms. In yet another case, the precursor can be a doped precursor (e.g., a doped precursor as described herein).

A variety of compounds may be used for the hydrocarbon precursor system. For example, the hydrocarbon precursor system may include aliphatic and aromatic compounds (e.g., alkanes, alkenes, alkynes, benzene, etc.), including substituted forms thereof. By using different hydrocarbon precursors, the type and amount of certain chemical bonds in the bottom layer may be varied. For example, the use of an unsaturated hydrocarbon precursor can provide a substrate having an increased unsaturated bond content (e.g., increased C=C and/or C≡C bond content), an increased sp2 carbon content, an increased sp carbon content, a reduced saturated bond content (e.g., a reduced C-C bond content), a reduced sp3 carbon content, and/or a reduced C-H bond content (e.g., compared to a film formed with an increased amount of a saturated hydrocarbon precursor or a reduced amount of an unsaturated hydrocarbon precursor). The choice of hydrocarbon precursor can depend on a variety of factors. In one non-limiting example, the hydrocarbon precursor includes a saturated precursor (e.g., having an increased C-H bond content compared to the C-C, C=C, or C≡C content), which can provide sufficient hydrogen atoms. Without wishing to be limited by mechanism, the selection of such a precursor can provide releasable hydrogen atoms that interact with atoms in the imaging layer and thus result in improved DtS compared to the use of an unsaturated precursor. However, in other non-limiting examples, the hydrocarbon precursor includes an unsaturated precursor (e.g., having an increased C-C, C=C, or C≡C content compared to the C-H bond content). Without wishing to be limited by mechanism, the selection of such a precursor can provide enhanced etch resistance compared to the use of a saturated precursor.

In certain embodiments, the bottom layer can be characterized by the presence of C=CH bonds (e.g., having a peak at about 3310 cm ^-1 in the FTIR spectrum) and/or C=C bonds (e.g., having a peak at about 1650 to 1600 cm ^-1 or 1000 to 660 cm ^-1 in the FTIR spectrum).

Table 9 provides examples of non-limiting hydrocarbon precursor treatment schemes. For Example 1, the hydrocarbon precursor is CH ₄ . For Example 11, the hydrocarbon precursor is acetylene (C ₂ H ₂ ). For Example 12, the hydrocarbon precursor is propyne (C ₃ H ₄ ). Different plasma types (e.g., ICP or CCP) can be used. In one case, using ICP allows for independent control of ion energy and ion density. Whether using ICP or CCP, the processing conditions can be optimized to obtain similar films. For example, CCP typically uses a higher self-bias voltage than ICP, thereby producing a plasma with higher ion energy. For example, this higher energy can be reduced by using a higher process pressure to achieve a process environment that is comparable to that obtained when using ICP. Thus, the methods herein may include the use of ICP or CCP along with modification of one or more process conditions (e.g., pressure, temperature, flow rate of precursor or inert gas, process time, etc.) to achieve the desired membrane composition and membrane properties. [ Table 9] : Processing scheme for hydrocarbon precursor Parameters Embodiment 1 Embodiment 11 Embodiment 12 CH ₄ flow rate 30 sccm 0 0 C ₂ H ₂ flow rate 0 50 sccm 0 C ₃ H ₄ flow rate 0 0 100 sccm He flow rate 660 sccm 1200 sccm 1200 sccm pressure 150 mTorr 500 mTorr 500 mTorr ESC temperature 20°C 20°C 20°C TCP Power 400 W --- --- Bias power 0 W 0 W @ 400 kHz; 200 W @ 60 MHz 0 W @ 400 kHz; 200 W @ 60 MHz Plasma type ICP CCP CCP Frequency --- 1000 Hz 1000 Hz DC% --- 20% 20%

In certain embodiments, unsaturated hydrocarbon precursors are used to improve etch resistance. FIG. 7 provides etch rates of bottom layers formed using C ₂ H ₂ precursors (or HC=CH, Example 11), C ₃ H ₄ precursors (HC=CCH ₃ , Example 12), and CH ₄ precursors (Example 1). Non-limiting etching conditions include using an ICP chamber with pressure = 5 mTorr; TCP = 350 W; TCCT = 2; bias power = 0 V; CH ₄ flow rate = 10 sccm; O ₂ flow rate = 60 sccm; Ar flow rate = 200 sccm; ESC temperature = 30°C. It can be seen that the use of unsaturated hydrocarbon precursors (e.g., having triple bonds) improves the etch resistance of the underlying layer compared to saturated hydrocarbon precursors ( e.g. , having only single bonds).

The bottom layer may also include one or more atoms having a high patterned radiation absorption cross section (e.g., an EUV absorption cross section equal to or greater than 1x10 ⁷ cm ² /mol). Such atoms include, for example, iodine (I). Iodine can be provided by any useful source. For example, the precursor used during deposition can be a dopant precursor, which is a hydrocarbon having one or more iodine atoms. Non-limiting precursors are aliphatic or aromatic compounds having one or more iodine atoms (e.g., alkanes, alkenes, or alkynes, including cyclic forms thereof, and benzene). Still other examples of the precursor include iodoacetylene (C ₂ HI), diiodoacetylene (C ₂ I ₂ ), vinyl iodide (C ₂ H ₃ I), methyl iodide (CH ₃ I), diiodomethane (CH ₂ I ₂ ), 1,1-diiodoethylene (C ₂ H ₂ I ₂ ), (E)-1,2-diiodoethylene (trans-C ₂ H ₂ I ₂ ), (Z)-1,2-diiodoethylene (cis-C ₂ H ₂ I ₂ ), allyl iodide (C ₃ H ₅ I), 1-iodo-1-propyne (C ₃ H ₃ I), iodocyclopropane (C ₃ H ₅ I), and 1,1-diiodocyclopropane (C ₃ H ₄ I ₂ ).

Any deposition conditions described herein can be combined to provide an effective bottom layer. For example, a pulse bias treatment can be used with any precursor described herein (e.g., a hydrocarbon precursor, an dopant precursor, or a combination thereof). In another case, a dopant precursor can be combined with any hydrocarbon precursor described herein. In addition, the treatment can include the use of one, two, three or more different precursors (e.g., two or more hydrocarbon precursors; and/or two or more dopant precursors). In another case, any hydrocarbon precursor described herein (e.g., a saturated or unsaturated hydrocarbon precursor) can be modified with one or more non-carbon impurities to produce a dopant precursor.

The combination of precursors can be selected to provide the desired film properties. For example, a specific hydrocarbon precursor (e.g., an unsaturated hydrocarbon precursor) can be selected to improve etch resistance. Next, certain impurities can be selected to provide a film with increased density or refractive index (e.g., impurities of O, Si, N, W, B, or I). In one case, the bottom layer can contain I, C, H, and O atoms; I, C, H, and Si atoms; I, H, N, O, and Si atoms; or I, C, H, N, O, and Si atoms.

Finally, other non-carbon impurities may also be selected to provide a film with enhanced EUV absorption (e.g., an impurity such as I or another impurity with an EUV absorption cross section equal to or greater than 1x10 ⁷ cm ² /mol). The thickness of the base layer may be controlled (e.g., greater than about 5 nm). Precursor (e.g., for base layer)

The bottom layer of this article can adopt any useful precursor or precursor combination. Such precursor systems can include hydrocarbon precursors containing only carbon (C) and hydrogen (H) atoms, wherein the precursor can be saturated (only having single bonds) or unsaturated (having one or more double bonds or triple bonds), as well as straight chain or ring. Still other precursor systems can contain one or more non-carbon impurity atoms, and such precursors are referred to as dopant precursors herein. This dopant precursor system can optionally include a combination of carbon atoms and non-carbon atoms. In some embodiments, any hydrocarbon precursor system herein can be modified by one or more impurity atoms to provide a dopant precursor. The generic term "precursor" may refer to hydrocarbon precursors and/or dopant precursors. In some cases, such precursors may be gases, thereby allowing vapor phase deposition within a processing chamber.

The hydrocarbon precursor generally includes a carbon-containing precursor. In some cases, the hydrocarbon precursor contains only C and H atoms. The hydrocarbon precursor can be, for example, a precursor defined by the chemical formula C _x H _y , wherein x is an integer from 1 to 10, and y is an integer from 2 to 24. Examples of such precursors include methane (CH ₄ ), acetylene (C ₂ H ₂ ), ethane (C ₂ H ₆ ), ethylene (C ₂ H ₄ ), propane (C ₃ H ₈ ), propylene (C ₃ H ₆ ), propyne (C ₃ H ₄ ), propadiene (C ₃ H ₄ ), cyclopropene (C ₃ H ₄ ), butane (C ₄ H ₁₀ ), butene (C ₄ H ₈ ), butadiene (C ₄ H ₆ ), cyclohexane (C ₆ H ₁₂ ), benzene (C ₆ H ₆ ), and toluene (C ₇ H ₈ ).

The hydrocarbon precursor may be an aliphatic compound (e.g., C _1-10 alkane, C _2-10 alkene, C _2-10 alkyne, including linear or cyclic forms thereof) or an aromatic compound (e.g., benzene and its polycyclic forms). The hydrocarbon precursor system may include a saturated bond (single bond, such as a CC bond or a CH bond) and/or an unsaturated bond (double bond or triple bond, such as a C=C, C≡C or C≡N bond).

Useful precursors for the bottom layer may also contain one or more impurity atoms. Such impurity atoms may be any useful non-carbon atoms, such as oxygen (O), silicon (Si), nitrogen (N), tungsten (W), boron (B), iodine (I), chlorine (Cl) and combinations thereof. Therefore, non-limiting impurity-containing precursors (also referred to herein as dopant precursors) may include O-containing precursors, Si-containing precursors, N-containing precursors, W-containing precursors, B-containing precursors, I-containing precursors or Cl-containing precursors. As described herein, such dopant precursors may be inorganic (lacking carbon atoms) or organic (including carbon atoms).

The O-containing precursor system may include a carbonyl precursor containing O and C atoms. In certain embodiments, the carbonyl precursor is reacted with hydrogen (H ₂ ) or a alkane, and optionally further reacted with a Si source or a Si-containing precursor. Still other O-containing precursor systems may include carbon monoxide (CO), carbon dioxide (CO 2 ), water (H ₂ O), oxygen (O ₂ ), ozone (O ₃ ), hydrogen peroxide (H ₂ O ₂ ), alcohols (e.g., triamyl alcohol, ethanol, propanol, etc.), polyols (e.g., diols, such as ethylene glycol), ketones, aldehydes, ethers, esters, carboxylic acids, alkoxysilanes, tetrahydrofurans, or furans.

The Si-containing precursor system may include silanes, halogenated silanes, aminosilanes, alkoxysilanes, organic silanes, etc. In a specific embodiment, the Si-containing precursor is co-reacted with an oxidant (e.g., any oxidant described herein, such as an O-containing precursor or a side oxygen carbon precursor, including CO and CO ₂ ). Non-limiting Si-containing precursors include polysilane (H3Si-(SiH2)n-SiH3), where n>0. Examples of silanes include silane (SiH ₄ ), disilane (Si ₂ H ₆ ), and organic silanes such as methylsilane, ethylsilane, isopropylsilane, tertiary butylsilane, dimethylsilane, diethylsilane, tri(tertiary butyl)silane, allylsilane, dibutylsilane, thexylsilane, isopentylsilane, tri(tertiary butyl)disilane, and the like.

Halogenated silanes include at least one halogen group and may or may not include H and/or C atoms. Examples of halogenated silanes are iodosilanes, bromosilanes, chlorosilanes, and fluorosilanes. Specific chlorosilanes are tetrachlorosilane, trichlorosilane, dichlorosilane, monochlorosilane, chloroallylsilane, chloromethylsilane, dichloromethylsilane, chlorodimethylsilane, chloroethylsilane, tributylchlorosilane, di(tributyl)chlorosilane, chloroisopropylsilane, dibutylchlorosilane, tributyldimethylchlorosilane, trihexyldimethylchlorosilane, and the like. Specific iodosilanes are tetraiodosilane, triiodosilane, diiodosilane, monoiodosilane, trimethylsilyl iodide, and the like.

Aminosilanes contain at least one nitrogen atom bonded to a silicon atom, but may also contain hydrogen, oxygen, halogens, and/or carbon atoms. Examples of aminosilanes are monoaminosilane ( _H3Si ( _NH2 ) ₄ ), diaminosilane ( _H2Si ( _NH2 ) ₂ ), triaminosilane (HSi( _NH2 ) ₃ ) and tetraaminosilane (Si( _NH2 ) ₄ ), and substituted monoaminosilanes, diaminosilanes, triaminosilanes and tetraaminosilanes, such as tributylaminosilane, methylaminosilane, tributylsilanamine, bis(tributylamino)silane ( _SiH2 (NHC( _CH3 ) ₃ ) ₂ , BTBAS), tert-butyl silylcarbamate, SiH( _CH3 )-(N(CH ₃ ) ₂ ) ₂ , SiHCl-(N( _CH3 ) ₂ ) ₂ , (Si( _CH3 ) _2NH ) ₃ , etc. A further example of aminosilane is trisilylamine (N( _SiH3 ) ₃ ).

Alkoxysilanes contain at least one oxygen atom bonded to a silicon atom, but may also contain hydrogen, nitrogen, halogen and/or carbon atoms. Examples of alkoxysilanes are monoalkoxysilane (H ₃ Si(OR)), dialkoxysilane (H ₂ Si(OR) ₂ ), trialkoxysilane (HSi(OR) ₃ ) and tetraalkoxysilane (Si(OR) ₄ ), wherein each R may independently be an optionally substituted alkyl or aryl group, and substituted monoalkoxysilane, dialkoxysilane, trialkoxysilane and tetraalkoxysilane, such as trimethoxymethylsilane (CH ₃ Si(OCH ₃ ) ₃ ), (3-aminopropyl)trimethoxysilane (NH ₂ (CH ₂ ) ₃ Si(OCH ₃ ) ₃ ), (3-aminopropyl)triethoxysilane (NH ₂ (CH ₂ ) ₃ Si(OCH ₂ CH ₃ ) ₃ ), triethoxyvinylsilane (CH ₂ =CHSi(OCH ₂ CH ₃ ) ₃ ), triethoxyethylsilane (CH ₃ CH ₂ Si(OCH ₂ CH ₃ ) ₃ ), trimethoxyphenylsilane (PhSi(OCH ₃ ) ₃ ), isobutyltriethoxysilane (i-BuSi(OCH ₂ CH ₃ ) ₃ ), diacetyloxydimethylsilane ((CH ₃ ) ₂ Si(OCOCH ₃ ) ₂ ), and the like. Still other examples include tetraethoxysilane (Si(OCH ₂ CH ₃ ) ₄ ), triethoxysilane (HSi(OCH ₂ CH ₃ ) ₃ ), tetramethoxysilane (Si(OCH ₃ ) ₄ ), and trimethoxysilane (HSi(OCH ₃ ) ₃ ).

The N-containing precursor contains at least one nitrogen atom, such as nitrogen ( _N2 ), ammonia ( _NH3 ), hydrazine ( _N2H4 ), amine compounds (e.g., carbon-containing amines) such as methylamine, _{dimethylamine} , ethylamine, isopropylamine, tertiary butylamine, di(tertiary butyl)amine, cyclopropylamine, dibutylamine, cyclobutylamine, isoamylamine, 2-methylbutyl-2-amine, trimethylamine, diisopropylamine, diethylisopropylamine, di(tertiary butyl)hydrazine, and aromatic amines such as aniline, pyridine and benzylamine. Other N-containing precursors may include nitriles (e.g., acetonitrile), amides, N-containing heterocyclic compounds or amino alcohols (e.g., ethanolamine). Amines may be primary, secondary, tertiary or quaternary (e.g., tetraalkylammonium compounds). The N-containing precursor may contain impurity atoms other than nitrogen. For example, hydroxylamine, tert-butyloxycarbonylamine and N-tert-butylhydroxylamine are all N-containing precursors.

The W-containing precursor includes a tungsten halide precursor, which may include tungsten fluoride, such as tungsten (VI) fluoride (WF ₆ ); and tungsten chloride, such as tungsten (VI) chloride (WCl ₆ ), tungsten (V) chloride (WCl ₅ ) and tungsten (VI) oxychloride (WOCl ₄ ). In some embodiments, metal organic tungsten precursors may be used, such as tungsten hexacarbonyl (W(CO) ₆ ), mesitylene tungsten tricarbonyl ([C ₆ H ₃ (CH3) ₃ ]W(CO) ₃ ), bis(tertiary butylimino)bis(dimethylamino)tungsten (VI) ([(CH ₃ ) ₃ CN] ₂ W[N(CH ₃ ) ₂ ] ₂ ), bis(cyclopentadienyl)tungsten (IV) dihydrogenate (H ₂ WCp ₂ ), and the like.

The B-containing precursors include boron halides (eg, BCl ₃ ), boranes (eg, B ₂ H ₆ ), borates (eg, B(OH) ₃ ), and organic boron compounds (eg, B(CH ₃ ) ₃ ). Non-limiting B-containing precursors include diborane (B ₂ H ₆ ), trimethyl borate (B[OCH ₃ ] ₃ ), triethyl borate (B[OCH ₂ CH ₃ ] ₃ ), triisopropyl borate (B[OCH(CH ₃ ) ₂ ] ₃ ), trimethylborane (B(CH ₃ ) ₃ ), triethylborane (B(C ₂ H ₅ ) ₃ ), triphenylborane (BPh ₃ ), tetrakis(dimethylamino)diboron (B ₂ (N(CH ₃ ) ₂ ) ₄ ), boron trifluoride (BF ₃ ), boron trichloride (BCl ₃ ), boron tribromide (BBr ₃ ), and boron iodide (BI ₃ ).

The I-containing precursor includes iodinated alkyl compounds, such as iodoacetylene (C ₂ H _I ), diiodoacetylene (C ₂ I ₂ ), vinyl iodide (C ₂ H ₃ I), methyl iodide (CH ₃ I), diiodomethane (CH ₂ I ₂ ), 1,1-diiodoethylene (C ₂ H ₂ I ₂ ), (E)-1,2-diiodoethylene (trans-C ₂ H ₂ I ₂ ), (Z)-1,2-diiodoethylene (cis-C ₂ H ₂ I ₂ ), allyl iodide (C ₃ H ₅ I), 1-iodo-1-propyne (C ₃ H ₃ I), iodocyclopropane (C ₃ H ₅ I) and 1,1-diiodocyclopropane (C ₃ H ₄ I ₂ ).

The Cl-containing precursor includes chlorinated alkyl compounds, such as chloroacetylene (C ₂ HCl), vinyl chloride (C ₂ H ₃ Cl), chloromethane (CH ₃ Cl), dichloromethane (CH ₂ Cl ₂ ), 1,1-dichloroethylene (C ₂ H ₂ Cl ₂ ), (E)-1,2-dichloroethylene (trans-C ₂ H ₂ Cl ₂ ), (Z)-1,2-dichloroethylene (cis-C ₂ H ₂ Cl ₂ ), allyl chloride (C ₃ H ₅ Cl), 1-chloro-1-propyne (C ₃ H ₃ Cl), chlorocyclopropane (C ₃ H ₅ Cl) and 1,1-dichlorocyclopropane (C ₃ H ₄ Cl ₂ ).

Other impurity atoms may be included, such as phosphorus (P). P-containing precursor systems may include phosphates, phosphines, phosphorus halides, organic phosphorus compounds, etc. Non-limiting P-containing precursor systems include triethyl phosphate (PO[OC ₂ H ₅ ] ₃ ), trimethyl phosphate (PO[OCH ₃ ] ₃ ), trimethyl phosphite (P(OCH ₃ ) ₃ ), tri(dimethylamino)phosphine (P[N(CH ₃ ) ₂ ] ₃ ), phosphorus trichloride (PCl ₃ ), trimethylsilylphosphine (P[Si(CH ₃ ) ₃ ] ₃ ) and phosphorus oxychloride (POCl ₃ ). Properties of the bottom layer

Any of the treatments and precursors described herein may be used to provide a useful underlayer. The composition of the underlayer may be tailored to include specific atoms. In one embodiment, the underlayer includes about 0-30 atomic % O (e.g., 1-30%, 2-30%, or 4-30%), about 20-50 atomic % H (e.g., 20-45%, 30-50%, or 30-45%), and/or 30-70 atomic % C (e.g., 30-60%, 30-65%, or 30-68%). In other embodiments, the underlayer includes the presence of unsaturated bonds (e.g., C=C, C≡C, and/or C≡N bonds). In yet other embodiments, the density of the underlayer is about 0.7 to 2.9 g/cm ³ .

The bottom layer can be characterized by increased etch selectivity and/or reduced undercut compared to a control film. In other embodiments, the bottom layer can be characterized by reduced line edge and line width roughness and/or reduced dose size compared to a control film. Non-limiting control films include those formed using saturated hydrocarbon precursors, formed in a pulsed bias, and/or formed in the absence of dopants. In one case, the control film is an AHM formed using methane. In another case, the control film is an AHM formed using acetylene. Patterned Structures

The patterned structure (or film) herein may include an imaging layer on the surface of a hard mask or substrate, and an underlayer under the imaging layer. In certain embodiments, the presence of the underlayer provides the imaging layer with increased radiation absorptivity and/or patterning properties.

In general, the absorption of photons through a layer is depth dependent. When a homogeneous layer or film is exposed to radiation, the lower portion of the layer will be exposed to a lower dose of radiation compared to the upper portion of the same layer because fewer photons reach the lower portion. Therefore, in order to ensure adequate and uniform exposure through the entire depth of a layer, sufficient radiation penetration of the layer must be provided. In certain embodiments, the bottom layer described herein provides higher absorption of radiation through the imaging layer. In addition, in some cases, the bottom layer can effectively generate more secondary electrons, thereby better exposing the lower portion of the patterned structure.

One or both of the base layer and the imaging layer may include a highly absorbing component. In one instance, both the base layer and the imaging layer include highly absorbing components, such as EUV absorption equal to or greater than 1 x 10 ⁷ cm ² /mol. The components in each of the absorbing layer and the imaging layer may be the same or different. In certain embodiments, the enhanced adhesion may reduce the radiation dose required to provide the desired patterned features in the imaging layer and/or the base layer.

The imaging layer may include any useful photoresist, such as the metal organic based photoresists described herein. When the photoresist material used has a significant inorganic component, for example it exhibits a primarily metal oxide framework, the base layer may advantageously be a carbon based film. In the case where device features that produce significant topography are present on the substrate to be patterned, another important function of the base layer may be to cover and planarize the existing topography so that subsequent patterning steps may be performed on a flat surface to have all areas of the pattern in focus. For such applications, the base layer (or at least one of the multiple base layers) may be applied using dry deposition or spin coating techniques. The layer system can include various AHM films with carbon-based and hydrogen-based components and can be doped with additional elements such as tungsten, boron, nitrogen or fluorine.

The base layer and the imaging layer, either alone or together, can be considered a film. In some embodiments, the film is a radiation sensitive film (e.g., an EUV sensitive film). The film can in turn be used as an EUV photoresist as further described herein. In certain embodiments, the layer or film can include one or more ligands (e.g., EUV labile ligands) that can be removed, cleaved, or crosslinked by radiation (e.g., EUV or DUV radiation).

The precursor may be used to provide a patternable film (or patterned radiation sensitive film or photopatternable film) that is sensitive to radiation. Such radiation may include EUV radiation, DUV radiation or UV radiation, which is provided by shining through a patterned mask as patterned radiation. The film itself may be altered by exposure to such radiation, such that the film is radiation sensitive or photosensitive. In a particular embodiment, the precursor is an organometallic compound that contains at least one metal center.

The precursor system can have any useful number and type of ligands. In some embodiments, the ligands can be characterized by their ability to react in the presence of a counter reactant or in the presence of patterned radiation. For example, the precursor system can include a ligand that reacts with a counter reactant, wherein the counter reactant can introduce a bond (e.g., an -O- bond) between metal centers. In another case, the precursor system can include a ligand that is eliminated in the presence of patterned radiation. Such EUV labile ligand systems can include branched or linear alkyl groups with β-hydrogen, as well as any alkyl group described herein for R in formula (I) or (II).

The precursor can be any practical metal-containing precursor, such as an organometallic reagent, a metal halide, or a capping agent (e.g., as described herein). In _a non-limiting example, the precursor comprises a structure having the chemical formula ( I ): _MaRb ( I ) wherein: M is a metal or atom having a high EUV absorption cross section; each R is independently H, a halogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted cycloalkenyl, an optionally substituted alkenyl, an optionally substituted alkynyl, an optionally substituted alkoxy, an optionally substituted alkanoyloxy, an optionally substituted aromatic, an optionally substituted amine, an optionally substituted bis(trialkylsilyl)amine, an optionally substituted trialkylsilyl, a pendoxy group, an anionic ligand, a neutral ligand or a polydentate ligand; a ≥ 1; and b ≥ 1.

In another non-limiting example, the precursor includes a structure having a chemical formula ( II ₎ : _MaRbLc ( II ) wherein: M is a metal or atom having a high EUV absorption cross section; each R is independently a halogen, an optionally substituted alkyl, an optionally substituted aromatic, an optionally substituted amine, an optionally substituted alkoxy or L; _each L is independently a ligand, an anionic ligand, a neutral ligand, a polydentate ligand, an ion or other part reactive with the relative reactant, wherein R and L together with M may optionally form a heterocyclic group, or wherein R and L together may optionally form a heterocyclic group; a ≥ 1; b ≥ 1; and c ≥ 1.

In some embodiments, each ligand in the precursor may be one that is reactive with the counter reactant. In one example, the precursor comprises a structure having formula ( II ), wherein each R is each L. In another example, the precursor comprises a structure having formula ( IIa ): M _a L _c ( IIa ) wherein: M is a metal or atom having a high EUV absorption cross section; each L is each a ligand, an ion, or other moiety that is reactive with the counter reactant, wherein two Ls together may optionally form a heterocyclic group; a ≥ 1; and c ≥ 1. In a specific embodiment of formula ( IIa ), a is 1. In further embodiments, c is 2, 3, or 4.

For any chemical formula herein, M may be a metal, or a metalloid, or an atom having a high patterned radiation absorption cross section (e.g., an EUV absorption cross section equal to or greater than 1x10 ⁷ cm ² /mol). In some embodiments, M is tin (Sn), bismuth (Bi), tellurium (Te), cesium (Cs), antimony (Sb), indium (In), molybdenum (Mo), halogen (Hf), iodine (I), zirconium (Zr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), platinum (Pt), and lead (Pb). In further embodiments, in chemical formula ( I ), ( II ), or ( IIa ), M is Sn, a is 1, and c is 4. In other embodiments, in formula ( I ), ( II ) or ( IIa ), M is Sn, a is 1, and c is 2. In specific embodiments, M is Sn(II) (e.g., in formula ( I ), ( II ) or ( IIa )), thereby providing a prodrug based on a Sn(II) compound. In other embodiments, M is Sn(IV) (e.g., in formula ( I ), ( II ) or ( IIa )), thereby providing a prodrug based on a Sn(IV) compound. In specific embodiments, the prodrug comprises iodine (e.g., in periodate).

For any chemical formula herein, each R is independently H, a halogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, an optionally substituted cycloalkenyl, an optionally substituted alkenyl, an optionally substituted alkynyl, an optionally substituted alkoxy (e.g., -OR ¹ , wherein R ¹ may be an optionally substituted alkyl), an optionally substituted alkanoyloxy, an optionally substituted aromatic group, an optionally substituted amine, an optionally substituted bis(trialkylsilyl)amine, an optionally substituted trialkylsilyl, a pendoxy group, an anionic ligand (e.g., an oxy, chloro, hydrogen, acetate, iminodiacetate, propionate, butyrate, benzoate, etc.), a neutral ligand, or a polydentate ligand.

In some embodiments, the optionally substituted amine group is -NR ¹ R ² , wherein each R ¹ and R ² are each H or alkyl; or wherein R ¹ and R ² together with the nitrogen atom to which they are each attached form a heterocyclic group as defined herein. In other embodiments, the optionally substituted bis(trialkylsilyl)amine group is -N(SiR ¹ R ² R ³ ) ₂ , wherein each R ¹ , R ² and R ³ are each optionally substituted alkyl. In yet other embodiments, the optionally substituted trialkylsilyl group is -SiR ¹ R ² R ³ , wherein each R ¹ , R ² and R ³ are each optionally substituted alkyl.

In other embodiments, the chemical formula includes a first R (or a first L) that is -NR ¹ R ² , and a second R (or a second L) that is -NR ¹ R ² , wherein each R ¹ and R ² are each H or an optionally substituted alkyl group; or wherein R ¹ from the first R (or the first L), and R ¹ from the second R (or the second L) together with the nitrogen atom and the metal atom to which they are attached form a heterocyclic group as defined herein. In yet other embodiments, the chemical formula includes a first R that is -OR ¹ , and a second R that is -OR ¹ , wherein each R ¹ is each H or an optionally substituted alkyl group; or wherein R ¹ from the first R, and R ¹ from the second R together with the oxygen atom and the metal atom to which they are attached form a heterocyclic group as defined herein.

In some embodiments, at least one of R or L (e.g., in Formula ( I ), ( II ) or ( IIa )) is an optionally substituted alkyl group. Non-limiting examples of alkyl groups include _{CnH2n +1} , where n is 1, 2, 3 or greater, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, dibutyl or tertiary butyl. In various embodiments, R or L has at least one β -hydrogen, β -halogen, or β -fluorine. In other embodiments, at least one of R or L is a halogen-substituted alkyl group (e.g., a fluorine-substituted alkyl group).

In other embodiments, each R or L, or at least one of R or L (e.g., in formula ( I ), ( II ), or ( IIa )) is a halogen. In particular, the precursor may be a metal halide. Non-limiting metal halides include SnBr ₄ , SnCl ₄ , SnI ₄ , and SbCl ₃ .

In some embodiments, each R or L, or at least one of R or L (e.g., in Formula ( I ), ( II ), or ( IIa )) may include a nitrogen atom. In certain embodiments, one or more R or L may be an optionally substituted amine, an optionally substituted monoalkylamine (e.g., -NR ¹ H, wherein R ¹ is an optionally substituted alkyl), an optionally substituted dialkylamine (e.g., -NR ¹ R ² , wherein each R ¹ and R ² are each optionally substituted alkyl), or an optionally substituted bis(trialkylsilyl)amine. Non-limiting R and L substituents may include, for example, _-NMe2 , -NHMe, _-NEt2 , -NHEt, -NMeEt, -N( t -Bu)-[ _CHCH3 ] ₂ -N( t -Bu)-(tbba), -N( _SiMe3 ) ₂ , and -N( _SiEt3 ) ₂ .

In some embodiments, each R or L, or at least one of R or L (e.g., in Formula ( I ), ( II ), or ( IIa )) may include a silicon atom. In certain embodiments, one or more R or L may be an optionally substituted trialkylsilyl group or an optionally substituted bis(trialkylsilyl)amine group. Non-limiting R and L substituents may include, for example, -SiMe ₃ , -SiEt ₃ , -N(SiMe ₃ ) ₂ , and -N(SiEt ₃ ) ₂ .

In some embodiments, each R or L, or at least one of R or L (e.g., in Formula ( I ), ( II ), or ( IIa )) may include an oxygen atom. In certain embodiments, one or more R or L may be an optionally substituted alkoxy group or an optionally substituted alkacyloxy group. Non-limiting R and L substituents may include, for example, methoxy, ethoxy, isopropoxy ( i -PrO), butoxy ( t -BuO), acetoxy (-OC(O) _-CH3 ), and -O=C( _CH3 )-CH=C( _CH3 )-O-(acac).

Any chemical formula herein may include one or more neutral ligands. Non-limiting neutral ligands include optionally substituted amines (e.g., NR ₃ or R ₂ N-Ak-NR ₂ , wherein each R may be H, optionally substituted alkyl, optionally substituted alkyl, or optionally substituted aromatic, and Ak is optionally substituted alkylene), optionally substituted phosphines (e.g., PR ₃ or R ₂ P-Ak-PR ₂ , wherein each R may be H, optionally substituted alkyl, optionally substituted alkyl, or optionally substituted aromatic, and Ak is optionally substituted alkylene), optionally substituted ethers (e.g., OR ₂ , wherein each R may be H, optionally substituted alkyl, optionally substituted alkyl, or optionally substituted aromatic), optionally substituted alkyl, optionally substituted alkene, optionally substituted alkyne, optionally substituted benzene, oxo, or carbon monoxide.

Any chemical formula herein may include one or more polydentate (eg, bidentate) ligands. Non-limiting polydentate ligands include diketo (e.g., acetylacetone (acac) or -OC(R ¹ )-Ak-(R ¹ )CO- or -OC(R ¹ )-C(R ² )-(R ¹ )CO-), bidentate chelated dinitrogen (e.g., -N(R ¹ )-Ak-N(R ¹ )- or -N(R ³ )-CR ⁴ -CR ² ═N(R ¹ )-), aromatic (e.g., -Ar-), amidino (e.g., -N(R ¹ )-C(R ² )-N(R ¹ )-), amine alkoxy (e.g., -N(R ¹ )-Ak-O- or -N(R ¹ ) ₂ -Ak-O-), diazadienyl (e.g., -N(R ¹ )-C(R ² )-C(R ² )-N(R ¹ )-), cyclopentadienyl, pyrazolyl, optionally substituted heterocyclic group, optionally substituted alkylene or optionally substituted heteroalkylene. In a specific embodiment, each R ¹ is independently H, optionally substituted alkyl, optionally substituted halogenated alkyl or optionally substituted aromatic group; each R ² is independently H or optionally substituted alkyl; R ³ and R ⁴ together form an optionally substituted heterocyclic group; Ak is an optionally substituted alkylene; and Ar is an optionally substituted arylene.

In certain embodiments, the precursor includes tin. In some embodiments, the tin prodrug comprises SnR, SnR ₂ , SnR ₄ or R ₃ SnSnR ₃ , wherein each R is independently H, a halogen, an optionally substituted C _1-12 alkyl, an optionally substituted C _1-12 alkoxy, an optionally substituted amine (e.g., -NR ¹ R ² ), an optionally substituted C _2-12 alkenyl, an optionally substituted C _2-12 alkynyl, an optionally substituted C _3-8 cycloalkyl, an optionally substituted aromatic group, a cyclopentadienyl, an optionally substituted bis(trialkylsilyl)amine (e.g., -N(SiR ¹ R ² R ³ ) ₂ ), an optionally substituted alkanoyloxy (e.g., acetoxy), a diketo (e.g., -OC(R ¹ )-Ak-(R ² )CO-) or bidentate chelated dinitrogen (e.g., -N(R ¹ )-Ak-N(R ¹ )-). In certain embodiments, each of R ¹ , R ² and R ³ is independently H or C _1-12 alkyl (e.g., methyl, ethyl, isopropyl, tertiary butyl or neopentyl); and Ak is an optionally substituted C _1-6 alkylene. In certain embodiments, each of R is independently halogen, an optionally substituted C _1-12 alkoxy, an optionally substituted amino, an optionally substituted aromatic, a cyclopentadienyl or a diketo. Non-limiting tin precursors include _SnF2 , _SnH4 , _SnBr4 , SnCl4, _SnI4 , _{tetramethyltin} ( _SnMe4 ), tetraethyltin ( _SnEt4 ), trimethyltin chloride ( _SnMe3Cl ), dimethyltin dichloride ( _SnMe2Cl2 ), monomethyltin trichloride ( _SnMeCl3 ), tetraallyltin, tetravinyltin, hexaphenylditin ( _IV ) ( _Ph3Sn - _SnPh3 , wherein Ph is phenyl), dibutyldiphenyltin ( _SnBu2Ph2 ), trimethyl(phenyl)tin ( _SnMe3Ph ), trimethyl(phenylethynyl)tin, _{tricyclohexyltin} hydroxide, tributyltin hydroxide ( _SnBu3 H), dibutyltin diacetate (SnBu ₂ (CH ₃ COO) ₂ ), tin(II) acetylacetonate (Sn(acac) ₂ ), SnBu ₃ (OEt) , SnBu ₂ (OMe) ₂ , SnBu ₃ (OMe) , Sn( t -BuO) ₄ , Sn( n -Bu)( t -BuO) ₃ , tetrakis(dimethylamino)tin (Sn(NMe ₂ ) ₄ ), tetrakis(ethylmethylamino)tin (Sn(NMeEt) ₄ ), tetrakis(diethylamino)tin (IV) (Sn(NEt ₂ ) ₄ ), (dimethylamino)trimethyltin (IV) (Sn(Me) ₃ (NMe ₂ )), Sn( i -Pr)(NMe ₂ ) ₃ , Sn( n -Bu)(NMe ₂ ) ₃ , Sn( s -Bu)(NMe ₂ ) ₃ , Sn( i -Bu)(NMe ₂ ) ₃ , Sn( t -Bu)(NMe ₂ ) ₃ , Sn( t -Bu) ₂ (NMe ₂ ) ₂ , Sn( t -Bu)(NEt ₂ ) ₃ , Sn(tbba) , Sn(II)(1,3-bis(1,1-dimethylethyl)-4,5-dimethyl-(4R,5R)-1,3,2-diazastannolidin-2-ylidene) or bis[bis(trimethylsilyl)amido]tin (Sn[N(SiMe ₃ ) ₂ ] ₂ ).

In other embodiments, the prodriver includes bismuth, such as in BiR ₃ , wherein each R is independently a halogen, an optionally substituted C _1-12 alkyl, a mono-C _1-12 alkylamine (e.g., —NR ¹ H), a di-C _1-12 alkylamine (e.g., —NR ¹ R ² ), an optionally substituted aromatic group, an optionally substituted bis(trialkylsilyl)amine (e.g., —N(SiR ¹ R ² R ³ ) ₂ ), or a diketo group (e.g., —OC(R ⁴ )-Ak-(R ⁵ )CO-). In a specific embodiment, each of R ¹ , R ² and R ³ is independently C _1-12 alkyl (e.g., methyl, ethyl, isopropyl, tertiary butyl or neopentyl); and each of R ⁴ and R ⁵ is independently H or an optionally substituted C _1-12 alkyl (e.g., methyl, ethyl, isopropyl, tertiary butyl or neopentyl). Non-limiting bismuth precursors include BiCl ₃ , BiMe ₃ , BiPh ₃ , Bi(NMe ₂ ) ₃ , Bi[N(SiMe ₃ ) ₂ ] ₃ and Bi(thd) ₃ , wherein thd is 2,2,6,6-tetramethyl-3,5-hexanedione.

In other embodiments, the precursor includes tellurium, such as _TeR2 or _TeR4 , wherein each R is independently a halogen, an optionally substituted _C1-12 alkyl group (e.g., methyl, ethyl, isopropyl, tertiary butyl or neopentyl), an optionally substituted _C1-12 alkoxy group, an optionally substituted aromatic group, a hydroxyl group, a pendoxy group or an optionally substituted trialkylsilyl group. Non-limiting tellurium precursors include dimethyl tellurium (TeMe ₂ ), diethyl tellurium (TeEt ₂ ), di(n-butyl) tellurium (Te( n -Bu) ₂ ), di(isopropyl) tellurium (Te( i -Pr) ₂ ), di(tertiary butyl) tellurium (Te( t -Bu) ₂ ), tertiary butyl tellurium hydroxide (Te( t -Bu)(H)), Te(OEt) ₄ , bis(trimethylsilyl) tellurium (Te(SiMe ₃ ) ₂ ), and bis(triethylsilyl) tellurium (Te(SiEt ₃ ) ₂ ).

The precursor may include antimony, for example in SbR ₃ , where each R is independently a halogen, an optionally substituted C _1-12 alkyl (e.g., methyl, ethyl, isopropyl, tertiary butyl, or neopentyl), an optionally substituted C _1-12 alkoxy, or an optionally substituted amine (e.g., -NR ¹ R ² , where each R ¹ and R ² are independently H or an optionally substituted C _1-12 alkyl). Non-limiting antimony precursors include SbCl ₃ , Sb(OEt) ₃ , Sb(O n -Bu) ₃ , and Sb(NMe ₂ ) ₃ .

Other promotors include indium promotors, such as in InR ₃ , where each R is independently a halogen, an optionally substituted C _1-12 alkyl (e.g., methyl, ethyl, isopropyl, tertiary butyl, or neopentyl), or a diketo group (e.g., -OC(R ⁴ )-Ak-(R ⁵ )CO-, where each R ⁴ and R ⁵ are independently H or C _1-12 alkyl). Non-limiting indium promotors include InCp (where Cp is cyclopentadienyl), InCl ₃ , InMe ₃ , In(acac) ₃ , In(CF ₃ COCHCOCH ₃ ) ₃ , and In(thd) ₃ .

The precursor may include iodine, such as RI, wherein R is iodine (I) or an optionally substituted C _1-12 alkyl group or periodate. Non-limiting iodine precursors include iodine gas (I ₂ ), diiodomethane (CH ₂ I ₂ ) and periodate.

Other promotors and non-limiting substituents are described herein. For example, the promotors may be any of the structures of the chemical formulas ( I ), ( II ), and ( IIa ) as described above; or any of the structures of the chemical formulas ( III ), ( IV ), ( V ), ( VI ), ( VII ), and ( VIII ) as described below. Any of the substituents M, R, X, or L described herein may be applied to any of the chemical formulas ( I ), ( II ), ( IIa ), ( III ), ( IV ), ( V ), ( VI ), ( VII ), and ( VIII ).

Still other exemplary EUV-sensitive materials, and processing methods and apparatus are described in U.S. Patent No. 9,996,004; International Patent Publication No. WO 2020/102085; and International Patent Publication No. WO 2019/217749, each of which is incorporated herein by reference in its entirety.

As described herein, the films, layers, and methods herein can be implemented using any practical precursor. In some examples, the precursor includes a metal halide having the following chemical formula ( III ): MX _n ( III ) wherein M is a metal, X is a halogen, and n is 2 to 4 depending on the selection of M. Exemplary metals for M include Sn, Te, Bi, or Sb. Exemplary metal halides include SnBr ₄ , SnCl ₄ , SnI ₄ , and SbCl ₃ .

Another non-limiting precursor includes a structure having the chemical formula ( IV ): _MRn ( IV ) wherein M is a metal; each R is independently H, an optionally substituted alkyl, an amine (e.g., _-NR2 , wherein each R is independently an alkyl), an optionally substituted bis(trialkylsilyl)amine (e.g., -N( _SiR3 ) ₂ , wherein each R is independently an alkyl), or an optionally substituted trialkylsilyl (e.g., _-SiR3 , wherein each R is independently an alkyl); and n is 2 to 4 depending on the selection of M. Exemplary metals for M include Sn, Te, Bi, or Sb. The alkyl group may be _{CnH2n +1} , wherein n is 1, 2, 3, or greater. Exemplary organometallic reagents include _SnMe4 , _SnEt4 , _TeRn , RTeR, tertiary butyl tellurium hydride (Te( t -Bu)(H)), dimethyl tellurium ( _TeMe2 ), di(tertiary butyl) tellurium (Te( t -Bu) ₂ ), di(isopropyl) tellurium (Te( i -Pr) ₂ ), bis(trimethylsilyl) tellurium (Te( _SiMe3 ) ₂ ), bis(triethylsilyl) tellurium (Te( _SiEt3 ) ₂ ), tris(bis(trimethylsilyl)amido) bismuth (Bi[N( _SiMe3 ) ₂ ] ₃ ), Sb( _NMe2 ) ₃ , and the like.

Another non-limiting precursor may include a capping agent having the following chemical formula ( V ): _MLn ( V ) wherein M is a metal; each L is each an optionally substituted alkyl, amine (e.g., ^-NR1R2 , wherein each ^R1 and ^R2 may be H, or any alkyl group as described herein), an alkoxy group (e.g., -OR, wherein R is any alkyl group as described herein), a halogen, or ^other organic substituent; and n is 2 to 4 depending on the selection of M. Exemplary metals for M include Sn, Te, Bi, or Sb. Exemplary ligands include dialkylamines (e.g., dimethylamine, methylethylamine, and diethylamine), alkoxy groups (e.g., tert-butyloxy and isopropoxy), halogens (e.g., F, Cl, Br, and I), or other organic substituents (e.g., acetylacetone or ^N2 , N3 ^- di-tert-butylbutane-2,3-diamine). Non-limiting capping agents include SnCl ₄ ; SnI ₄ ; Sn(NR ₂ ) ₄ , wherein each R is independently methyl or ethyl; or Sn( t -BuO) ₄ . In some embodiments, a plurality of ligand types are present.

The precursor may include an _alkyl substituted end-capping reagent having the following chemical formula ( VI ): _RnMXm ( VI ) wherein M is a metal, R is a _C2-10 alkyl or a substituted alkyl having a β -hydrogen, and X is a suitable leaving group after reaction with the alkyl group of the exposed alkyl group. In various embodiments, n = 1 to 3, and m = 4-n, 3-n or 2-n, as long as m > 0 (or m ≥ 1). For example, R may be tertiary butyl, tertiary pentyl, tertiary hexyl, cyclohexyl, isopropyl, isobutyl, dibutyl, n-butyl, n-pentyl, n-hexyl, or a derivative thereof having a heteroatom at the β position. Suitable heteroatoms include halogens (F, Cl, Br or I), or oxygen (-OH or -OR). X may be a dialkylamino group (eg, dimethylamino, methylethylamino, and diethylamino), an alkoxy group (eg, tert-butyloxy, isopropoxy), a halogen group (eg, F, Cl, Br, and I), or another organic ligand. Examples of alkyl-substituted end-capping agents include tertiary butyl tin (dimethylamino) (Sn( t - _Bu )(NMe2) ₃ ), normal butyl tin (dimethylamino) (Sn( n -Bu)( _NMe2 ) ₃ ), tertiary butyl tin (diethylamino) (Sn( t -Bu)( _NEt2 ) ₃ ), di(tertiary butyl) di(dimethylamino) (Sn( t -Bu) ₂ ( _NMe2 ) ₂ ), dibutyl tin (dimethylamino) (Sn( s -Bu)( _NMe2 ) ₃ ), normal pentyl tin (dimethylamino) (Sn(n-pentyl)( _NMe2 ) ₃ ), isobutyl tin (dimethylamino) (Sn( i -Bu)( _NMe2 ) ₃ ). ), isopropyltin(dimethylamino)tin (Sn( i -Pr)(NMe ₂ ) ₃ ), tertiary butyltin(tertiary butoxy)tin (Sn( t -Bu)( t -BuO) ₃ ), n-butyltin(tertiary butoxy)tin (Sn( n -Bu)( t -BuO) ₃ ) or isopropyltin(tertiary butoxy)tin (Sn( i -Pr)( t -BuO) ₃ ).

In various embodiments, the precursor includes at least one alkyl group on each metal atom, which can survive the gas phase reaction, and other ligands or ions coordinated to the metal atom can be replaced by the counter reactant. Therefore, another non-limiting precursor includes an _{organometallic} reagent having the chemical formula ( VII ): _MaRbLc ( VII ) wherein M is a _metal ; R is an optionally substituted alkyl group; L is a ligand, ion or other moiety reactive with the counter reactant; a ≥ 1; b ≥ 1; and c ≥ 1. In specific embodiments, a = 1 and b + c = 4. In some embodiments, M is Sn, Te, Bi or Sb. In certain embodiments, each L is each an amine group (e.g., -NR ¹ R ² , wherein each R ¹ and R ² can be H or any alkyl group as described herein), or a halogen (e.g., F, Cl, Br, or I). Exemplary reagents include SnMe ₃ Cl, SnMe ₂ Cl ₂ , SnMeCl ₃ , SnMe(NMe ₂ ) ₃ , SnMe ₂ (NMe ₂ ) ₂ , SnMe ₃ (NMe ₂ ), and the like.

In other embodiments, non-limiting precursors include organometallic reagents having the chemical formula ( VIII ): M _a L _c ( VIII ) wherein M is a metal; L is a ligand, ion or other moiety reactive with the counter reactant; a ≥ 1; and c ≥ 1. In certain embodiments, c = n-1, and n is 2, 3 or 4. In some embodiments, M is Sn, Te, Bi or Sb. Preferably, the counter reactant has the function of replacing the reactive moiety, ligand or ion (e.g., L in the chemical formula herein) to connect at least two metal atoms via chemical bonding.

In any of the embodiments herein, R may be an optionally substituted alkyl group (e.g., a C _1-10 alkyl group). In one embodiment, the alkyl group is substituted with one or more halogens (e.g., a halogen-substituted C _1-10 alkyl group, including one, two, three, four or more halogens such as F, Cl, Br, or I). Exemplary R substituents include C _n H _2n+1 , wherein preferably n ≥ 3; and C _n F _x H _(2n+1-x) , wherein 2n+1 ≤ x ≤ 1. In various embodiments, R has at least one β -hydrogen, β -halogen, or β -fluorine. For example, R can be selected from the group consisting of isopropyl, n-propyl, tertiary butyl, isobutyl, n-butyl, di-butyl, n-pentyl, isopentyl, tertiary pentyl, di-pentyl, and mixtures thereof.

In any embodiment herein, L can be any moiety that is easily displaced by a relative reactant to generate a M-OH moiety, for example, a moiety selected from the group consisting of an amine group (e.g., -NR ¹ R ² , wherein each R ¹ and R ² can be H or any alkyl group as described herein), an alkoxy group (e.g., -OR, wherein R is any alkyl group as described herein), a carboxylate, a halogen (e.g., F, Cl, Br or I), and mixtures thereof.

Preferably, the counter-reactant has the function of replacing a reactive moiety, ligand or ion (e.g., L in the chemical formula herein) to connect at least two metal atoms via chemical bonding. Exemplary counter-reactants include oxygen-containing counter-reactants, such as oxygen (O ₂ ), ozone (O ₃ ), water, peroxides (e.g., hydrogen peroxide), oxygen plasma, water plasma, alcohols, dihydroxy alcohols, polyhydroxy alcohols, fluorinated dihydroxy alcohols, fluorinated polyhydroxy alcohols, fluorinated glycols, formic acid and other sources of hydroxyl moieties, and combinations thereof. In various embodiments, the counter-reactant reacts with the precursor by forming an oxygen bridge between adjacent metal atoms. Other possible counter-reactants include hydrogen sulfide and hydrogen disulfide, which can crosslink metal atoms via sulfide bridges, and bis(trimethylsilyl)telluride, which can crosslink metal atoms via tellurium bridges. In addition, hydrogen iodide can be used to incorporate iodine into the film.

Still other non-limiting relative reactants include chalcogenide precursors having the formula _ZR2 , wherein: Z is sulfur, selenium or tellurium; and each R is independently H, optionally substituted alkyl (e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl, tertiary butyl, etc.), optionally substituted alkenyl, optionally substituted aromatic, optionally substituted amine, optionally substituted alkoxy, or optionally substituted trialkylsilyl.

Exemplary organometallic reagents include SnMeCl ₃ , ( N ² , N ³ -di-tert-butylbutane-2,3-diamino)tin(II) (Sn(tbba)), bis(bis(trimethylsilyl)amido)tin(II), tetrakis(dimethylamido)tin(IV) (Sn(NMe ₂ ) ₄ ), tertiary butyltris(dimethylamido)tin (Sn( t -butyl)(NMe ₂ ) ₃ ), isobutyltris(dimethylamido)tin (Sn( i -Bu)(NMe ₂ ) ₃ ), normal butyltris(dimethylamido)tin (Sn( n -Bu)(NMe ₂ ) ₃ ), secondary butyltris(dimethylamido)tin (Sn( s -Bu)(NMe ₂ ) ₃ ), isopropyltin( i -Pr)( _NMe2 ) ₃ , n-propyltin(diethylamino)tin (Sn( n -Pr)( _NEt2 ) ₃ ), and homologous alkyltin(tert-butyloxy)tin compounds, such as tert-butyltin(tert-butyloxy)tin (Sn( t -Bu)( t -BuO) ₃ ). In some embodiments, the organometallic reagent is partially fluorinated.

In some embodiments, the patterned structure may include a surface layer or film of SnO _x containing exposed hydroxyl or hydroxyl-terminated groups. Without being limited to the mechanism, function, or utility of the present technology, it is believed that the hydroxyl-terminated SnO _x layer may provide benefits such as improved adhesion of materials deposited on the substrate surface and enhanced absorption of EUV (or other radiation) during patterning. Sensitivity and resolution to EUV or other radiation may depend on the properties of the SnO _x layer, such as thickness, density, and short-range charge transfer characteristics. In various embodiments, the SnO _x layer has a thickness of 0.1 nm to 20 nm, 0.2 nm to 10 nm, or 0.5 nm to 5 nm.

In some embodiments, the hydroxyl-terminated SnO _x layer is deposited on the surface of the substrate by vapor phase deposition. In such methods, the deposition includes reacting Sn-X _n with an oxygen-containing counter reactant, wherein X is a ligand, such as a dialkylamine (e.g., dimethylamine, methylethylamine, and diethylamine), an alcohol (e.g., tert-butyloxy and isopropoxy), a halogen (e.g., F, Cl, Br, and I), or other organic substituents (e.g., acetylacetone, N2,N3-di(tert-butyl)-butane-2,3-diamine). For example, Sn-X _n can be SnCl ₄ , SnI ₄ or Sn(NR ₂ ) ₄ , wherein R is methyl or ethyl, or Sn(t-BuO) ₄ . In some embodiments, there are multiple ligand types. The oxygen-containing counter reactant can be selected from the group consisting of water, hydrogen peroxide, formic acid, alcohol, oxygen, ozone and combinations thereof.

Suitable vapor deposition processes include chemical vapor deposition (CVD), atomic layer deposition (ALD), plasma enhanced chemical vapor deposition (PECVD), or plasma enhanced atomic layer deposition (PEALD). In some embodiments, the deposition is ALD, which is a cyclic process of depositing Sn- _Xn and depositing an oxygen-containing counter reactant. In some embodiments, the deposition is by CVD with simultaneous flow of Sn- _Xn and an oxygen-containing counter reactant. Materials and processes useful herein for depositing _SnOx layers are described in Atomic Layer Deposition of Tin Dioxide Nanofilms: A Review, 40 Rev. Adv. Mater. Sci. 262 (2015) by Nazarov et al. SnO _x substrates can be deposited by CVD or ALD processing, as described herein.

Surface activation operations can be used to activate the surface for future operations. For example, for _SiOx surfaces, water or oxygen/hydrogen plasmas can be used to generate hydroxyl groups on the surface. For carbon-based or hydrocarbon-based surfaces, water, hydrogen/oxygen or _CO2 plasmas or ozone treatments can be used to generate carboxylic acid and/or hydroxyl groups. Such methods can prove important in improving the adhesion of photoresist features to substrates that might otherwise delaminate or peel in the solvents used for development.

Adhesion can also be enhanced by introducing roughness in the substrate surface to increase the surface area available for interaction and directly improve mechanical adhesion. For example, a sputter plating process using Ar or other non-reactive ion bombardment can first be used to produce a rough surface. The surface can then be capped with the desired surface functional groups described above (e.g., hydroxyl and/or carboxylic acid groups). For carbon, a combined approach can be adopted, in which a chemically reactive oxygen-containing plasma, such as _CO2 , _O2 , _H2O (or a mixture of H2 and _O2 ) can be used to etch a thin layer of the film with local inhomogeneities and simultaneously capped with -OH, -OOH or -COOH groups. This can be done with or without bias. Combined with the above-mentioned surface modification strategies, this method can achieve the dual purpose of surface roughening and chemical activation of substrate surfaces for direct attachment of inorganic metal oxide-based photoresists or as an intermediate surface modification for further functionalization.

The patterned structure may include any useful substrate. For example, an input wafer may be prepared with a substrate surface of the desired material, where the topmost material is the layer into which the photoresist pattern is transferred. While the material selection may vary depending on the integration, it is generally desirable to select a material that can be etched with high selectivity to (i.e., much faster than) the EUV photoresist or imaging layer. In some embodiments, the substrate is a hard mask that is used for photolithographic etching of the underlying semiconductor material. The hard mask may include any of a variety of materials, including amorphous carbon (aC), tin oxide (e.g., _SnOx ), silicon oxide (e.g., _SiOx , including _SiO2 ), silicon oxynitride (e.g., _SiOxNy ), silicon oxycarbon ( _e.g. , _{SiOxCy )} , silicon nitride (e.g., _Si3N4 ), titanium oxide (e.g., _TiO2 ), titanium nitride (e.g., TiN) _, tungsten (e.g., W), doped carbon (e.g., W-doped C), tungsten oxide (e.g., _WOx ), bismuth oxide (e.g., _HfO2 ), zirconium oxide (e.g., _ZrO2 ), antimony oxide ( _Sb2O3 ), zinc oxide (ZNO), _indium oxide ( _In2O3 ), tellurium ( _Te ), and tellurium oxide ( _TeO2 ) and aluminum oxide (e.g., Al ₂ O ₃ ). Suitable substrate materials may include various carbon-based films (e.g., ashable hard masks (AHMs), silicon-based films (e.g., SiOx, SiCx, SiOxCy, SiOxNy, SiOxCyNz), a-Si:H, polysilicon, or SiN), or any other (usually sacrificial) film applied to facilitate patterning processes). For example, the substrate may preferably include SnO _x , such as SnO ₂ . In various embodiments, the layer may be 1 nm to 100 nm thick, or 2 nm to 10 nm thick.

In various embodiments, the surface (e.g., the surface of the substrate and/or the film) comprises exposed hydroxyl groups located on its surface. In general, the surface can be any surface that comprises an exposed hydroxyl surface or has been treated to produce an exposed hydroxyl surface. Such hydroxyl groups can be formed on the surface by surface treating the substrate using oxygen plasma, water plasma, or ozone. In other embodiments, the surface of the film can be treated to provide exposed hydroxyl groups, over which a capping layer can be applied. In various embodiments, the thickness of the hydroxyl-terminated metal oxide layer is 0.1 nm to 20 nm, 0.2 nm to 10 nm, or 0.5 nm to 5 nm.

The embodiments disclosed herein describe the deposition of materials on a substrate such as a wafer, substrate, or other workpiece. The workpiece can be of various shapes, sizes, and materials. In this application, the terms "semiconductor wafer,""wafer,""substrate,""wafersubstrate," and "partially fabricated integrated circuit" are used interchangeably. It will be understood by those of ordinary skill in the art to which the invention pertains that the term "partially fabricated integrated circuit" can refer to a silicon wafer during any of the many stages of integrated circuit fabrication being performed thereon. Wafers or substrates used in the semiconductor device industry typically have a diameter of 200 mm, 300 mm, or 450 mm. Unless otherwise noted, the process details described herein (e.g., flow rates, power levels, etc.) are related to processing a 300 mm diameter substrate, or to a processing chamber configured to process a 300 mm diameter substrate, and may be appropriately scaled for substrates or chambers of other sizes. In addition to semiconductor wafers, other workpieces for which the embodiments disclosed herein may be used include various articles of manufacture, such as printed circuit boards, etc. The processes and apparatus may be used to manufacture semiconductor devices, displays, etc. Lithographic Processing

EUV lithography utilizes EUV photoresists, which may be polymer-based chemically amplified photoresists fabricated by liquid-based spin-coating techniques, or metal oxide-based photoresists fabricated by dry vapor deposition techniques. Such EUV photoresists may include any EUV-sensitive film or material described herein. The lithography method may include patterning the photoresist, such as exposing the EUV photoresist to EUV radiation to form a photopattern, and then developing the pattern by removing a portion of the photoresist according to the photopattern to form a mask.

It should also be understood that while the present disclosure is about lithographic patterning techniques and materials implemented by EUV lithography, it may also be applicable to other next generation lithography techniques. In addition to EUV, the radiation sources most relevant to this lithography are DUV (deep UV), X-ray, and electron beam, where EUV includes the standard 13.5 nm EUV wavelength currently in use and under development, DUV usually refers to the use of 248 nm or 193 nm excimer laser sources, X-ray forms include EUV at the lower energy range of the X-ray range, and electron beams can cover a wide range of energies. Such a method includes contacting a substrate (e.g., optionally having exposed hydroxyl groups) with a precursor (e.g., any of those described herein) to form a metal oxide (e.g., a layer comprising a metal oxide bonding network, which may include other non-metallic and non-oxygen groups) film on the surface of the substrate as an imaging/PR layer. The specific method may depend on the specific materials and applications used in the semiconductor substrate and the final semiconductor device. Therefore, the methods described in this application are merely examples of methods and materials that can be used in current technology. In some embodiments, lithography includes using a radiation source with a wavelength between 10 nm and 400 nm.

Direct photopatternable EUV resists can be composed of or contain metals and/or metal oxides. Metals/metal oxides are highly promising because they enhance absorption of EUV photons and generate secondary electrons and/or show enhanced etch selectivity to underlying film stacks and device layers. To date, these resists have been developed using wet (solvent) methods, which require moving the wafer onto a track where it is exposed to the developing solvent, dried, and baked. Wet development not only limits throughput, but can also lead to line collapse due to surface tension effects during solvent evaporation between fine features.

Dry development techniques have been proposed to overcome these issues by eliminating substrate delamination and interface failures. Dry development also has its own challenges, including etch selectivity between unexposed and EUV exposed photoresist materials, which can result in higher dose size requirements for effective photoresist exposure compared to wet development. Suboptimal selectivity can also lead to PR corner rounding due to longer exposure time to the etching gas, which can increase line CD variation in subsequent transfer etch steps. Additional processing used during lithography is described in detail below. Deposition Processing Including Dry Deposition

As described above, the present disclosure provides methods for fabricating a base layer and an imaging layer on a semiconductor substrate, wherein the base layer and the imaging layer can be patterned using EUV or other next generation lithography techniques. In some embodiments, dry deposition can use any practical precursor (e.g., a hydrocarbon precursor, a doped precursor, a metal halide, a capping reagent, or an organometallic reagent described herein) to provide the base layer and the imaging layer. The method includes fabricating a polymerized organometallic material in a vapor phase and depositing it over the base layer. In other embodiments, a spin coating formulation can be used. The deposition process can include applying an EUV sensitive material as a photoresist film or an EUV sensitive film.

Such EUV sensitive films include materials that undergo changes after exposure to EUV, such as loss of large side ligands bonded to metal atoms in low-density M-OH-rich materials, allowing them to crosslink to denser M-O-M bonded metal oxide materials. In other embodiments, EUV exposure causes further crosslinking between ligands bonded to metal atoms, thereby providing a denser M-L-M bonded organometallic material, where L is a ligand. In yet other embodiments, EUV exposure causes loss of ligands to provide M-OH materials that can be removed by positive-tone developers.

After EUV patterning, film regions are created that have altered physical or chemical properties relative to unexposed regions. These properties can be implemented in subsequent processing, such as to dissolve unexposed or exposed regions, or to selectively deposit materials on exposed or unexposed regions. In some embodiments, under the conditions under which such subsequent processing is performed, the unexposed film has a hydrophobic surface and the exposed film has a hydrophilic surface (it should be understood that the hydrophilic properties of the exposed and unexposed regions are relative to each other). For example, removal of the material can be performed by leveraging differences in the chemical composition, density, and crosslinking of the film. Removal can be by wet processing or dry processing, as further described herein.

The thickness of the EUV light patternable film formed on the surface of the substrate can vary depending on the surface characteristics, the materials used and the processing conditions. In various embodiments, the film thickness can range from about 0.5 nm to about 100 nm. Preferably, the film has sufficient thickness to absorb most of the EUV light under EUV patterning conditions. For example, the total absorptivity of the photoresist film can be 30% or less (e.g., less than 10% or less than 5%), so that the photoresist material at the bottom of the photoresist film is sufficiently exposed. In some embodiments, the film thickness is from 10 nm to 20 nm. Without limiting the mechanism, function or application of the present disclosure, it is believed that, unlike the wet spin coating process in the art, the process disclosed herein has fewer restrictions on the surface adhesion properties of the substrate and can therefore be applied to a wide variety of substrates. Additionally, as described above, the deposited film may be closely conformal to substrate features, providing the advantage of not "filling in" or otherwise planarizing the features when forming a mask over a substrate (e.g., a substrate having underlying features).

The film (e.g., base layer and/or imaging layer) may be composed of a metal oxide layer deposited by any practical method. Such a metal oxide layer may be deposited or coated by using any EUV sensitive material described herein, such as a precursor (e.g., a metal-containing precursor, a metal halide, a capping reagent, or an organometallic reagent) in combination with a counter reactant. In an exemplary process, the metal oxide layer is provided by forming a polymerized organometallic material in the gas phase or in-situ on the substrate surface. The metal oxide layer may be used as a film, an adhesion layer, or a capping layer.

Optionally, the metal oxide layer may include a hydroxyl-terminated metal oxide layer, which may be deposited using a capping reagent (e.g., any of those described herein) and an oxygen-containing counter reactant. Such a hydroxyl-terminated metal oxide layer may be used, for example, as an adhesion layer between two other layers, such as between the substrate and the film and/or between the photoresist layer and the underlying layer.

Exemplary deposition techniques (e.g., for films) include any of those described herein, such as ALD (e.g., thermal ALD and plasma-enhanced ALD), spin coating deposition, PVD, including PVD co-sputtering, CVD (e.g., PE-CVD, or LP-CVD), sputtering deposition, electron beam deposition, including e-beam co-evaporation, etc., or combinations thereof, such as ALD with a CVD component, such as a non-continuous ALD-like process in which the precursor and the counter reactant are separated in time or space.

Further description of the method of using precursors and their deposits as EUV photoresist films for use with the present disclosure can be found in International Application No. PCT/US19/31618, filed on May 9, 2019, and entitled “METHODS FOR MAKING EUV PATTERNABLE HARD MASKS,” published as International Publication No. WO2019/217749. The film may include optional materials other than the precursors and counter-reactants to change the chemical or physical properties of the film, such as changing the sensitivity of the film to EUV or enhancing the etch resistance. Such optional materials may be introduced as dopants during vapor phase formation, for example, before deposition on the substrate, after the film is deposited, or at both times. In some embodiments, a mild remote H ₂ plasma may be introduced to, for example, replace some Sn-L bonds with Sn-H, which may increase the reactivity of the photoresist under EUV.

Generally, methods may include mixing a vapor stream of a precursor (e.g., a metal-containing precursor such as an organometallic reagent) with an optional vapor stream of a counter-reactant to form a polymerized organometallic material; and depositing the organometallic material onto the surface of the semiconductor substrate. In some embodiments, the act of mixing the precursor with the optional counter-reactant may form a polymerized organometallic material. As will be appreciated by one of ordinary skill in the art, the mixing and depositing aspects of the process may be performed simultaneously in a substantially continuous process.

In an exemplary continuous CVD process, two or more gas streams from sources of precursors and optional counter-reactants are directed to a deposition chamber of a CVD apparatus with separate inlet paths and are mixed and reacted in the vapor phase in the deposition chamber to form a polymerized material (e.g., by forming metal-oxygen-metal bonds) or a film on the substrate. For example, separate injection ports or a dual chamber showerhead may be used to direct the gas streams. The apparatus is configured to allow the gas streams of the precursor and optional counter-reactants to mix within the chamber, allowing the precursor and optional counter-reactants to react to form a polymerized organometallic material or film (e.g., a metal oxide coating or a polymerized material, such as by forming metal-oxygen-metal bonds).

For the deposition of metal oxides, the CVD process is typically performed at low pressure, such as from 0.1 Torr to 10 Torr. In some embodiments, the process is performed at a pressure of from 1 Torr to 2 Torr. The substrate temperature is preferably lower than the temperature of the reactant stream. For example, the substrate temperature can be from 0°C to 250°C, or from room temperature (e.g., 23°C) to 150°C.

For deposition of accumulated polymeric materials, CVD processes are typically conducted at low pressures, such as from 10 mTorr to 10 Torr. In some embodiments, the process is conducted at pressures from 0.5 to 2 Torr. The substrate temperature is preferably equal to or lower than the temperature of the reactant stream. For example, the substrate temperature may be from 0°C to 250°C, or from room temperature (e.g., 23°C) to 150°C. In various processes, deposition of the polymerized organometallic material on the substrate is conducted at a rate that is inversely proportional to the substrate temperature. Without limiting the mechanism, function, or application of the present disclosure, it is believed that the products from this vapor phase reaction become heavier in molecular weight as metal atoms are crosslinked by the counter reactants and then condensed or otherwise deposited on the substrate. In various embodiments, steric hindrance of the large alkyl groups further prevents the formation of a tightly packed network and produces a low density film with increased porosity.

A possible advantage of using a dry deposition method is that it is easy to adjust the composition of the film as it grows. In a CVD process, this can be achieved by varying the relative flow rates of the first precursor and the second precursor during deposition. Deposition is performed at temperatures between 30°C and 200°C and pressures between 0.01 Torr and 100 Torr, but more commonly between about 0.1 Torr and 10 Torr.

A film (e.g., a metal oxide coating, or a polymeric material that accumulates, for example, by forming metal-oxygen-metal bonds) can also be deposited by an ALD process. For example, a precursor and optional counter-reactant can be directed at separate times to present an ALD cycle. The precursor reacts on the surface to form a monolayer of material at a time in each cycle. This allows excellent control of the uniformity of the film thickness across the surface. The ALD process is typically performed at low pressure, for example from 0.1 Torr to 10 Torr. In some embodiments, the process is performed at 1 Torr to 2 Torr. The substrate temperature can be from 0°C to 250°C, or from room temperature (e.g., 23°C) to 150°C. The treatment may be a thermal treatment or preferably a plasma assisted deposition.

Any deposition method described herein may be modified to allow for the use of two or more different precursors. In one embodiment, the precursors may include the same metal, but different ligands. In another embodiment, the precursors may include different metal families. In a non-limiting example, alternating flows of various volatile precursors may provide a mixed metal-containing layer, such as using a metal alkoxide precursor with a first metal (e.g., Sn) and a silicon-based precursor with a different second metal (e.g., Te).

The processing described herein may be used to achieve surface modification. In some iterations, vapor of a precursor may be passed through the wafer. The wafer may be heated to provide thermal energy for the reaction being performed. In some iterations, the heating may be between about 50°C and about 250°C. In some cases, precursor pulses separated by pump and/or purge steps may be used. For example, a first precursor may be pulsed between multiple pulses of a second precursor pulse to form ALD or ALD-like growth. In other cases, the two precursors may be flowed simultaneously. Examples of elements that are practical for surface modification include I, F, Sn, Bi, Sb, Te, and oxides or alloys of these compounds.

The processes herein may be used to deposit thin metal oxides or metals by ALD or CVD. Examples include tin oxide (SnOx), bismuth oxide (BiOx), and Te. After deposition, the _film may be capped using an _alkyl substituted precursor in the form of _MaRbLc as described elsewhere herein. Counter reactants may be used to better remove ligands, and multiple cycles may be repeated to ensure complete saturation of the substrate surface. The surface may then be prepared for deposition of EUV sensitive films. One possible method is to make thin films of SnOx. Possible chemistries include growing _SnO2 by cycling tetrakis(dimethylamino)tin with counter reactants such as water or _O2 plasma. After growth, a capping reagent may be used. For example, isopropyltris(dimethylamino)tin vapor can be flowed over the surface.

The deposition process can be applied to any practical surface. As referred to herein, a "surface" is a surface on which a current technology film is deposited, or a surface that is exposed to EUV during processing. Such a surface can exist on a substrate (e.g., a film can be deposited on it), on a film (e.g., a capping layer can be deposited on it), or on an underlying layer.

Any practical substrate may be used, including any material suitable for lithographic processing, particularly for the fabrication of integrated circuits and other semiconductor devices. In some embodiments, the substrate is a silicon wafer. The substrate may be a silicon wafer having an irregular surface topography on which features (underlying morphological features) are created.

Such underlying topographic features may include areas where material has been removed (e.g., by etching) or areas where material has been added (e.g., by deposition) during processing prior to performing the methods of the present technology. Such pre-processing may include methods of the present technology of depositing two or more feature layers on a substrate, or other processing methods in an iterative process. Without limiting the mechanism, function, or application of the present technology, it is believed that in some embodiments, the methods of the present technology provide advantages over methods known in the art of depositing photolithographic films on a substrate surface using rotational casting methods. These advantages may arise from the conformality of the films of the present technology to the underlying features without "filling in" or otherwise planarizing such features, and the ability to deposit films on a variety of material surfaces. EUV Exposure Process

Exposure of the film to EUV can provide EUV exposed regions having activated reaction centers, which include metal atoms (M) generated by EUV-mediated cleavage events. Such reaction centers can include dangling metal bonds, M-H groups, cleaved M-ligands, dimeric M-M bonds, or M-O-M bridges.

The EUV exposure may have a wavelength ranging from about 10 nm to about 20 nm, such as from 10 nm to 15 nm, such as 13.5 nm, in a vacuum environment. In particular, patterning may provide EUV exposed areas and non-EUV exposed areas to form a pattern.

The present technology may include patterning using EUV, as well as DUV or electron beam. In such patterning, radiation is focused onto one or more areas of an imaging layer. Exposure is typically performed so that the imaging layer film includes one or more areas that are not exposed to the radiation. The resulting imaging layer may include a plurality of exposed and unexposed areas, creating a pattern consistent with other features of a transistor or semiconductor device, wherein the other features of the transistor or semiconductor device are formed by adding or removing material from the substrate during subsequent substrate processing. Practical EUV, DUV and electron beam radiation methods and apparatus herein include methods and apparatus known in the art.

In some EUV lithography techniques, a known photoresist process is used to pattern an organic hard mask (e.g., an ashing hard mask of PECVD amorphous hydrogenated carbon). During photoresist exposure, EUV radiation is absorbed in the photoresist and underlying substrate to generate high-energy photoelectrons (e.g., about 100 eV), which in turn eject low-energy secondary electrons (e.g., about 10 eV) that diffuse laterally over a few nanometers. These electrons increase the scale of chemical reactions within the photoresist, increasing its EUV dose responsiveness. However, a secondary electron pattern that is essentially random is superimposed on the optical image. This unwanted secondary electron exposure results in a loss of resolution, observable line edge roughness, and line width deviations in the patterned photoresist. During the subsequent patterning transfer etch, these defects are replicated in the material to be patterned.

Disclosed herein are vacuum integrated metal hard mask processing and related vacuum integrated hardware that combine film formation (deposition/condensation) with photolithography with significantly improved EUV lithography (EUVL) performance (e.g., reduced line edge roughness).

In various embodiments described herein, a deposition (e.g., condensation) process (e.g., ALD or MOCVD performed in a PECVD tool such as Lam Vector®) may be used to form a thin film containing a metal film, such as a photosensitive metal salt or a metal-containing organic compound (organometallic compound) having strong absorption in EUV (e.g., at a wavelength of about 10 nm to 20 nm), such as at the wavelength of an EUVL light source (e.g., 13.5 nm = 91.8 eV). Such a film, upon EUV exposure, photodecomposes and forms a metal mask, which is a patterned transfer layer during subsequent etching (e.g., in a conductor etching tool such as Lam 2300® Kiyo®).

After deposition, the EUV-patternable film is typically patterned by exposure to an EUV beam at relatively high pressure. For EUV exposure, the metal-containing film can then be deposited in a chamber integrated with a lithography platform (e.g., a wafer stepper such as the TWINSCAN NXE: 3300B® platform supplied by ASML of Veldhoven, NL) and placed under vacuum. It is transmitted to avoid reactions before exposure. The fact that EUVL also requires significantly reduced pressures to allow for strong optical absorption of incident photons by surrounding air (such as H ₂ O, O ₂ , etc.) facilitates integration with lithography tools. In other embodiments, the deposition of the photosensitive metal film and the EUV exposure can be performed in the same chamber. Development processes, including dry development

EUV exposed or non-EUV exposed areas may be removed by any practical development process. In one embodiment, the EUV exposed areas may have activated reaction centers, such as metal dangling bonds, MH groups, or dimeric MM bonds. In certain embodiments, MH groups may be selectively removed by using one or more dry development processes (e.g., halogenated chemicals). In other embodiments, MM bonds may be selectively removed by using wet development processes, such as using hot ethanol and water to provide soluble M(OH) _n groups. In yet other embodiments, EUV exposed areas are removed by using wet development (e.g., by using a positive-tone developer). In some embodiments, non-EUV exposed areas are removed by using dry development.

The dry development process may include the use of halides, such as HCl or HBr based processes. Although the present disclosure is not limited to any particular theory or mechanism of operation, the method is understood to utilize the chemical reactivity of the dry deposited EUV resist film with cleaning chemicals (e.g., HCl, HBr, and BCl ₃ ) to form volatile products using vapor or plasma. The dry deposited EUV resist film can be removed at an etch rate of up to 1 nm/s. The rapid removal of the dry deposited EUV resist film using these chemicals is applicable to chamber cleaning, backside cleaning, wafer edge cleaning, and PR development. While the film can be removed using vapors at various temperatures (e.g., HCl or HBr at temperatures above -10°C, or BCl ₃ at temperatures above 80°C), plasma can also be used to further accelerate or enhance the reactivity.

Plasma treatment includes transformer coupled plasma (TCP), inductively coupled plasma (ICP) or capacitively coupled plasma (CCP), and uses equipment and techniques known in the art. For example, the treatment can be performed at a pressure of >0.5mTorr (e.g., from 1mTorr to 100mTorr), a power level of <1000W (e.g., <500W). The temperature can be 30°C to 300°C (e.g., 30°C to 120°C), at a flow rate of 100 to 1000 standard cubic centimeters per minute (sccm), such as about 500sccm, for 1 to 3000 seconds (e.g., 10 seconds to 600 seconds).

When the halogenide reactant stream is hydrogen and halogenide gas, remote plasma/UV radiation is used to generate radicals from _H2 and _Cl2 and/or _Br2 , and the hydrogen and halogenide radicals are flowed to the reaction chamber to contact the patterned EUV photoresist on the substrate layer of the wafer. Suitable plasma power can range from 100W to 500W with no bias. It should be understood that although these conditions are suitable for use with certain processing reactors, such as the Kiyo etch tool available from Lam Research Corporation, Fremont, CA, a wide range of processing conditions can be used depending on the characteristics of the processing reactor.

In a thermal development process, the substrate is exposed to a dry developing chemical (e.g., a Lewis acid) in a vacuum chamber (e.g., an oven). A suitable chamber may include a vacuum line, a dry developing halogenated hydrogen chemical gas (e.g., HBr, HCl) line, and a heater for temperature control. In some embodiments, the interior of the chamber may be coated with an anti-corrosion film, such as an organic polymer or an inorganic coating. One such coating is polytetrafluoroethylene (PTFE, such as Teflon ^™ ). Such a material can be used in the thermal treatment of the present disclosure without the risk of being removed by plasma exposure.

Depending on the photoresist film and its composition and properties, the processing conditions for dry development can be 100 sccm to 500 sccm of reactant flow (e.g., 500 sccm of HBr or HCl), a temperature of -10°C to 120°C (e.g., -10°C), a pressure of 1 mTorr to 500 mTorr (e.g., 300 mTorr), without plasma and for about 10 seconds to 1 minute.

In various embodiments, the disclosed methods combine all dry steps of film deposition, vapor deposition formation, (EUV) lithography photopatterning, and dry development. In such processing, the substrate can go directly into a dry development/etch chamber after photopatterning in an EUV scanner. Such processing can avoid the material and throughput costs associated with wet development. Dry processing can also provide more tunability and provide further CD control and/or scum removal.

In various embodiments, _EUV photoresists containing some metal, metal _oxide, and organic content can be dry developed by heat, plasma (for example, including, for example, light activated plasma that can be heated by lamps or heated by UV lamps), or a combination of heat and plasma methods while flowing a dry developing gas including a compound of the formula RxZy, where R = B, Al, Si, C, S, SO, x > 0 and Z = Cl, H, Br, F, _CH4 , and y > 0. Dry development can produce positive-tone results, where the _{RxZy species} selectively removes exposed material, leaving the unexposed counterpart as a mask. In some embodiments, the exposed portion of an organotin oxide based photoresist film is removed by dry development according to the present disclosure. Positive-tone dry development can be achieved by selective dry development (removal) of EUV exposed areas, where the EUV exposed areas are exposed to a flow of hydrogen halides or hydrogen and halides (including HCl and/or HBr) without igniting the plasma, or a flow of _H2 and _Cl2 and/or _Br2 that uses remote plasma or UV radiation generated from the plasma to generate free radicals.

Wet developing methods may also be used. In certain embodiments, such wet developing methods are used to remove EUV exposed areas to provide positive tone photoresist or negative tone photoresist. Exemplary and non-limiting wet developing can include using an alkaline developer (e.g., an aqueous alkaline developer), such as those including the following: ammonium, such as ammonium hydroxide ([NH ₄ ] ⁺ [OH] ⁻ ); an ammonium-based ionic liquid, such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), or other quaternary alkylammonium hydroxides; an organic amine, such as a mono-, di-, or tri-organic amine (e.g., dimethylamine, diethylamine, ethylenediamine, triethylenetetramine); or an alkanolamine, such as monoethanolamine, diethanolamine, triethanolamine, or diethyleneglycolamine. In other embodiments, the alkaline developer may include ^a nitrogen-containing base, such as ^a compound having the formula ^RN1NH2 , _RN1RN2NH ^{, RN1RN2RN3N, or RN1RN2RN3RN4N + XN1-, wherein RN1, RN2, RN3 , and RN4 are each independently an organic substituent (} e.g., an optionally substituted alkyl or any of those described herein), or ^two or more organic substituents ^that may be combined with each other ^{, and XN1- may} include ^OH- , ^F- , ^Cl- , ^Br- , ^I-, or other quaternary ammonium cation species known in the art. These bases may also include heterocyclic nitrogen compounds known in the art, some of which are described herein.

Other developing methodologies may include the use of an acidic developer (e.g., an aqueous acidic developer or an acidic developer in an organic solvent), wherein the acidic developer includes a halogen (e.g., HCl or HBr), an organic acid (e.g., formic acid, acetic acid, or citric acid), or an organic fluorine compound (e.g., trifluoroacetic acid; or an organic developer such as a ketone (e.g., 2-heptanone, cyclohexanone, or acetone), an ester (e.g., γ-butyrolactone or ethyl 3-ethoxypropionate (EEP)), an alcohol (e.g., isopropyl alcohol (IPA)), or an ether such as a glycol ether (e.g., propylene glycol methyl ether (PGME) or propylene glycol methyl ether acetate (PGMEA)), and combinations thereof.

In certain embodiments, the positive-tone developer is an aqueous alkaline developer (e.g., including NH ₄ OH, TMAH, TEAH, TPAH, or TBAH). In other embodiments, the negative-tone developer is an aqueous acidic developer, an acidic developer in an organic solvent, or an organic developer (e.g., HCl, HBr, formic acid, trifluoroacetic acid, 2-heptanone, IPA, PGME, PGMEA, or a combination thereof). Post-coating treatment

The methods herein may include any useful post-coating treatments as described below.

For backside and edge cleaning processes, vapor and/or plasma can be confined to specific areas of the wafer to ensure that only the backside and edge are removed without any film degradation on the front side of the wafer. The dry deposited EUV resist films removed are typically composed of Sn, O, and C, but the same cleaning method can be extended to films of other metal oxide resists and materials. In addition, this method can also be used for film stripping and PR reprocessing.

Depending on the photoresist film and its composition and properties, suitable processing conditions for dry edge and backside cleaning may be a reactant flow of 100 sccm to 500 sccm (e.g., 500 sccm of HBr, HCl or _H2 and _Cl2 or _Br2 , _BCl3 or _H2 ), a temperature of -10°C to 120°C (e.g., 20°C), a pressure of 20 mTorr to 500 mTorr (e.g., 300 mTorr), a plasma power of 0 to 500 W at a high frequency (e.g., 13.56 MHz), and a time of about 10 to 20 seconds. It should be understood that while these conditions are suitable for some processing reactors, such as the Kiyo etch tool available from Lam Research Corporation, Fremont, CA, a wider range of processing conditions may be used depending on the capabilities of the processing reactor.

Photolithography processing typically involves one or more bake steps to promote the chemical reactions needed to create a chemical contrast between exposed and unexposed areas of the photoresist. For high volume manufacturing (HVM), such bake steps are typically performed on a track where multiple wafers are baked on a heated plate at a preset temperature under ambient air or, in some cases, _N2 flow. More careful control of the bake perimeter during these bake steps, as well as the introduction of additional reactive gas components into the perimeter, can help further reduce dose requirements and/or improve pattern fidelity.

According to various aspects of the present disclosure, one or more post-treatments for metal and/or metal oxide based photoresists after deposition (e.g., post-application bake (PAB) and/or after exposure (e.g., post-exposure bake (PEB) and/or after development (e.g., post-development bake (PDB)) can improve the material property difference between the exposed and unexposed photoresists, thereby reducing the dose size (DtS), improving the PR profile, and improving the line edge roughness and line width roughness (LER/LWR) after subsequent dry development. Such treatments may involve thermal treatments that utilize controlled temperature, gas ambient, and humidity to improve dry development performance in subsequent processing. In some examples, remote plasma may be used.

In the case of post-coating treatments (e.g., PAB), thermal treatments utilizing controlled temperature, gas ambient (e.g., air, _H2O , _CO2 , CO, _O2 , _O3 , _CH4 , _CH3OH , _N2 , _H2 , _NH3 , _N2O , NO, Ar, He, or mixtures thereof) or under vacuum, and humidity may be used to alter the composition of the unexposed metal and/or metal oxide photoresist after deposition and prior to exposure. This change may increase the EUV sensitivity of the material and, accordingly, may allow for lower dose sizes and edge roughness to be achieved after exposure and dry development.

In the case of post-exposure treatment (e.g., PEB), thermal treatment with controlled temperature, gas atmosphere (e.g., air, _H2O , _CO2 , CO, _O2 , _O3 , _CH4 , _CH3OH , N2, _H2 , _NH3 , _N2O , _NO , Ar, He, or mixtures thereof) or under vacuum, and humidity can be used to change the composition of both the unexposed and exposed photoresists. The change can enhance the composition/material property difference between the unexposed and exposed photoresists, as well as the etch rate difference of the dry developing etch gas between the unexposed and exposed photoresists. Thus, higher etch selectivity can be achieved. Due to the improved selectivity, a more rectangular PR profile can be obtained, accompanied by improved surface roughness and/or less photoresist residue/scum. In a specific embodiment, PEB can be performed in air and optionally in the presence of humidity and _CO2 .

In the case of post-development processing (e.g., post-development baking or PDB), thermal treatment using controlled temperature, gas atmosphere (e.g., air, _H2O , _CO2 , CO, _O2 , _O3 , _CH4 , _CH3OH , _N2 , _H2 , _NH3 , _N2O , NO, Ar, He, or mixtures thereof) or under vacuum (e.g., with UV), and humidity can be used to change the composition of the unexposed photoresist. In certain embodiments, the conditions can also include the use of plasma (e.g., plasma including _O2 , _O3 , Ar, He, and mixtures thereof). This change can increase the hardness of the material, which can be helpful if the film is to be used as a photoresist mask when etching the underlying substrate.

In these cases, in an alternative embodiment, remote plasma treatment may be used instead of thermal treatment to increase reactive species, reduce the energy barrier to reaction and improve yield. Remote plasma may generate more reactive free radicals, thereby reducing the reaction temperature/time of the treatment, resulting in improved yield.

Thus, one or more treatments may be applied to modify the photoresist itself to improve the selectivity of dry development. Such thermal or free radical modifications may increase the contrast between unexposed and exposed materials, thereby improving the selectivity of subsequent development steps. The resulting difference in material properties between the unexposed and exposed materials may be adjusted by adjusting processing conditions, including temperature, airflow, humidity, pressure and/or RF power. Dry development enables a larger processing window that is not limited by the solubility of the material in the wet developer solvent, allowing more aggressive conditions to be applied, further enhancing the material contrast that can be achieved. The resulting high material contrast provides a wider processing margin for dry development, thereby increasing productivity, reducing costs and improving defect performance.

One important limitation of wet developing photoresist films is the limited temperature bake. Since wet developing relies on the solubility of the material, heating to or above 220°C, for example, can greatly increase the degree of crosslinking of both the exposed and unexposed areas of the metal-containing PR film, rendering both insoluble in the wet developing solvent, causing the film to no longer be reliably wet developed. For dry developed photoresist films [where the etch rate difference between exposed and unexposed regions of the PR (i.e., selectivity) is determined by removing only the exposed and unexposed portions of the photoresist], the processing temperature in the PAB, PEB, or PDB can be varied within a wider range to adjust and optimize the processing process, such as from about 90°C to 250°C (e.g., 90°C to 190°C) for PAB, and from about 170°C to 250°C or higher, such as 190°C to 240°C for PEB and/or PDB. It has been found that higher processing temperatures within the above ranges result in reduced etch rates and greater etch selectivity.

In certain embodiments, PAB, PEB and/or PDB processing may be performed with a gas ambient flow rate of 100 sccm to 10,000 sccm, a moisture content of a few % to 100% (e.g., 20%-50%), a pressure between atmospheric and vacuum, and a duration of about 1 minute to 15 minutes, such as about 2 minutes.

These findings can be used to adjust processing conditions to customize or optimize the process for specific materials and environments. For example, for a given EUV dose, the selectivity achieved by thermally treating a PEB at 220°C to 250°C in air at about 20% humidity for about 2 minutes can be similar to the selectivity achieved without such thermal treatment conditions with an EUV dose that is about 30% higher. Thus, depending on the selectivity requirements/limitations of the semiconductor processing operation, thermal treatments as described herein can be used to reduce the required EUV dose. Alternatively, if higher selectivity is required and higher doses can be tolerated, even higher selectivities can be achieved, up to 100 times higher with exposure than without exposure.

Still other steps may include in-situ metrology, where physical and structural properties (e.g., critical dimensions, film thickness, etc.) can be evaluated during photolithography processing. Modules used to perform in-situ metrology include, for example, scatterometry, elliptical polarization, downstream mass spectrometry, and/or plasma enhanced downstream optical emission spectroscopy film sets.

FIG3A is a diagram of the interaction of an oxidizing gas with activatable moieties on and within a top surface of a baked sensitive underlayer beneath an imaging layer having exposed and unexposed areas. The baked sensitive underlayer includes a top underlayer surface and a bottom underlayer surface; the imaging layer above it includes an imaging layer top surface and an imaging layer bottom surface. The oxidizing gas diffuses from the imaging layer top surface through the imaging layer and through the imaging layer bottom surface and oxidizes activatable moieties on and within the top surface of the baked sensitive underlayer, such as C-H bonds (as shown), to release reactive species, such as oxygen radicals. The reactive species thus released can then diffuse into the imaging layer through the bottom surface of the imaging layer, diffuse into the imaging layer from the top surface of the bottom layer and interact with the imaging layer, for example reacting with the imaging layer to promote crosslinking. The crosslinking can occur to some extent in both exposed and unexposed areas of the imaging layer; however, crosslinking occurs preferentially and to a greater extent in the exposed areas. With the contribution of the generated reactive species from in and above the bottom layer, crosslinking by heating alone or by delivering an oxidizing gas while heating the substrate pedestal is more effective and efficient than reactive species generated solely by the oxidizing gas. Preferential cross-linking in the exposed areas can be used to 1) improve patterned structure properties, such as reducing dose size, 2) increase adhesion, and 3) enhance the contrast between exposed and unexposed areas of the photoresist.

FIG. 3B is a bar graph showing C-H loss resulting from post-exposure baking of patterned structures having an underlayer treated with different amounts of an oxidizing gas according to certain disclosed embodiments. Four different underlayers (SHD2, S0, SHD1, and SHD DC10) having activatable portions and a control (Si-silicon wafer lacking an underlayer) were post-exposure baked in the presence of different amounts of oxygen (from 0% to 50%) as the oxidizing gas. The treatment temperature was 210° C. for 240 seconds. C-H loss was measured by FTIR, where an increase in C-H loss indicates a decrease in dose size. The data indicates that the amount of oxidant required to produce a result can vary depending on the selected underlayer.

Figure 4 is a graphical representation of the data from Figure 3B. This demonstrates the synergy between certain underlayers and the oxidizing gas environment. For 0% _O2 , there is no change in CH loss, but as _O2 increases, a dramatic increase in CH loss is observed for the photoresist deposited on the bake-sensitive underlayer (compared to the Si, control underlayer with no activatable portion). In addition, different underlayers have different sensitivities to the addition of _O2 because they react differently.

The formula for synergy is shown in Figure 5A. In this formula, CHLossTotal represents the _total CH loss from EUV+PEB (post-exposure bake); _CHLossBake = CH loss due to PEB component; _CHLossEUV = CH loss due to EUV exposure component, and _{CHComponentSynergy} = CH loss due to synergy between EUV and PEB (i.e., when run sequentially). This formula was used to interpret the data of CH loss values measured by FTIR under different conditions and represents the data plotted in Figures 5B and 5C. The degree of synergy will depend on the base layer selected. The CH loss of the combined EUV+bake step is greater than the sum of the CH losses of each step (the definition of synergy). The amount of this synergy (measured by CH loss) depends on the characteristics of the underlying layer. This is important because it measures the priority of the interaction of active species generated from the UL with the exposed pattern on the unexposed area. This provides a greater chemical/material contrast between the two areas and allows differentiation between the exposed pattern and the unexposed material in the photoresist film. Synergy refers to an unexpected positive effect produced by a combination of conditions and/or materials that is greater than a simple additive effect. This synergy can be due to the simultaneous interaction of processing conditions (use of oxidizing gases), processing steps (baking and EUV exposure), and/or materials (e.g., baking a sensitive underlying layer).

FIG. 5B is a graphical representation of EUV exposure dose-dependent C-H losses resulting from a post-exposure bake of a patterned structure in the absence of an underlayer. The control is a bare silicon wafer. The control was tested in the absence of a bake, and at two different bake temperatures. The calculated CH losses shown are those after subtracting the contribution of the bake step to the CH losses (as determined from the equation of FIG. 5A ). The difference in CH losses between “no bake” (i.e., processed only by EUV exposure) and 200°C or 210°C (i.e., underlayers processed by both EUV exposure and post-exposure bake) indicates the synergistic benefit when the wafers are subjected to both EUV exposure and post-exposure bake relative to the control samples (no bake of the sensitive underlayer).

FIG5C is a graphical representation of EUV exposure dose-dependent CH loss resulting from post-exposure baking at different temperatures for a patterned structure having a bake-sensitive bottom layer SHD2 according to certain disclosed embodiments, showing the synergistic effect of EUV exposure followed by a post-exposure bake. The bake-sensitive bottom layer was tested in the absence of baking and also at two different baking temperatures. The calculated CH loss shown has the contribution of the bake step to the CH loss (determined according to the equation of FIG5A) subtracted. The difference in controlled CH loss between “no bake” (i.e., EUV exposure only) and 200°C or 210°C (i.e., EUV exposure and post-exposure bake) shows the synergistic effect when the patterned structure including the bake-sensitive underlayer is subjected to EUV exposure and post-exposure bake. The difference between the no bake condition and the EUV treatment plus bake condition shows that the effect of having a bake-sensitive underlayer (Figure 5C) on CH loss is much greater than a simple additive effect compared to the absence of the bake-sensitive underlayer (Figure 5B). In addition, this synergistic effect is observed at a much lower dose when the bake-sensitive underlayer is included in the patterned structure.

FIG6A is a bar graph showing CH loss measured by FTIR for an imaging layer deposited on control Si (lacking an underlayer) compared to four different baked sensitive underlayers (UL1, UL2, UL3, and UL4) below the imaging layer after baking at 210°C for 240 seconds at 600 Torr in the presence of an oxidizing gas mixture of 21% _O2 and 79% _N2 . The data indicate that the CH loss is directly caused by the interaction between the baked sensitive underlayer and the imaging layer above it.

FIG6B is a graph showing the CH loss of FIG6A plotted against the experimentally observed dose size for a 14 nM L/S patterned wafer . The linear correlation between dose size and CH loss (determined by FTIR) demonstrates the ability of the CH loss data to clearly predict dose size.

The present disclosure also includes any apparatus configured to perform any of the methods described herein. In one embodiment, an apparatus for depositing a film includes: a deposition module including a chamber for depositing one or more precursors to provide a base layer and/or an imaging layer; a patterning module including an EUV light lithography tool having a sub-30 nm wavelength radiation source; and a developing film stack including a chamber for developing the film including these layers.

The apparatus may further include a controller having instructions for use by the modules. In one embodiment, the controller includes one or more memory devices, one or more processors, and system control software encoded with instructions for performing film deposition. Such inclusions may include in a deposition module for depositing one or more precursors to provide a base layer and/or an imaging layer; in a patterning film group, patterning the layer with a sub-30 nm resolution by EUV exposure to form a pattern in the film; and in a developing film group, developing the film. In a specific embodiment, the developing film group provides for removing EUV exposed or non-EUV exposed areas to provide a pattern in the film.

FIG. 7 is a schematic diagram of an embodiment of a processing station 300 having a processing chamber body 302 for maintaining a low pressure environment suitable for implementing the vapor deposition and dry development embodiments described herein. A plurality of processing stations 300 may be included in a common low pressure processing tool environment. For example, FIG. 8 is a diagram of an embodiment of a multi-station processing tool 400, such as a VECTOR® processing tool available from Lam Research Corporation, Fremont, CA. In some embodiments, one or more hardware parameters of the processing station 300 include those discussed in detail below and may be programmatically adjusted by one or more computer controllers 350.

The processing stations may be configured as modules within a cluster tool. FIG. 10 illustrates a semiconductor processing cluster tool architecture having vacuum integrated deposition and patterning modules suitable for implementing the embodiments described herein. Such a cluster processing tool architecture may include PR and bottom layer deposition, resist exposure (EUV scanner), resist dry development, and etching modules as described above and further described below with reference to FIGS. 11-12.

In some embodiments, certain processing functions may be performed in series in the same module, such as vapor deposition (e.g., PECVD), dry development, and etching. Embodiments of the present disclosure relate to an apparatus for processing a substrate, the apparatus having a processing chamber including a substrate support, a processing gas source coupled to the processing chamber and associated flow control hardware, substrate handling hardware coupled to the processing chamber, and a controller having a processor and a memory. In some embodiments, the processor and the memory are communicatively coupled to each other, the processor being operably coupled to at least the flow control hardware and the substrate processing hardware, and the memory storing computer executable instructions for performing operations in the method for fabricating a patterned structure described herein.

For example, the memory may store computer executable instructions for providing a hard mask disposed on a substrate, such as by chemical vapor deposition (e.g., PECVD). As described above, a suitable hard mask may be, for example, an amorphous carbon ashable hard mask film that is undoped or doped with B or W.

The memory may also store instructions for depositing an underlayer on the substrate and/or hard mask, wherein the underlayer is configured to increase adhesion between the substrate and/or hard mask and a subsequently formed EUV-sensitive inorganic photoresist and reduce the EUV dose used for effective EUV exposure of the photoresist. For example, as described above, the underlayer may be or include a vapor-deposited film of hydrated carbon doped with non-carbon impurities (e.g., any impurity atoms herein, such as O, Si, N, W, B, I, Cl, etc.), the film having a thickness of no more than about 25 nm, and may contain about 0-30% O. In some embodiments, the underlayer may be vapor-deposited on the substrate and/or hard mask by PECVD or ALD using a hydrocarbon precursor and/or a dopant precursor. In other embodiments, a bottom layer may be vapor-phase deposited on a substrate and/or hard mask by PECVD or ALD using a side-oxygenated carbon precursor co-reacted with _H2 or a hydrocarbon. In a variation of this embodiment, the side-oxygenated carbon precursor may be further co-reacted with a Si source dopant during deposition. In other embodiments, a bottom layer may be vapor-phase deposited on a substrate and/or hard mask by PECVD or ALD using a Si-containing precursor co-reacted with an oxidant (e.g., any O-containing precursor described herein). In a variation of this embodiment, the Si-containing precursor is further co-reacted with a C source dopant. In some embodiments, the photoresist base layer may be vapor deposited on the substrate by PECVD, for example, by adjusting the flow of precursors into the PECVD processing chamber to achieve the desired composition of the base layer as a termination operation for vapor deposition on the substrate.

The memory may also store instructions for forming an EUV-sensitive inorganic photoresist on the photoresist base layer. Suitable EUV-sensitive inorganic photoresist may be a metal oxide film, such as an EUV-sensitive tin oxide-based photoresist, as described above.

Referring back to FIG. 7 , the processing station 300 is fluidly connected to a reactant delivery system 301a for delivering a process gas to a distributed showerhead 306. The reactant delivery system 301a optionally includes a mixing tank 304 for mixing and/or blending the process gas delivered to the showerhead 306. One or more mixing tank inlet valves 320 may control the introduction of the process gas to the mixing tank 304. In the case of plasma exposure, plasma may also be delivered to the showerhead 306, or plasma may be generated in the processing station 300. As described above, in at least some embodiments, thermal exposure without plasma is preferred.

FIG. 7 includes an optional vaporization point 303 for vaporizing liquid reactants to be supplied to a mixing tank 304. In some embodiments, a liquid flow controller (LFC) may be provided upstream of the vaporization point 303 to control the mass flow of liquid used for vaporization and delivery to the processing station 300. For example, the LFC may include a thermal mass flow meter (MFM) downstream of the LFC. The plunger valve of the LFC may then be adjusted in response to a feedback control signal provided by a proportional-integral-derivative (PID) controller electrically connected to the MFM.

The showerhead 306 distributes the process gas toward the substrate 312. In the embodiment shown in Figure 7, the substrate 312 is located below the showerhead 306 and is shown as being placed on a pedestal 308. The showerhead 306 can have any suitable shape and can have any suitable number and configuration of ports to distribute the process gas to the substrate 312.

In some embodiments, the pedestal 308 may be raised or lowered to expose the substrate 312 to the volume between the substrate 312 and the showerhead 306. It will be appreciated that in some embodiments, the pedestal height may be programmatically adjusted by a suitable computer controller 350.

In some embodiments, the susceptor 308 can be temperature controlled via a heater 310. In some embodiments, the susceptor 308 can be heated to a temperature greater than 0°C and up to over 300°C, such as 50-120°C, such as about 65-80°C, during non-plasma heat exposure of the photo-patterned photoresist to a hydrohalide dry developing chemistry (e.g., HBr or HCl) as described in the disclosed embodiments.

Additionally, in some embodiments, pressure control of the processing station 300 may be provided by a butterfly valve 318. As shown in the embodiment of FIG. 7 , the butterfly valve 318 regulates the vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, pressure control of the processing station 300 may also be adjusted by varying the flow of one or more gases directed to the processing station 300.

In some embodiments, the position of the showerhead 306 relative to the base 308 can be adjusted to change the volume between the substrate 312 and the showerhead 306. In addition, it will be appreciated that the vertical position of the base 308 and/or showerhead 306 can be changed by any suitable mechanism within the scope of the present disclosure. In some embodiments, the base 308 can include a rotation axis to rotate the position of the substrate 312. It will be appreciated that in some embodiments, one or more of these exemplary adjustments can be programmatically performed by one or more suitable computer controllers 350.

In cases where plasma may be used, such as in dry development embodiments based on mild plasma and/or in etching operations performed in the same chamber, the showerhead 306 and the pedestal 308 are electrically connected to a radio frequency (RF) power source 314 and a matching network 316 for powering the plasma. In some embodiments, the plasma energy may be controlled by controlling one or more of the processing station pressure, gas concentration, RF source power, RF source frequency, and plasma power pulse time. For example, the RF power source 314 and the matching network 316 may be operated at any suitable power to form a plasma having a desired free radical species composition. An example of a suitable power is up to about 500 W. Similarly, the RF power source 314 may provide RF power at any suitable frequency. In some embodiments, the RF power supply 314 may be configured to control the high frequency RF power supply and the low frequency RF power supply independently of each other. Examples of low frequency RF frequencies may include, but are not limited to, frequencies between about 50 kHz and about 1000 kHz. Examples of high frequency RF frequencies may include, but are not limited to, frequencies between about 1.8 MHz and about 2.45 GHz (e.g., about 13.56 MHz). It will be appreciated that any suitable parameters may be adjusted in a discrete or continuous manner to provide the plasma energy required for the surface reaction. In one non-limiting example, the plasma power may be intermittently pulsed to reduce ion bombardment of the substrate surface relative to a continuously powered plasma. The RF power supply may be operated at any suitable duty ratio. Examples of suitable duty cycles include, but are not limited to, duty cycles between about 5% and 90%. Acceptable process pressures are between about 20 mTorr and 5 Torr.

In some examples, the RF power may be continuous or pulsed between one or more levels. If pulsed operation is used, the pulsing may be performed using a frequency in the range of 1 Hz to 1 MHz. In some examples, the chamber pressure is maintained at a predetermined pressure in the range of 5 mTorr to 450 mTorr. In other examples, deposition and processing are performed at a pressure in the range of 5 mTorr to 150 mTorr. In still other examples, deposition and processing are performed at a pressure in the range of 5 mTorr to 35 mTorr.

In some deposition processes, the duration of the plasma strike is on the order of seconds or longer. In certain embodiments, shorter plasma strikes may be used. These plasma strikes may be on the order of 10 milliseconds to 1 second, typically about 20 to 80 milliseconds, with 50 milliseconds being a specific example. Such short RF plasma strikes require extremely fast plasma stabilization. To achieve this, the plasma generator can be configured so that the impedance match is set to a specific voltage while allowing the frequency to float. Traditionally, high frequency plasmas are generated at an RF frequency of about 13.56 MHz. In various embodiments disclosed herein, the frequency is allowed to float to values different from the standard value. By allowing the frequency to float while fixing the impedance match to a predetermined voltage, the plasma can stabilize more quickly; this result can be important when using very short plasma shots associated with certain types of deposition cycles.

In some embodiments, instructions for use by the controller 350 may be provided via input/output control (IOC) sequence instructions. In one example, instructions for setting conditions for a process phase may be included in a corresponding recipe phase of a process recipe. In some cases, the process recipe phases may be arranged in sequence so that instructions for all process phases are executed simultaneously with their process phases. In some embodiments, instructions for setting one or more reactor parameters may be included in a recipe phase. For example, a recipe phase may include instructions for setting the flow rates of an oxygen-carbon precursor and _H2 or an alkane co-reactant and optional dopants on the photoresist bottom layer side. In some embodiments, the controller 350 may include any of those described below with reference to the system controller 450 of FIG. 8.

As described above, one or more processing stations may be included in a multi-station processing tool. FIG8 shows a schematic diagram of an embodiment of a multi-station processing tool 400 having an inbound load lock chamber 402 and an outbound load lock chamber 404, one or both of which may include a remote plasma source. A robot 406 under atmospheric pressure is configured to move wafers from a wafer boat loaded via a cassette 408 into the inbound load lock chamber 402 through an atmospheric vent 410. The wafer is placed on a pedestal 412 in the inbound load lock chamber 402 by the robot 406, the atmospheric vent 410 is closed, and the load lock chamber is evacuated. Where the inbound load lock chamber 402 includes a remote plasma source, the wafer may be exposed to remote plasma treatment within the load lock chamber to treat the surface prior to being introduced into the processing chamber 414. Additionally, the wafer may be heated within the inbound load lock chamber 402, for example to remove moisture and adsorbed gases. Next, the chamber transfer port 416 to the processing chamber 414 is opened and another robot (not shown) places the wafer into the reactor and is positioned on a pedestal at the first station shown in the reactor for processing. While the embodiment depicted in FIG. 8 includes a load lock chamber, it will be appreciated that in some embodiments, the wafer may be provided directly to the processing station.

The illustrated processing chamber 414 includes four processing stations, which are numbered from 1 to 4 in the embodiment shown in FIG. 8 . Each station has a heated pedestal (shown as pedestal 418 for station 1) and a gas line inlet. It will be appreciated that in some embodiments, each processing station may have different or multiple purposes. For example, in some embodiments, a processing station may switch between dry development and etching processing modes. Additionally or alternatively, in some embodiments, the processing chamber 414 may include one or more matched pairs of dry development and etching processing stations. Although the illustrated processing chamber 414 includes four stations, it will be appreciated that a processing chamber according to the present disclosure may have any suitable number of stations. For example, in some embodiments, a processing chamber may have five or more stations; while in other embodiments, a processing chamber may have three or fewer stations.

FIG. 8 illustrates an embodiment of a wafer handling system 490 for transporting wafers within a processing chamber 414. In some embodiments, the wafer handling system 490 may transport wafers between various processing stations and/or between a processing station and a load lock chamber. It will be appreciated that any suitable wafer handling system may be used. Non-limiting examples include a wafer carousel and a wafer handling robot. FIG. 9 also illustrates an embodiment of a system controller 450 that is used to control processing conditions and hardware states of the processing tool 400. The system controller 450 may include one or more memory devices 456, one or more mass storage devices 454, and one or more processors 452. The processor 452 may include a CPU or computer, analog and/or digital input/output connections, a stepper motor controller board, etc.

In some embodiments, the system controller 450 controls all activities of the processing tool 400. The system controller 450 executes system control software 458, which is stored in the mass storage device 454, loaded into the memory device 456, and executed on the processor 452. Alternatively, the control logic can be hard-coded into the controller 450. Application specific integrated circuits, programmable logic devices (e.g., field programmable gate arrays or FPGAs), etc. can be used for these purposes. In the following discussion, wherever "software" or "code" is used, functionally equivalent hard-coded logic can be used there. The system control software 458 may include a plurality of instructions for controlling: timing, gas mixtures, gas flow rates, chamber and/or station pressures, chamber and/or station temperatures, wafer temperatures, target power levels, RF power levels, substrate pedestals, chuck and/or susceptor positions, and other parameters of a particular process performed by the process tool 400. The system control software 458 may be configured in any suitable manner. For example, subroutines or control objects for various process tool components may be written to control the operation of the process tool components used to perform various process tool processes. The system control software 458 may be coded in any suitable computer readable programming language.

In some embodiments, the system control software 458 may include input/output control (IOC) sequence instructions for controlling the various parameters described above. In some embodiments, other computer software and/or programs stored on the mass storage device 454 and/or the memory device 456 associated with the system controller 450 may be used. Examples of programs or portions of programs for this purpose include substrate positioning programs, process gas control programs, pressure control programs, heater control programs, and plasma control programs.

The substrate positioning program may include program code used by processing tool components to load a substrate onto the pedestal 418 and control the spacing between the substrate and other components of the processing tool 400 .

The process gas control program may include code for controlling the composition (e.g., HBr or HCl as described herein) and flow rate of a hydrohalide gas, and optionally for flowing the gas into one or more process stations to stabilize the pressure within the process station prior to deposition. The pressure control program may include code for controlling the pressure within the process station, such as by adjusting a throttle valve in the exhaust system of the process station, the gas flow into the process station, etc.

The heater control program may include code for controlling the flow of current to a heating unit that heats the substrate. Alternatively, the heater control program may control the delivery of a heat transfer gas (e.g., helium) to the substrate.

The plasma control program may include code for setting RF power levels applied to processing electrodes within one or more processing stations according to embodiments herein.

The pressure control program may include code for maintaining pressure within a reaction chamber according to embodiments herein.

In some embodiments, there may be a user interface associated with the system controller 450. The user interface may include a graphical software display that displays screen, equipment and/or processing conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, etc.

In some embodiments, the parameters adjusted by the system controller 450 may be related to processing conditions. Non-limiting examples include process gas composition and flow, temperature, pressure, plasma conditions (e.g., RF bias power level, frequency, and exposure time), etc. These parameters may be provided to the user in the form of a recipe that may be input using the user interface.

A plurality of signals for monitoring the process may be provided through analog and/or digital input connections of the system controller 450 from various process tool sensors. These signals for controlling the process may be output on analog and digital output connections of the process tool 400. Non-limiting examples of process tool sensors that may be monitored include mass flow controllers, pressure sensors (e.g., manometers), thermocouples, etc. Appropriately programmed feedback and control algorithms may be used with the data from these sensors to maintain process conditions.

The system controller 450 may provide program instructions for implementing the above-described deposition process. The program instructions may control various process parameters, such as direct current (DC) power levels, RF bias power levels, pressure, temperature, etc. The instructions may control these parameters to operate the photoresist base layer deposition process according to various embodiments described herein.

The system controller 450 will typically include one or more memory devices and one or more processors configured to execute instructions so that the apparatus will perform methods according to the disclosed embodiments. A machine-readable medium containing instructions for controlling processing operations according to the disclosed embodiments may be coupled to the system controller 450.

In some embodiments, the system controller 450 is part of a system, which may be part of the examples described above. Such a system may include a semiconductor processing apparatus, including one or more processing tools, one or more chambers, one or more processing platforms, and/or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronic components that control their operation before, during, and after processing semiconductor wafers or substrates. The electronic components may be referred to as "controllers" that control various components or sub-components of one or more systems. Depending on the processing conditions and/or system type, the system controller 450 may be programmed to control any of the processes disclosed herein, including the delivery of process gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid transport settings, position and handling settings, and the transfer of wafers into and out of tools, other transport tools, and/or load lock chambers connected or interfaced with a particular system.

In broad terms, the system controller 450 may be defined as an electronic device having various integrated circuits, logic, memory, and/or software to receive instructions, issue instructions, control operations, allow clean operations, allow endpoint measurements, etc. The integrated circuits may include a chip that stores program instructions in the form of firmware, a digital signal processor (DSP), a chip defined as an application specific integrated circuit (ASIC), and/or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). The program instructions may be instructions communicated to the system controller 450 in the form of various independent settings (or program files) to define operating parameters for performing specific processing on a semiconductor wafer, for a semiconductor wafer, or for a system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to accomplish one or more processing steps during the processing of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits and/or dies of a wafer.

In some embodiments, the system controller 450 may be part of or coupled to a computer that is integrated and coupled to the system, or otherwise networked to the system, or a combination thereof. For example, the system controller 450 may be located in the "cloud," or in all or part of a FAB host computer system, and may allow remote access to substrate processing. The computer may allow remote access to the system to monitor the current progress of processing operations, view the history of past processing operations, view trends or performance metrics from multiple processing operations, change parameters of a current process, set processing steps after the current process, or start a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system via a network, which may include a local area network or the Internet. The remote computer may include a user interface that enables the input or programming of parameters and/or settings, which are then transmitted from the remote computer to the system. In some examples, the system controller 450 receives instructions in the form of data that are specific parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of processing to be performed, as well as the type of tool that the system controller 450 is configured to connect to or control. Thus, as described above, the system controller 450 may be distributed, for example, by including one or more discrete controllers that are networked to each other and operate toward a common purpose (e.g., the processing and control described herein). An example of a controller distributed for this purpose would be one or more integrated circuits located on the chamber that communicate with one or more integrated circuits located remotely (e.g., on a stage or as part of a remote computer) that combine to control the steps on the chamber.

Without limitation, exemplary systems may include plasma etching chambers or modules, deposition chambers or modules, spin-clean chambers or modules, metal plating chambers or modules, cleaning chambers or modules, edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, ALD chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, EUV lithography chambers (scanners) or modules, dry development chambers or modules, and any other semiconductor processing system that may be related to or used in the processing and/or manufacturing of semiconductor wafers.

As described above, depending on one or more processing steps to be performed by the tool, the system controller 450 may communicate to one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a host computer, another controller, or tools used in material transport to bring containers of wafers into and out of tool locations and/or loading ports in a semiconductor manufacturing facility.

In some embodiments, an inductively coupled plasma (ICP) reactor may be suitable for etching operations, which are suitable for implementing some of the presently described embodiments. Although an ICP reactor is described herein, it should be understood that a capacitively coupled plasma reactor may also be used in some embodiments.

9 schematically illustrates a cross-sectional view of an inductively coupled plasma apparatus 500 suitable for use in implementing certain embodiments or aspects of embodiments, such as dry development and/or etching, an example of which is a Kiyo® reactor manufactured by Lam Research Corp. of Fremont, Calif. In other embodiments, other tools or tool types having the functionality to perform the dry development and/or etching processes described herein may be used for implementation.

The inductively coupled plasma apparatus 500 includes a main processing chamber 524 structurally defined by a chamber wall 501 and a window 511. The chamber wall 501 may be machined from stainless steel or aluminum. The window 511 may be machined from quartz or other dielectric materials. An optional internal plasma grid 550 divides the main processing chamber into an upper sub-chamber 502 and a lower sub-chamber 503. In most embodiments, the plasma grid 550 may be removed, thereby utilizing the chamber space formed by the sub-chambers 502 and 503. The chuck 517 is disposed in the lower sub-chamber 503 and is close to the bottom inner surface. The chuck 517 is configured to receive and hold a semiconductor wafer 519 on which etching and deposition processes are performed. When present, the chuck 517 can be an electrostatic chuck for supporting the wafer 519. In some embodiments, when present on the chuck 517, a rim ring (not shown) surrounds the chuck 517 and has an upper surface that is substantially planar with the top surface of the wafer 519. The chuck 517 also includes electrostatic electrodes for clamping and dechucking the wafer 519. Filters and a DC fixture power supply (not shown) can be provided for this purpose. Other control systems for lifting the wafer 519 from the chuck 517 may also be provided. The chuck 517 may be charged using an RF power supply 523. The RF power supply 523 is connected to the matching circuit 521 via a connector 527. The matching circuit 521 is connected to the chuck 517 via a connector 525. In this method, the RF power supply 523 is connected to the chuck 517. In various embodiments, the bias power of the electrostatic chuck may be set to approximately 50 V, or may be set to a different bias power depending on the process performed by the disclosed embodiment. For example, the bias power may be between approximately 20 V and approximately 100 V, or between approximately 30 V and approximately 150 V.

The element for generating plasma includes a coil 533 disposed on the window portion 511. In some embodiments, the coil is not used in the disclosed embodiments. The coil 533 is processed from a conductive material and includes at least one complete turn. The example of the coil 533 shown in Figure 9 includes three turns. The cross-section of the coil 533 is shown with symbols, and the coil with "X" extends spirally into the page, while the coil with "●" extends spirally out of the page. The element for generating plasma also includes an RF power supply 541, which is configured to supply RF power to the coil 533. Generally speaking, the RF power supply 541 is connected to the matching circuit 539 through the connector 545. The matching circuit 539 is connected to the coil 533 through the connector 543. In this manner, the RF power source 541 is connected to the coil 533. An optional Faraday shield 549a is disposed between the coil 533 and the window 511. The Faraday shield 549a may be maintained in a spaced relationship relative to the coil 533. In some embodiments, the Faraday shield 549 is disposed immediately above the window 511. In some embodiments, the Faraday shield 549a is between the window 511 and the chuck 517. In some embodiments, the Faraday shield 549b is not maintained in a spaced relationship relative to the coil 533. For example, the Faraday shield 549b may be located directly below the window 511 without a gap. The coil 533, the Faraday shield 549a and the window 511 are arranged substantially parallel to each other. The Faraday shield 549a can prevent metal or other species from being deposited on the window 511 of the processing chamber 524.

Process gases may flow into the processing chamber via one or more main gas inlets 560 disposed in the upper subchamber 502 and/or via one or more side gas inlets 570. Similarly, although not explicitly shown, similar gas inlets may be used to supply process gases to a capacitively coupled plasma processing chamber. A vacuum pump (e.g., a primary or secondary mechanical dry pump and/or a turbomolecular pump 540) may be used to draw process gases out of the processing chamber 524 and to maintain pressure within the processing chamber 524. For example, during a purge operation of an ALD, a vacuum pump may be used to evacuate the lower subchamber 503. A valve-controlled conduit may be used to connect vacuum pump fluid to the processing chamber 524 to selectively control the application of the vacuum environment provided by the vacuum pump. This may be accomplished by using a closed loop controlled flow restriction device such as a throttling valve (not shown) or a bell valve (not shown) during an ongoing plasma process. Similarly, a vacuum pump and valve-controlled fluid connection to a capacitively coupled plasma processing chamber may also be used.

During operation of the apparatus 500, one or more process gases may be supplied via the gas inlets 560 and/or 570. In some embodiments, process gases may be supplied only via the main gas inlet 560, or only via the side gas inlet 570. In some cases, the gas inlets shown in the figure may be replaced, for example, with more complex gas inlets, one or more showerheads. The Faraday shield 549a and/or the optional grid 550 may include internal passages and holes to allow process gases to be delivered to the processing chamber 524. One or both of the Faraday shield 549a and the optional grid 550 may act as a showerhead to deliver the process gas. In some embodiments, the liquid vaporization and delivery system may be located upstream of the processing chamber 524. Once the liquid reactant or precursor is vaporized, the vaporized reactant or precursor may be introduced into the processing chamber 524 through the gas inlet 560 and/or 570.

RF power is supplied from RF power source 541 to coil 533, causing RF current to flow through coil 533. RF current flowing through coil 533 generates an electromagnetic field around coil 533. The electromagnetic field generates an induced current in upper sub-chamber 502. The generated various ions and free radicals physically and chemically interact with wafer 519 to etch the features of wafer 519 and selectively deposit layers on wafer 519.

If the plasma grid 550 is used and there are upper subchamber 502 and lower subchamber 503, the induced current acts on the gas present in the upper subchamber 502 to generate an electron-ion plasma in the upper subchamber 502. The optional internal plasma grid 550 limits the amount of hot electrons in the lower subchamber 503. In some embodiments, the apparatus 500 is designed and operated so that the plasma present in the lower subchamber 503 is an ion-ion plasma.

Although both the upper electron-ion plasma and the lower ion-ion plasma may contain positive and negative ions, the ion-ion plasma will have a greater ratio of negative to positive ions. Volatile etching and/or deposition byproducts may be removed from the lower subchamber 503 via port 522. The chuck 817 disclosed herein may operate at elevated temperatures ranging between about 10° C. and about 250° C. The temperature will depend on the processing operation and the specific recipe.

When installed in a clean room or processing facility, the apparatus 500 can be coupled to a plurality of facilities (not shown). The facilities include piping that provides process gases, vacuum, temperature control, and environmental particle control. When installed in a target processing facility, these facilities can be coupled to the apparatus 500. In addition, the apparatus 500 can be coupled to a transfer chamber, allowing a robot to transfer semiconductor wafers in and out of the apparatus 500 using typical automation.

In some embodiments, a system controller 530 (which may include one or more physical or logical controllers) controls some or all operations of the processing chamber 524. The system controller 530 may include one or more memory devices and one or more processors. In some embodiments, the apparatus 500 includes a switching system for controlling flow rates and durations when performing the disclosed embodiments. In some embodiments, the apparatus 500 may have a switching time of up to about 500 ms or up to about 750 ms. The switching time may depend on the chemicals being flowed, the recipe selection, the reactor architecture, and other factors.

In some embodiments, the system controller 530 is part of a system, which may be part of the examples described above. Such a system may include a semiconductor processing apparatus, including one or more processing tools, one or more chambers, one or more processing platforms, and/or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronic components that control their operation before, during, and after processing semiconductor wafers or substrates. The electronic components may be integrated into the system controller 530, and various components or sub-components of one or more systems may be controlled. Depending on the processing conditions and/or system type, the system controller can be programmed to control any of the processes disclosed herein, including the delivery of process gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow settings, fluid transport settings, position and operating settings, and the transfer of wafers into and out of tools, other transport tools, and/or load lock chambers connected or interfaced with a particular system.

Broadly speaking, the system controller 530 may be defined as an electronic device having various integrated circuits, logic, memory, and/or software to receive instructions, issue instructions, control operations, allow clean operations, allow endpoint measurements, etc. The integrated circuits may include a chip that stores program instructions in the form of firmware, a digital signal processor (DSP), a chip defined as an application specific integrated circuit (ASIC), and/or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). The program instructions may be instructions communicated to the controller in the form of various independent settings (or program files) to define operating parameters for performing specific processing on a semiconductor wafer, for a semiconductor wafer, or for a system. In some embodiments, the operating parameters may be part of a recipe defined by a process engineer to accomplish one or more processing steps during the processing of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits and/or dies of a wafer.

In some embodiments, the system controller 530 may be part of or coupled to a computer that is integrated and coupled to the system, or that is otherwise networked to the system, or a combination thereof. For example, the controller may be located in the "cloud," or all or part of a FAB host computer system, and may allow remote access to substrate processing. The computer may allow remote access to the system to monitor the current progress of processing operations, view the history of past processing operations, view trends or performance metrics from multiple processing operations, change parameters of a current process, set processing steps after the current process, or start a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system via a network, wherein the network may include a local area network, or the Internet. The remote computer may include a user interface that enables the input or programming of parameters and/or settings, which are then transmitted from the remote computer to the system. In some examples, the system controller 530 receives instructions in the form of data that are specific parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of processing to be performed, as well as the type of tool that the controller is configured to connect to or control. Therefore, as described above, the system controller 530 can be distributed, for example, by including one or more discrete controllers that are networked to each other and operate toward a common purpose (e.g., the processing and control described herein). An example of a distributed controller for this purpose would be one or more integrated circuits located on the chamber that communicate with one or more integrated circuits located remotely (e.g., on a stage or as part of a remote computer) and that combine to control the steps on the chamber.

Without limitation, exemplary systems may include plasma etching chambers or modules, deposition chambers or modules, spin-clean chambers or modules, metal plating chambers or modules, cleaning chambers or modules, edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (e.g., PECVD) chambers or modules, ALD chambers or modules, ALE chambers or modules, ion implantation chambers or modules, track chambers or modules, EUV lithography chambers (scanners) or modules, dry development chambers or modules, and any other semiconductor processing system that may be related to or used in the processing and/or manufacturing of semiconductor wafers.

As described above, depending on one or more processing steps to be performed by the tool, the controller may communicate to one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a host computer, another controller, or tools used in material transport to bring containers of wafers into and out of tool locations and/or loading ports in a semiconductor manufacturing facility.

EUVL patterning can be performed using any suitable tool (often referred to as a scanner), such as the TWINSCAN NXE: 3300B® platform supplied by ASML of Veldhoven, NL. The EUVL patterning tool can be a stand-alone device from which substrates are moved in and out for the deposition and etching described herein. Alternatively, as described below, the EUVL patterning tool can be a module located on a larger multi-component tool. Figure 10 shows a semiconductor processing cluster tool architecture 600 having vacuum integrated deposition, EUV patterning, and dry development/etching modules connected to a vacuum transfer module, which is suitable for performing the processing described herein. Although the processing can be performed without such vacuum integrated equipment, such equipment may be advantageous in some embodiments.

FIG. 10 illustrates a semiconductor processing cluster tool architecture having vacuum integrated deposition and patterning modules coupled to a vacuum transfer module suitable for use in performing the processes described herein. The arrangement of transfer modules that "transfer" wafers between a plurality of storage facilities and processing modules may be referred to as a "cluster tool architecture" system. Depending on the requirements of a particular process, deposition and patterning modules are vacuum integrated. Other modules (e.g., for etching) may also be included on the cluster.

A vacuum transfer module (VTM) 638 is interconnected with four processing modules 620a-620d, wherein the processing modules can be independently optimized to perform various processing operations. For example, the processing modules 620a-620d can be implemented to perform deposition, evaporation, ELD, dry development, etching, stripping and/or other semiconductor processing. For example, module 620a can be an ALD reactor, wherein the ALD reactor is operable to perform in a non-plasma thermal atomic layer deposition described herein, such as a Vector tool available from Lam Research Corporation, Fremont, CA. And module 620b can be a PECVD tool, such as a Lam Vector®. It should be understood that the drawings are not necessarily drawn to scale.

Gas chambers 642 and 646 (also referred to as load lock chambers, or transfer modules) are interconnected with VTM 638 and patterning module 640. For example, as described above, a suitable patterning module may be the TWINSCAN NXE: 3300B® platform supplied by ASML of Veldhoven, NL. This tool architecture allows the workpiece (e.g., semiconductor substrate, or wafer) to be transported under vacuum without reacting prior to exposure. The fact that EUVL also requires significant depressurization in view of the strong optical absorption of incident photons by ambient gases (e.g., _H2O , _O2 , etc.) promotes the integration of deposition modules with lithography tools.

As described above, this integrated architecture is only one possible embodiment of a tool for performing the process. The process may also be performed as a module using the more known standalone EUVL scanner and deposition reactors (e.g., Lam Vector tool) either standalone or integrated with other tools (e.g., etch, strip, etc.) (e.g., Lam Kiyo or Gamma tools) in a cluster architecture, such as described with reference to FIG. 9 but without an integrated patterning module.

Gas chamber 642 may be an "output" load lock, referring to transferring substrates from the VTM 638 supplying deposition module 620a to patterning module 640, while gas chamber 646 may be an "input" load lock, referring to transferring substrates from the patterning module 640 back to the VTM 638. The input load lock chamber 646 may also provide an interface to the outside of the tool to place and remove substrates. Each processing module has a facet that connects the module to the VTM 638. For example, deposition processing module 620a has facet 636. Inside each facet, sensors (e.g., sensors 1-18 are shown) are used to detect the passage of wafer 626 as it moves between the respective stations. Patterning module 640 and air chambers 642 and 646 may similarly be equipped with additional dimensions and sensors (not shown).

The main VTM robot 622 transfers wafers 626 between modules, including plenums 642 and 646. In one embodiment, the robot 622 has one arm, and in another embodiment, the robot 622 has two arms, each of which has an end effector 624 that picks up a wafer (e.g., wafer 626) for transport. The front-end robot 644 is used to transfer wafers 626 from the output plenum 642 to the patterning module 640, and from the patterning module 640 to the input plenum 646. The front-end robot 644 can also transfer wafers 626 between the input load lock chamber and the outside of the tool to place or remove substrates. Since the input plenum module 646 has the ability to match the environment between atmosphere and vacuum, the wafer 626 can be moved between the two pressure environments without being damaged.

It should be noted that EUVL tools typically operate at a higher vacuum than deposition tools. If so, it is necessary to increase the vacuum environment of the substrate during transfer between the deposition and EUVL tools to allow the substrate to be degassed before entering the patterning tool. The output plenum 642 can provide this function by maintaining the transferred wafer at a lower pressure (no higher than the pressure in the patterning module 640) for a period of time and exhausting any off-gassing so that the optics of the patterning module 640 are not contaminated by off-gassing from the substrate. A suitable pressure for the output, off-gas plenum is no more than 1E-8 Torr.

In some embodiments, a system controller 650 (which may include one or more physical or logical controllers) controls some or all operations of the cluster tool and/or its respective modules. It should be noted that the controller may be local to the cluster architecture, or may be located external to the cluster architecture in a manufacturing floor, or connected to the cluster architecture via a network at a remote location. The system controller 650 may include one or more memory devices and one or more processors. The processor may include a central processing unit (CPU) or computer, analog and/or digital input/output connections, stepper motor controller boards, and other similar components. A plurality of instructions for performing appropriate control operations are executed on the processor. These instructions may be stored on a memory device associated with the controller, or they may be provided over a network. In some embodiments, the system controller executes system control software.

The system control software may include a plurality of instructions for controlling the application time and/or intensity of any type of tool or module operation. The system control software may be configured in any suitable manner. For example, subroutines or control objects for various processing tool components may be written to control the processing tool components to perform operations required for various processing tool processes. The system control software may be coded in any suitable computer readable programming language. In some embodiments, the system control software includes input/output control (IOC) sequence instructions for controlling the various parameters described above. For example, each stage of a semiconductor processing process may include one or more instructions executed by a system controller. For example, instructions for setting processing conditions for condensation, deposition, evaporation, patterning and/or etching stages may be included in the corresponding recipe stages.

In various embodiments, an apparatus for forming a negative pattern mask is provided. The apparatus may include a processing chamber for patterning, deposition, and etching, and a controller including instructions for forming the negative pattern mask. The instructions may be encoded for patterning features in a chemically amplified (CAR) photoresist on a semiconductor substrate by EUV exposure in the processing chamber to expose the surface of the substrate, dry developing the photo-patterned photoresist, and using the patterned photoresist as a mask to etch the underlying layer or layer stack.

It should be noted that the computer controlling the movement of the wafers may be local to the cluster architecture, or may be external to the cluster architecture in the fabrication floor, or connected to the cluster architecture via a network at a remote location. The controller described above with reference to any of Figures 7, 8 or 9 may be implemented with the tool in Figure 10.

FIG. 11 shows an example of a deposition chamber (e.g., for vapor-based deposition, such as for imaging layers and/or base layers). As shown, the apparatus 700 includes a processing chamber 702, which includes a lid 708 and a wafer transfer channel 704, the dimensions of which are customized to allow a substrate 722 to pass therethrough and to allow the substrate 722 to be placed on a wafer support 724. The wafer transfer channel 704 can have a gate 706, or a similar door mechanism that can be operated to seal or unseal the wafer transfer channel. For example, the substrate 722 can be provided to the processing chamber 702 via a wafer handling robot in an adjacent transfer chamber.

The wafer support 724 may include, for example, an ESC 726 to provide a wafer support surface for the substrate 722. The ESC 726 may include a bottom plate 734 that engages the top surface of the top plate 728. In the illustrated example, the top plate 728 has two separate electronic systems embedded therein. One such system is an electrostatic chuck electrode system that may have one or more chuck electrodes 732 to generate a charge within the substrate 722, causing the substrate 722 to be attracted against the wafer support surface of the top plate 728.

Other systems are thermal control systems that can be used to control the temperature of the substrate 722 during processing conditions. In FIG. 11 , the thermal control system features four annular resistive heater tracks 730a, 730b, 730c, and 730d disposed below the clamping electrode 732. Each resistive heater track 730a/b/c/d can be independently controlled to provide various radial heating profiles within the top plate 728, such as in some cases to maintain the substrate 722 with a temperature uniformity of ±0.5°C. Other embodiments may use a single zone heating system, or a multiple zone heating system with more or less than four zones. In some embodiments such as the temperature control mechanism described above, heat pumps or Peltier junctions may be used instead of resistive heating tracks.

The ESC 726 may also include a bottom plate 734 to provide structural support to the bottom side of the top plate 728, and it may also serve as a heat sink. For example, the bottom plate 734 may include one or more heat exchange channels 736; and a heat exchange medium (e.g., water or an inert fluorinated liquid) may be circulated through the heat exchange channels 736 during use.

The ESC 726 may be supported by a wafer support housing 742 that is connected to or supported by wafer support posts 744. The wafer support posts 744 may have routing channels 748 or other passages for routing cables (e.g., for providing power), fluid flow conduits (e.g., for conveying heat exchange media), and other equipment to the bottom side of the base plate 734 and/or top plate 728.

The apparatus 700 of FIG. 11 also includes a wafer support z-actuator 746 that can provide movable support for the wafer support post 744. The wafer support z-actuator 746 can be actuated to move the wafer support post 744 and the wafer support member 724 supported thereby vertically upward or downward within the reaction volume 720 of the processing chamber 702, for example, by up to several inches. When doing so, the gap distance X between the substrate 722 and the bottom side of the showerhead 710 can be adjusted depending on various processing conditions.

The wafer support 724 may also include one or more edge rings that can be used to control and/or fine-tune various processing conditions. In FIG. 11 , for example, an upper edge ring 738 is provided on top of lower edge rings 740a and 740b, and thus lower edge rings 740a and 740b are supported by a wafer support housing 742 and a third lower edge ring 740c.

The apparatus 700 may also include a system for removing process gases from the process chamber 702 during or after processing. For example, the process chamber 702 may include an annular plenum 756 surrounding the wafer support column 744. Thus, the annular plenum 756 may be fluidly connected to a vacuum foreline 752, which may be connected to a vacuum pump. A regulator valve 754 may be provided between the vacuum foreline 752 and the process chamber 702, and the regulator valve 754 may be actuated to control the flow into the vacuum foreline 752. In some embodiments, a baffle 750 may be provided to reduce the likelihood of developing flow non-uniformities in the reactants flowing across the substrate 722, wherein the baffle 750 is, for example, an annular plate or other structure that allows the gas flow entering the annular plenum 756 to be more evenly distributed around the periphery of the wafer support pillar 744.

As shown, the showerhead 710 is a dual plenum showerhead 710 and includes a first plenum 712 that provides a process gas through a first inlet 716, and a second plenum 714 that provides a process gas through a second inlet 718. Two or more plenums may be used to maintain isolation between the precursor and the counter reactant before release. In some embodiments, a single plenum is used to transport the precursor into the reaction space 720 of the processing chamber 702. Each gas chamber may have a set of corresponding gas distribution ports, wherein the gas distribution ports are connected to the fluid of the reaction space 720 through the panel of the shower head 710 (the panel is a part of the shower head 710 between the lowest gas chamber and the reaction space 720).

The first inlet 716 and the second inlet 718 of the showerhead 710 can provide a process gas via a gas supply system, which can be configured to provide one or more precursors and/or counter reactants as described herein. The first valve manifold 768a can be configured to provide one or more precursors to the first inlet 716, and the second valve manifold 768b can be configured to provide other precursors or other reactants to the second inlet 718. In this example, the first valve manifold 768a, for example, includes a plurality of valves A1-A5. Valve A2, for example, can be a three-way valve having a port connected to the first vaporizer 772a fluid, another port connected to the bypass line 770a fluid, and a third port connected to the port on another three-way valve A3 fluid. Similarly, valve A4 can be another three-way valve having one port fluidly connected to the second vaporizer 772b, another port fluidly connected to the bypass line 770a, and a third port fluidly connected to a port on another three-way valve A5. One of the other ports on valve A5 can be fluidly connected to the first inlet 716, and the remaining port on valve A5 can be fluidly connected to one of the remaining ports on valve A3. Thus, the remaining port on valve A3 can be fluidly connected to valve A1, which can be fluidly interposed between valve A3 and a purge gas source 774 such as nitrogen, argon, or other suitable inert gas (for the precursor and/or the counter reactant). In some embodiments, only the first valve manifold is used.

For the purposes of this disclosure, the term "fluidly connected" is used with respect to volumes, chambers, holes, etc. that can be connected to each other to form a fluid connection, similar to the term "electrically connected" is used with respect to components that are connected to each other to form an electrical connection. If the term "fluid intermediary" is used, it is used to refer to a component, volume, chamber, or hole being fluidly connected to at least two other components, volumes, chambers, or holes, so that a fluid flowing from one of these other components, volumes, chambers, or holes to the other or another of these other components, volumes, chambers, or holes will first flow through the "fluid intermediary" component before reaching the other or another of these other components, volumes, chambers, or holes. For example, if a pump is fluid interposed between a reservoir and an outlet, fluid flowing from the reservoir to the outlet will first flow through the pump before reaching the outlet.

The first valve manifold 768a can be, for example, controllable to allow vapor from one or both of the vaporizers 772a and 772b to flow to the processing chamber 702, or through the first bypass line 770a into the vacuum foreline 752. The first valve manifold 768a can also be controllable to allow purge gas to flow from the purge gas source 774 into the first inlet 716.

It will be appreciated that the second valve manifold 768b can be controlled in a similar manner (e.g., by controlling valves B1-B5) to provide steam from vaporizers 772c and 772d to the second inlet 718 or to the second bypass line 770b. It will be further appreciated that different manifold configurations can also be used, including a single unit manifold that includes multiple valves for controlling the flow of precursors, counter reactants, or other reactants to the first inlet 716 and the second inlet 718.

As mentioned earlier, some apparatuses 700 may feature a smaller number of steam sources, such as only two vaporizers 772, in which case the valve manifold 768 may be modified to have a smaller number of valves, such as only valves A1-A3.

As described above, an apparatus, such as an apparatus 700 that can be used to provide dry deposition of films, can be configured to maintain a specific temperature profile within the processing chamber 702. In particular, such an apparatus 700 can be configured to maintain the substrate 722 at a relatively low temperature, such as 25°C to 50°C, which is lower than most configurations of the apparatus 700 that are in direct contact with precursors and/or counter reactants.

To provide such temperature control, various heating systems may be included in the apparatus 700. For example, the processing chamber 702 may have a socket portion for receiving the cartridge heater 758, such as vertical holes for receiving the cartridge heater 758 may be drilled into the four corners of the housing of the chamber 702. In some embodiments, a heater cover 760 may be used to cover the showerhead 710, wherein the heater cover 760 may be used to apply heat to the entire exposed upper surface of the showerhead 710 to keep the temperature of the showerhead elevated. It may also be helpful to heat the various gas lines that are used to direct the vaporized reactants from the vaporizer 772 to the showerhead 710. For example, a resistive heater can be placed around these gas lines and used to heat them to a higher temperature. Any gas line and even the gate valve 706 in Figure 11 can be heated actively or indirectly.

The various operating systems of the apparatus 700 may be controlled by a controller 784, which may include one or more processors 786 and one or more memory devices 788, which are operatively coupled to each other and to communicate with the various systems and subsystems of the apparatus 700 to provide control functions for these systems. For example, the controller 784 may be configured to control valves A1-A5 and B1-B5, various heaters 758, 760, vaporizer 772, regulator valve 754, gate valve 706, wafer support z-actuators, etc.

Another feature that the apparatus 700 may include is shown in FIG. 12 , which depicts a close-up side cross-sectional view and a plan view of a portion of the substrate 722, top plate 728, and upper edge ring 738 of FIG. 11 . As shown, in some embodiments, the substrate 722 may be elevated off a majority of the top plate 728 by a plurality of protrusions 776, which may be shallow bosses that protrude a slight distance from the nominal upper surface of the top plate 728, thereby providing a backside gap 778 between the underside of the substrate 722 and a majority of the top plate 728. A circumferential wall feature 777 may be disposed at the periphery of the top plate 728. The circumferential wall feature 777 may extend around the entire circumference of the top plate 728 and nominally have the same height as the protrusions 776. During processing operations, a substantially inert gas, such as helium, may flow into the backside gap 778 through the one or more gas ports 782. The gas may then flow radially outward before encountering the circumferential wall feature 777, which may then restrict such radial outward flow and cause a high pressure region of the gas to be trapped between the substrate 722 and the top plate 728. Inert gas that leaks through the circumferential wall 777 may ultimately flow out through the radial gap 780 between the outer edge of the substrate 722 and a portion of the upper edge ring 738. This gas can be used to protect the underside of the substrate 722 from undesired effects of the processing operation being performed by preventing the gas released from the showerhead 710 from reaching the underside of the substrate 722. At the same time, the gas released into the back gap 778 region can also serve to increase the thermal coupling between the substrate 722 and the top plate 728, thereby allowing the top plate 728 to more effectively heat or cool the substrate 722. Due to the higher pressure provided by the circumferential wall, the gas in the back gap 778 region can also have a higher density than the gas in the rest of the chamber, and therefore can provide more effective thermal coupling between the substrate 722 and the top plate 728.

Controller 784 may be configured, for example, via execution of computer-executable instructions, to drive device 700 to perform various operations consistent with the disclosure provided above.

Once the imaging layer and/or base layer are deposited on the substrate 722, the substrate 722 may be transferred to one or more subsequent processing chambers or tools (e.g., any of those described herein) for additional operations as described above. Further deposition apparatus is described in International Patent Application No. PCT/US2020/038968, filed on June 22, 2020, entitled “APPARATUS FOR PHOTORESIST DRY DEPOSITION,” the entire contents of which are incorporated herein by reference. Conclusion

Patterned structures and schemes, as well as related processes and apparatus for introducing a photoresist underlayer configured to increase adhesion between a substrate (e.g., a hard mask) and the photoresist and/or reduce the EUV dose used for effective photoresist exposure during EUV lithography have been disclosed and described herein.

It should be understood that the examples and embodiments described herein are for illustrative purposes only, and that various modifications and variations based on the examples and embodiments will be suggested to those of ordinary skill in the art of the present invention. Although various details are omitted for the purpose of clarity, various design alternatives may be implemented. Therefore, the examples presented are to be regarded as illustrative rather than restrictive, and the present disclosure is not limited to the details given herein, but may be modified within the scope of the present disclosure.

The following example claims provide further description of certain embodiments of the present disclosure. The present disclosure is not necessarily limited to these embodiments.

1~18: Sensor 100: Method 202: Substrate 204: Hard mask 206: Bottom layer 208: Imaging layer 212: Substrate 214: Hard mask 216: Bottom layer 216A: Hydrogen (H) atoms 218: Imaging layer 218A: Metal (M) atoms 226: Bottom layer 228: Imaging layer 300: Processing station 301a: Reactant delivery system 302: Processing chamber body 303: Vaporization point 304: Mixing tank 306: Shower head 308: Base 310: Heater 312: Substrate 314: Radio frequency (RF) power source 316: Matching network 318: Butterfly valve 320: Mixing tank inlet valve 350: Computer controller 400: Multi-station processing tool 402: Inbound load lock chamber 404: Outbound load lock chamber 406: Robot 408: Transfer box 410: Atmosphere vent 412: Base 414: Processing chamber 416: Chamber transfer port 418: Base 450: System controller 452: Processor 454: Storage device 456: Memory device 458: System control software 490: Wafer handling system 500: Inductively coupled plasma equipment 501: Chamber wall 502: Upper subchamber 503: Lower subchamber 511: Window 517: Chuck 519: Semiconductor wafer 521: Matching circuit 522: Port 523: RF power supply 524: Main processing chamber 525: Connector 527: Connector 530: System controller 533: Coil 539: Matching circuit 540: Turbomolecular pump 541: RF power supply 543: Connector 545: Connector 549: Faraday shield 550: Internal plasma grid 560: Main gas inlet 570: Side gas inlet 600: Semiconductor processing cluster tool architecture 620a~620d: Processing module 622: Main VTM robot 624: End effector 626: Wafer 636: Dimensional surface 638: Vacuum transfer module (VTM) 640: Patterning module 642: Gas chamber 644: Front-end robot 646: Gas chamber 650: System controller 700: Equipment 702: Processing chamber 704: Wafer transfer channel 706: Gate valve 708: Cover 710: Shower head 712: First gas chamber 714: Second gas chamber 716: First inlet 718: Second inlet 720: Reaction space 722: Substrate 724: Wafer support 726: Electrostatic chuck (ESC) 728: Top plate 730a~730d: Resistive heater track 732: Clamping electrode 734: Bottom plate 736: Heat exchange channel 738: Upper edge ring 740a~740c: Lower edge ring 742: Wafer support housing 744: Wafer support column 746: Wafer support z-actuator 748: Routing channel 750: Baffle 752: Vacuum foreline 754: Regulator valve 756: Ring chamber 758: Cassette heater 760: Heater cover 768a: First valve manifold 768b: Second valve manifold 770a: First bypass line 770b: Second bypass line 772a~772d: Carburetor 774: Blowing gas source 776: Protrusion 777: Circumferential wall feature 778: Back gap 780: Radial gap 782: Gas port 784: Controller 786: Processor 788: Memory device A1~A5, B1~B5: Valve

FIG. 1 presents a process flow diagram of a non-limiting method 100 according to certain disclosed embodiments.

2A to 2F present schematic diagrams of exemplary patterned structures. Provided are stages in the fabrication of an exemplary patterned structure as described herein (A to C); a cross-sectional view showing possible interactions between imaging layer 218 and underlying layer 216 (D); a non-limiting reaction scheme within the imaging layer (E); and a non-limiting reaction scheme between imaging layer 228 and underlying layer 226 according to certain disclosed embodiments (F).

3A is a schematic diagram of the interaction of exposed photoresist and unexposed photoresist on a baked sensitive underlayer in the presence of an oxidizing agent according to certain disclosed embodiments.

3B is a bar graph illustrating C—H loss resulting from a post-exposure bake of a patterned structure having an underlayer treated with different amounts of an oxidizing gas according to certain disclosed embodiments.

4 is a graphical representation of C—H loss resulting from a post-exposure bake of a patterned structure having an underlying layer treated with different amounts of an oxidizing gas, according to certain disclosed embodiments.

FIG. 5A illustrates a formula for calculating synergy according to certain disclosed embodiments.

5B is a graphical representation of C—H loss resulting from post-exposure baking of a controlled patterned structure without an underlayer (lacking an activatable moiety) at different temperatures according to certain disclosed embodiments.

5C is a graphical representation of C—H loss resulting from post-exposure baking of a patterned structure with an activatable underlayer at different temperatures according to certain disclosed embodiments.

6A is a bar graph showing C-H loss caused by baking alone (without EUV exposure) for a patterned structure with a bake sensitive underlayer compared to a non-bake sensitive underlayer according to certain disclosed embodiments.

6B is a graph showing the correlation of dose size and C—H loss as measured by FTIR according to certain disclosed embodiments.

FIG. 7 presents a schematic diagram of an embodiment of a processing station 300 for dry development according to certain disclosed embodiments.

FIG. 8 presents a schematic diagram of an embodiment of a multi-station processing tool 400 according to certain disclosed embodiments.

FIG. 9 presents a schematic diagram of an embodiment of an inductively coupled plasma apparatus 500 according to certain disclosed embodiments.

FIG. 10 presents a schematic diagram of an embodiment of a semiconductor processing cluster tool architecture 600 according to certain disclosed embodiments.

FIG. 11 depicts a schematic cross-sectional view of an example of a dry deposition apparatus 700 according to certain disclosed embodiments.

Figure 12 depicts detailed side cross-sectional and plan views of a portion of a top plate, base plate, and edge ring according to certain disclosed embodiments.

100:Methods

Claims (96)

An optimized method for forming a patterned structure comprises: providing a substrate; selecting a carbon-containing underlayer including a plurality of activatable portions for deposition on the substrate, wherein the carbon-containing underlayer is selected to produce a reactive species after activation by heating, treatment with an oxidizing gas, treatment with an inert gas, or a combination thereof; depositing the selected carbon-containing underlayer on the substrate; and forming a film of a radiation-sensitive imaging layer on the selected carbon-containing underlayer; and whereby the interaction between the reactive species and the film reduces the amount of radiation used for effective photoresist exposure of the patterned structure. An optimized method for forming a patterned structure as claimed in claim 1, wherein the activatable parts include hydroxyl groups, carboxyl groups, peroxy groups, ^sp2 carbons, sp2 carbons, unsaturated carbon-containing bonds, allyl CH bonds, ether α-position CH bonds, vinyl CH bonds, aldehyde CH bonds, tertiary CH bonds, benzyl CH bonds, ketone α-position CH bonds or combinations thereof. The optimized method for forming a patterned structure as claimed in claim 1, wherein the carbon-containing base layer comprises a carbon-doped film. An optimized method for forming a patterned structure as claimed in claim 3, wherein the carbon-doped film is doped with halogens, metals, organometallic complexes, hydrogen, oxygen or a combination thereof. An optimized method for forming a patterned structure as claimed in claim 4, wherein the metal comprises antimony, tin, bismuth, indium, tellurium, gold, platinum, palladium, nirconium, iridium, titanium, ruthenium, rhodium, silver, tungsten or a combination thereof. An optimized method for forming a patterned structure as claimed in claim 4, wherein the organic metal complex comprises an organic metal complex having an oxidizable metal-carbon bond. An optimized method for forming a patterned structure as claimed in claim 6, wherein the organic metal complex having an oxidizable metal-carbon bond comprises organic ruthenium, organic platinum, organic palladium, organic iridium, organic gold, organic benzenium or organic rhodium. An optimized method for forming a patterned structure as claimed in claim 1, wherein heating includes heating to a temperature of approximately 100°C to 250°C. The optimized method for forming a patterned structure of claim 1, wherein the oxidizing gas comprises chlorine, nitric oxide, nitrogen dioxide, carbon monoxide, carbon dioxide, hydrogen peroxide, ozone, oxygen or a combination thereof. An optimized method for forming a patterned structure as claimed in claim 1, wherein the oxidizing gas is supplied in an inert gas as an oxidizing gas mixture. An optimized method for forming a patterned structure as claimed in claim 10, wherein the oxidizing gas is supplied in an amount of about 10% to about 100% of the oxidizing gas mixture. The optimized method for forming a patterned structure as claimed in claim 1, wherein the inert gas comprises helium, neon, argon, krypton, xenon, radon, nitrogen or a combination thereof. An optimized method for forming a patterned structure as claimed in claim 3, wherein the carbon-doped film is doped with halogen, antimony, tin, bismuth, indium or tellurium, and the activation includes heating. An optimized method for forming a patterned structure as claimed in claim 1, wherein the activatable parts include ^sp2 carbon, sp2 carbon, unsaturated carbon-containing bonds, allyl CH bonds, ether α-position CH bonds, vinyl CH bonds, tertiary CH bonds, benzyl CH bonds or combinations thereof; and the activation includes heating and treatment with an oxidizing gas. A method for manufacturing a patterned structure, comprising: providing a substrate; depositing a baked sensitive base layer on the substrate; forming a film of a radiation sensitive imaging layer on the baked sensitive base layer; exposing the film to extreme ultraviolet radiation to produce a film comprising a plurality of exposed areas and a plurality of unexposed areas; baking the film comprising the exposed areas and the unexposed areas to activate the baked sensitive base layer to generate reactive substances, wherein the reactive substances generated in the baked sensitive base layer preferentially interact with the exposed areas to form exposed crosslinked areas; and developing the film comprising the exposed crosslinked areas and the unexposed areas; Whereby, the interaction between the reactive species and the exposed regions reduces the amount of radiation used for effective photoresist exposure of the patterned structure; and wherein exposing the cross-linked regions increases the contrast between the exposed regions and the unexposed regions. A method for manufacturing a patterned structure, comprising: providing a substrate; depositing a bake-sensitive base layer on the substrate, the bake-sensitive base layer comprising a top base layer surface and a bottom base layer surface; forming a film including a radiation-sensitive imaging layer on the top base layer surface of the bake-sensitive base layer; baking the film to activate the bake-sensitive base layer, thereby generating a reactive substance, wherein the reactive substance generated in the bake-sensitive base layer interacts with the film; and thereby, the interaction between the reactive substance and the film reduces the amount of radiation used for effective photoresist exposure of the patterned structure. A method for manufacturing a patterned structure, comprising: providing a substrate; depositing a baked sensitive base layer on the substrate; forming a film including a radiation sensitive imaging layer on the baked sensitive base layer; exposing the film to extreme ultraviolet radiation to produce an exposed film; and baking the exposed film to activate the baked sensitive base layer to produce reactive substances, wherein the reactive substances produced in the baked sensitive base layer interact with the exposed film; and whereby the interaction between the reactive substances and the exposed film reduces the amount of radiation used for effective photoresist exposure of the patterned structure. A method for manufacturing a patterned structure as claimed in claim 17, wherein the baking includes heating, contacting the film with an inert gas, contacting the film with an oxidizing gas, or a combination thereof. A method for manufacturing a patterned structure as claimed in claim 17, wherein the reactive substance interacts with the exposed film to promote cross-linking of the exposed film. A method for manufacturing a patterned structure as claimed in claim 17, wherein the reactive substance is an oxygen-containing reactive substance. A method for manufacturing a patterned structure as in claim 18, wherein the baking comprises heating to a temperature of approximately 75°C to 280°C. A method for manufacturing a patterned structure as claimed in claim 18, wherein the oxidizing gas comprises chlorine, nitric oxide, nitrogen dioxide, carbon monoxide, carbon dioxide, hydrogen peroxide, ozone, oxygen or a combination thereof. A method for manufacturing a patterned structure as claimed in claim 18, wherein the oxidizing gas is supplied in an inert gas as an oxidizing gas mixture. A method for manufacturing a patterned structure as claimed in claim 23, wherein the oxidizing gas is supplied in an amount of about 10% to about 100% of the oxidizing gas mixture. The method of manufacturing a patterned structure as claimed in claim 17 further includes improving the adhesion between the substrate and the radiation-sensitive imaging layer due to the interaction between the reactive substance and the exposed film. A method for manufacturing a patterned structure as claimed in claim 18, wherein the inert gas comprises helium, neon, argon, krypton, xenon, radon, nitrogen or a combination thereof. A method for manufacturing a patterned structure as claimed in claim 17, wherein the bake-sensitive bottom layer comprises a carbon-containing film or a silicon-containing film. A method for manufacturing a patterned structure as in claim 27, wherein the bake-sensitive base layer comprises a carbon-containing film. A method for manufacturing a patterned structure as claimed in claim 17, wherein the baking-sensitive base layer includes a plurality of activatable moieties, and the activatable moieties include hydroxyl groups, carboxyl groups, peroxide groups, ^sp2 carbons, sp carbons, unsaturated carbon-containing bonds, allyl CH bonds, ether α-position CH bonds, vinyl CH bonds, aldehyde CH bonds, tertiary CH bonds, benzyl CH bonds, ketone α-position CH bonds or combinations thereof. A method for manufacturing a patterned structure as claimed in claim 27, wherein the bake-sensitive base layer includes a carbon-doped film or a silicon-doped film. A method for manufacturing a patterned structure as claimed in claim 30, wherein the carbon-doped film is doped with halogens, metals, organometallic complexes, hydrogen, oxygen or a combination thereof. A method for manufacturing a patterned structure as claimed in claim 31, wherein the metal comprises antimony, tin, bismuth, indium, tellurium, gold, platinum, palladium, nirconium, iridium, titanium, ruthenium, rhodium, silver, tungsten or a combination thereof. A method for manufacturing a patterned structure as claimed in claim 31, wherein the organic metal complex comprises an organic metal complex having an oxidizable metal-carbon bond. A method for manufacturing a patterned structure as claimed in claim 33, wherein the organic metal complex having an oxidizable metal-carbon bond comprises organic ruthenium, organic platinum, organic palladium, organic iridium, organic gold, organic benzenium or organic rhodium. A method for manufacturing a patterned structure as claimed in claim 30, wherein the silicon-doped film is doped with halogens, metals, carbon, hydrogen, oxygen or a combination thereof. A method for manufacturing a patterned structure as claimed in claim 17, wherein the bake-sensitive bottom layer has a thickness of no more than 60 nm. A method for manufacturing a patterned structure as claimed in claim 17, wherein the reactive substance includes peroxyl radicals, hydroperoxyl radicals, oxygen radicals, hydroxyl radicals, hydrogen radicals, formate radicals, iodine radicals, carbon dioxide, carbon monoxide, water, iodine, hydrogen iodide, antimony hydride, hydrogen telluride, bismuth hydride, formate anions, superoxide anions or combinations thereof. A method for manufacturing a patterned structure as claimed in claim 17, wherein: the substrate is a partially fabricated semiconductor device film stack; the substrate further comprises or is a hard mask, an amorphous carbon film, an amorphous carbon hydride film, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a silicon carbide film, a silicon boron nitride film, an amorphous silicon film, a polycrystalline silicon film or a combination thereof; the radiation sensitive imaging layer comprises a tin oxide based photoresist or a tin oxide hydroxide based photoresist; and the bake sensitive bottom layer comprises a vapor phase deposited film of carbon hydride doped with oxygen, silicon, nitrogen, tungsten, boron, iodine, chlorine or a combination of any two or more thereof, wherein the film has a thickness not exceeding 60 nm. A method for manufacturing a patterned structure as claimed in claim 38, wherein the bake-sensitive base layer is vapor deposited on the substrate using a olefin precursor in the absence or presence of a carbon-containing precursor, thereby providing a carbon-containing film; and optionally wherein the carbon-containing precursor co-reacts with hydrogen or a olefin, and optionally further co-reacts with a silicon source dopant. A method for making a patterned structure as claimed in claim 39, wherein the hydrocarbon precursor comprises an alkane, an alkene or an alkyne. The method of manufacturing a patterned structure as claimed in claim 39, wherein the bake-sensitive bottom layer is in the presence of a nitrogen-containing precursor, a tungsten-containing precursor, a boron-containing precursor, an iodine-containing precursor, a chlorine-containing precursor, a bromine-containing precursor, a fluorine-containing precursor, a platinum-containing precursor, a ruthenium-containing precursor, an iridium-containing precursor, a gold-containing precursor In the case of a precursor containing tantalum, a precursor containing palladium, a precursor containing rhodium, a precursor containing zirconium, a precursor containing antimony, a precursor containing indium, a precursor containing bismuth, a precursor containing tellurium, a precursor containing tin, a precursor containing silver, a precursor containing titanium, or a combination thereof, vapor deposition is performed using the hydrocarbon precursor to provide a doped film. A method for manufacturing a patterned structure as claimed in claim 41, wherein the doped film includes iodine, a combination of iodine and silicon, or a combination of iodine, silicon and nitrogen. A method of manufacturing a patterned structure as claimed in claim 38, wherein the bake sensitive base layer is vapor deposited on the substrate using a silicon-containing precursor that co-reacts with an oxidant, and wherein the silicon-containing precursor is optionally further co-reacted with a carbon source dopant. A method for manufacturing a patterned structure as claimed in claim 38, wherein the bake-sensitive base layer is vapor deposited on the substrate by plasma enhanced chemical vapor deposition, wherein the plasma enhanced chemical vapor deposition is used as a termination operation for the vapor deposition on the substrate. A method for manufacturing a patterned structure as claimed in claim 38, wherein the bake-sensitive base layer is vapor deposited on the substrate by plasma enhanced chemical vapor deposition or atomic layer deposition. The method of manufacturing a patterned structure as claimed in claim 17 further includes modifying the bake-sensitive base layer to provide a roughened surface, and optionally exposing the bake-sensitive base layer or the roughened surface to an oxygen-containing plasma after deposition to provide an oxygen-containing surface. A patterned structure includes: a radiation-sensitive imaging layer disposed above a substrate; and a baked sensitive base layer disposed between the substrate and the radiation-sensitive imaging layer, the baked sensitive base layer being configured to reduce the amount of radiation used for effective photoresist exposure of the radiation-sensitive imaging layer. The patterned structure of claim 47, wherein the bake-sensitive bottom layer comprises a carbon-containing film or a silicon-containing film. The patterned structure of claim 48, wherein the bake sensitive base layer comprises a carbon containing film. A patterned structure as in claim 49, wherein the carbon-containing film comprises a hydroxyl group, a carboxyl group, a peroxide group, an ^sp2 carbon, an sp carbon, an unsaturated carbon-containing bond, an allyl CH bond, an ether α-position CH bond, a vinyl CH bond, an aldehyde CH bond, a tertiary CH bond, a benzyl CH bond, a ketone α-position CH bond or a combination thereof. A patterned structure as claimed in claim 48, wherein the bake-sensitive bottom layer comprises a carbon-doped film or a silicon-doped film. A patterned structure as in claim 51, wherein the carbon-doped film is doped with halogens, metals, organometallic complexes, hydrogen, oxygen or a combination thereof. A patterned structure as in claim 52, wherein the metal comprises antimony, tin, bismuth, indium, tellurium, gold, platinum, palladium, nirconium, iridium, titanium, ruthenium, rhodium, silver, tungsten, or a combination thereof. The patterned structure of claim 52, wherein the organometallic complex comprises an organometallic complex having an oxidizable metal-carbon bond. The patterned structure of claim 54, wherein the organic metal complex having an oxidizable metal-carbon bond comprises organic ruthenium, organic platinum, organic palladium, organic iridium, organic gold, organic benzenium or organic rhodium. A patterned structure as claimed in claim 51, wherein the silicon-doped film is doped with halogen, metal, carbon, hydrogen or a combination thereof. A patterned structure as in claim 51, wherein the carbon-doped film comprises about 0.01 to 20 atomic % of the dopant. A patterned structure as in claim 47, wherein the radiation-sensitive imaging layer comprises an extreme ultraviolet-sensitive inorganic photoresist layer, a chemical vapor deposition film, a spin-on film, a tin oxide film, or a tin oxide hydroxide film. A patterned structure as in claim 47, wherein the substrate is or includes a hard mask, an amorphous carbon film, a boron-doped amorphous carbon film, a tungsten-doped amorphous carbon film, an amorphous hydrogenated carbon film, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a silicon carbide film, a silicon boron nitride film, an amorphous silicon film, a polycrystalline silicon film or a combination thereof. The patterned structure of claim 47, wherein the bake sensitive base layer has a thickness of about 2 to 60 nm. A patterned structure as in claim 47, wherein the bake sensitive underlayer comprises a density of about 0.7 to 2.9 g/ ^cm3 ; optionally, wherein the bake sensitive underlayer further provides higher etch selectivity; and optionally, wherein the bake sensitive underlayer further provides lower line edge and line width roughness and/or lower dose to size. A method comprising: Spinning an organic metal imaging layer onto a baked sensitive underlayer on a substrate; and wherein the baked sensitive underlayer is configured to reduce the amount of radiation used for effective photoresist exposure of the organic metal imaging layer. The method of claim 62, further comprising exposing the organometallic imaging layer to extreme ultraviolet radiation. The method of claim 63 further comprises: After exposing the organometallic imaging layer to extreme ultraviolet radiation, developing the organometallic imaging layer using wet developing technology. The method of claim 64, wherein the wet developing is performed using an alkaline developer, an ammonium-based ionic liquid, a glycol ether, an organic acid, a ketone or an alcohol. The method of claim 64, wherein the wet developing is performed using tetramethylammonium hydroxide, propylene glycol methyl ether, propylene glycol methyl ether acetate, 2-heptanone, ethanol, or a combination thereof. The method of claim 62 further comprises performing a post-coating bake at a temperature below 250°C after spin coating. The method of claim 62, further comprising performing a post-exposure bake at a temperature below 280°C. The method of claim 68, further comprising performing a post-development bake at a temperature below 280°C. The method of claim 62, wherein the bake-sensitive base layer is provided by plasma enhanced chemical vapor deposition or vapor deposition. The method of claim 62, wherein the organic metal imaging layer comprises organic tin. The method of claim 62, wherein the organic metal imaging layer comprises organic zirconium, organic antimony, organic zinc, organic uranium, organic zinc, organic tellurium, organic indium or a combination thereof. The method of claim 62, further comprising providing a hard mask between the substrate and the bake-sensitive bottom layer. As in the method of claim 73, wherein the hard mask is a grayable hard mask. The method of claim 62, wherein the bake-sensitive underlayer comprises hydrogenated carbon. A method as claimed in claim 62, wherein the bake-sensitive underlayer comprises carbon hydride doped with oxygen, silicon, nitrogen, tungsten, boron, iodine, chlorine, bromine, fluorine, platinum, ruthenium, iridium, gold, palladium, rhodium, nimum, antimony, indium, bismuth, tellurium, tin, silver, titanium or any two or more thereof; and optionally, the carbon hydride doped with iodine is configured to improve the generation of secondary electrons after exposure to radiation. A method as in claim 62, wherein the bake sensitive underlayer comprises a density of approximately 0.7 to 2.9 g/ ^cm3 ; and optionally, wherein the bake sensitive underlayer further provides higher etch selectivity; and optionally, wherein the bake sensitive underlayer further provides lower line edge and line width roughness and/or lower dose size. A method comprising: providing a baking sensitive base layer on a substrate, the baking sensitive base layer being a vapor-deposited film of carbon hydride; spin-coating an organic tin imaging layer on the baking sensitive base layer; exposing the organic tin imaging layer to extreme ultraviolet radiation; and developing the organic tin imaging layer using a wet developing technique. The method of claim 78, wherein the wet developing is performed using an alkaline developer, an ammonium-based ionic liquid, a glycol ether, an organic acid, a ketone or an alcohol. The method of claim 78, wherein the wet developing is performed using tetramethylammonium hydroxide, propylene glycol methyl ether, propylene glycol methyl ether acetate, 2-heptanone, ethanol, or a combination thereof. The method of claim 78 further includes performing a post-coating bake at a temperature below 250°C after spin coating. The method of claim 78, further comprising performing a post-exposure bake at a temperature below 280°C after exposure. The method of claim 82 further includes performing a post-development bake at a temperature below 280°C after development. The method of claim 78, wherein the bake-sensitive base layer is provided by plasma enhanced chemical vapor deposition. The method of claim 78, further comprising providing an ashable hard mask between the substrate and the bake-sensitive bottom layer after spin coating. A method for manufacturing a patterned structure as claimed in claim 31, wherein the carbon-doped film is a carbon-doped organic metal complex carbon-containing film, and the carbon-doped organic metal complex carbon-containing film is formed by vapor deposition of a carbon-containing film precursor and an organic metal complex. A method for manufacturing a patterned structure as claimed in claim 31, wherein the carbon-doped film is a carbon-containing film doped with an organic metal complex, and the carbon-containing film doped with an organic metal complex is formed by alternating deposition of a carbon-containing film precursor and an organic metal complex. A method for manufacturing a patterned structure as claimed in claim 31, wherein the carbon-doped film is a carbon-doped organic metal complex film, and the carbon-doped organic metal complex film is formed by immersing the baking sensitive base layer in a solution of the organic metal complex. A method for manufacturing a patterned structure as in claim 88, wherein the carbon-containing film doped with an organic metal complex comprises an organic metal complex layer located above the bake-sensitive bottom layer. A method for manufacturing a patterned structure as claimed in claim 88, wherein the carbon-containing film doped with an organic metal complex comprises an organic metal complex dispersed within the bake-sensitive underlayer. A method for manufacturing a patterned structure as claimed in claim 88, wherein the carbon-containing film doped with an organic metal complex includes an organic metal complex layer located above the bake-sensitive bottom layer, and the organic metal complex dispersed in the bake-sensitive bottom layer. A method for manufacturing a patterned structure, comprising: providing a substrate; depositing a doped baked sensitive base layer on the substrate, wherein the doped baked sensitive base layer is doped with an impurity, and the impurity comprises iodine, antimony, bismuth, tellurium and a combination thereof; forming a film of a radiation sensitive imaging layer on the doped baked sensitive base layer; exposing the film to extreme ultraviolet radiation to produce a film comprising a plurality of exposed areas and a plurality of unexposed areas; The film including exposed areas and unexposed areas is baked to activate the doped baked sensitive bottom layer to generate reactive substances, wherein the reactive substances generated in the doped baked sensitive bottom layer preferentially interact with the exposed areas to form exposed cross-linked areas; and The film including the exposed cross-linked areas and unexposed areas is developed; Thereby, the interaction between the reactive substances and the exposed areas reduces the amount of radiation used for effective photoresist exposure of the patterned structure; And, wherein exposing the cross-linked areas increases the contrast between the exposed areas and the unexposed areas. A method for making a patterned structure as claimed in claim 92, wherein exposing the film to extreme ultraviolet radiation activates the doped baked sensitive base layer to produce reactive species. A method for manufacturing a patterned structure, comprising: providing a substrate; depositing a doped baked sensitive base layer on the substrate, the doped baked sensitive base layer comprising a top base layer surface and a bottom base layer surface, wherein the doped baked sensitive base layer is doped with a dopant comprising antimony, bismuth, tellurium and a combination thereof; vapor-depositing a film comprising a radiation sensitive imaging layer on the top base layer surface of the doped baked sensitive base layer; and baking the film to release the dopant from the doped baked sensitive base layer, thereby generating a dopant-reactive substance, wherein the generated dopant-reactive substance interacts with the film; and Thereby, the interaction between the doped reactive species and the film reduces the amount of radiation used for effective photoresist exposure of the patterned structure. A method of making a patterned structure as claimed in claim 94, wherein vapor depositing a film comprising a radiation sensitive imaging layer on the top substrate surface of the doped baked sensitive substrate produces a doping reactive substance. An apparatus for processing a substrate, comprising: a processing chamber including a substrate support; a processing gas source connected to the processing chamber and flow control hardware; substrate handling hardware connected to the processing chamber; and a controller having a processor and a memory, wherein the processor and the memory are connected to each other for communication, the processor is connected to at least the flow control hardware and the substrate handling hardware for operation, and the memory stores computer executable instructions for executing the operations recorded in the optimization method for forming a patterned structure of claim 1.

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