CN1696829A - Chemically Amplified Photoresist Composition - Google Patents

Abstract

The invention relates to a chemical amplification photoresist composition, which is a high molecular polymer containing a structural unit shown as the right formula , wherein R is¹Is hydrogen, C₁－C₄Alkyl group of (5), trifluoromethyl group (CF)₃) (ii) a Q is C₄－C₁₂A cyclic alkyl group of ; r²Comprises the following steps: H. c₁－C₄Alkyl group of (5), trifluoromethyl group (CF)₃)；R³Is C₄－C₁₂Acid sensitive groups of branched or cyclic alkanes; and x + y + z is 1. The chemical amplification photoresist composition can be applied to the common photolithography process at present, in particular to the photolithography process aiming at a light source with the wavelength of 193nm, and can obtain excellent photolithography pattern, resolution, profile and light sensitivity.

Description

Chemically Amplified Photoresist Composition

technical field

The present invention relates to a photoresist composition, in particular to a chemically amplified photoresist composition containing a novel polymer.

Background technique

With the rapid increase of the integration level of semiconductor integrated circuits, the line width required by lithography technology is also getting smaller and smaller. Theoretically, in order to make the pattern resolution obtained by the lithography process better, a short-wavelength light source or an optical system with a larger numerical aperture can be used. Therefore, in order to facilitate the mass production of 1G byte DRAM in response to the design rule of integrated circuits, it is an inevitable trend to advance the line width of the optical lithography process to below 0.13 microns. However, the current KrF (248nm) excimer laser ( Excimer laser) is not suitable for the process of components below 0.13 microns, so the process below 0.13 microns will be carried out by ArF (193nm) excimer laser lithography.

The ArF lithography process using chemically amplified resist is currently the most promising technology to push the process line width below 0.09 microns (90 nm). However, the characteristics of a good 193nm photoresist must have high resolution (below 0.13 microns), large depth of focus (DOF) and process width, good thermal stability and adhesion, high sensitivity (<5mj/cm2), Good plasma etch resistance, moderate dissolution rate, and compatibility with standard chemicals used in the IC industry (such as 2.38% TMAH developer), etc., are all necessary conditions for the development of 193nm photoresists.

In the early development of 193nm photoresists, acrylic polymers were the main polymers, but in order to improve the acrylic polymers’ lack of etching resistance and hydrophilicity, many high-molecular polymers with ring structures were derived. Molecular polymers, such as cycloolefin-maleic anhydride copolymer ( C yclo- O lefin-co-Maleic Anhydride ; COMA, the following documents will be referred to as COMA), polycycloolefin polymer ( C yclo- Olefin Copolymer ; COC, the following documents will be referred to as COC) and cycloolefin-maleic anhydride-acrylic copolymer (Cyclo-Olefin-co-Maleicanhydride-co-acrylate) and so on. However, these high molecular polymers all have some disadvantages, such as the difficulty of using special transition metal catalysts to catalyze the synthesis, the difficulty of removing metal ions after synthesis, excessive absorption, and poor hydrophilicity. In order to improve the shortcomings of the above-mentioned high molecular polymers, it is necessary to develop new high molecular polymer structures.

Vinyl ether-maleic anhydride polymer ( Vinyl Ether - Maleic Anhydride copolymer; VEMA, the following documents will be referred to as VEMA) can improve the shortcomings of the above-mentioned copolymers, for example: more convenient and simple free radical polymerization can be used This type of high molecular polymer is obtained by synthetic method. The photoresist made of this type of high molecular polymer has excellent adhesion to the substrate, and its anti-etching performance is better than that of acrylic high molecular polymer. Absorption is lower than that of norbornene.

Recently, VEMA-related literature has been published, initially in Sang-Jun Choi et al. in Proceedings of SPIE, 3999, 54-61 (2000) and J.Photopolym.Sci.Technol., 13, 419-426 (2000) The structure of VEMA polymer is proposed. Among them, vinyl ether monomers substituted by linear alkyl groups or vinyl ether compounds with naphthenic substituents on the main chain are selected, such as: 3,4-dihydro-2H-pyran (3,4-dihydro-2H -pyran; DHP) and 3,4-dihydro-2-ethoxy-2H-pyran (3,4-dihydro-2-ethoxy-2H-pyran; DHEP), with maleic anhydride and acid-sensitive acrylic Monomers make up copolymers.

Georoge G.Barclay et al. also disclosed polymers with similar structures in U.S. Patent No. 6,306,554. A Norbornene structural monomer was added to the polymer composition to adjust the properties of the polymer , Vinyl Ether (Vinyl Ether; VE) disclosed in the patent, in addition to the above-mentioned DHEP, also has 3,4-dihydro-2-methoxy-2H-pyran (3,4-dihydro-2-mthoxy-2 H -Pyran (DHMP) and other vinyl ethers with naphthenic substituents on the main chain. The preferred weight-average molecular weight (Mw) of this type of polymer falls between 2,000 and 20,000, and the preferred polydispersity result is about 2 or less, and the proportion of acid-sensitive acrylic monomers in the polymer composition disclosed in the synthesis example is relatively high, as high as 40-60%.

However, the high molecular polymers disclosed above still have some unsatisfactory aspects. The vinyl ether monomers used in the aforementioned VEMA polymers are all vinyl ethers with naphthenic substituents on the main chain, and their reactivity is worse than that of vinyl ethers with naphthenic substituents on the side chains. When the reaction occurs, its reactivity is also very different from that of other monomers. Therefore, the heterogeneity of the polymer chain structure is high, while the synthesis yield and weight average molecular weight are low, and the degree of polydispersity becomes high, resulting in the complexity of the synthesis reaction. Especially after introducing another norbornene structural monomer, it becomes more complicated, which increases the difficulty and uncontrollability of the polymerization reaction. On the contrary, the side chain substituents of vinyl ethers are straight-chain structures. Although the obtained polymer chain structure has high uniformity, the synthesis yield and weight-average molecular weight are also high, and the polydispersity is narrowed, but the macromolecular polymer Etching resistance is weakened. The present invention discloses the use of vinyl ethers with naphthenic substituents on the side chains, which have both excellent reactivity and anti-etching properties, and are developed with maleic anhydride and appropriate acid-sensitive acrylic monomers. High molecular polymer with excellent reactivity and etch resistance.

The synthesis of vinyl ether monomers was first prepared by Reppe et al. in 1956 by the action of alcohols and acetylene. The reaction must be carried out under high pressure (20-50atm) and high temperature (180-200°C), using potassium hydroxide as a catalyst, or in the presence of an organometallic catalyst, for example: Y.Okimoto et al. J.Am.Chem. Soc., 124, 1590 (2002). Therefore, the development space of VEMA polymer is limited. Recently, however, B.A.Trofimov et al mentioned in Synthesis, 11, 1521 (2000) that under milder conditions, a variety of ethylene can be synthesized by the action of appropriate alcohols and potassium hydroxide with acetylene in DMSO as a solvent. Ether compounds.

In addition, the present invention also discloses the composition of VEMA high molecular polymer, which breaks through the situation in the above-mentioned literature that the proportion of acid-sensitive acrylic monomers in the main high molecular polymer composition must be higher than 40 molar ratio to have a good effect. By adjusting the proportion of acid-sensitive acrylic monomers in the composition of the polymer, the properties of the polymer such as hydrophilicity, adhesion, dry etching resistance, thermal properties and penetration can be adjusted to make the photoresist The application of the agent is more flexible.

The present invention also discloses another high molecular polymer, which is the above high molecular polymer, and then introduces an acrylic monomer with a ring-shaped alkyl group to solve the problem of introducing norbornene (Norbornene) structural monomer into the VEMA high molecular polymer. , causing the complexity of the synthesis reaction, and improving the simplicity and controllability of the polymerization reaction. The cyclic alkyl acrylic monomer also has the function of adjusting the properties of the high molecular polymer in the photoresist, by adjusting the cyclic alkyl acrylic monomer and the acid-sensitive acrylic monomer To adjust the polymer's hydrophilicity, adhesion, dry etching resistance, thermal properties and penetration, etc., to make the modification technology of the photoresist polymer more flexible And diversity, it has enhanced applicability in 193nm lithography imaging process, and has better resolution, contour and sensitivity.

The novel photoresist composition disclosed by the present invention can simultaneously have excellent properties such as good hydrophilicity, adhesion, and dry etching resistance. These superior properties will increase the adhesion between the photoresist composition and the substrate, increase the light The film-forming properties of the resist and the photoresist pattern after development are not easy to dump. In addition, due to the good hydrophilicity, the developer can be evenly distributed on the surface of the photoresist, improving the uniformity and precise resolution of the surface of the photoresist pattern.

Contents of the invention

The purpose of the present invention is to provide a chemically amplified photoresist composition, which has excellent resolution, profile and sensitivity, and can be applied to lithographic imaging process.

The chemically amplified photoresist of the present invention has excellent resolution, profile and sensitivity, and is suitable for 193nm or 157nm lithography manufacturing method.

A chemically amplified photoresist composition of the present invention is characterized in that it is a high molecular polymer containing structural units of the following formula (II):

Wherein R ¹ is hydrogen, C ₁ -C ₄ alkyl, trifluoromethyl; Q is: C ₄ -C ₁₂ cyclic alkyl; R ² is hydrogen, C ₁ -C ₄ alkyl, trifluoro Methyl; R ³ is an acid-sensitive group of C ₄ -C ₁₂ branched or cyclic alkanes; R ⁴ is hydrogen, C ₁ -C ₄ alkyl, trifluoromethyl; R ⁵ is C ₄ -C12 Cycloalkane substituents; and x+y+z+w=1.

Wherein Q is selected from the following groups: cyclohexyl, isobornyl, adamantyl, tricyclo[5.2.1.0 ^2,6 ]decane-8-yl, tetracyclo[6.2.1.1 ^3,6 .0 ^2,7 ] dodec-9-yl.

Wherein R ^is tertiary butyl, 1-methyl-1-cyclohexyl, 1-ethyl-1-cyclohexyl, 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl , 8-methyltricyclo[5.2.1.0 ^2,6 ]decane-8-yl, 8-ethyltricyclo[5.2.1.0 ^2,6 ]decane-8-yl, 9-methyltetracyclo[ 6.2.1.1 ^3,6 .0 ^2,7 ]dodec-9-yl, or 9-ethyltetracyclo[6.2.1.1 ^3,6 .0 ^2,7 ]dodec-9-yl.

Wherein R ⁴ is hydrogen, C1-C ₄ alkyl, trifluoromethyl.

where x/(x+y+z+w)=0.1 to 0.425; y/(x+y+z+w)=0.1 to 0.425; and z/(x+y+z+w)=0.1 to 0.8; w/(x+y+z+w)=0.05 to 0.5.

Wherein the polymer has a glass transition temperature between 50 and 350°C, a weight average molecular weight between 1,000 and 300,000, a polydispersity between 1 and 3, and a thermal cracking temperature greater than 80°C.

Wherein the structural unit of formula (II) is formula (II-1), (II-2), (II-3), (II-4), (II-5), (II-6), (II- 7), or (II-8).

one of the .

These also include photoacid generators.

Wherein the photoacid generator is selected from at least one of the following compounds:

Wherein n is an integer from 1 to 12; m is an integer from 1 to 12.

The weight of the photoacid generator is 0.1 to 20 parts per 100 parts of the resin.

These also include acid scavengers.

Wherein the acid scavenger is at least one selected from the following compounds: tetrabutylammonium hydroxide, tetrabutylammonium lactate, tributylamine, trioctylamine, triethanolamine, three [2-(2-methoxy Ethoxy) ethyl] amine, N-(2,3-dihydroxypropyl) hexahydropyridine, N-(2-hydroxyethyl) hexahydropyridine, morphine, N-(2-hydroxyethyl) it Lin, N-(2-hydroxyethyl)pyrrolidine, and N-(2-hydroxyethyl)pyridine.

The added amount of the acid scavenger is 0.1 to 50% of the molar ratio of the photoacid generator.

The novel photoresist composition disclosed by the present invention can simultaneously have excellent properties such as good hydrophilicity, adhesion, and dry etching resistance. These superior properties will increase the adhesion between the photoresist composition and the substrate, increase the light The film-forming properties of the resist and the photoresist pattern after development are not easy to dump. In addition, due to the good hydrophilicity, the developer can be evenly distributed on the surface of the photoresist, improving the uniformity and precise resolution of the surface of the photoresist pattern.

Detailed ways

Regarding the preparation of the chemically amplified photoresist composition of the present invention, the high molecular polymer containing the structural unit of formula (I) or formula (II) is a structural repeating unit containing the compound of formula (III)

R ¹ ＝C _n H _2n+1 (n＝0～4), CF ₃ Q＝Alicyclic group

Wherein R ¹ is H or C ₁ -C ₄ alkyl or trifluoromethyl (CF ₃ ); Q is a C ₄ -C ₁₂ cyclic alkanes substituent. The compound of formula (III) is a vinyl ether monomer with a cycloalkane substituent on the side chain, and a vinyl ether monomer with a non-vinyl functional group on the cycloalkane substituent, that is, the non-cycloalkane substituent is in the main chain The above vinyl ether monomers, nor the vinyl ether monomers whose side chain substituents are linear structures. If the compound of formula (III) carries out self-addition reaction under appropriate conditions, it can form a homopolymer (homopolymer), and if it carries out a copolymerization reaction with maleic anhydride, the high molecular polymer that can be prepared is an alternating copolymer ( Altemating copolymer) structure type.

The above-mentioned high molecular polymer containing the structural unit of formula (I) or formula (II) of the present invention is composed of the compound of formula (III) and maleic anhydride, and then collocated with other different types of acrylic monomers with protective groups Or import other different types of acrylic monomers with cyclic alkyl groups for copolymerization reaction to prepare various types of high molecular polymers.

Regarding the preparation of the compound of formula (III), the following formula method can be used for synthesis, but not limited to the following synthesis:

Take appropriate alcohols and pass through acetylene in the KOH/DMSO system, and keep stirring for one hour under sufficient pressure and temperature. After the solution is cooled, add water to dilute, extract, dry and concentrate to obtain light yellow naphthenic substituent vinyl ether compounds.

Aforesaid formula (III) compound can carry out copolymerization reaction with maleic anhydride, and the high molecular polymer prepared is the structure type of alternating copolymer (altemating copolymer), as formula (IV)

R ¹ ＝C _n H _2n+1 (n＝0～4), CF ₃ Q＝Alicyclic group

Wherein R ¹ is H or C ₁ -C ₄ alkyl or trifluoromethyl (CF ₃ ); Q is a C ₄ -C ₁₂ cyclic alkanes substituent.

The aforesaid high molecular polymer containing the structural units of formula (I) and formula (II) of the present invention is composed of the compound of formula (III) and maleic anhydride, and then collocated with other different kinds of acrylic monomers with protective groups or Then introduce other different types of acrylic monomers with cyclic alkyl groups for copolymerization reaction, and prepare various types of high molecular polymers. And this key compound formula (III), because the vinyl ether monomer developed by the present invention, its vinyl functional group is not located on the cycloalkane substituent, so the reaction difference between the vinyl ether monomer and other monomers is reduced; And because the vinyl ether monomer developed by the present invention has a cycloalkane substituent, it also has good etching resistance, and by utilizing its own high polarity, a photoresist polymer with superior properties can be obtained. In addition to the above-mentioned reactivity, etch resistance and polarity, the selection principles of compound formula (III), its absorbance under 193nm light source, good adhesion to the substrate and raw material cost are still important reference indicators. Formula (III) compound structural class is enumerated as follows: (wherein R ¹ is H or C ₁ -C ₄ alkyl or CF ₃ fluoromethane group)

There are no special restrictions on the selection of other different types of acrylic monomers with protective groups described in the structural composition of high molecular polymers containing structural units of formula (I) and formula (II); The acrylic monomer with a protective group with lower absorption makes the prepared high molecular polymer have better penetration characteristics in the application of 193nm light source lithography process. In addition to factors such as absorbency, further screening is carried out according to characteristics such as polarity and adhesion to substrates to obtain suitable high molecular polymers. The aforementioned acrylic monomers with protective groups are listed below: (wherein R ² is H or C ₁ -C ₄ alkyl or trifluoromethyl (CF ₃ ))

Another high molecular polymer disclosed by the present invention, such as formula (II), is the high molecular polymer of the aforementioned formula (I) and then introduces an acrylic monomer with a ring-shaped alkyl group. And other different kinds of acrylic monomers with ring-shaped alkyl groups described in the polymer structure of formula (II), compared with the introduction of norbornene (Norbornene) monomer, the simplicity of the polymerization reaction is comparable to that of The ease of control is improved, and the properties of the high molecular polymer in the photoresist are adjusted by adjusting the ratio of the cyclic alkyl acrylic monomer to the acid-sensitive acrylic monomer in the high molecular polymer composition. The selection can be adjusted according to properties such as polarity, adhesion, etch resistance, thermal properties and penetration. Applicable acrylic monomers with cyclic alkyl groups are listed below: (wherein R ⁴ is hydrogen, C ₁ -C ₄ alkyl or trifluoromethyl (CF ₃ ))

The acrylic monomers with cyclic alkyl groups listed above make the modification technology of photoresist polymers more flexible and diverse, and enhance their applicability in 193nm lithography imaging process. With better resolution, outline and light sensitivity.

As mentioned above, the compound of formula (III) and maleic anhydride is combined with other different types of acrylic monomers with protective groups or introduced into other different types of acrylic monomers with cyclic alkyl groups. Copolymerization reaction to prepare a wide variety of different types of high molecular polymers. However, the present invention selects vinyl ether monomers and acrylic monomers with protective groups from the different types of vinyl functional groups listed above that are not located on the naphthenic substituents, or introduces different types of acrylic monomers with cyclic alkyl groups. The acrylic monomer is substituted into the polymer structure in the aforementioned formula (I) and formula (II) of the present invention to prepare a variety of different types of copolymers to construct VEMA polymers with various superior properties. The following section discusses the monomer composition ratio of the synthesized VEMA polymer, the technology related to the polymerization reaction, and the physical properties of the polymer.

The high molecular weight polymer of the present invention can be used alone or in combination of two or more kinds as a composition of a chemically amplified photoresist.

The technology related to the polymerization of high molecular polymers used in the present invention has no specific process restrictions. Addition polymerization, preferably free radical polymerization, is used to mix the above-mentioned high molecular monomers to be reacted in the catalyst initiator The polymerization reaction is carried out under conditions such as appropriate reaction temperature and feed composition ratio. The catalyst initiator can be the conventional catalyst initiator used by those skilled in the art. Preferred catalyst initiators are generally known free radical initiators, and free radical initiators include azonitriles (azonitriles), alkyl peroxides (alkyl peroxides), acyl peroxides (acylperoxides) , organic peroxides (hydroperoxides) and ketone peroxides (ketoneperoxides), peroxyesters (peresters) and peroxycarbonates (peroxy caronates) and other types, the following are suitable and preferred free radical initiators: Tertiary butyl peroxide (tert-butylperoxide; BPO), acetyl peroxide (acetyl peroxide), 2,2'-azo-bis-isobutyronitrile (2,2'-azo-bis-isobutyronitrile; AIBN), 2,2′-azobismethylnitrile (2,2′-azo-bis-2-methylbutyronitrile; AMBN), dimethyl 2,2′-azobisisobutyl ester free radical initiation agent (dimethyl-2, 2′-azo-bis-isobutyrate radical initiator; V-601), etc. In the presence of nitrogen, according to the thermal cracking characteristics of the free radical initiator, select the appropriate reaction temperature and suitable reaction solvent, and cooperate with other appropriate reaction conditions to carry out the polymerization reaction, so that the free radical initiator can exert better reaction efficiency and improve Improve the reaction yield, improve the applicability of the polymerization technology implemented, and complete the preparation of high-quality VEMA polymers.

The above-mentioned VEMA polymer of the present invention is soluble in a photoresist solvent. The physical properties of polymers are that the glass transition temperature (Tg) is between 50 and 250°C, the weight average molecular weight (Mw) is between 1,000 and 300,000, and the degree of polydispersity (PDI) is between 1 and 3. , The thermal cracking temperature (Td) is greater than 80°C. However, the preferred physical properties of high molecular polymers are that the glass transition temperature Tg is between 60 and 210°C, the weight average molecular weight is between 3,000 and 50,000, the polydispersity is between 1 and 3, and the decomposition temperature Td Greater than 80°C. A suitable method for measuring the weight-average molecular weight and polydispersity of high molecular weight polymers is gel permeation chromatography (gel permeation chromatography).

The chemically amplified photoresist composition of the present invention mainly comprises a high molecular weight polymer with a structural unit of formula (I) or formula (II), and may include other components according to actual application requirements: photoacid generator (Photo- Acid generator, PAG), acid scavenger (Acid quencher), additive (additive) and solvent (solvent) and other components.

The photoacid generator used in the present invention is not particularly limited, as long as it can produce acid after being irradiated with radiation such as ultraviolet rays, the other basic requirements are that it has a low absorption under a 193nm light source and can have A certain degree of stability, so as not to affect the reliability of the process. A preferred photoacid generator can be: (C _n F _2n+1 in the following structural formula, wherein n is an integer of 1 to 12; C _m H _2m+1 in the structural formula, wherein m is an integer of 1 to 12)

The photoacid generators mentioned above may be used alone, or in combination of two or more. Under 100 parts by weight of the resin, the photoacid generator can be added in an amount of 0.1 to 20 parts, and preferably added in an amount of 0.5 to 7 parts (all ratios here are calculated by weight).

The purpose of the acid scavenger of the present invention is to adjust the diffusion characteristics of the acid ions produced by the PAG in the photoresist, so as to make the photoresist better. The preferred acid scavengers suitable for the present invention are:

Tetrabutylammonium hydroxide, tetrabutylammonium lactate, tributylamine, trioctylamine, triethanolamine, tris[2-(2-methoxy Ethoxy) ethyl]amine (tris[2-(2-methoxyethoxy)ethyl]amine), N-(2,3-dihydroxypropyl)hexahydropyridine (N-(2,3-dihydroxypropyl)piperidine), N-(2-hydroxyethyl)hexahydropyridine (N-(2-hydroxyethyl)piperidine), morpholin, N-(2-hydroxyethyl)morpholin , N-(2-hydroxyethyl)pyrrolidine, or N-(2-hydroxyethyl)piperazine, etc. The addition amount of the acid scavenger can be 0.1 to 50% mole ratio of the photoacid generator, and the preferred addition amount is 1 to 25 mole% of the photoacid generator.

The additives of the present invention are not particularly limited, and appropriate amounts of sensitizers, dissolution inhibitors, surfactants, stabilizers, Dyes and other polymers enable the photoresist to meet the required requirements and standards.

The solvent used to manufacture the chemically amplified photoresist composition of the present invention is also not particularly limited, and the types are listed as follows: higher alcohols (for example: n-octanol), ester derivatives of glycolic acid (for example: methyl lactate, ethyl lactate or ethyl glycolate), ester derivatives of glycol ethers (for example: ethylene glycol ethyl ether acetate, ethylene glycol methyl ether acetate or propylene glycol monomethyl ether acetate), ketoesters (e.g. methyl pyruvate or ethyl pyruvate), alkoxy carboxylates (e.g. ethyl 2-ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate ester or methyl ethoxypropionate), ketone derivatives (e.g. methyl ethyl ketone, methyl amyl ketone, acetylacetone, cyclopentanone, cyclohexanone or 2-heptanone), ketone ethers Derivatives (for example: diacetone alcohol methyl ether), ketone alcohol derivatives (for example: acetol or diacetone), alcohol ether derivatives (for example: ethylene glycol butyl ether or propylene glycol ethyl ether), amide derivatives (for example: dimethylacetamide or dimethylformamide), ether derivatives such as anisole or diglyme, or mixtures thereof. Among them, n-octanol, propylene glycol monomethyl ether acetate, 2-ethoxy ethyl acetate, 3-methoxy methyl propionate, ethoxy methyl propionate, methyl ethyl ketone, methyl pentyl The solvent of methyl ketone, cyclopentanone, methyl lactate, ethyl lactate, ethylene glycol butyl ether, propylene glycol ethyl ether or a mixture thereof as the main component is preferred.

The proper weight of solvent is 200 to 2000 parts per 100 parts of high molecular weight polymer, and the preferred addition amount is 400 to 1000 parts (all ratios here are calculated by weight).

The chemically amplified photoresist composition of the present invention is obtained by mixing the above components. The above high molecular polymer can be dissolved in a solvent first, and then mixed with other components. Alternatively, other components except the high molecular polymer are first mixed and dissolved in a solvent, and then mixed into the high molecular polymer.

The amount of impurities (such as trace metals and halogens) contained in the chemically amplified photoresist composition should be reduced as much as possible. Before the components are mixed to obtain the chemically amplified photoresist composition, purification technology can be applied first. Improves purity. Alternatively, the components can be mixed first to produce a chemically amplified photoresist composition, and then subjected to purification techniques before use.

The chemically amplified photoresist composition of the present invention can be maturely applied in the general lithographic imaging process. In particular, the chemically amplified photoresist composition of the present invention can be applied to the microscopic In addition to the lithographic imaging process, it is more suitable for the lithographic imaging process applied to 193nm light.

The chemically amplified photoresist composition of the present invention can be patterned by using the currently well-known lithographic imaging process. For example, the chemically amplified photoresist composition is coated on the substrate, followed by baking, exposure, development and other lithographic imaging process steps to achieve.

The substrate can be a silicon wafer or a variety of materials, and the coating can be performed by methods such as spin coating, spray coating or roll coating. After the substrate is coated, it is usually heated on a heating plate to remove the solvent, and then exposed through a photomask to form the desired pattern on the substrate.

The developer can be selected from ammonia, triethylamine, dimethylamine methanol, tetramethylammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate or trimethylhydroxyethylammonium hydroxide, etc. alkaline aqueous solution.

The chemically amplified photoresist composition of the present invention has excellent resolution, profile and sensitivity, and has excellent performance in depth of focus, exposure boundary and removal boundary.

Embodiments In order to better understand the technical content of the present invention, preferred specific examples are listed as follows.

Preparation Example 1

Synthesis of polymer formula (I-1a)

Add 30 milliliters of tetrahydrofuran (THF), 2.84 grams of tert-butyl methacrylate, 3.92 grams of maleic anhydride, and 5.04 grams of cyclohexyl vinyl ether into the reactor, and then add Starter 2,2'-azobisisobutyl (AIBN) 4.6 grams, and heat up to about 50 ° C, after the reaction is complete, add 50 ml of tetrahydrofuran, and then pour the reaction product into a container containing 1 liter of isopropanol In the container, a white solid is precipitated, filtered and dried to obtain 9.43 grams of a high molecular polymer white powder of formula (I-1a), with a yield of 80%, measured by GPC, with a weight average molecular weight of 13,100, and a glass transition temperature Tg = 146°C.

Preparation example 2-27

Synthesis of polymer formula (I-2a) to formula (I-9a), formula (I-1b) to formula (I-9b), and formula (I-1c) to formula (I-9c)

Repeat the steps of Preparation Example 1, and use different monomers or compositions to carry out polymerization to obtain polymers with different structures such as formula (I-2a) to formula (I-9a), formula (I-1b) to formula (I-9b), and formula (I-1c) to formula (I-9c), all are white powder. The synthesis results are shown in the table below.

The following are the techniques for the convenience of setting forth the invention. In the preparation example, the synthesis of the high molecular polymer is specifically cited as formula (I-1) to formula (I-9), and formula (II-1) to formula (II-8) as the main high Molecular platform (polymer platform) for illustration. See the above-mentioned formula (I-1) to formula (I-9), and formula (II-1) to formula (II-8) shown in the polymer platform item column in the following table:

Wherein, formula (I-1) to formula (I-9) are marked with a, b, c to represent different compositions, and formula (II-1) to formula (II-8) are marked with a, b to represent various compositions. Each of the preparation examples (preparation examples 1 to 43) in the preparation examples of the following high molecular polymers is to clarify the preparation methods and synthesis results of the above-mentioned various formulas, and the structural composition and synthesis of the high molecular polymers in the preparation examples 1 to 43 The result is the following table:

Example 1

Photoresist composition formulation

4 grams of the formula ((I-1a) polymer obtained in Preparation Example 1, triphenylsulfonium perfluoro-1-butane sulfonate (triphenylsulfonium perfluoro-1-butane sulfonate; TPS-PFBS) 0.08 gram and 0.80 grams of tert-butyl cholate (TBC), 35 grams of propylene glycol monomethyl ether acetate (PGMEA) and 20 mg of tetrabutylammonium hydroxide Mix evenly, and then filter the solution with a 0.45 μm filter, then coat the solution on a silicon wafer, and spin coat at 3000 rpm for 20 seconds to obtain a uniform film.

The film was then dried at 130°C for 60 seconds to obtain a film with a thickness of 290.2 nm. Then irradiate the film with 193nm irradiation energy of 10-30mj/cm2 deep ultraviolet (DUV), and heat it on a 130°C hot plate for 90 seconds for post-exposure baking.

Then use 2.38% tetramethyl ammonium hydroxide (tetramethyl ammonium hydroxide; TMAH) aqueous solution to develop the irradiated film, wash with deionized water, spin dry, scan and analyze the microstructure pattern of the photoresist with an electron microscope, it shows that it has 0.13μm resolution structure.

Embodiment 2～11, photoresist composition formula

Repeat the step of embodiment 1, change the high molecular polymer obtained by other preparation examples to replace the high molecular polymer of embodiment 1, its result is as shown in the table below:

  High Molecular Polymer Film thickness (nm) Resolution (μm) Example 1 (I-1a) 290.2 0.13 Example 2 (I-4b) 296.5 0.15 Example 3 (I-4c) 288.3 0.15 Example 4 (I-5b) 278.3 0.15 Example 5 (I-6c) 269.8 0.18 Example 6 (I-8a) 267.1 0.14 Example 7 (II-1a) 262.9 0.15 Example 8 (II-4a) 316.4 0.15

Example 9 (II-5a) 309.7 0.14 Example 10 (II-6a) 309.7 0.13 Example 11 (II-7a) 309.7 0.14

The chemically amplified photoresist composition of the present invention can be maturely applied in general lithographic imaging process, especially 193nm lithographic imaging process, and has excellent resolution, profile and sensitivity.

Comparative Example of Invention

In order to facilitate the description of the novelty and progress of the inventive technology, the polymer platform (polymer platform) of formula (IV) is specifically cited in the comparative example for the convenience of illustration. Formula (IV) sees the polymer platform item column in the following table:

Wherein, the structural composition condition of formula (IV) is compared with the high molecular polymer formula (I-10) prepared by using the published technology of the present invention, and its structural composition and synthesis results of the high molecular polymer quoted in the comparative example are as follows :

Comparative example 1

The synthesis of macromolecular polymer formula (IV)

Add 30 ml of tetrahydrofuran, 8-methyltricyclo[5.2.1.0 ^2,6 ]decane-8-yl methyl acrylate (8-methyltricyclo[5.2.1.0 ^2,6 ]dec-8-ylmethacrylate into the reactor ) 4.68 grams, 3.92 grams of maleic anhydride, 3,4-dihydro-2H-pyran (3,4-dihydro-2H-pyran) 3.36 grams, and then add the initiator 2,2'-azobisiso Butyl (AIBN) 0.65 g, and heat up to about 70 ° C, after the reaction is complete, add 20 ml of tetrahydrofuran, and then pour the reaction product into a container with 1 liter of isopropanol to produce a white solid precipitate, which is filtered and dried , 5.69 grams of white polymer powder of formula (IV) can be obtained, with a yield of 47.63%, measured by GPC, with a weight average molecular weight of 12,600 and a glass transition temperature Tg of 145.45°C. Since the reaction rate of 8-methyltricyclo[5.2.1.0 ^2,6 ]decane-8-yl methacrylate is much faster than maleic anhydride and 3,4-dihydro-2H-pyran, the yield is more Derived from the self-polymerization of 8-methyltricyclo[5.2.1.0 ^2,6 ]decane-8-yl methacrylic polymer, the composition uniformity of the prepared polymer is poor, and of course the yield will be low. reduce.

If the mode of monomer feeding in the polymer synthesis procedure of formula (IV) is changed, the situation of low yield and uneven reaction can be slightly improved. However, the use of this feeding method will result in difficult reaction control, and the properties of the finished products in each batch are not the same.

But take the high molecular polymer synthesis program of formula (I-10) prepared by the technology of the present invention as an example, compare with the high molecular polymer synthetic program of formula (IV), the high molecular polymer synthetic program of formula (I-10) The procedure is simple and easy to control, the synthesis yield is high (80.65%), and the composition uniformity of the prepared polymer is good. At the same time, it can also react with acrylic monomer uniformly to form a four-component polymer platform, which can be adjusted flexibly properties of polymers. This shows that the goal of the present invention is to actively develop a polymer platform with good reactivity and economic benefits, and the polymer platform has excellent extension and modification potential, so that the prepared chemically amplified photoresist composition has excellent lithography performance.

To sum up, the present invention shows its characteristics different from the prior art in terms of purpose, method and effect, or in terms of its technical level and research and development design. However, it should be noted that the above-mentioned embodiments are only illustrated for the sake of illustration, and the scope of rights claimed by the present invention should be based on the scope of the patent application, rather than limited to the above-mentioned embodiments.

Claims (13)

1. A chemically amplified photoresist composition, characterized in that it is a polymer containing the following formula (II) structural unit

Wherein R ¹ is hydrogen, C ₁ -C ₄ alkyl, trifluoromethyl; Q is: C ₄ -C ₁₂ cyclic alkyl; R ² is hydrogen, C ₁ -C ₄ alkyl, trifluoro Methyl; R ³ is an acid-sensitive group of C ₄ -C ₁₂ branched or cyclic alkanes; R ⁴ is hydrogen, C ₁ -C ₄ alkyl, trifluoromethyl; R ⁵ is C ₄ -C12 Cycloalkane substituents; and x+y+z+w=1. 2. The chemically amplified photoresist composition as claimed in claim 1, wherein Q is selected from the group consisting of: cyclohexyl, isobornyl, adamantyl, tricyclic [5.2. 1.0 ^2,6 ]decane-8-yl, tetracyclo[6.2.1.1 ^3,6 .0 ^2,7 ]dodecyl-9-yl. 3. chemically amplified photoresist composition as claimed in claim 1, is characterized in that, wherein R ³ is tertiary butyl, 1-methyl-1-cyclohexyl, 1-ethyl-1-cyclohexyl, 2-Methyl-2-adamantyl, 2-ethyl-2-adamantyl, 8-methyltricyclo[5.2.1.0 ^2,6 ]decane-8-yl, 8-ethyltricyclo[ 5.2.1.0 ^2,6 ]decane-8-yl, 9-methyltetracyclo[6.2.1.1 ^3,6 .0 ^2,7 ]dodecyl-9-yl, or 9-ethyltetracyclo[6.2 .1.1 ^3,6 .0 ^2,7 ]dodec-9-yl. 4. The chemically amplified photoresist composition according to claim 1, wherein ^R4 is hydrogen, C1- _C4 alkyl, trifluoromethyl. 5. The chemically amplified photoresist composition according to claim 1, wherein x/(x+y+z+w)=0.1 to 0.425; y/(x+y+z+w)= 0.1 to 0.425; and z/(x+y+z+w)=0.1 to 0.8; w/(x+y+z+w)=0.05 to 0.5. 6. The chemically amplified photoresist composition according to claim 1, wherein the high molecular polymer has a glass transition temperature between 50 and 350°C and a weight average molecular weight between 1,000 and 300,000 The polydispersity is between 1 and 3, and the thermal cracking temperature is greater than 80°C. 7. The chemically amplified photoresist composition as claimed in claim 1, wherein the structural unit of the formula (II) is a formula (II-1), (II-2), (II-3), (II-4), (II-5), (II-6), (II-7), or (II-8).

one of the . 8. The chemically amplified photoresist composition according to claim 1, further comprising a photoacid generator. 9. The chemically amplified photoresist composition as claimed in claim 8, wherein the photoacid generator is selected from at least one of the following compounds:

Wherein n is an integer from 1 to 12; m is an integer from 1 to 12. 10. The chemically amplified photoresist composition as claimed in claim 8, wherein the photoacid generator is added in an amount of 0.1 to 20 parts by weight per 100 parts by weight of the resin. 11. The chemically amplified photoresist composition according to claim 8, further comprising an acid scavenger. 12. The chemically amplified photoresist composition according to claim 11, wherein the acid scavenger is selected from at least one of the following compounds: tetrabutylammonium hydroxide, tetrabutylammonium lactate , tributylamine, trioctylamine, triethanolamine, tris[2-(2-methoxyethoxy)ethyl]amine, N-(2,3-dihydroxypropyl)hexahydropyridine, N-(2- Hydroxyethyl)hexahydropyridine, morphine, N-(2-hydroxyethyl)morpholin, N-(2-hydroxyethyl)pyrrolidine, and N-(2-hydroxyethyl)pyridine. 13. The chemically amplified photoresist composition as claimed in claim 11, wherein the acid scavenger is added in a molar ratio of 0.1 to 50% of the photoacid generator.