WO2015129275A1

WO2015129275A1 - Reagent for Enhancing Generation of Chemical Species

Info

Publication number: WO2015129275A1
Application number: PCT/JP2015/001005
Authority: WO
Inventors: Satoshi Enomoto
Original assignee: Toyo Gosei Co Ltd
Current assignee: Toyo Gosei Co Ltd
Priority date: 2014-02-26
Filing date: 2015-02-26
Publication date: 2015-09-03
Anticipated expiration: 2016-08-26

Abstract

A reagent that enhances acid generation of a photoacid generator and compositions containing such reagent are disclosed.

Description

Reagent for Enhancing Generation of Chemical Species

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. section 119(e) of U.S. Provisional Patent Application Serial No. 61/944,958 filed on February 26, 2014, the disclosure of which is hereby incorporated herein in its entirety by this reference.

Several aspects of the present invention relate to the fields of reagents or chemical agents formed from such reagents enhancing a generation of a chemical species such as acid and base. Such chemical agent also enhances generation of a chemical species as an acid generation enhancer (AGE) or photosensitizer.

Background

Current high-resolution lithographic processes are based on chemically amplified resists (CARs) and are used to pattern features with dimensions less than 100 nm.

The method for forming pattern features with dimensions less than 100 nm is disclosed in US 7851252 (filed on February 17, 2009).

A reagent relating to an aspect of the present invention, the reagent is characterized by that: the reagent is capable of generating a chemical agent which can be excited by an excitation light of which wavelength is longer than a wavelength of at least one of cutoff wavelength, an absorption end and an absorption maximum in an ultraviolet-visible absorption spectrum of a compound.

With regard to the reagent, it is preferred that the compound is capable of undergoing a reaction in the presence of a chemical species.

With regard to the reagent, it is preferred that the chemical species is generated from a precursor. Typical examples of such chemical species are acid, base and radical while typical examples of the precursor are photoacid generator (PAG), photobase generator (PBG) and photoradical initiator.

With regard to the reagent, it is preferred that the excitation light is equal to or longer than 300 nm. For example, i-line or the third harmonic of Nd: YAG laser can be used as the excitation light.

With regard to the reagent, it is preferred that the compound has at least one pi-electron system.

With regard to the reagent, it is preferred that the compound has at least one aromatic group.

With regard to the reagent, it is preferred that the compound has an absorption maximum in a range from 200 nm to 300 nm.

With regard to the reagent, it is preferred that wherein the reagent is capable of generating the chemical agent by a first exposure of at least one of a composition containing the reagent, a solution containing the composition and a film formed of the composition to at least one of a first electromagnetic ray and a first particle ray.

With regard to the reagent, it is preferred that the first electromagnetic ray and the first particle ray are a EUV light and an electron beam, respectively.

With regard to the reagent, it is preferred that the compound has a group capable of undergoing a reaction. The reaction may occur in the presence of a chemical species.

With regard to the reagent, it is preferred that such chemical species is acid.

With regard to the reagent, it is preferred that, by the excitation light, the chemical agent is excited to its excited state from which an electron is donated to a precursor to generate a chemical species.

With regard to the reagent, it is preferred that the chemical species is capable of reacting with the compound.

With regard to the reagent, it is preferred that the compound has a moiety of a phenol derivative.

A composition relating to an aspect of the present invention includes: a compound. It is preferred that the compound is capable of being converted into a product by a first exposure of at least one of the composition, a solution containing the composition and a film formed of the composition to at least one of a first electromagnetic ray and a first particle ray directly or indirectly followed by a second exposure of at least one of the composition, the solution and the film to a second electromagnetic ray; and a wavelength of the second electromagnetic ray is longer than a wavelength of at least one of cutoff wavelength, an absorption end and an absorption maximum in a ultraviolet-visible absorption spectrum of the compound.

With regard to the composition, it is preferred that the compound has at least one aromatic ring.

With regard to the composition, it is preferred that the composition further includes a precursor which is capable of generating a chemical species. It is preferred that chemical species is generated by the second exposure of at least one of the composition, the solution and the film to a second electromagnetic ray; and the compound is capable of being converted into the product by reacting with the chemical species.

A typical example of such precursor is photoacid generator (PAG). Such composition may further include a resin having acid-dissociable groups. In such case, typically, the content of the acid generator in the composition is 0.1 to 20 parts by mass with respect to 100 parts by mass of such resin. Preferably, such composition may include 0.5 to 10 parts by mass of PAG with respect to 100 parts by mass of such resin. Such composition can exhibit good sensitivity and developability. If the content of the acid generator is less than 0.1 parts by mass, the sensitivity and the developability of the resist material may decrease.

With regard to the composition, it is preferred that the composition further includes a first reagent which is capable of generating a chemical agent. It is preferred that the chemical agent is capable of enhancing a generation of the chemical species from the precursor.

With regard to the composition, it is preferred that, by the second exposure, the chemical agent is excited to its excited state from which an electron is donated to the precursor to generate the chemical species.

With regard to the composition, it is preferred that the chemical agent has an aromatic ring and a carbonyl group connected to the aromatic ring.

With regard to the composition, it is preferred that the composition further includes a first additive.

With regard to the composition, it is preferred that the first additive is capable of suppressing diffusion of the chemical species.

With regard to the composition, it is preferred that the compound has at least one group capable of undergoing a reaction in the presence of the chemical species.

With regard to the composition, it is preferred that the composition further includes a second additive which acts as a surfactant agent.

With regard to the composition, it is preferred that at the composition further includes a third additive which acts as a cross linker.

With regard to the composition, it is preferred that the compound has an absorption maximum in a range from 200 nm to 300 nm.

With regard to the composition, it is preferred that the compound has a first moiety of a phenol derivative.

With regard to the composition, it is preferred that the compound has a first moiety capable of undergoing a reaction in the presence of the chemical species.

With regard to the composition, it is preferred that the compound is capable of being polymerized or undergoing a cross-linking reaction.

With regard to the composition, it is preferred that the compound has a first moiety capable of reacting with a third additive.

With regard to the composition, it is preferred that the third additive is a cross linker.

With regard to the composition, it is preferred that the composition is used as a negative tone photoresist.

A method of manufacturing a device relating to an aspect of the present invention includes: forming a film containing the composition described above; performing the first exposure of the film; and performing the second exposure of the film.

A chemical agent relating to an aspect of the present invention is characterized by that: a first interaction of the chemical agent with a precursor occurs such that chemical agent donates at least one of electron and energy to the precursor or the chemical agent accepts at least one of electron and energy from the precursor; and a generation of a chemical species from the precursor is enhanced by the first interaction.

With regard to the chemical agent, it is preferred that the chemical species is acid.

With regard to the chemical agent, it is preferred that the chemical agent is a ketyl radical.

With regard to the chemical agent, it is preferred that the chemical agent has at least one aryl group.

With regard to the chemical agent, it is preferred that the at least one aryl group has at least one electron-donating substituent.

With regard to the chemical agent, it is preferred that the chemical agent is converted to a first product through the first interaction.

With regard to the chemical agent, a second interaction of the chemical agent with a first additive may occur.

With regard to the chemical agent, it is preferred that the first interaction inhibits the second interaction or the first interaction supersedes the second interaction.

With regard to the chemical agent, the second interaction may be accompanied with an encounter of the chemical agent and the first additive.

With regard to the chemical agent, the first interaction may be a long-range interaction. Examples of such long-range interaction are electron transfer and energy transfer, which take place without molecular encounter.

With regard to the chemical agent, the second interaction may be a short-range interaction. An example of such short-range interaction is bimolecular reaction. For example, the second interaction may result in abstraction of a hydrogen atom of the first additive.

With regard to the chemical agent, it is preferred that the chemical agent does not donate an electron or energy to the first additive.

With regard to the chemical agent, it is preferred that a number of multiple bonds contained in the first product is greater than a number of multiple bonds contained in the chemical agent.

With regard to the chemical agent, it is preferred that the first additive suppresses diffusion of the chemical species.

With regard to the chemical agent, a typical example of the first additive is a base such as amine.

With regard to the chemical agent, it is preferred that the chemical agent in its ground state donates an electron to the precursor.

A reagent relating to an aspect of the present invention is characterized by that the reagent generates the chemical agent explained above.

With regard to the reagent, it is preferred that the reagent has its hydrogen atom abstracted to generate the chemical agent.

With regard to the reagent, it is preferred that the reagent has its hydrogen atom abstracted by a radical generated by at least one of a first electromagnetic ray and a first particle ray.

With regard to the reagent, it is preferred that the reagent has its hydrogen atom abstracted by a radical generated by at least one of a EUV light and an electron beam.

A composition relating to an aspect of the present invention includes: a first reagent; and a precursor. It is preferred that a generation of a chemical species from the precursor is capable of occurring and the generation of the chemical species is capable of being enhanced by a first interaction of the precursor with at least one of the first reagent and a first chemical agent generated from the first reagent.

With regard to the composition, it is preferred that the first interaction is a long-range interaction.

With regard to the composition, it is preferred that the first interaction is at least one of electron transfer and energy transfer.

An example of such first additive is quencher which suppresses diffusion of such chemical species such as acid in an irradiated area of a film formed by application of such composition. Such quencher can contribute to suppression of penetration of such chemical species into undesired area to improve pattern resolution. Acid can be generated from PAG by exposure of such film to an electromagnetic ray or a particle ray. Moreover, such quencher can improve storage stability of such composition and reduction of the change of line width in post-exposure delay because such quencher can trap such chemical species.

In the event that such composition includes a resin having acid-dissociable groups, the content of such quencher is 15 parts by mass or less, preferably 10 parts by mass or less, and still more preferably 5 parts by mass or less, with respect to 100 parts by mass of such resin. If the amount of such quencher is more than 15 parts by mass, the sensitivity may decrease. If the amount of such quencher is less than 0.001 parts by mass, the shape or the dimensional accuracy of the resist pattern may deteriorate depending on the process conditions. A nitrogen-containing organic compound such as amine or a photodegradable base is preferably used as such quencher. Only one kind of quencher or a plurality of kinds of quencher can be used for improvement of the performance of such composition. A typical example of such photodegradable base is an onium salt compound that exhibits acid diffusion controllability by decomposing with a light irradiation. Specific examples of such sulfonium salt compound and iodonium salt compound are triphenyl sulfonium benzoate and diphenyl iodonium acetate, respectively.

With regard to the composition, it is preferred that the composition includes a compound which is capable of reacting with the chemical species.

With regard to the composition, it is preferred that the composition includes a compound which is at least one group capable of undergoing a reaction in the presence of the chemical species.

With regard to the composition, it is preferred that the composition includes a second additive which acts as a surfactant agent.

Such surfactant can improve the applicability, striation, developability, and the like. Examples of the surfactant include nonionic surfactants such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate; commercially available products such as KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, Polyflow No. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), EFTOP EF301, EFTOP EF303, EFTOP EF352 (manufactured by JEMCO, Inc.), Megafac F171, Megafac F173 (manufactured by DIC Corporation), Fluorad FC430, Fluorad FC431 (manufactured by Sumitomo 3M Ltd.), Asahi Guard AG710, Surflon S-382, Surflon SC-101, Surflon SC-102, Surflon SC-103, Surflon SC-104, Surflon SC-105, Surflon SC-106 (manufactured by Asahi Glass Co., Ltd.); and the like. These surfactants may be used either individually or in combination. The surfactant is normally used in an amount of 2 parts by mass or less based with respect to 100 parts by mass of a resin having acid-dissociable groups.

With regard to the composition, it is preferred that a third additive which acts as a cross linker. A typical example of such cross linker is compounds having at least N-alkoxymethyl group such as N,N-bis(ethoxymethyl)-n-butylamine and hexakis(methoxymethyl)melamine. The preferable content of such cross linker is in the range from 0.001 to 50 parts by mass with respect to 100 parts by mass of such composition.

With regard to the composition, it is preferred that the generation of chemical species is capable of being enhanced by the first chemical agent.

With regard to the composition, it is preferred that the first chemical agent is capable of donating an electron to the precursor.

With regard to the composition, it is preferred that the first chemical agent is capable of being oxidized by donating the electron to the precursor.

With regard to the composition, it is preferred that the first chemical agent is capable of reacting with the first additive.

With regard to the composition, it is preferred that the first chemical agent is capable of reacting with the first additive through a second interaction of the first additive and at least one of the first reagent and the first chemical agent.

With regard to the composition, it is preferred that the second interaction is a short-range interaction.

With regard to the composition, it is preferred that the first chemical agent is capable of abstracting a hydrogen atom of the first additive.

With regard to the composition, it is preferred that the first additive is capable of reacting with the chemical species.

With regard to the composition, it is preferred that the first additive is base such as amine.

With regard to the composition, it is preferred that the first interaction is capable of occurring by exciting at least one of the first reagent and the first chemical agent.

With regard to the composition, it is preferred that the first chemical agent is a ketyl radical.

With regard to the composition, it is preferred that the first chemical agent is a ketone.

With regard to the composition, it is preferred that the first chemical agent acts as a photosensitizer.

With regard to the composition, it is preferred that the composition includes a second reagent and the generation of the chemical species is capable of being enhanced by a third interaction of the precursor with at least one of the second reagent and a second chemical agent generated from the second reagent.

With regard to the composition, it is preferred that the second chemical agent is capable of enhancing the generation of the chemical species.

With regard to the composition, it is preferred that: the composition further includes a second reagent; the generation of the chemical species is capable of being enhanced by a third interaction of the precursor with at least one of the second reagent and a second chemical agent generated from the second reagent; and the first interaction is an interaction between the precursor and the first chemical agent in its ground state.

With regard to the composition, it is preferred that the third interaction is an interaction between the precursor and the second chemical agent.

With regard to the composition, it is preferred that the second reagent acts as a photosensitizer.

With regard to the composition, it is preferred that the composition further includes a cross linker and a compound. The compound may be capable of reaction with cross linker in the presence of the chemical species.

A polymer relating to an aspect of the present invention includes: a first moiety which is capable of reacting with a chemical species; a second moiety which is capable of enhancing a generation of the chemical species through a first interaction of at least one of the second moiety and a fourth moiety converted from the second moiety with a precursor capable of generating the chemical species.

With regard to the polymer, it is preferred that the chemical species is acid; and the first interaction is at least one of an electron transfer and an energy transfer.

A polymer relating to an aspect of the present invention includes: a first moiety which is capable of reacting with a chemical species; a second moiety; and a third moiety which is capable of generating the chemical species, wherein the second moiety is capable of enhancing a generation of the chemical species through a first interaction of at least one of the second moiety and a fourth moiety converted from the second moiety with the third moiety.

With regard to the polymer, it is preferred that diffusion of the chemical species is capable of being suppressed by a first additive.

With regard to the polymer, it is preferred that the first additive is capable of reacting with the at least one of the second moiety and the fourth moiety through a second interaction between the first additive and the at least one of the second moiety and the fourth moiety.

With regard to the polymer, it is preferred that the polymer includes a fifth moiety and the fifth moiety is capable of enhancing a generation of the chemical species through a third interaction of at least one of the fifth moiety and a sixth moiety converted from the fifth moiety with the third moiety.

With regard to the polymer, it is preferred that the first interaction is at least one of an electron transfer and an energy transfer.

With regard to the polymer, it is preferred that the third interaction is at least one of an electron transfer and an energy transfer.

With regard to the polymer, it is preferred that the first interaction is an electron transfer from the fourth moiety in its ground state to the third moiety.

With regard to the polymer, it is preferred that the third interaction is an electron transfer from the sixth moiety in its excited state to the third moiety.

A method of manufacturing a device relating to an aspect of the present invention: forming a film containing one of the above compositions; and first exposing the film to at least one of a first electromagnetic ray and a first particle ray.

Typical examples of such device are integrated circuit, optical element and electro-optical element such as display element.

With regard to the method, it is preferred that the first interaction occurs in the first exposing of the film.

With regard to the method, it is preferred that the method further includes: second exposing the film to at least one of a second electromagnetic ray and a second particle ray.

With regard to the method, it is preferred that the first interaction occurs in the second exposing of the film.

With regard to the method, it is preferred that the first electromagnetic ray and the first particle ray are a EUV light and an electron beam, respectively.

With regard to the method, it is preferred that the second electromagnetic ray is a UV light or a visible light.

A method of manufacturing a device relating to an aspect of the present invention, forming a film containing any one of the polymers explained above; and first exposing the film to at least one of a first electromagnetic ray and a first particle ray.

With regard to the method, it is preferred that the method further includes performing a development of the film after the second exposing of the film.

With regard to the method, it is preferred that portions of the film exposed to the at least one of the first electromagnetic ray and the first particle ray remain after the performing of the development.

In the drawings, which illustrate what is currently considered to be the best mode for carrying out the invention:

[Fig. 1] FIG. 1 shows a fabrication process of an IC.

DETAILED DESCRIPTION

Experimental Procedures:

Synthesis of 1-(4-methoxyphenyl)ethanol (Reagent 1)

5.0 g of 4-methoxyacetophenone and 0.10 g of potassium hydroxide are dissolved in ethanol. 1.04 g of sodium boronhydride is added to the ethanol solution containing 4-methoxyacetophenone and potassium hydroxide. The mixture is stirred at 25 degrees Celsius for 3 hours. Since then, alkali in the mixture is neutralized by 10 % aqueous solution of hydrochloric acid. The organic phase is collected through separation by liquid extraction using 100 g of dichloromethane. The organic phase is washed with water. Thereafter, dichloromethane is distilled away. Thereby 4.31 g of 1-(4-methoxy-phenyl)ethanol is obtained.

Chem.1

Synthesis of 2,2',4-trimethoxybenzophenone

2.50 g of 4'-hydroxy-2,4-dimethoxybenzophenone 2.44 g of dimethyl sulfate and 2.68 g of potassium carbonate are dissolved in 20.0 g of acetone. The mixture is stirred at reflux temperature for 2 hours. Since then, the mixture is cooled to 25 degrees Celsius and it is further stirred for 10 minutes after addition of 60.0 g of water and a deposit is filtrated. Then the deposit is dissolved in 30.0 g ethyl acetate and the organic phase is washed with water. Thereafter, ethyl acetate is distilled away, and the resultant is purified by recrystallization using 25.0 g of ethanol. Thereby 1.60 g of 2,2',4-trimethoxybenzophenone is obtained.

Synthesis of (2,4-dimethoxyphenyl)-(4-methoxyphenyl)-dimethoxymethane

7.00 g of 2,2',4-trimethoxybenzophenone, is dissolved in 27.8 g of thionyl chloride. The mixture is stirred at reflux temperature for 5 hours. Since then, thionyl chloride is distilled away and the resultant is dissolved in 15 g of toluene. Then the prepared solution is added dropwise over 1h to 30 g of a methanol solution containing 5.0 g of sodium methoxide at 5 degrees Celsius. After the addition is complete, the mixture is warmed up to 25 degrees Celsius with stirring for 2 hours. Then, the mixture is further stirred after an addition of 50 g of pure water. Then methanol is distilled away, and the resultant is extracted by 35 g of toluene and the organic phase is washed with water. Thereafter, toluene is distilled away. Thereby 3.87 g of crude (2,4-dimethoxyphenyl)-(4-methoxyphenyl)-dimethoxymethane is obtained as an oil.

Synthesis of 2-(2,4-dimethoxyphenyl)-2-(4-methoxyphenyl)- 1,3-dioxolane (Reagent 2)

3.8 g of crude (2,4-dimethoxyphenyl)-(4-methoxyphenyl)-dimethoxymethane, 0.03 g of compher sulfonic acid and 2.03 g of ethylene glycol are dissolved in 5.7 g of tetrahydrofuran. The mixture is stirred at 25 degrees Celsius for 72 hours. Since then, the organic solvent is distilled away and the resultant is dissolved in 11 g of dichloromethane. Then, the mixture is further stirred after addition of 5 % aqueous solution of sodium carbonate and the organic phase is washed with 5 % aqueous solution of sodium carbonate and water. Thereafter, dichloromethane is distilled away, and the residue is purified by silica gel column chromatography (ethyl acetate: hexane: triethylamine = 10:90:0.01). Thereby 2.1 g of (2,4-dimethoxyphenyl)-(4-methoxyphenyl)-1,3-dioxolane is obtained.

Chem.2

Synthesis of bis-(4-methoxy-phenyl)-dimethoxymethane

2.0 g of 4,4'-dimethoxy-benzophenone, 0.05 g of bismuth (III) trifruolomethanesulfonate and 5.7 g of trimethyl orthofomate are dissolved in 5.0g of methanol. The mixture is stirred at reflux temperature for 42 hours. Since then, the mixture is cooled to 25 degrees Celsius and further stirred after addition of 5 % aqueous NaHCO₃ solution. Then extracted with 30 g ethyl acetate and the organic phase is washed with water. Thereafter, ethyl acetate is distilled away, and the resultant is purified by silica gel column chromatography (ethyl acetate: hexane = 1:9). Thereby 1.71 g of bis-(4-methoxy-phenyl)-dimethoxymethane is obtained.

Synthesis of bis-(4-methoxy-phenyl)-1,3-dioxolane (Reagent 3)

Synthesis of bis-(4-methoxy-phenyl)-1,3-dioxolane as a target substance is synthesized and obtained according to the synthesis of the Reagent 2 mentioned above, except for using bis-(4-methoxy-phenyl)-dimethoxymethane instead of (2,4-dimethoxyphenyl)-(4-methoxyphenyl)-dimethoxymethane for the synthesis of Reagent 2.

Chem.3

Synthesis of 2,4-dimethoxy-4'-(2-vinyloxy-ethoxy)-benzophenone

2.00 g of 2,4-dimethoxy-4'-hydroxybenzophenone, 2.48g of 2-chloroethyl vinyl ether and 3.21 g of potassium carbonate are dissolved in 12.0 g of dimethyl formamide. The mixture is stirred at 110 degrees Celsius for 15 hours. Since then, the mixture is cooled to 25 degrees Celsius and it is further stirred after addition of 60.0 g of water. Then extracted with 24.0 g toluene and the organic phase is washed with water. Thereafter, toluene is distilled away. Thereby 3.59 g of 2,4-dimethoxy-4'-(2-vinyloxy-ethoxy)-benzophenone is obtained.

Synthesis of 2,4-dimethoxy-4'-(2-hydroxy-ethoxy)-benzophenone

3.59 g of 2,4-dimethoxy-4'-(2-vinyloxy-ethoxy)-benzophenone, 0.28 g of pyridinium p-toluenesulfonate and 2.1 g of water are dissolved in 18.0 g of acetone. The mixture is stirred at 35 degrees Celsius for 12 hours. Since then, the mixture is further stirred after addition of 3 % aqueous solution of sodium carbonate. Then extracted with 28.0 g ethyl acetate and the organic phase is washed with water. Thereafter, ethyl acetate is distilled away. Thereby 3.04 g of 2,4-dimethoxy-4'-(2-hydroxy-ethoxy)-benzophenone is obtained.

Synthesis of 2, 4-dimethoxy-4'-(2-acetoxy-ethyl)-benzophenone

3.0 g of 2, 4-dimethoxy-4'-(2-hydroxy-ethoxy)-benzophenone and 1.1 g of acetic anhydride are dissolved in 21 g of tetrahydrofuran. 1.2 g of triethylamine dissolved in 3.6 g of tetrahydrofuran is added dropwise to the tetrahydrofuran solution containing 2, 4-dimethoxy-4'-(2-hydroxy-ethoxy)-benzophenone over 10 minutes. After that the mixture is stirred at 25 degrees Celsius for 3 hours. Since then, the mixture is further stirred after addition of water. Then extracted with 30 g ethyl acetate and the organic phase is washed with water. Thereafter, ethyl acetate is distilled away, and the residue is purified by silica gel column chromatography (ethyl acetate: hexane = 1: 9). Thereby 2.72 g of 2, 4-dimethoxy-4'-(2-acetoxy-ethyl)- benzophenone is obtained.

Synthesis of (2, 4-dimethoxyphenyl)-[4'-(2-hydroxy-ethoxy)-phenyl]- dimethoxymethane

Synthesis of (2, 4-dimethoxyphenyl)-[4'-(2-hydroxy-ethoxy)-phenyl]-dimethoxymethane as a target substance is synthesized and obtained according to the synthesis of (2,4-dimethoxyphenyl)-(4-methoxyphenyl)-dimethoxymethane mentioned above, except for using 2, 4-dimethoxy-4'-(2-acetoxy-ethyl)-benzophenone instead of 2, 2', 4-trimethoxybenzophenone for the synthesis of (2,4-dimethoxyphenyl)-(4-methoxyphenyl)-dimethoxymethane.

Synthesis of (2, 4-dimethoxyphenyl)-[4'-(2-hydroxy-ethoxy)-phenyl]-1, 3-dioxolane

Synthesis of (2, 4-dimethoxyphenyl)-[4'-(2-hydroxy-ethoxy)-phenyl]-1, 3-dioxolane as a target substance is synthesized and obtained according to the synthesis of Reagent 2 mentioned above, except for using (2, 4-dimethoxyphenyl)-[4'-(2-hydroxy-ethoxy)-phenyl]-dimethoxymethane instead of (2,4-dimethoxyphenyl)-(4-methoxyphenyl)-dimethoxymethane for the synthesis of Reagent 2.

(2, 4-dimethoxyphenyl)-[4'-(2-methacyloxy-ethoxy)-phenyl]-1,3-dioxolane (Monomer 1) as a target substance is synthesized and obtained according to the synthesis of 2, 4-dimethoxy-4'-(2-acetoxy-ethyl)-benzophenone mentioned above, except for using methacrylic anhydride instead of acetic anhydride for the synthesis of 2, 4-dimethoxy-4'-(2-acetoxy-ethyl)-benzophenone.

Chem.4

Synthesis of 1-[4-(2-vinyloxy-ethoxy)-phenyl]-ethanone

1.00 g of 4-hydroxyacetophenoe, 2.48 g of 2-chloroethyl vinyl ether and 3.21 g of potassium carbonate are dissolved in 12.0 g of dimethyl formamide. The mixture is stirred at 110 degrees Celsius for 15 hours. Since then, the mixture is cooled to 25 degrees Celsius and it is further stirred after addition of 60.0 g of water. Then extracted with 24.0 g toluene and the organic phase is washed with water. Thereafter, toluene is distilled away. Thereby 1.90 g of 1-[4-(2-vinyloxy-ethoxy)-phenyl]-ethanone is obtained.

Synthesis of 1-[4-(2-hydroxy-ethoxy)-phenyl]-ethanone

Synthesis of 1-[4-(2-hydroxy-ethoxy)-phenyl]-ethanone as a target substance is synthesized and obtained according to the synthesis of the 2,4-dimethoxy-4'-(2-hydroxy-ethoxy)-benzophenone mentioned above, except for using 1-[4-(2-vinyloxy-ethoxy)-phenyl]-ethanone instead of 2,4-dimethoxy-4',-(2-vinyloxy-ethoxy) -benzophenone for the synthesis of 2,4-dimethoxy-4'-(2-hydroxy-ethoxy)-benzophenone.

Synthesis of 2 -methyl-acrylic acid 2-(4-acetyl-phenoxy)-ethyl ester

Synthesis of 2-methyl-acrylic acid 2-(4-acetyl-phenoxy)-ethyl ester as a target substance is synthesized and obtained according to the synthesis of 2, 4-dimethoxy-4'-(2-acetoxy-ethyl)-benzophenone mentioned above, except for using 1-[4-(2-hydroxy-ethoxy)-phenyl]-ethanone and methacrylic anhydride instead of 2, 4-dimethoxy-4'-(2-hydroxy-ethoxy)-benzophenone and acetic anhydride, respectively, for synthesis of 2, 4-dimethoxy-4'-(2-acetoxy-ethyl)-benzophenone

Synthesis of 2-methyl-acrylic acid 2-[4-(1-hydroxy-ethyl)-phenoxy]-ethyl ester (Monomer 2)

3.0 g of 2-methyl-acrylic acid 2-(4-acetyl-phenoxy)-ethyl ester is dissolved in 24.0 g of tetrahydrofuran. 0.92 g of sodium boron hydride dissolved in water is added to the tetrahydrofuran solution. The mixture is stirred at 25 degrees Celsius for 2 hours. Since then, the mixture is added to the 60 g of water. Then extracted with 20.0 g ethyl acetate and the organic phase is washed with water. Thereafter, ethyl acetate is distilled away. Thereby 2.5 g of 2-methyl-acrylic acid 2-[4-(1-hydroxy-ethyl)-phenoxy]-ethyl ester is obtained.

Chem.5

A solution containing 10.0 g of acetoxystyrene, 2.68g of acenaphthylene, 1.18 g of 4-methoxystyrene, 1.01 g of dimethyl-2,2' -azobis(2-methylpropionate) and 20.7 g of tetrahydrofuran is prepared. The prepared solution is added dropwise over 4 hours to 7.1 g of tetrahydrofuran placed in flask with stirring and boiling under nitrogen atmosphere. After the addition of the prepared solution, the mixture is heated to reflux for 2 hours and cooled to room temperature. Addition of the mixture by drops to a mixed liquid containing 182 g of hexane and 20 g of tetrahydrofuran with vigorously stirring precipitates the copolymer. The copolymer is isolated by filtration. Purification of the copolymer is carried out by vacuum drying following twice washings by 63 g of hexane, and thereby 9.4 g of white powder of the copolymer (Resin A) is obtained.

Chem.6

A solution containing 6.0 g of Resin A, 6.0 g of triethylamine, 6.0 g of methanol, 1.5 g of deionized water are dissolved in 30 g of propylene glycol monomethylether. The mixture is stirred at reflux temperature for 6 hours. Since then, the mixture is cooled at 25 degrees Celsius. Then addition of the mixture by drops to a mixed liquid containing 30 g of acetone and 30 g of deionized water with vigorously stirring precipitates the copolymer. The copolymer is isolated by filtration. Purification of the copolymer is carried out by vacuum drying following twice washings by 30 g of deionized water, and thereby 4.3 g of white powder of the copolymer (Resin B) is obtained.

Chem.7

A solution containing 10.0 g of 4-hydroxyphenyl methacrylate, 1.34 g of acenaphthylene, 1.18 g of 4-methoxystyrene, 0.98 g of Monomer 1, 0.60 g of Monomer 2, 0.59 g of 1,1-difluoro-2-(2-methyl-acryloyloxy)-ethanesulfonate, 0.90 g of dimethyl-2,2'-azobis(2-methylpropionate) and 18.9 g of tetrahydrofuran is prepared. 5-phenyl-dibenzothiophenium 1,1-difluoro-2-(2-methyl-acryloyloxy)-ethanesulfonate functions as a PAG moiety. The prepared solution is added dropwise for 4 hours to 6.5 g of tetrahydrofuran placed in flask with stirring and boiling. After the addition of the prepared solution, the mixture is heated to reflux for 2 hours and cooled to room temperature. Addition of the mixture by drops to a mixed liquid containing 167 g of hexane and 19 g of tetrahydrofuran with vigorously stirring precipitates the copolymer. The copolymer is isolated by filtration. Purification of the copolymer is carried out by vacuum drying following twice washings by 58 g of hexane and twice washing by methanol. Thereby 10.1 g of white powder of the copolymer (Resin C) is obtained.

Chem.8

Preparation of samples for sensitivity evaluation (the "Evaluation Samples")

Evaluation Samples 1-9 are prepared by dissolving in 7000 mg of cyclohexanone at least four constituents among the following materials: (i) 0.043 mmol of a PAG selected from a group of consisting of diphenyliodonium nonafluorobutanesulfonate (DPI-PFBS) and phenyl dibenzothionium nonafuorobutanesulfonate (PBpS-PFBS); (ii) a resin selected from a group consisting of 500 mg of Resin B and 493 mg of Resin C ; (iii) at least one additive selected from a group consisting of Reagents mentioned above; (iv) 0.0043mmol of trioctylamine as an acid quencher; (v) 0.50 mg of a surfactant agent containing fluorine atom; and (vi) 0.086 mmol of N,N-bis(ethoxymethyl)-n-butylamine as a cross linker.

Reagent 1 and C-5 moiety of Resin C can generate corresponding ketyl radicals by having a hydrogen atom abstracted which is bonded to the carbon atom bonded the hydroxy group. Such ketyl radical can donate a PAG to induce generation of acid from the PAG. In other words, Reagent 1 and C-5 moiety can act as an acid generation enhancer (AGE). Deprotected derivatives of Reagents 2 and 3 can act as photosensitizers when UV irradiations are carried out.

The cross linker can react with the phenol moieties of Resin B and C to form polymers having higher molecular-weight. Alternatively, a cross-liking reaction between the phenol moieties and the cross linker can occur in the presence of acid. Such polymertizaion or cross-linking reaction can make a portion where acid is generated of a film of a composition insoluble. In other words, such composition can be used as negative tone photoresist.

Chem.9

DPI-PFBS has higher electron acceptability than PBpS-PFBS.

Before applying the Evaluation Samples to Si wafers, hexamethyldisilazane (HMDS, Tokyo Chemical Industry) is spin-coated at 2000 rpm for 20 seconds on the surfaces of the Si wafers and baked at 110 degrees Celsius for 1 minute.

Then, the Evaluation Samples are spin-coated on the surfaces of the Si wafers which have been treated with HMDS at 4000 rpm for 20 seconds to form coating films. The prebake of the coating films is performed at 110 degrees Celsius for 60 seconds. Then the coating films of the Evaluation Samples are exposed to 30keV EB output from EB drawing system. Since then, irradiations of the coating films with a UV light are carried out at an ambient condition.

After that the UV light exposure, a post-exposure-bake (PEB) is carried out at 110 degrees Celsius for 60 seconds. The coating films are developed with NMD-3 (tetra-methyl ammonium hydroxide 2.38 %, Tokyo Ohka Kogyo) for 60 seconds at 25 degrees Celsius and rinsed with deionized water for 10 seconds.

The thickness of the coating films measured using a film thickness measurement tool is approximately 150 nm.

A sensitivity (E_size) is evaluated by measuring the dose size to form a pattern constituted by 100 nm lines where the thickness of the coating film is not zero and 100 nm spaces where the thickness of the coating film is zero using 30 keV EBL system JSM-7000F Beam Draw (JEOL) and FL-6BL (bright line is mainly from 350 nm to 400 nm, Hitachi). Moreover, surface roughness and pattern shapes formed in the coating film are evaluated by mean of scanning probe microscopy using SPM9600 (SHIMADZU).

Each of Evaluation Samples 1 and 2 contains Resin B having phenol to react with the cross linker in the presence of acid and DPI-PFBS as a PAG. Between them, the EB dose size measured for Evaluation Sample 2 containing Reagents 1 and 2 is small compared to the dose size measured for Evaluation Sample 1 containing none of Reagents 1 and 2. In other words, the sensitivity of Evaluation Sample 2 is higher than that of Evaluation Sample 1.

This indicates that at least one of Reagents 1 and 2 improves efficiency of acid generation.

Each of Evaluation Samples 3-8 contains Resin B and PBpS-PFBS as a PAG. Among them, the EB dose sized measured for Evaluation Samples 4-8 containing Reagent 1 and any one of Reagents 2 and 3 are small compared to Evaluation Sample 3 containing none of Reagents 1, 2 and 3. In other words, the sensitivities of Evaluation Samples 4-8 are higher than that of Evaluation Sample 3.

This indicates that at least one of Reagents 1, 2 and 3 improves efficiency of acid generation.

The EB dose sizes measured for Evaluation Sample 5 containing Reagent 3 of which deprotected derivative act as photosensitizer when UV irradiations following EB exposures are carried out are slightly smaller than Evaluation Sample 3 containing none of Reagents 1, 2 and 3, but greater than Evaluation Sample 4 containing the same constituents as Evaluation Sample 5 except for Reagent 2.

Reagent 2 has electron-donating ability higher than Reagent 3 since the total number of electron-donating substituents on aromatic rings of Reagent 2 is greater that of Reagent 3.

This indicates that efficiency of electron transfer plays an important role in enhancement of acid generation. Such electron transfer can be induced by a light irradiation.

Such photosensitizer generated in situ has at least two aromatic rings or two pi-electron systems interacting mutually more strongly than the corresponding precursors such as Reagent 2 and Reagent 3.

This is because such photosensitizer have a multiple bond which is connected to the at least two aromatic rings or two pi-electron systems and through which the at least two aromatic rings or two pi-electron systems interacts mutually while interaction between the at least two aromatic rings or two pi-electron systems of the corresponding precursors is weaker.

The pattern shape evaluation for Evaluation Sample 6 which does not contain quencher which can neutrize acid shows pattern bridging, which means a contact between portions cured by the agency of acid generated by the light irradiation. This is because absence of such quencher allows diffusion of acid.

In contrast, such pattern bridging is not clearly observed for the rest of Evaluation Samples containing quencher. This is because acid diffusion is suppressed due to quenching generated acid by quencher.

Typically, it is preferred that the concentration of quencher is 10 mol% for PAG for formation of 20-nm 1:1 lines and spaces and a pattern more finespun than that.

It is more preferable that the concentration of quencher is equal to or greater than 15 mol% for PAG to obtain such fine pattern with clearer rectangular shape because increase of quencher concentration can make bimolecular reaction between quencher and an electron donor such as ketyl radical and photosensitizer comparable to electron transfer from such electron donor.

Further, it is more preferable that the concentration of quencher is equal to or greater than 20 mol% for PAG to obtain such fine pattern.

The surface roughness evaluation for Evaluation Sample 7 not containing the surfactant agent containing fluorine atoms shows large surface roughness. Low surface tension of a composition containing such surfactant agent can contribute to the flatness of the vapor-liquid interface of the composition disposed on a substrate.

In addition to this, the following mechanism contributes the flatness of the coating film. Evaporation rate of solvent or compound with a low molecular-weight of the composition disposed on the substrate is controlled since fluorine atoms of such surfactant agent are eccentrically-located in the vicinity of the vapor-liquid interface of the composition disposed on a substrate. Therefore, flatness of the surface of the coating film is improved.

Incorporation of fluorine atoms into compositions increases the sensitivity to EB or EUV light exposure and enhances acid generation efficiency. Addition of the surfactant agent containing atoms such as fluorine atom which increase sensitivity to EB or EUV light exposure enhances formation of photosensitizer by deprotection reaction of protection group by acid as understood from comparison between Evaluation Sample 4 and Evaluation Sample 7.

Regarding Evaluation Sample 8 which does not contain the cross linker, clear pattern formation is not observed. This is because the cross linker connects chains of Resin B to each other by the agency of acid to make Resin B insoluble.

The dose size measured for Evaluation Sample 9 containing Resin C instead of Reagent 1, Reagent 2 and a PAG when UV irradiation is carried out is small compared to the doze size of Evaluation Sample 4. Resin C has both C-6 acting as a PAG, C-4 of which deprotected derivative acting as a photosensitizing moiety and C-5 moiety acting as an AGE a in the same molecule.

In other words, a compound having both electron donor and electron acceptor or energy donor and energy acceptor in the same molecule enables improvement of efficiency of a reaction induced by electron transfer or energy transfer.

Therefore, in Resin C, the photosensitizing moieties are considered to easily donate an electron to the PAG moiety compared to Resin B which has none of electron donor and acceptor.

Incorporation of the moieties of C-4 and C-5 moiety into resins enables homogeneous dispersion of electron donor and photosensitizing moiety which is converted from C-4 moiety. This may also contribute to improvement of sensitivity in acid generation efficiencies.

Photosensitizers and photosensitizing moieties mentioned above have at least two aromatic rings or two pi-electron systems interacting mutually more strongly compared to the corresponding precursors and the prodromal moieties.

Evaluation of sample shelf life

Evaluation Sample 10 is prepared by dissolving 0.00043mmol of 3,5-di-tert-butyl-4-hydroxytoluene (BHT) to Evaluation Sample 4. After that Evaluation Sample 4 as a control sample and Evaluation Sample 10 are stored for 2 weeks at 50 degrees Celsius under ambient atmosphere. Since then, the control sample and Evaluation Sample 10 are measured sensitivity due to above-mentioned the dose sizes measurement process.

The shelf life evaluation of the control sample shows semi-rectangular shape by storing several days under ambient atmosphere. This result implies that Reagent 1 changes to a corresponding ketone by aerial oxidation during storage period and the corresponding ketone slightly acts as a photosensitizer.

Therefore the PAG generates acid even in areas not exposed to EB due to second UV exposure without photomask of the corresponding ketone. As a result cross linking reactions of Resin B occur even in the unexposed areas.

On the other hand, pattern shape of Evaluation Sample 10 is the same as Evaluation Sample 4 in Table 2 by addition of an amount of oxidation inhibitor. Therefore oxidation inhibitor has efficacy for enhancing long term stability of samples including an AGE or a precursor of photosensitizer.

FIG. 1 shows fabrication processes of a device such as integrated circuit (IC) using a negative tone photoresist including Resin B, PBpS-PFBS as a PAG, Reagent 1 and Reagent 2.

A silicon wafer is provided. The surface of the silicon wafer is oxidized by heating the silicon wafer in the presence of molecular oxygen.

A solution of the photoresist is applied to the surface of the silicon wafer by spin coating to form a coating film. The coating film is prebaked.

An irradiation of the coating film with a EUV light through a mask is carried out after prebake of the silicon wafer.

The deprotection reaction of Reagent 2 contained in the photoresist is induced by acid generated by exposure of the PAG to the EUV light and electron donation to the PAG from a ketyl radical formed from Reagent 1 by the EUV-light irradiation. The PAG generates acid by accepting an electron from the ketyl radical. Reagent 1 acts as an AGE.

Instead of the EUV light, EB is also used for the deprotection reaction of Reagent 2. In that case, mask may not be always used.

After the EUV irradiation of the coating film, an irradiation of the coating film with a light of which wavelength is equal to or longer than 300 nm is carried out without mask.

Development of the coating film which has been irradiated with the EUV light and the light of which wavelength is equal to or longer than 300 nm is performed after the prebake. Only portions of the coating film exposed to the EUV light or the EB remain after the development.

The coating film and the silicon wafer are exposed to plasma. After that, the remaining portions of the coating film are removed.

An electronic device such as integrated circuit is fabricated utilizing the processes shown in FIG. 1. The deterioration of the device due to the irradiation with a light is suppressed compared to existing photoresists since times for irradiation of the coating film is shortened.

Claims

A composition, comprising:
a compound,
wherein:
the compound is capable of being converted into a product by a first exposure of at least one of the composition, a solution containing the composition and a film formed of the composition to at least one of a first electromagnetic ray and a first particle ray directly or indirectly followed by a second exposure of at least one of the composition, the solution and the film to a second electromagnetic ray; and
a wavelength of the second electromagnetic ray is longer than a wavelength of at least one of cutoff wavelength, an absorption end and an absorption maximum in a ultraviolet-visible absorption spectrum of the compound.
The composition of claim 1,
wherein the compound has at least one aromatic ring.
The composition of claim 1 or 2, further comprising:
a precursor which is capable of generating a chemical species,
wherein:
the chemical species is generated by the second exposure of at least one of the composition, the solution and the film to a second electromagnetic ray; and
the compound is capable of being converted into the product by a reaction in the presence of the chemical species.
The composition of any one of claims 1-3, further comprising:
a first reagent which is capable of generating a chemical agent,
wherein the chemical agent is capable of enhancing a generation of the chemical species from the precursor.
The composition of claim 4,
wherein, by the second exposure, the chemical agent is excited to its excited state from which an electron is donated to the precursor to generate the chemical species.
The composition of claim 4 or 5,
wherein the chemical agent has an aromatic ring and a carbonyl group connected to the aromatic ring.
The composition of any one of claims 1-6, further comprising:
a first additive.
The composition of claim 7,
wherein the first additive is capable of suppressing diffusion of the chemical species.
The composition of any one of claims 1-8,
wherein the compound is capable of being polymerized or undergoing a cross-liking reaction in the presence of the chemical species.
The composition of any one of claims 1-9, further comprising:
a second additive which acts as a surfactant agent.
The composition of any one of claims 1-10, further comprising:
a third additive which acts as a cross linker.
The composition of any one of claims 1-11,
wherein the compound has an absorption maximum in a range from 200 nm to 300 nm.
The composition of any one of claims 1-12,
wherein the compound has a first moiety of a phenol derivative.
The composition of any one of claims 1-13,
wherein the compound has a first moiety capable of undergoing a reaction.
The composition of claim 14,
wherein the reaction occurs in the presence of a chemical species.
The composition of any one of claims 1-15,
wherein the product has a carbonyl group.
The composition of any one of claims 1-16,
wherein the compound has at least one of hydroxy group and acetal group.
A method of manufacturing a device, the method comprising:
forming a film containing the composition of any one of claims 1-17; and
performing the first exposure of the film; and
performing the second exposure of the film.
The method of claim 18, further comprising:
performing a development of the film after the second exposure of the film.
The method of claim 19,
wherein portions of the film exposed to the at least one of the first electromagnetic ray and the first particle ray remain after the performing of the development.