WO2009104717A1

WO2009104717A1 - Polymer compound

Info

Publication number: WO2009104717A1
Application number: PCT/JP2009/052971
Authority: WO
Inventors: 修中山; 隆司福本; 峰規川上; 誠杉浦; 士朗楠本
Original assignee: 株式会社クラレ; Jsr株式会社
Priority date: 2008-02-22
Filing date: 2009-02-20
Publication date: 2009-08-27
Also published as: JPWO2009104717A1; JP5466511B2

Abstract

Provided is a polymer compound that is a photoresist composition able to form photoresist films having excellent acid reactivity and thermal stability, minimal swelling during development, and a refractive index at a 193 nm wavelength of preferably 1.72 or higher, and that is for obtaining photoresist compositions able to be patterned as photoresist films, and that has the below compound as at least one of the starting materials.

Description

High molecular compound

The present invention relates to a polymer compound obtained by polymerizing a raw material containing an acrylate derivative having two sulfur atoms. The polymer compound of the present invention is useful as a raw material for a photoresist composition containing the polymer compound as a component.

In recent years, in the field of electronic device manufacturing typified by integrated circuit element manufacturing, there has been an increasing demand for higher integration of devices, and therefore, a photolithography technique for forming a fine pattern is required. For this reason, development of a photoresist composition corresponding to photolithography in which radiation having a wavelength of 200 nm or less such as ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), or the like has been actively conducted, A chemically amplified type comprising a polymer compound having an acid-dissociable functional group and a compound that generates an acid upon irradiation with radiation (hereinafter referred to as “exposure”) (hereinafter referred to as “photoacid generator”). Many photoresist compositions have been proposed. This polymer compound having an acid-dissociable functional group basically has a structure in which a part of the alkali-soluble part of the alkali-soluble polymer compound is protected with an appropriate acid-dissociable functional group. The selection of the group is very important in adjusting the function as a photoresist composition.
As existing acid dissociable functional groups, 1) those having an adamantane structure (see Patent Document 1 and Non-Patent Document 1), 2) those having a tetrahydropyranyl group (see Patent Document 2), and the like are known. . The acid-dissociable functional group is required to have both high reactivity with an acid and stability that does not decompose in the baking process, and thermal stability is required to be 130 ° C. or higher (Non-patent Document 3). reference). However, although the tetrahydropyranyl group of 2) has an advantage of high reactivity as acid dissociation property, it lacks thermal stability and is not satisfactory in basic performance as a resist.

One of the major problems in lithography technology in recent years is line width variation of the formed pattern called line width roughness (hereinafter referred to as “LWR”), and its allowable value is less than 8% of the line width. It is calculated | required (refer nonpatent literature 3). In order to improve LWR, it is necessary to suppress pattern deformation due to swelling, that is, the polymer compound that is a component of the photoresist composition is difficult to swell.
A polymer compound into which an acid-dissociable functional group having an adamantane structure of 1) is introduced has high reactivity with acids and thermal stability. However, the polymer compound is highly hydrophobic and does not have sufficient affinity with the developer, resulting in a portion that does not dissolve in the exposed portion during development, which causes swelling, resulting in LWR. There is a problem of becoming larger. For this reason, development of a polymer compound for a photoresist composition that is less likely to swell is still eagerly desired, and the development of a compound having an acid-dissociable functional group to achieve this is strongly desired. is there.

In the future, it will be required to form a finer resist pattern (for example, a fine resist pattern having a line width of about 90 nm). In order to achieve the formation of a resist pattern having a line width finer than 90 nm, it is conceivable to shorten the light source wavelength of the exposure apparatus or increase the numerical aperture (NA) of the lens. However, a new expensive exposure apparatus is required to shorten the light source wavelength. Further, when the lens has a high NA, the resolution and the depth of focus are in a trade-off relationship. Therefore, there is a problem that the depth of focus decreases even if the resolution is increased.

Recently, a liquid immersion lithography (liquid immersion lithography) method has been reported as a lithography technique that can solve such problems. In this method, at the time of exposure, a liquid refractive index medium (immersion liquid) such as pure water or a fluorine-based inert liquid having a predetermined thickness is formed on at least the photoresist film between the lens and the photoresist film on the substrate. It is a method of interposing. In this method, a light source having the same exposure wavelength is used by replacing the exposure optical path space, which has conventionally been an inert gas such as air or nitrogen, with a liquid having a higher refractive index (n), such as pure water. However, as in the case of using a light source with a shorter wavelength or the case of using a high NA lens, high resolution is achieved (having high resolution) and there is no reduction in the depth of focus. By using such immersion exposure, it is possible to realize the formation of a resist pattern that is low in cost, superior in resolution, and excellent in depth of focus by using a lens mounted on an existing apparatus. , Has attracted a lot of attention.

However, in the immersion exposure process, if the refractive index of the liquid refractive index medium (immersion liquid) is higher than the refractive index of the photoresist film, for example, light is transferred from the immersion liquid to the photoresist film according to Snell's law. Difficult to enter. Therefore, there is a possibility that basic performance such as sensitivity is deteriorated. Further, if the immersion liquid has a high refractive index, the difference in refractive index between the immersion liquid and the photoresist film becomes large, and light is totally reflected at the interface between the immersion liquid and the photoresist film. Therefore, no light is incident on the photoresist film, so that sufficient sensitivity cannot be obtained, and it is expected that the throughput of the resist process is significantly reduced.

Therefore, in particular, when using an immersion liquid having a refractive index of 1.70 or more at a wavelength of 193 nm (an immersion liquid having a high refractive index), for example, a photoresist film having a refractive index higher than that of the immersion liquid. Has been proposed (see Non-Patent Documents 4 and 5).

Prior art documents

JP-A-9-73173 JP-A-5-88367

However, the photoresist film formed of the material (photoresist composition) of Non-Patent Documents 4 and 5 has a high refractive index at a wavelength of 193 nm, but cannot form a resist pattern and has a function as a photoresist film. is not. Therefore, a photoresist composition that can form a photoresist film having a high refractive index at a wavelength of 193 nm (for example, a refractive index of 1.72 or more) and that can be patterned as a photoresist film is desired. ing.

In order to solve the above-described problems, the present invention has been made by paying attention to the acid dissociable functional group of the compound having an acid dissociable functional group and intensively examining it. An object of the present invention is a photoresist composition that is excellent in acid reactivity and thermal stability, has a small swelling during development, and can form a photoresist film having a refractive index at a wavelength of 193 nm of preferably 1.72 or more. An object of the present invention is to provide a polymer compound for obtaining a photoresist composition that can be patterned as a photoresist film.

That is, the present invention
1. The following general formula (1)

(Wherein R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. The combination of R ² , R ³ and R ⁴ is
1) R ² , R ³ and R ⁴ are each independently a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms or a cyclic group having 3 to 6 carbon atoms. Represents an alkyl group. ;
2) R ² and R ³ are connected to represent an alkylene group having 3 to 6 carbon atoms, and R ⁴ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, or a branched alkyl group having 3 to 6 carbon atoms. Or a cyclic alkyl group having 3 to 6 carbon atoms. Or 3) R ² represents a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms, and R ³ and R ⁴ represents an alkylene group having 3 to 6 carbon atoms linked to each other. One of them.
The combination of n, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ is
1) When n = 0, R ⁵ and R ⁸ are each independently a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, or 3 to 3 carbon atoms 6 cyclic alkyl groups are represented. Each of R ⁶ and R ⁷ independently represents a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms; Or R ⁶ and R ⁷ are linked to each other to represent an alkylene group having 3 to 6 carbon atoms. Or 2) When n = 1 or 2, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each independently a hydrogen atom or a linear alkyl group having 1 to 6 carbon atoms. Represents a branched alkyl group having 3 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms. One of them. )
An acrylic ester derivative represented by the formula [hereinafter referred to as an acrylic ester derivative (1). ] A polymer compound obtained by polymerizing a raw material containing the compound [hereinafter referred to as polymer compound (8). ],
2. 1. In the above 1., wherein n is 0 or 1, and R ³ is a hydrogen atom. A polymer compound (8) according to any one of
3. n. wherein n is 0 or 1, and R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are hydrogen atoms. 3. The polymer compound (8) according to 4, and 1. The content of the structural unit based on the acrylate derivative (1) is in the range of 10 to 90 mol%. ~ 3. A polymer compound (8) according to any one of
Is achieved by providing

According to the present invention, there is provided a photoresist composition which is excellent in acid reactivity and thermal stability, has a small swelling during development, and can form a photoresist film having a refractive index of 1.72 or more at a wavelength of 193 nm, A polymer compound for obtaining a photoresist composition that can be patterned as a photoresist film can be provided.

It is a figure which shows the correlation with the exposure amount of the light irradiated to the photoresist film formed with the photoresist compositions b and d obtained by the reference examples 7 and 8, and the film thickness of the said photoresist film (reference examples 23 and 24). reference).

BEST MODE FOR CARRYING OUT THE INVENTION

[Acrylic acid ester derivative (1)]
First, the acrylate derivative (1), which is a raw material for the polymer compound of the present invention, will be described.
R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group. R ¹ is preferably a hydrogen atom or a methyl group, and more preferably a methyl group.

The combination of R ² , R ³ and R ⁴ is one of the following 1) to 3).
1) R ² , R ³ and R ⁴ are each independently a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms or a cyclic group having 3 to 6 carbon atoms. Represents an alkyl group.
2) R ² and R ³ are connected to represent an alkylene group having 3 to 6 carbon atoms, and R ⁴ is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, or a branched alkyl group having 3 to 6 carbon atoms. Or a cyclic alkyl group having 3 to 6 carbon atoms.
3) R ² represents a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, or a cyclic alkyl group having 3 to 6 carbon atoms, and R ³ and R ⁴ are And represents an alkylene group having 3 to 6 carbon atoms.
Examples of the linear alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. Examples of the branched alkyl group having 3 to 6 carbon atoms include isopropyl group, isobutyl group, sec-butyl group and the like. Examples of the cyclic alkyl group having 3 to 6 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.
Examples of the alkylene group having 3 to 6 carbon atoms when R ² and R ³ are linked include a propane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. And hexane-1,6-diyl group. Of these, a butane-1,4-diyl group is preferred.
Examples of the alkylene group having 3 to 6 carbon atoms when R ³ and R ⁴ are linked include, for example, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5- Examples thereof include a diyl group and a hexane-1,6-diyl group.
The combination of R ^2, R ³ and R ⁴ is preferably the above-mentioned 1), R ^2, R ³ and R ⁴ are more preferably a hydrogen atom or a methyl group, respectively, in particular R ³ is a hydrogen atom It is preferable that both are hydrogen atoms.

The combination of n, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ is either 1) or 2) below.
1) When n = 0, R ⁵ and R ⁸ are each independently a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, or 3 to 3 carbon atoms 6 cyclic alkyl groups are represented. Each of R ⁶ and R ⁷ independently represents a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms; Or R ⁶ and R ⁷ are linked to each other to represent an alkylene group having 3 to 6 carbon atoms.
2) When n = 1 or 2, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each independently a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, carbon A branched alkyl group having 3 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms is represented.
Examples of the linear alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group. Examples of the branched alkyl group having 3 to 6 carbon atoms include isopropyl group, isobutyl group, sec-butyl group and the like. Examples of the cyclic alkyl group having 3 to 6 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.
Examples of the alkylene group having 3 to 6 carbon atoms in which R ⁶ and R ⁷ are linked include, for example, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and hexane. -1,6-diyl group and the like. Of these, a butane-1,4-diyl group is preferred.
n is preferably 0 or 1, and more preferably 0.
When n is 0, R ⁵ , R ⁶ , R ⁷ and R ⁸ are each preferably a hydrogen atom or a methyl group, and R ⁵ , R ⁶ , R ⁷ and R ⁸ are all hydrogen atoms. More preferably, R ⁵ and R ⁸ are both methyl groups, and R ⁶ and R ⁷ are both hydrogen atoms.
When n is 1, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each preferably a hydrogen atom or a methyl group, and R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are more preferably hydrogen atoms.

Specific examples of the acrylate derivative (1) include, for example, the following formulas (1-a) to (1-x)

(In the formula, n is as defined above. P represents 1 or 2.)
However, it is not particularly limited to these.

[Production method of acrylic ester derivative (1)]
The acrylic ester derivative (1) is, for example, the following general formula (2)

(In the formula, n, R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are as defined above.)
Dithiol [hereinafter referred to as dithiol (2). ] With a base, then the following general formula (4)

Wherein R ² , R ³ and R ⁴ are as defined above. R ¹¹ represents a linear alkyl group having 1 to 3 carbon atoms or a branched alkyl group having 3 to 6 carbon atoms. ¹³ represents a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, or a cyclic alkyl group having 3 to 6 carbon atoms, and X represents a chlorine atom, a bromine atom or iodine Represents an atom.)
[Hereinafter referred to as halide (4). And the following general formula (5)

(Wherein R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ and n are as defined above) [hereinafter referred to as alcohol (5 ). And then converting the alcohol (5) to the acrylate derivative (1) (see the chemical reaction formula below), but is not particularly limited thereto.

In the above chemical reaction formula, n, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹³ and X are as defined above. It is. R ¹² represents a linear alkyl group having 1 to 3 carbon atoms or a branched alkyl group having 3 to 6 carbon atoms.
Examples of the linear alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, and an n-propyl group. Examples of the branched alkyl group having 3 to 6 carbon atoms include isopropyl group, isobutyl group, sec-butyl group and the like. R ¹² is preferably a linear alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group.
In the above chemical reaction formula, each of n, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , in dithiol (2), acetal (3), halide (4), and alcohol (5), Preferred groups of R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are n, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R in the acrylate derivative (1). ⁷ , R ⁸ , R ⁹ and R ¹⁰ are the same as preferred groups. R ¹¹ and R ¹³ are each preferably a linear alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group. X is preferably a chlorine atom or a bromine atom.

Hereinafter, the first to third steps will be described in order.
(First step)
In the first step, a halide (4) is synthesized by an acetal exchange reaction.
By reacting an acetal corresponding to the halide (4) (referred to as acetal (3)) with an acid anhydride in the presence of an acid catalyst, the halide (4) can be easily synthesized (Tetrahedron, Vol. .50, No. 26, p. 7897-7902 (1994)).
As the acetal (3) used in the first step, those which are industrially available and those produced by subjecting a corresponding α-haloketone compound or α-haloaldehyde to a conventional acetalization reaction can be used.
Specific examples of the acetal (3) include, for example, chloroacetaldehyde = dimethyl = acetal, chloroacetaldehyde = diethyl = acetal, bromoacetaldehyde = dimethyl = acetal, bromoacetaldehyde = diethyl = acetal, 1-bromo-2,2-dimethoxypropane, 1-iodo-2,2-diethoxypropane, 2-bromo-3,3-diethoxybutane, 1-chloro-2,2-dimethoxyhexane, 1-chloro-2,2-dimethoxyheptane, 1-chloro- Examples include, but are not limited to, 2,2-dimethoxycyclopentane, 1-chloro-2,2-dimethoxycyclohexane, 1-bromo-2,2-dimethoxycycloheptane.

Examples of the acid anhydride used in the first step include acetic anhydride, propionic anhydride, butanoic anhydride and the like, and acetic anhydride is preferable from the viewpoint of economy and ease of post-treatment. The amount of the acid anhydride to be used is preferably in the range of 0.5 to 3 times mol, preferably 0.7 to 2 times mol of the acetal (3) from the viewpoint of economy and ease of post-treatment. The range is more preferable, and the range of 0.8 to 1.5 times mol is more preferable.

The first step can be performed in the presence or absence of a solvent. The solvent is not particularly limited as long as it does not inhibit the reaction. For example, aliphatic hydrocarbons such as hexane, heptane, and octane; aromatic hydrocarbons such as toluene, xylene, and cymene; halogenated carbons such as methylene chloride and dichloroethane. Hydrogen; ethers such as tetrahydrofuran (THF) and diisopropyl ether are listed. These can be used individually by 1 type or in mixture of 2 or more types. Moreover, it is preferable to use an acid anhydride as a solvent and reaction agent from a viewpoint of environmental load reduction.
When a solvent is used, the amount used is preferably in the range of 0.1 to 10 times by mass with respect to the acetal (3), from the viewpoint of economy and ease of post-treatment, and 0.1 to 5 A range of mass times is more preferable.

In the first step, an acid catalyst is used. Examples of the acid catalyst include carboxylic acids such as acetic acid, propionic acid, and benzoic acid; sulfonic acids such as p-toluenesulfonic acid and methanesulfonic acid; and mineral acids such as sulfuric acid, hydrochloric acid, and phosphoric acid. The amount of the acid catalyst used is preferably in the range of 0.0001 to 0.1 moles relative to the acetal (3), from the viewpoint of economy and ease of post-treatment, More preferably, it is in the range of double mole.

The reaction temperature in the first step varies depending on the types of the acetal (3) and the acid catalyst, but is generally preferably in the range of 0 to 100 ° C, more preferably in the range of 10 to 70 ° C.
The pressure in the first step varies depending on the types of the acetal (3), the acid catalyst, the acid anhydride and the solvent, but can be carried out at normal pressure or under reduced pressure.

The reaction in the first step can be stopped by neutralizing the acid catalyst or by removing the acid catalyst from the reaction system.
Examples of the neutralizing agent include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate; alkali metal hydrogen carbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate; triethylamine And tertiary amines such as tributylamine; nitrogen-containing heterocyclic aromatic compounds such as pyridine. Among these, alkali metal hydrogen carbonate is preferable, and sodium hydrogen carbonate is more preferable.
When a neutralizing agent is used, the amount used is preferably in the range of 1 to 3 equivalents with respect to the acid catalyst from the viewpoints of economy and ease of post-treatment. In addition, you may dilute by adding the said solvent which can be used for reaction, before adding a neutralizing agent.
Examples of the method for stopping the reaction by removing the acid catalyst from the reaction system include a method of diluting the reaction solution during the reaction with an appropriate reaction solvent and then washing with water or alkaline water. Preferred examples of the solvent include the same solvents as those described above that can be used for the reaction in the first step. When diluting with a solvent, the amount used is preferably in the range of 0.1 to 10 times by mass with respect to the total mass of the reaction solution from the viewpoint of economy and ease of post-treatment. A range of 1 to 5 times by mass is more preferable.
Examples of the basic substance in alkaline water include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate, potassium carbonate, and potassium hydrogen carbonate. When alkaline water is used, the amount of the basic substance used is preferably in the range of 0.1 to 3 equivalents relative to the acid catalyst from the viewpoints of economy and ease of post-treatment.

The purity of the product in the first step can be increased by usual organic compound separation and purification operations such as solvent extraction, distillation, column chromatography, and recrystallization.

(Second step)
The second step is a step of reacting dithiol (2) with a base (hereinafter referred to as second step-1), and a halide (4) is added to the reaction solution obtained in the second step-1, thereby adding alcohol. (5) is obtained (hereinafter referred to as second step-2), and if necessary, the step of hydrolyzing the ester (6) by-produced in the second step-2 (hereinafter referred to as second step-3). And post-processing steps.

Specific examples of the alcohol (5) obtained in the second step include, but are not limited to, alcohols of the following formula.

For the second step, the method described in “Gazzetta Chimica Italiana, Vol. 127, No. 1, p. 11-17 (1997)” can be referred to.

(Second step-1)
The second step-1 is a step of producing a salt of dithiol (2) by reacting dithiol (2) with a base.
Examples of the dithiol (2) used in the second step-1 include 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 2,3-butanedithiol, 2,3-dimethyl- 2,3-butanedithiol, 1,2-propanedithiol, 2-methyl-1,2-propanedithiol, 2-methyl-2,3-butanedithiol, 3,4-hexanedithiol, 2,5-dimethyl-3 , 4-hexanedithiol, 1,2-butanedithiol, 1,2-pentanedithiol, 3,4-octanedithiol, 3,3-dimethyl-1,2-butanedithiol, 1,2-cyclopentanedithiol, 1, 2-cyclohexanedithiol, 1,3-butanedithiol, 2-methyl-1,3-butanedithiol, 2,4-pentanedithiol 2,2-dimethyl-1,3-propanedithiol, 3-methyl-1,3-butanedithiol, 2-methyl-2,4-pentanedithiol, 2-ethyl-1,3-propanedithiol, 2,4- Examples include, but are not limited to, dimethyl-2,4-pentanediol, 2,2-diethyl-1,3-propanediol, and 2,4-hexanedithiol.

The second step-1 is preferably carried out in the presence of a solvent. The solvent is not particularly limited as long as it does not inhibit the reaction. For example, dialkyl ethers such as diethyl ether, tetrahydrofuran, diisopropyl ether, t-butyl methyl ether, cyclopropyl methyl ether; 1,2-dimethoxyethane, diethylene glycol dimethyl ether, (Poly) alkylene glycol dialkyl ethers such as ethylene glycol dimethyl ether; amides such as N, N-dimethylformamide and the like. You may use these individually by 1 type or in mixture of 2 or more types. Among these, from the viewpoint of reaction selectivity, ether solvents (for example, dialkyl ethers and (poly) alkylene glycol dialkyl ethers) are preferable, and 1,2-dimethoxyethane is more preferable.
The amount of the solvent used is preferably in the range of 1 to 15 times by mass with respect to dithiol (2), and more preferably in the range of 3 to 10 times by mass, from the viewpoint of economy and ease of post-treatment. preferable.

The base used in the second step-1 may be either an inorganic base or an organic base. Examples of the inorganic base include alkali metal hydrides such as sodium hydride, lithium hydride and potassium hydride; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate Etc. Examples of the organic base include sodium methoxide, triethylamine, 4- (N, N-dimethylamino) pyridine, N, N-dimethylaniline, pyridine, tributylamine, diazabicyclo [2.2.2] octane, and the like. It is done. You may use these individually by 1 type or in mixture of 2 or more types. Among these, alkali metal hydrides are preferable and sodium hydride is more preferable from the viewpoints of availability, handling, reaction yield, and economy. The amount of the base used is preferably in the range of 0.8 to 4 mol, more preferably in the range of 1.5 to 2.5 mol with respect to 1 mol of dithiol (2), from the viewpoints of economy and post-treatment. Is more preferable. If the base is within the above range, the yield of alcohol (5) in the second step-2 will be good.

The procedure of the second step-1 is not particularly limited. For example, when sodium hydride is used as a base, dithiol (2) is dropped into a solution in which sodium hydride is suspended in an appropriate solvent. The method is preferred.
The reaction temperature in the second step-1 varies depending on the type of dithiol (2) and the base, but is generally preferably in the range of 0 to 100 ° C, more preferably in the range of 5 to 70 ° C. More preferably, it is in the range of ˜50 ° C.
The pressure in the second step-1 varies depending on the type of dithiol (2), base and solvent used, but can be carried out under any pressure, and is preferably carried out under normal pressure.
The reaction time in the second step-1 is preferably in the range of 0.1 to 5 hours, more preferably in the range of 0.1 to 2 hours after the addition of dithiol (2). In particular, when sodium hydride is used as the base, it is preferably in the range of 0.1 to 3 hours and more preferably in the range of 0.1 to 1.5 hours after the addition of dithiol (2). When sodium hydride is used as the base, hydrogen is generated as the reaction proceeds, but hydrogen generation is stopped within the range of 0.1 to 3 hours.

(Second step-2)
The second step-2 is carried out by reacting the reaction liquid containing the salt of dithiol (2) obtained in the second step-1 with the halide (4) obtained in the first step.
The procedure of the second step-2 is not particularly limited. For example, the halide (4) obtained in the first step is added dropwise to the reaction solution containing the dithiol (2) salt obtained in the second step-1. Can be done in a way.
The reaction temperature in the second step-2 varies depending on the type of dithiol (2), base, solvent and halide (4) obtained in the first step used in the second step-1, but is generally 0-100 ° C. Is preferable, and a range of 10 to 80 ° C. is more preferable.
The pressure in the second step-2 varies depending on the type of dithiol (2), base, solvent and halide (4) obtained in the first step used in the second step-1, but can be carried out under any pressure. It is preferable to carry out under normal pressure.
The reaction time of the second step-2 is preferably in the range of 0.1 to 10 hours after the addition of the halide (4) obtained in the first step, and more preferably in the range of 0.5 to 5 hours. preferable. In particular, when sodium hydride is used as the base, it is preferably in the range of 0.1 to 8 hours, preferably in the range of 0.5 to 4 hours after the addition of the halide (4) obtained in the first step. Is more preferable. If it is this range, the conversion rate of the halide (4) obtained at the 1st process will become 98% or more normally.

In the second step-2, the ester (6) is by-produced together with the target alcohol (5). When the ester (6) is analyzed by gas chromatography, it is generally produced as a by-product in a ratio of alcohol (5): ester (6) = 10: 90 to 70:30 (area ratio).

(Second step-3)
The second step-3 is a step of improving the yield of the target alcohol (5) by appropriately hydrolyzing the by-produced ester (6) after completion of the reaction of the second step-2. The second step-3 is performed by adding water or alkaline water to the reaction solution obtained in the second step-2 and stirring.

Since the number of moles of the base used in the second step-1 often exceeds the number of moles of the halide used in the second step-2, when water is used in the second step-3, water is added. The pH of the solution is generally in the range of 10-14 (alkaline), more often in the range of 11-13. The amount of water used is 0 with respect to the total liquid mass in the second step-2, considering not only the theoretical amount necessary to hydrolyze the by-produced ester (6) but also the post-treatment step. The range is preferably 1 to 5 times by mass, more preferably 0.1 to 1 times by mass.

When alkaline water is used, the basic substance in the alkaline water is preferably an inorganic salt. Examples of the inorganic salt include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; sodium carbonate and potassium carbonate. Alkali metal carbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate.
The amount of the basic substance used is preferably in the range of 0.1 to 5 moles, preferably 0.5 to 3 moles per mole of ester (6), from the viewpoints of economy and ease of post-treatment. A range is more preferable. Further, the concentration of the alkaline water is not particularly limited, and usually a range of 0.01 to 20% by mass can be used.
In addition, after adding water in the second step-3, it is possible to adopt a method of adding alkaline water or simply adding a basic substance as necessary.

The temperature when water or alkaline water is added in the second step-3 is preferably in the range of 0 to 100 ° C., more preferably in the range of 10 to 80 ° C., and in the range of 20 to 50 ° C. More preferably. The temperature during mixing after adding water or alkaline water is not particularly limited, but is preferably in the range of 20 to 100 ° C., and more preferably 50 to 100 ° C. from the viewpoint of shortening the reaction time.
The pressure in the second step-3 varies depending on the dithiol (2) used in the second step-1, the base, the solvent and the type of the halide (4) obtained in the first step. It is possible to carry out under normal pressure.
Although there is no particular limitation on the reaction time of the second step-3, the change with time of the alcohol (5) and the ester (6) is traced by gas chromatography or the like, and mixing is performed when the yield of the alcohol (5) is not increased. It is desirable to quit. Mixing may be continued beyond this point, but the yield of alcohol (5) tends to decrease gradually. When the yield of the alcohol (5) reaches the highest point, the ratio of the alcohol (5) to the ester (6) is approximately alcohol (5): ester (6) = 70: It is in the range of 30 to 99: 1 (area ratio).

The hydrolysis reaction in Step 2-3 can be stopped by neutralizing excess base. Examples of the neutralizing agent include mineral acids such as sulfuric acid, hydrochloric acid, and phosphoric acid. These acids may be diluted to an appropriate concentration with water. The target pH for neutralization is preferably in the range of 7-8.

The target alcohol (5) in the liquid after completion of the hydrolysis reaction in the second step-3 can be increased in purity by ordinary organic compound separation and purification operations such as solvent extraction, distillation, column chromatography, and recrystallization. Is possible.

(Third step)
The third step is a step of introducing a polymerizable group into the alcohol (5) obtained in the second step.
Is not particularly limited to the manufacturing method of introducing a polymerizable group into the alcohol (5), the alcohol (5) and the general formula CH ₂ = CR ^¹ COX ^1, the general formula _{^{(CH 2 = CR 1 CO)}} 2 O, formula _{^{CH 2 = CR 1 COOC (=}} O) R 14 or the general formula CH ₂ = CR ¹ COOSO compound represented by ₂ R ^15, (hereinafter, referred to these compounds and the polymerizable group-introducing agent.) the basic substance The reaction is carried out in the presence.
In the polymerizable group-introducing agent, any of R ¹ also the same as R ¹ in the acrylic acid ester derivative (1), it is also preferred group same. X ¹ represents a chlorine atom, a bromine atom or an iodine atom. R ¹⁴ represents a t-butyl group or a 2,4,6-trichlorophenyl group. R ¹⁵ represents a methyl group or a p-tolyl group.

Specific examples of the polymerizable group-introducing agent represented by the general formula CH ₂ ═CR ¹ COX ¹ used in the third step include acrylic acid chloride, methacrylic acid chloride, 2-trifluoromethylacrylic acid chloride and the like. It is done.
Specific examples of the polymerizable group-introducing agent represented by the general formula (CH ₂ ═CR ² CO) ₂ O include acrylic acid anhydride, methacrylic acid anhydride, and anhydrous 2-trifluoromethyl acrylic acid.
Specific examples of the polymerizable group-introducing agent represented by the general formula CH ₂ ═CR ² COOC (═O) R ¹⁴ include, for example, acrylic acid pivalic acid anhydride, acrylic acid 2,4,6-trichlorobenzoic acid anhydride, Methacrylic acid pivalic anhydride, methacrylic acid 2,4,6-trichlorobenzoic anhydride, 2-trifluoromethylacrylic acid pivalic anhydride, 2-trifluoromethylacrylic acid 2,4,6-trichlorobenzoic anhydride Such as things.
Specific examples of the polymerizable group-introducing agent represented by the general formula CH ₂ = CR ² COOSO ₂ R ¹⁵ include acrylic acid methanesulfonic acid anhydride, acrylic acid p-toluenesulfonic acid anhydride, and methacrylic acid methanesulfonic acid anhydride. Methacrylic acid p-toluenesulfonic acid anhydride, 2-trifluoromethylacrylic acid methanesulfonic acid anhydride, 2-trifluoromethylacrylic acid p-toluenesulfonic acid anhydride, and the like.
Among these, the polymerizable group introducing agent represented by the general formula CH ₂ = CR ¹ COX ¹ is preferable, and acrylic acid chloride and methacrylic acid chloride are more preferable.
The amount of the polymerizable group-introducing agent used is preferably in the range of 0.8 to 5 moles relative to 1 mole of the alcohol (5), from the viewpoint of economy and ease of post-treatment, and 0.8 to 3 More preferred is the molar range.

As the basic substance used in the third step, either an inorganic base or an organic base can be used. Examples of the inorganic base include alkali metal hydrides such as sodium hydride and potassium hydride; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkali metal carbonates such as sodium carbonate and potassium carbonate. . Examples of the organic base include tertiary amines such as triethylamine, tributylamine, N, N-dimethylaniline and diazabicyclo [2.2.2] octane; pyridine, 4- (N, N-dimethylamino) pyridine and the like. Examples thereof include nitrogen heteroaromatic compounds. You may use these individually by 1 type or in mixture of 2 or more types. Of these, tertiary amines are preferred.
The amount of the basic substance used is preferably in the range of 0.8 to 5 mol, more preferably in the range of 0.8 to 3 mol with respect to 1 mol of the alcohol (5), from the viewpoints of economy and post-treatment. Is more preferable.

The third step can be performed in the presence or absence of a solvent. The solvent is not particularly limited as long as it does not adversely influence the reaction. For example, ethers such as diethyl ether, diisopropyl ether and tetrahydrofuran; aliphatic hydrocarbons such as hexane, heptane and octane; methylene chloride, 1,2-dichloroethane and the like Halogenated hydrocarbons; aromatic hydrocarbons such as toluene, xylene, and cymene; N, N-dimethylformamide; dimethyl sulfoxide and the like. You may use these individually by 1 type or in mixture of 2 or more types.
When a solvent is used, the amount used is not particularly limited, but it is usually preferably in the range of 0.1 to 20 parts by weight, preferably 0.1 to 10 parts by weight with respect to 1 part by weight of the alcohol (5). More preferred is the range of parts.

The third step is preferably performed in the range of −80 to 100 ° C., more preferably in the range of −50 to 80 ° C., and further preferably performed at −20 to 40 ° C. The reaction time varies depending on the type and amount of the alcohol (5) and the polymerizable group introducing agent, the type and amount of the basic substance, the type and amount of the solvent, the reaction temperature, etc. The range is 10 hours.

In the third step, the reaction can be stopped by adding water and / or alcohol. Examples of such alcohol include methanol, ethanol, n-propanol, i-propanol and the like.
From the viewpoint of completely decomposing the unreacted polymerizable group-introducing agent and suppressing by-products, the amount of water and / or alcohol used is 1 mol of excess of the polymerizable group-introducing agent relative to the alcohol (5). It is preferable to use 1 mol or more.

The acrylic ester derivative (1) obtained through the third step is preferably separated and purified by a conventional method as necessary. For example, the reaction mixture can be washed with water, concentrated, and the purity can be increased by a method used for separation and purification of ordinary organic compounds such as distillation, column chromatography, or recrystallization.
In addition, if necessary, metal in nitrilotriacetic acid, ethylenediaminetetraacetic acid treatment with chelating agent, zeta plus (trade name: manufactured by Cuno Co., Ltd.) or protego (product name: manufactured by Nihon Microlith Co., Ltd.) It is also possible to reduce the metal content in the obtained acrylic ester derivative (1) by the removal filter treatment.

[Polymer Compound (8)]
By polymerizing a raw material containing at least the acrylic ester derivative (1) to obtain a polymer compound (8), it can be used as a component of a photoresist composition.
The polymer compound (8) is a polymer obtained by polymerizing the acrylic ester derivative (1) alone or a copolymer obtained by copolymerizing the acrylic ester derivative (1) and another polymerizable compound. And a structural unit based on the acrylate derivative (1). Usually, the content ratio of the structural unit based on the acrylate derivative (1) in the polymer compound (8) is not particularly limited. From the viewpoint of reduction, it is preferably in the range of 10 to 90 mol%, more preferably in the range of 20 to 80 mol%. Specific examples of the structural unit based on the acrylate derivative (1) include those represented by the following formulas (1′-a) to (1′-x), but are not limited thereto.

Other raw materials that can be copolymerized with the acrylate derivative (1), that is, other polymerizable compounds [hereinafter referred to as copolymerizable monomer (7). Specific examples of the compound (I) to (IX) represented by the following chemical formulas

(Wherein R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ¹⁷ represents a polymerizable group, R ¹⁸ represents a hydrogen atom or —COOR ¹⁹ , and R ¹⁹ represents 1 to 3 carbon atoms) And R ²⁰ represents an alkyl group or a cycloalkyl group in which the carbon atoms forming the ring may be substituted with oxygen atoms.)
However, it is not particularly limited to these.
In the comonomer (7), examples of the alkyl group having 1 to 3 carbon atoms independently represented by R ¹⁶ and R ¹⁹ include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Examples of the alkyl group represented by R ²⁰ include alkyl having 1 to 8 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, and t-butyl. Group and the like. Examples of the cycloalkyl group in which the carbon atom forming the ring represented by R ²⁰ may be substituted with an oxygen atom include a cyclopentyl group, a cyclohexyl group, a 1-methylcyclohexyl group, a cyclooctyl group, a tetrahydropyran-2-yl group, And 4-methyltetrahydropyran-4-yl group. Examples of the polymerizable group represented by R ¹⁷ include an acryloyl group, a methacryloyl group, a 2-trifluoromethylacryloyl group, a vinyl group, and a crotonoyl group.
R ¹⁶ is preferably a hydrogen atom, a methyl group, an ethyl group, or an isopropyl group. R ¹⁷ is preferably an acryloyl group or a methacryloyl group. R ¹⁸ is preferably a hydrogen atom. R ²⁰ is preferably an alkyl group having 1 to 8 carbon atoms.
As the other polymerizable compound that can be copolymerized with the acrylate derivative (1), the above compounds (I), (II), (IV), (V), (VI), (IX) are preferable, (II), (IV), and (VI) are more preferable.

(Method for producing polymer compound (8))
The polymer compound (8) can be produced by radical polymerization according to a conventional method. In particular, a method for synthesizing a polymer compound having a small molecular weight distribution includes living radical polymerization. A general radical polymerization method includes, as necessary, one or more kinds of acrylic acid ester derivatives (1) and, if necessary, one or more kinds of the above copolymerizable monomers (7), a radical polymerization initiator and a solvent, In addition, the polymerization is carried out in the presence of a chain transfer agent as required.
Hereinafter, this radical polymerization method will be described.

The method for carrying out radical polymerization is not particularly limited, and conventional methods such as those used in the production of acrylic polymer compounds such as solution polymerization, emulsion polymerization, suspension polymerization and bulk polymerization can be used.
Examples of radical polymerization initiators include hydroperoxide compounds such as t-butyl hydroperoxide and cumene hydroperoxide; dialkyl such as di-t-butyl peroxide, t-butyl-α-cumyl peroxide, and di-α-cumyl peroxide. Peroxide compounds; diacyl peroxide compounds such as benzoyl peroxide and diisobutyryl peroxide; and azo compounds such as 2,2′-azobisisobutyronitrile and dimethyl-2,2′-azobisisobutyrate.
The amount of the radical polymerization initiator used depends on the polymerization conditions such as the acrylic ester derivative (1), the comonomer (7), the chain transfer agent and the solvent used in the polymerization reaction; the polymerization temperature and the like. Although it can select suitably, it points out the total amount of all the polymerizable compounds [Acrylic ester derivative (1) and a comonomer (7), and so on. In general, it is preferably in the range of 0.005 to 0.2 mol, more preferably in the range of 0.01 to 0.15 mol with respect to 1 mol.

Examples of the chain transfer agent include thiol compounds such as dodecanethiol, mercaptoethanol, mercaptopropanol, mercaptoacetic acid, and mercaptopropionic acid. You may use these individually by 1 type or in mixture of 2 or more types.
When a chain transfer agent is used, the amount used is usually in the range of 0.005 to 0.2 mol and in the range of 0.01 to 0.15 mol with respect to 1 mol of all polymerizable compounds. Is preferred.

The radical polymerization is usually carried out in the presence of a solvent. The solvent is not particularly limited as long as the polymerization reaction is not inhibited. For example, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether propionate, ethylene glycol Glycol ethers such as monobutyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether; esters such as ethyl lactate, methyl 3-methoxypropionate, methyl acetate, ethyl acetate, propyl acetate; acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, Methyl amyl ketone, cyclopentanone, cyclohexanone What ketone diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, ethers such as 1,4-dioxane. You may use these individually by 1 type or in mixture of 2 or more types.
The amount of the solvent used is usually in the range of 0.5 to 20 parts by mass with respect to 1 part by mass of the total polymerizable compound, and is preferably in the range of 1 to 10 parts by mass from the viewpoint of economy. .

The reaction temperature for radical polymerization is usually preferably from 40 to 150 ° C., and more preferably from 60 to 120 ° C. from the viewpoint of the stability of the resulting polymer compound (8).
The reaction time for radical polymerization varies depending on the acrylic ester derivative (1), the comonomer (7), the polymerization initiator, the type and amount of the solvent used, and the polymerization conditions such as the reaction temperature. It is preferably in the range of ˜48 hours, and more preferably in the range of 1 hour to 24 hours.

The polymer compound (8) thus obtained can be isolated by ordinary operations such as reprecipitation.
Examples of the solvent used in the reprecipitation operation include aliphatic hydrocarbons such as pentane and hexane; alicyclic hydrocarbons such as cyclohexane; aromatic hydrocarbons such as benzene and xylene; methylene chloride, chloroform, chlorobenzene, and dichlorobenzene. Nitrogenated hydrocarbons such as nitromethane; Nitriles such as acetonitrile and benzonitrile; Ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran and 1,4-dioxane; Ketones such as acetone and methyl ethyl ketone; Acetic acid and the like Carboxylic acid; Esters such as ethyl acetate and butyl acetate; Carbonates such as dimethyl carbonate, diethyl carbonate, and ethylene carbonate; Methanol, ethanol, propanol, isopropyl alcohol Include water; le, alcohols such as butanol. You may use these individually by 1 type or in mixture of 2 or more types.
The amount of the solvent used varies depending on the kind of the polymer compound (8) and the kind of the solvent, but usually it is preferably in the range of 0.5 to 100 parts by mass with respect to 1 part by mass of the polymer compound (8). From the viewpoint of economy, it is more preferably in the range of 1 to 50 parts by mass.
The polymer compound isolated in this way can also be dried by vacuum drying or the like.

Specific examples of the polymer compound (8) obtained by the above method include polymer compounds represented by the following chemical structural formulas (8-1) to (8-96) (wherein R ²¹ to R ³⁵ are Each independently represents a hydrogen atom, a methyl group or a trifluoromethyl group, and a, b, c, d and e represent the molar ratios of the respective repeating units, and a + b = 1 and c + d + e = 1. Are not limited to these.

The weight average molecular weight (Mw) of the polymer compound (8) is not particularly limited, but is preferably in the range of 500 to 50000, more preferably in the range of 1000 to 30000. Highly useful. The measurement of the weight average molecular weight (Mw) is as described in Examples.

[Photoresist composition (9)]
A photoresist composition can be prepared by blending the polymer compound (8), a solvent and a photoacid generator described later, and a basic compound, a surfactant and other additives as required. .
Hereinafter, a photoresist composition containing the polymer compound (8) [hereinafter referred to as a photoresist composition (9)]. ] Will be described.

(solvent)
Examples of the solvent to be blended in the photoresist composition (9) include propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether propionate, and ethylene glycol monobutyl ether. Glycol ethers such as ethylene glycol monobutyl ether acetate and diethylene glycol dimethyl ether; esters such as ethyl lactate, methyl 3-methoxypropionate, methyl acetate, ethyl acetate, propyl acetate; acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl amyl Ketone, cyclopentanone, cyclohexanone, etc. Ketones; diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, ethers such as 1,4-dioxane. You may use these individually by 1 type or in mixture of 2 or more types.
The compounding amount of the solvent is usually in the range of 1 to 50 parts by mass, preferably in the range of 2 to 25 parts by mass with respect to 1 part by mass of the polymer compound (8).

(Photoacid generator)
There is no restriction | limiting in particular as a photo-acid generator, The photo-acid generator conventionally used for the chemically amplified resist can be used conventionally. Examples of the photoacid generator include nitrobenzyl derivatives such as 2-nitrobenzyl p-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, and 2,4-dinitrobenzyl p-toluenesulfonate; Sulfonic acid esters such as 2,3-tris (methanesulfonyloxy) benzene, 1,2,3-tris (trifluoromethanesulfonyloxy) benzene, 1,2,3-tris (p-toluenesulfonyloxy) benzene; bis ( Benzenesulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (n-butyl) Sulfonyl) di Diazomethane derivatives such as zomethane; triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, trifluoromethanesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, tris (trifluoromethanesulfonate) Butoxyphenyl) sulfonium, p-toluenesulfonic acid triphenylsulfonium, p-toluenesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, p-toluenesulfonic acid tris (p-tert-butoxyphenyl) sulfonium, trifluoromethanesulfonic acid Trinaphthylsulfonium, cyclohexylmethyl trifluoromethanesulfonate (2-oxocyclohexyl) sulfonium, Onium salts such as (2-norbornyl) methyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, 1,2'-naphthylcarbonylmethyltetrahydrothiophenium triflate; bis-O- (p-toluenesulfonyl) -α -Glyoxime derivatives such as dimethylglyoxime and bis-O- (n-butanesulfonyl) -α-dimethylglyoxime; N-hydroxysuccinimide methanesulfonate, N-hydroxysuccinimide trifluoromethanesulfonate, N-hydroxysuccinimide 1 -Propanesulfonic acid ester, N-hydroxyimide p-toluenesulfonic acid ester, N-hydroxynaphthalimide methanesulfonic acid ester, N-hydroxynaphthalimide benzenesulfonic acid ester Sulfonic acid ester derivatives of N-hydroxyimide compounds such as ter; 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxynaphthyl)- 4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2 -[2- (5-methyl-2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3,5-dimethoxyphenyl) ethenyl]- And halogen-containing triazine compounds such as 4,6-bis (trichloromethyl) -1,3,5-triazine. You may use these individually by 1 type or in mixture of 2 or more types.
The compounding amount of the photoacid generator is usually 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer compound (8) from the viewpoint of ensuring the sensitivity and developability of the photoresist composition (9). The range is preferably in the range of 0.5 to 10 parts by mass.

(Basic compound)
In the photoresist composition (9), in order to improve the resolution by suppressing the acid diffusion rate in the photoresist film, the characteristics of the photoresist composition (9) are not hindered if necessary. It can be blended in a range of amounts. Examples of such basic compounds include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N- (1-adamantyl) acetamide, benzamide, N-acetyl. Ethanolamine, 1-acetyl-3-methylpiperidine, pyrrolidone, N-methylpyrrolidone, ε-caprolactam, δ-valerolactam, 2-pyrrolidinone, acrylamide, methacrylamide, t-butylacrylamide, methylenebisacrylamide, methylenebismethacrylamide Amides such as N-methylolacrylamide, N-methoxyacrylamide and diacetoneacrylamide; pyridine, 2-methylpyridine, 4-methylpyridine, nicotine, quinoline, Lysine, imidazole, 4-methylimidazole, benzimidazole, pyrazine, pyrazole, pyrrolidine, Nt-butoxycarbonylpyrrolidine, piperidine, tetrazole, morpholine, 4-methylmorpholine, piperazine, 1,4-diazabicyclo [2.2.2 ] Amines such as octane, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine and triethanolamine can be mentioned. These can be used individually by 1 type or in mixture of 2 or more types.
When a basic compound is blended, the blending amount varies depending on the type of basic compound to be used, but it is usually preferably in the range of 0.01 to 10 moles per mole of the photoacid generator. More preferably, it is in the range of 0.05 to 1 mole.

(Surfactant)
In order to improve applicability, the photoresist composition (9) may further contain a surfactant in an amount that does not impair the characteristics of the photoresist composition (9), if desired.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, and the like. You may use these individually by 1 type or in mixture of 2 or more types.
When the surfactant is blended, the blending amount is usually 2 parts by mass or less with respect to 100 parts by mass of the polymer compound (8).

(Other additives)
Further, the photoresist composition (9) includes other additives such as a sensitizer, an antihalation agent, a shape improver, a storage stabilizer, an antifoaming agent, and the like. It can be blended in an amount that is not inhibited.

(Formation of photoresist pattern)
The photoresist composition (9) is applied to a substrate, usually pre-baked at 70 to 160 ° C. for 1 to 10 minutes, irradiated with radiation through a predetermined mask (exposure), and then 1 to 5 at 70 to 160 ° C. A predetermined resist pattern can be formed by post-exposure baking for a minute to form a latent image pattern and then developing with a developer.

For exposure, various wavelengths of radiation, such as ultraviolet rays and X-rays, can be used. For semiconductor resists, excimer lasers such as g-line, i-line, XeCl, KrF, KrCl, ArF, and ArCl are usually used. However, among these, it is preferable to use an ArF excimer laser from the viewpoint of fine processing.
Exposure is preferably in the range of 0.1 ~ 1000mJ / cm ^2, and more preferably in the range of 1 ~ 500mJ / cm ^2.

Examples of the developer include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate and aqueous ammonia; alkylamines such as ethylamine, diethylamine and triethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; tetramethylammonium hydroxy And an alkaline aqueous solution in which a quaternary ammonium salt such as tetraethylammonium hydroxide is dissolved. Among these, it is preferable to use an alkaline aqueous solution in which a quaternary ammonium salt such as tetramethylammonium hydroxide or tetraethylammonium hydroxide is dissolved.
The concentration of the developer is usually preferably in the range of 0.1 to 20% by mass, and more preferably in the range of 0.1 to 10% by mass.

(Immersion exposure method)
The photoresist composition (9) can be applied to an immersion exposure method. When the photoresist composition (9) is applied to an immersion exposure method, pure water or an immersion exposure liquid having a refractive index greater than or equal to the refractive index of water at a wavelength of 193 nm may be used as the immersion exposure liquid. it can.
The immersion exposure liquid having a refractive index at a wavelength of 193 nm which is used in the immersion exposure step is equal to or higher than the refractive index of water, and has a refractive index at a wavelength of 193 nm which is higher than the refractive index of water (1.44). As long as there is no particular limitation, various liquids can be used.
Moreover, when a photoresist film is formed with the photoresist composition (9), a photoresist film having a refractive index of 1.72 or more at a wavelength of 193 nm can be obtained. With such a photoresist composition, even when an immersion liquid having a refractive index of 1.70 or more (an immersion liquid having a high refractive index) is used in the immersion exposure process, the photoresist film Problems such as exposure light being totally reflected at the interface between the liquid and the immersion liquid are unlikely to occur, and deterioration of basic performance (for example, reduction in sensitivity) due to total reflection of exposure light can be prevented.
The refractive index of the photoresist film is determined by using a spectroscopic ellipsometer (for example, “VUV-VASE”, manufactured by JA Woollam), and irradiating light having a wavelength of 193 nm on the photoresist film having a film thickness of 30 to 300 nm. It is the value measured.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples. The methods for measuring Mw and Mn and calculating the degree of dispersion in each example are as follows.

(Measurement of Mw and Mn and calculation of dispersity)
The weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) using a differential refractometer as a detector and tetrahydrofuran (THF) as an eluent under the following conditions. It calculated | required as a conversion value by the calibration curve created with the standard polystyrene. Further, the dispersity (Mw / Mn) was determined by dividing the weight average molecular weight (Mw) by the number average molecular weight (Mn).
GPC measurement: TSK-gel SUPER HZM-H (trade name: 4.6 mm × 150 mm) and TSK-gel SUPER HZ2000 (trade name: Tosoh Corp., 4.6 mm × 150 mm) as columns ) Using one connected in series, measurement was performed under the conditions of a column temperature of 40 ° C., a differential refractometer temperature of 40 ° C., and an eluent flow rate of 0.35 mL / min.

<Synthesis Example 1-1> Synthesis of 2-chloro-1-methoxyethyl acetate (first step)

Chloroacetaldehyde = dimethyl = acetal 169.3 g (1.36 mol) and acetic anhydride 139.3 g (1.37 mmol) were placed in a 500 mL four-necked flask equipped with a thermometer, a dropping funnel and a stirrer. The flask was cooled in a water bath, and 0.27 g of concentrated sulfuric acid was slowly added dropwise with stirring. The mixture was stirred for 50 hours at an internal temperature of 20 to 30 ° C., and then stirred for 3 hours while being heated to 50 ° C. After lowering the internal temperature of the reaction solution to room temperature, transfer to a 1 L separatory funnel, add 147.8 g of diisopropyl ether, wash twice with 59.0 g of 7% aqueous sodium hydrogen carbonate solution, and distill off the solvent under reduced pressure. As a result, 221.8 g of a distilled stock solution was obtained. For the distillation, a molecular distillation apparatus “MS-300” (manufactured by SHIBATA) was used. The distillation stock solution was allowed to flow at a pressure of 1330 Pa and a temperature of 30 ° C. to obtain 188.5 g of a high-boiling fraction. The high boiling fraction was allowed to flow at a pressure of 1330 Pa and a temperature of 40 to 50 ° C., and 163.5 g (1.01 mol) of 2-chloro-1-methoxyethyl acetate was obtained as a colorless and transparent liquid in the low boiling fraction ( (Purity 94.0%, yield 74%).

<Synthesis Example 1-2> Synthesis of 1,4-dithian-2-ol (second step)

1390 g of 1,2-dimethoxyethane was placed in a 3 L four-necked flask equipped with a thermometer, a dropping funnel and a stirrer, and the atmosphere in the flask was replaced with nitrogen. While cooling the flask in a water bath, 79.0 g (1.96 mol) of sodium hydride (60%) was added and stirred for 30 minutes. After attaching a reflux condenser, 181.2 g (1.92 mol) of 1,2-ethanedithiol was slowly added dropwise from the dropping funnel so that the temperature was in the range of 25-30 ° C. At this time, gas generation was observed. After stirring for about 30 minutes from the end of dropping, 154.3 g (0.96 mol) of 2-chloro-1-methoxyethyl acetate obtained in Synthesis Example 1-1 from the dropping funnel so that the temperature is in the range of 25 to 30 ° C. The solution was slowly dripped into. After completion of the dropwise addition, stirring was continued at 25 to 35 ° C. for 3 hours. At this time, analysis by gas chromatography revealed that the conversion of 2-chloro-1-methoxyethyl acetate was 99.2%.
(Hydrolysis of 1,4-dithian-2-yl acetate)
From the dropping funnel, 906.5 g of water was slowly dropped in a temperature range of 25 to 60 ° C., and after the dropping, the water bath was heated and the temperature was kept at 60 ° C. for 12 hours. At this time, when analyzed by gas chromatography, the ratio of 1,4-dithian-2-ol to 1,4-dithian-2-yl acetate was 1,4-dithian-2-ol: 1,4-dithiane- 2-yl = acetate = 85: 15 (area ratio).
From the dropping funnel, a 10% aqueous hydrochloric acid solution was added dropwise at a temperature in the range of 10 to 15 ° C. to adjust the pH to 8.1 (drop amount 112.6 g). The obtained liquid was transferred to a separatory funnel having an internal volume of 5 L, and extracted twice with 1670 g of diisopropyl ether. Two portions of the obtained extract were put into a separatory funnel having an internal volume of 5 L, washed sequentially with 801 g of water and 504 g of saturated brine, and the solvent was distilled off under reduced pressure to obtain 285.9 g of concentrate. The obtained concentrate was charged with 47.5 g of diisopropyl ether, 85.2 g of n-hexane and a small amount of crystal seeds, and slowly cooled to 0 ° C. The precipitate was collected by filtration, transferred to a 300 mL eggplant flask, added with 320 g of n-hexane, and stirred at 25 ° C. for 1 hour. The precipitate was filtered again and dried at room temperature under reduced pressure to obtain 73.8 g (0.52 mol) of 1,4-dithian-2-ol having the following physical properties as a white solid (purity 94) 0.1%, yield 53%).

¹ H-NMR (300 MHz, CDCl ₃ , TMS, ppm) δ: 2.52-2.62 (3H, m), 2.85 (1H, dd, J = 2.1, 13.4 Hz); 52-3.64 (1H, br), 3.86 (1H, ddd, J = 5.0, 5.2, 12.1 Hz), 4.28 (1H, ddd, J = 4.8, 4. 9, 12.1 Hz), 5.03 (1H, ddd, J = 1.9, 5.8, 7.7 Hz)

<Synthesis Example 1-3> Synthesis of 1,4-dithian-2-yl methacrylate (third step)

Into a 1 L four-neck flask equipped with a thermometer, a dropping funnel and a stirrer, 34.5 g (238 mmol) of 1,4-dithian-2-ol obtained in Synthesis Example 1-2, 349.3 g of THF, phenothiazine 0 .47 g was added and the atmosphere in the flask was replaced with nitrogen. With the flask cooled in an ice bath, 48.2 g (476 mmol) of triethylamine was added dropwise from the dropping funnel so that the temperature was in the range of 5 to 8 ° C.
Next, 30.4 g (287.9 mmol) of methacrylic acid chloride was added dropwise so that the temperature was in the range of 5 to 10 ° C. After completion of the dropwise addition, stirring was continued at 3-6 ° C. for 2.5 hours. At this time, when analyzed by gas chromatography, the conversion of 1,4-dithian-2-ol was 99.6%.
From the dropping funnel, 233 g of water was slowly added dropwise so that the temperature was less than 20 ° C., and after the addition, the ice bath was removed and the internal temperature was adjusted to 24 ° C. 1.46 g of 4-dimethylaminopyridine was added and stirred at 24-26 ° C. for 2 hours. At this time, when analyzed by gas chromatography, the ratio of methacrylic anhydride to 1,4-dithian-2-yl methacrylate was methacrylic anhydride: 1,4-dithian-2-yl methacrylate = 0. 1: 99.9 (area ratio).
The obtained liquid was transferred to a separatory funnel having an internal volume of 2 L and extracted three times with 240 g of ethyl acetate. Three times of the obtained extract was put into a separatory funnel having a content volume of 2 L, washed with 230 g of 1% aqueous hydrochloric acid solution three times, 116 g of water, 118 g of saturated aqueous sodium hydrogen carbonate solution, twice with 118 g of water, and washed successively with 100 g of saturated brine did. 0.010 g of p-methoxyphenol and 0.020 g of phenothiazine were added, and the solvent was distilled off under reduced pressure to obtain 55.0 g of a distilled stock solution. For the distillation, a molecular distillation apparatus “MS-300” (manufactured by SHIBATA) was used. The distillation stock solution was allowed to flow at a pressure of 13.3 to 20.0 Pa and a temperature of 40 to 45 ° C. to obtain 47.4 g of a high-boiling fraction. The high-boiling fraction was flowed at a pressure of 10.7 to 13.3 Pa and a temperature of 55 to 60 ° C., and 37.8 g of 1,4-dithian-2-yl methacrylate having the following physical properties was exhibited in the low-boiling fraction. 182 mmol) was obtained as a colorless and transparent liquid (purity 98.4%, yield 76%).
In addition, logP which is a log value of an octanol / water partition coefficient and SP which is a solubility parameter were calculated using Hamiltonian PM5 of calculation software “CAChe” (trade name; Fujitsu Limited).

¹ H-NMR (300 MHz, CDCl ₃ , TMS, ppm) δ: 2.00 (3H, s), 2.68-2.82 (2H, m), 2.94 (1H, dd, J = 5. 2,14.1 Hz), 3.10 (1 H, ddd, J = 2.2, 13.2 Hz), 3.30-3.41 (2 H, m), 5.67 (1 H, s), 5. 87-5.92 (1H, m), 6.28 (1H, s)
log P: 1.77
SP: 17.6 (J / mol) ^0.5

<Synthesis Example 1-4> Synthesis of 1,4-dithiepan-2-ol (second step)

1390 g of 1,2-dimethoxyethane was placed in a 3 L four-necked flask equipped with a thermometer, a dropping funnel and a stirrer, and the atmosphere in the flask was replaced with nitrogen. While cooling the flask in a water bath, 79.0 g (1.96 mol) of sodium hydride (60%) was added and stirred for 30 minutes. After the reflux condenser was attached, 209.9 g (1.92 mol) of 1,3-propanedithiol was slowly added dropwise from the dropping funnel so that the temperature was in the range of 25 to 30 ° C. At this time, gas generation was observed. After stirring for about 30 minutes from the end of dropping, 154.3 g (0.96 mol) of 2-chloro-1-methoxyethyl acetate obtained in Synthesis Example 1-1 from the dropping funnel so that the temperature falls within the range of 25 to 30 ° C. The solution was slowly added dropwise. After completion of the dropping, stirring was continued at 25-30 ° C. for 5 hours. At this time, analysis by gas chromatography revealed that the conversion of 2-chloro-1-methoxyethyl acetate was 98.9%.
(Hydrolysis of 1,4-dithiepan-2-yl acetate)
From the dropping funnel, 906.0 g of water was slowly dropped in a temperature range of 25-60 ° C., and after the dropping, the water bath was heated and stirring was continued for 12 hours while maintaining the temperature at 60 ° C. At this time, when analyzed by gas chromatography, the ratio of 1,4-dithiepan-2-ol to 1,4-dithiepan-2-yl acetate is 1,4-dithiepan-2-ol: 1,4-dithiepan- 2-yl = acetate = 82: 18 (area ratio).
A 10% aqueous hydrochloric acid solution was added dropwise from the dropping funnel at a temperature in the range of 10 to 15 ° C. to adjust the pH to 8.2. The resulting liquid was transferred to a separatory funnel having an internal volume of 5 L and extracted twice with 1650 g of diisopropyl ether. Put the resulting extract twice into a 5 L separatory funnel, wash sequentially with 800 g of water and 500 g of saturated brine, evaporate the solvent under reduced pressure, and purify the concentrate by silica gel column chromatography. Gave 40.8 g (0.26 mol) of 1,4-dithiepan-2-ol (purity 97.1%, yield 27.5%).

<Synthesis Example 1-5> Synthesis of 1,4-dithiepan-2-yl methacrylate (third step)

To a four-necked flask with an internal volume of 100 mL equipped with a thermometer, a dropping funnel and a stirrer, 3.68 g (23.8 mol) of 1,4-dithiepan-2-ol obtained in Synthesis Example 1-4, 34.9 g of THF, 47 mg of phenothiazine was added, and the atmosphere in the flask was replaced with nitrogen. With the flask cooled in an ice bath, 4.82 g (47.6 mmol) of triethylamine was added dropwise from the dropping funnel so that the temperature was in the range of 5 to 8 ° C.
Next, 3.04 g (28.8 mmol) of methacrylic acid chloride was added dropwise so that the temperature was in the range of 5 to 10 ° C. After completion of the dropwise addition, stirring was continued at 3 to 7 ° C. for 3 hours. At this time, when analyzed by gas chromatography, the conversion of 1,4-dithiepan-2-ol was 99.2%.
From the dropping funnel, 23.3 g of water was slowly added dropwise so that the temperature was less than 20 ° C. After the dropping, the ice bath was removed and the internal temperature was adjusted to 24 ° C. 4-dimethylaminopyridine (0.15 g) was added, and the mixture was stirred at 23 to 26 ° C. for 2 hours. At this time, when analyzed by gas chromatography, the ratio of methacrylic anhydride to 1,4-dithiepan-2-yl methacrylate was methacrylic anhydride: 1,4-dithiepan-2-yl methacrylate = 0. 1: 99.9 (area ratio). The obtained liquid was transferred to a separatory funnel having an internal volume of 200 mL and extracted three times with 25 g of ethyl acetate. Three times of the extract thus obtained was placed in a separatory funnel having an internal volume of 200 mL, washed with 23 g of 1% hydrochloric acid aqueous solution three times, water 15 g, saturated sodium hydrogen carbonate aqueous solution 15 g, water 15 g twice, and saturated brine 10 g successively. did. By adding 2.0 mg of p-methoxyphenol and 2.0 mg of phenothiazine, the solvent was distilled off under reduced pressure, and the concentrate was purified by silica gel column chromatography to obtain 1,4-dithiepan-2-yl methacrylate. 4.36 g (19.5 mmol) was obtained (purity 97.7%, yield 81.9%).

<Synthesis Example 1-6> Synthesis of 5,6-dimethyl-1,4-dithian-2-ol (second step)

In a 300 mL four-necked flask equipped with a thermometer, a dropping funnel and a stirrer, 139 g of 1,2-dimethoxyethane was placed, and the atmosphere in the flask was replaced with nitrogen. While cooling the flask in a water bath, 7.90 g (197 mol) of sodium hydride (60%) was added and stirred for 30 minutes. After attaching a reflux condenser, 2,4.2 g (192 mmol) of 2,3-butanedithiol was slowly added dropwise from the dropping funnel so that the temperature was in the range of 25 to 30 ° C. At this time, gas generation was observed. After stirring for about 30 minutes from the end of dropping, 15.4 g (94.9 mmol) of 2-chloro-1-methoxyethyl acetate obtained in Synthesis Example 1-1 from the dropping funnel was adjusted to a temperature in the range of 25 to 30 ° C. The solution was slowly added dropwise. After completion of the dropping, stirring was continued at 25-30 ° C. for 5 hours. At this time, when analyzed by gas chromatography, the conversion of 2-chloro-1-methoxyethyl acetate was 98.8%.
(Hydrolysis of 5,6-dimethyl-1,4-dithian-2-yl acetate)
From the dropping funnel, 90.0 g of water was slowly dropped in a temperature range of 25 to 60 ° C., and after the dropping, the water bath was heated and stirring was continued for 12 hours while maintaining the temperature at 60 ° C. When analyzed by gas chromatography at this time, the ratio of 5,6-dimethyl-1,4-dithian-2-ol to 5,6-dimethyl-1,4-dithian-2-yl acetate is 5,6- Dimethyl-1,4-dithian-2-ol: 5,6-dimethyl-1,4-dithian-2-yl acetate = 88: 12 (area ratio).
A 10% aqueous hydrochloric acid solution was added dropwise from the dropping funnel at a temperature in the range of 10 to 15 ° C. to adjust the pH to 8.2. The obtained liquid was transferred to a separatory funnel having an internal volume of 500 mL and extracted twice with 160 g of diisopropyl ether. Put the obtained extract twice into a separatory funnel with an internal volume of 500 mL, wash sequentially with 10 g of water and 20 g of saturated brine, evaporate the solvent under reduced pressure, and purify the concentrate by silica gel column chromatography. Gave 9.09 g (54.1 mmol) of 5,6-dimethyl-1,4-dithian-2-ol (purity 97.8%, yield 57.0%).

<Synthesis Example 1-7> Synthesis of 5,6-dimethyl-1,4-dithian-2-yl methacrylate (third step)

In a 100 mL four-necked flask equipped with a thermometer, a dropping funnel and a stirrer, 4.00 g (23.8 mol) of 5,6-dimethyl-1,4-dithian-2-ol obtained in Synthesis Example 1-6 was obtained. ), 34.9 g of THF and 47 mg of phenothiazine were added, and the atmosphere in the flask was replaced with nitrogen. With the flask cooled in an ice bath, 4.82 g (47.6 mmol) of triethylamine was added dropwise from the dropping funnel so that the temperature was in the range of 5 to 8 ° C.
Next, 3.04 g (28.8 mmol) of methacrylic acid chloride was added dropwise so that the temperature was in the range of 5 to 10 ° C. After completion of the dropwise addition, stirring was continued at 3 to 7 ° C. for 3 hours. At this time, when analyzed by gas chromatography, the conversion of 5,6-dimethyl-1,4-dithian-2-ol was 99.0%.
From the dropping funnel, 23.3 g of water was slowly added dropwise so that the temperature was less than 20 ° C. After the dropping, the ice bath was removed and the internal temperature was adjusted to 24 ° C. 4-dimethylaminopyridine (0.15 g) was added, and the mixture was stirred at 23 to 26 ° C. for 2 hours. At this time, when analyzed by gas chromatography, the ratio of methacrylic anhydride to 5,6-dimethyl-1,4-dithian-2-yl methacrylate was methacrylic anhydride: 5,6-dimethyl-1,4. -Dithian-2-yl methacrylate = 0.1: 99.9 (area ratio).
The obtained liquid was transferred to a separatory funnel having an internal volume of 200 mL and extracted three times with 25 g of ethyl acetate. Three times of the extract thus obtained was placed in a separatory funnel having an internal volume of 200 mL, washed with 23 g of 1% hydrochloric acid aqueous solution three times, water 15 g, saturated sodium hydrogen carbonate aqueous solution 15 g, water 15 g twice, and saturated brine 10 g successively. did. By adding 2.0 mg of p-methoxyphenol and 2.0 mg of phenothiazine, the solvent was distilled off under reduced pressure, and the concentrate was purified by silica gel column chromatography to obtain 5,6-dimethyl-1,4-dithiane- 2.85 g (20.3 mmol) of 2-yl methacrylate was obtained (purity 97.2%, yield 85.3%).

<Reference Example 1> Evaluation of reactivity of acrylic ester derivative (1) to acid Into an NMR tube, 1,4-dithian-2-yl methacrylate obtained in Synthesis Example 1-3 was 2.73 × 10 ^{−. 4} mol, 1,1,2,2-tetrachloroethane-d ₂ 0.69 mL, and methanesulfonic acid 1.47 × 10 ⁻⁶ mol were added, and the cap was capped and shaken well.
After the NMR tube is immersed in an oil bath at 120 ° C. for several seconds to several minutes, the NMR tube is taken out, placed in an ice bath, the reaction solution is cooled, and ¹ H-NMR is immediately analyzed by “NMR Gemini-300” (trade name: Varian). Manufactured). In the NMR chart of the reacted methacrylic acid ester, unreacted methacrylic acid ester and acrylic acid produced by the reaction were observed, and the conversion rate of the dissociation reaction was determined from each vinyl proton. Thereafter, the same NMR tube was immersed in an oil bath at 120 ° C. for several seconds to several minutes, cooled in an ice bath, and ¹ H-NMR measurement was repeated several times to obtain several conversion rates with respect to the reaction time. The conversion rate with respect to the time obtained here is expressed by the following first-order reaction rate equation (Equation 1).

(In the formula, k represents a rate constant (s ⁻¹ ), t (s) represents time, and X represents a conversion rate.)
The time constant (s) was plotted on the X axis and ln (1-X) was plotted on the Y axis, and the rate constant of the deprotection reaction of the methacrylate ester at 120 ° C. was determined from the slope of the straight line.
For comparison, 2-methacryloyloxy-2-methyladamantane, which is generally used, was selected, and the rate constant at 120 ° C. was determined in the same manner as 1,4-dithian-2-yl methacrylate. By dividing the rate constant of 1,4-dithian-2-yl methacrylate deprotection by the rate constant of 2-methacryloyloxy-2-methyladamantane deprotection, 1,4-dithian-2- The relative activity of yl methacrylate to 2-methacryloyloxy-2-methyladamantane was determined and used as an index of reactivity with acid (deprotection activity).
The above operation and analysis were performed even at 140 ° C. The results are shown in Table 1.

<Reference Example 2> Evaluation of reactivity of acrylic ester derivative (1) to acid In Reference Example 1, instead of 1,4-dithian-2-yl methacrylate, 1 obtained in Synthesis Example 1-5 Except that, 4-dithiepan-2-yl methacrylate was used, the experiment was conducted in the same manner as in Reference Example 1, and the reactivity to acid (deprotection activity) was evaluated in the same manner. The results are shown in Table 1.

<Reference Example 3> Evaluation of reactivity of acrylic ester derivative (1) to acid In Reference Example 1, instead of 1,4-dithian-2-yl methacrylate, 5 obtained in Synthesis Example 1-7 , 6-dimethyl-1,4-dithian-2-yl methacrylate was used in the same manner as in Reference Example 1, and the reactivity to acid (deprotection activity) was determined in the same manner. Evaluation was performed. The results are shown in Table 1.

<Reference Examples 4 to 6> Activation energy of deprotection reaction of acrylic ester derivative (1) The rate constants of the deprotection reaction at 120 ° C. and 140 ° C. determined by the analysis of Reference Examples 1 to 3 are expressed by the following formulas (Formula 2) And the activation energy (E) of the deprotection reaction of each acrylate derivative (1) was determined. The results are shown in Table 2.

(Where k ₁ is the rate constant (s ⁻¹ ) of the deprotection reaction at 120 ° C., k ₂ is the rate constant (s ⁻¹ ) of the deprotection reaction at 140 ° C., and E is the activation energy of the deprotection reaction ( kcal / mol), R is a gas constant (1.987 cal · K ⁻¹ · mol ⁻¹ , T ₁ represents an absolute temperature (K) of 120 ° C., and T ₂ represents an absolute temperature (K) of 140 ° C.)

From Table 1 and Table 2, the acrylic acid ester derivative (1) has a high reactivity with respect to acid when compared with known methacrylic acid esters (see Reference Examples 1 to 3) and activity. It can be said that it is useful as a raw material for a chemically amplified resist because of its low chemical energy (see Reference Examples 4 to 6).

<Example 1> Production of polymer compound a 1,4-dithiane obtained in Synthesis Example 1-3 was placed in a round bottom flask having an internal volume of 50 ml equipped with an electromagnetic stirrer, a reflux condenser and a thermometer under a nitrogen atmosphere. 1.00 g (4.89 mmol) of -2-yl methacrylate, 4.00 g of 1,4-dioxane and 99.7 mg (0.401 mmol) of 2,2′-azobis (2,4-dimethylvaleronitrile) are charged. The polymerization reaction was performed at 60 ° C. for 3 hours.
The obtained reaction mixture is dropped into methanol at about 20 times the mass of the reaction mixture at room temperature while stirring, and the resulting precipitate is collected by filtration and washed with the same amount of methanol as above. Gave a white precipitate. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 0.56 g of a polymer compound a consisting of the following repeating units. Mw of the obtained polymer compound a was 23800, and the degree of dispersion was 2.90.

<Example 2> Production of polymer compound b 1,4-dithiane obtained in Synthesis Example 1-3 was placed in a 200-ml round bottom flask equipped with an electromagnetic stirrer, a reflux condenser and a thermometer in a nitrogen atmosphere. -2-yl methacrylate 8.16 g (39.1 mmol), 3-hydroxy-1-adamantyl methacrylate 9.25 g (39.1 mmol), 1,4-dioxane 168.0 g and 2,2′-azobis 1.95 g (7.86 mmol) of (2,4-dimethylvaleronitrile) was charged, and a polymerization reaction was performed at 60 to 65 ° C. for 4 hours.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 150.0 g of THF was dropped into methanol of the same mass as above while stirring, and the resulting precipitate was collected by filtration and washed with methanol of the same mass as above to obtain a white precipitate. Obtained. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 10.3 g of a polymer compound b consisting of the following repeating units. Mw of the obtained polymer compound b was 13600, and the degree of dispersion was 1.50.

<Example 3> Production of polymer compound c 1,4-dithiane obtained in Synthesis Example 1-3 in a 200 ml round bottom flask equipped with an electromagnetic stirrer, a reflux condenser and a thermometer under a nitrogen atmosphere -2-yl methacrylate 8.00 g (38.4 mmol), 5-methacryloyloxy-2,6-norbornanecarbolactone 8.53 g (38.4 mmol), 1,4-dioxane 130.0 g and 2,2 ′ -Azobis (2,4-dimethylvaleronitrile) 3.89 g (15.7 mmol) was charged, and a polymerization reaction was performed at 60 to 65 ° C for 3 hours.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 80.0 g of 1,4-dioxane is added dropwise to methanol with the same mass as above while stirring, and the resulting precipitate is collected by filtration and washed with the same mass of methanol as above. Gave a white precipitate. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 12.1 g of a polymer compound c consisting of the following repeating units. Mw of the obtained polymer compound c was 10600, and the degree of dispersion was 1.83.

<Example 4> Production of polymer compound d In Example 3, instead of 8.53 g (38.4 mmol) of 5-methacryloyloxy-2,6-norbornanecarbolactone, 6.53 g of α-methacryloyloxy-γ-butyrolactone ( 38.4 mmol), and the amount of 2,2′-azobis (2,4-dimethylvaleronitrile) used was changed from 3.89 g (15.7 mmol) to 1.95 g (7.83 mmol). The polymerization reaction was carried out under the same charge and conditions as in 3.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 80.0 g of 1,4-dioxane is added dropwise to methanol with the same mass as above while stirring, and the resulting precipitate is collected by filtration and washed with the same mass of methanol as above. Gave a white precipitate. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 9.4 g of a polymer compound d having the following repeating units. The obtained polymer compound d had an Mw of 8600 and a dispersity of 1.67.

Example 5 Production of Polymer Compound e In Example 4, the amount of α-methacryloyloxy-γ-butyrolactone used was changed from 6.53 g (38.4 mmol) to 4.36 g (25.6 mmol) to 2,2 ′. -Polymerization reaction under the same charge and conditions as in Example 4 except that the amount of azobis (2,4-dimethylvaleronitrile) used was changed from 1.95 g (7.83 mmol) to 1.64 (6.62 mmol) Went.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 80.0 g of 1,4-dioxane is added dropwise to methanol with the same mass as above while stirring, and the resulting precipitate is collected by filtration and washed with the same mass of methanol as above. Gave a white precipitate. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 10.2 g of a polymer compound e having the following repeating units. The obtained polymer compound e had an Mw of 9900 and a dispersity of 1.75.

<Example 6> Production of polymer compound f 1,4-dithiane obtained in Synthesis Example 1-3 in a 100 ml round bottom flask equipped with an electromagnetic stirrer, a reflux condenser and a thermometer under a nitrogen atmosphere -2-yl methacrylate 3.88 g (18.7 mmol), 3-hydroxy-1-adamantyl methacrylate 2.95 g (12.5 mmol), 5-methacryloyloxy-2,6-norbornanecarbolactone 4.16 g (18.7 mmol), 1,4-dioxane 100.0 g and 2,2′-azobis (2,4-dimethylvaleronitrile) 2.48 g (10.0 mmol) were charged and polymerized at 60 to 65 ° C. for 4 hours. Reaction was performed.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 80.0 g of 1,4-dioxane is added dropwise to methanol with the same mass as above while stirring, and the resulting precipitate is collected by filtration and washed with the same mass of methanol as above. Gave a white precipitate. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 6.5 g of a polymer compound f comprising the following repeating units. The obtained polymer compound f had an Mw of 12,800 and a dispersity of 1.82.

<Example 7> Production of polymer compound g In Example 6, instead of 4.16 g (18.7 mmol) of 5-methacryloyloxy-2,6-norbornanecarbolactone, 3.18 g of α-methacryloyloxy-γ-butyrolactone ( The polymerization reaction was carried out under the same charge and conditions as in Example 6 except that 18.7 mmol) was used.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 80.0 g of 1,4-dioxane is added dropwise to methanol with the same mass as above while stirring, and the resulting precipitate is collected by filtration and washed with the same mass of methanol as above. Gave a white precipitate. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 5.61 g of a polymer compound consisting of the following repeating units. The obtained polymer compound g had an Mw of 11900 and a dispersity of 1.65.

<Example 8> Production of polymer compound h 1,4-dithiepan obtained in Synthesis Example 1-5 was placed in a 100-ml round bottom flask equipped with an electromagnetic stirrer, reflux condenser and thermometer in a nitrogen atmosphere. -2-yl methacrylate 2.18 g (9.78 mmol), 3-hydroxy-1-adamantyl methacrylate 2.31 g (9.78 mmol), 1,4-dioxane 42.0 g and 2,2′-azobis 0.49 g (1.97 mmol) of (2,4-dimethylvaleronitrile) was charged, and a polymerization reaction was performed at 60 to 65 ° C. for 4 hours.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 37.5 g of THF was dropped into methanol of the same mass as above while stirring, and the resulting precipitate was collected by filtration and washed with methanol of the same mass as above to obtain a white precipitate. Obtained. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 2.68 g of a polymer compound h composed of the following repeating units. The obtained polymer compound h had an Mw of 14400 and a dispersity of 1.59.

<Example 9> Production of polymer compound i 1,4-dithiepan obtained in Synthesis Example 1-5 was placed in a 100-ml round bottom flask equipped with an electromagnetic stirrer, a reflux condenser and a thermometer under a nitrogen atmosphere. -2-yl methacrylate 2.09 g (9.35 mmol), 3-hydroxy-1-adamantyl methacrylate 1.48 g (6.25 mmol), 5-methacryloyloxy-2,6-norbornanecarbolactone 2.08 g (9.35 mmol), 50.0 g of 1,4-dioxane and 1.24 g (5.0 mmol) of 2,2′-azobis (2,4-dimethylvaleronitrile) were charged and polymerized at 60 to 65 ° C. for 4 hours. Reaction was performed.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 40.0 g of 1,4-dioxane is dropped into methanol of the same mass as above while stirring, and the resulting precipitate is collected by filtration and washed with the same mass of methanol as described above. Gave a white precipitate. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 3.09 g of a polymer compound i comprising the following repeating units. The obtained polymer compound i had an Mw of 14,000 and a dispersity of 1.77.

<Example 10> Production of polymer compound j In Example 8, 5,6 obtained in Synthesis Example 1-7 instead of 2.18 g (9.78 mmol) of 1,4-dithiepan-2-yl methacrylate The polymerization reaction was carried out under the same charge and conditions as in Example 8, except that -dimethyl-1,4-dithian-2-yl methacrylate 2.34 (9.78 mmol) was used.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 37.5 g of THF was dropped into methanol of the same mass as above while stirring, and the resulting precipitate was collected by filtration and washed with methanol of the same mass as above to obtain a white precipitate. Obtained. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 2.76 g of a polymer compound j consisting of the following repeating units. Mw of the obtained polymer compound j was 15800, and the degree of dispersion was 1.49.

Example 11 Production of Polymer Compound k In Example 9, 5,6 obtained in Synthesis Example 1-7 instead of 2.09 g (9.35 mmol) of 1,4-dithiepan-2-yl methacrylate The polymerization reaction was carried out under the same charge and conditions as in Example 9, except that -dimethyl-1,4-dithian-2-yl methacrylate 2.23 (9.35 mmol) was used.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 40.0 g of 1,4-dioxane is dropped into methanol of the same mass as above while stirring, and the resulting precipitate is collected by filtration and washed with the same mass of methanol as described above. Gave a white precipitate. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 2.69 g of a polymer compound k having the following repeating units. The obtained polymer compound k had an Mw of 15900 and a dispersity of 1.68.

<Comparative Synthesis Example 1> Synthesis of Polymer Compound A To a 200-ml round bottom flask equipped with an electromagnetic stirrer, a reflux condenser and a thermometer, 2-methyl-2-adamantyl methacrylate was added under a nitrogen atmosphere. 0 g (42.3 mmol), 3-hydroxy-1-adamantyl methacrylate 10.0 g (42.7 mmol), propylene glycol monomethyl ether 80.0 g and 2,2′-azobisisobutyronitrile 1.40 g (8 .53 mmol) and a polymerization reaction was carried out at 81-87 ° C. for 2 hours. The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 100.0 g of THF was dropped into methanol of the same mass as above while stirring, and the resulting precipitate was collected by filtration and washed with methanol of the same mass as above to obtain a white precipitate. Obtained. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 13.2 g of polymer compound A composed of the following repeating units. The obtained polymer compound A had an Mw of 16,100 and a dispersity of 1.68.

Comparative Synthesis Example 2 Synthesis of Polymer Compound B In Comparative Synthesis Example 1, tetrahydropyran-2-yl methacrylate was used instead of 10.0 g (42.3 mmol) of 2-methyl-2-adamantyl methacrylate. The polymerization reaction was carried out under the same charge and conditions as in Comparative Synthesis Example 1 except that 39 g (42.7 mmol) was used.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 100.0 g of THF was dropped into methanol of the same mass as above while stirring, and the resulting precipitate was collected by filtration and washed with methanol of the same mass as above to obtain a white precipitate. Obtained. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 9.96 g of a polymer compound B composed of the following repeating units. The obtained polymer compound B had Mw of 13,200 and a dispersity of 1.71.

<Comparative Synthesis Example 3> Synthesis of Polymer Compound C 1-Methyl-1-cyclohexyl = methacrylate in a 200 ml round bottom flask equipped with an electromagnetic stirrer, reflux condenser and thermometer in a nitrogen atmosphere. 14 g (50.2 mmol), 3-hydroxy-1-adamantyl methacrylate 11.82 g (50.0 mmol), 1,4-dioxane 101.4 g and 2,2′-azobisisobutyronitrile 1.24 g ( 7.55 mmol), and a polymerization reaction was carried out at 80 to 82 ° C. for 5 hours. The obtained reaction mixture was dropped into a water-methanol mixed solution (mass ratio water: methanol = 1: 3) of about 20 times mass with respect to the reaction mixture at room temperature while stirring, and a precipitate formed. Filtered. A solution obtained by dissolving the precipitate in 140.0 g of THF was dropped into a water-methanol mixed solution (mass ratio water: methanol = 1: 3) having the same mass as above while stirring, and the resulting precipitate was collected by filtration. A white precipitate was obtained by washing with a water-methanol mixed solution (mass ratio water: methanol = 1: 3) having the same mass as above. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 11.8 g of a polymer compound C consisting of the following repeating units. The obtained polymer compound C had Mw of 12,600 and a dispersity of 1.83.

Comparative Synthesis Example 4 Synthesis of Polymer Compound D 4.39 g of 2-methacryloyloxy-2-methyladamantane was placed in a 100 ml round bottom flask equipped with an electromagnetic stirrer, a reflux condenser and a thermometer under a nitrogen atmosphere. (18.7 mmol), 3-hydroxy-1-adamantyl methacrylate 2.95 g (12.5 mmol), α-methacryloyloxy-γ-butyrolactone 3.18 g (18.7 mmol), methyl ethyl ketone 35.4 g and 2,2 0.66 g (4.0 mmol) of '-azobisisobutyronitrile was charged, and a polymerization reaction was performed at 80 ° C. for 4 hours. The obtained reaction mixture was dropped into methanol of about 20 times mass at room temperature while stirring to obtain a white precipitate. The precipitate was collected by filtration and dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 6.06 g of a polymer compound D consisting of the following repeating units. The obtained polymer compound D had Mw of 10,000 and a dispersity of 1.50.

Comparative Synthesis Example 5 Synthesis of Polymer Compound E In Comparative Synthesis Example 4, tetrahydropyran-2-yl methacrylate 3.18 g instead of 4.39 g (18.7 mmol) of 2-methacryloyloxy-2-methyladamantane The polymerization reaction was carried out under the same charge and conditions as in Comparative Synthesis Example 4 except that (18.7 mmol) was used. The obtained reaction mixture was dropped into methanol of about 20 times mass at room temperature while stirring to obtain a white precipitate. The precipitate was collected by filtration and dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 5.82 g of a polymer compound E consisting of the following repeating units. The obtained polymer compound E had an Mw of 6500 and a dispersity of 1.60.

<Comparative Synthesis Example 6> Synthesis of Polymer Compound F In Comparative Synthesis Example 4, 3.41 g of 1-methyl-1-cyclohexyl methacrylate instead of 4.39 g (18.7 mmol) of 2-methacryloyloxy-2-methyladamantane The polymerization reaction was carried out under the same charge and conditions as in Comparative Synthesis Example 4 except that (18.7 mmol) was used. The obtained reaction mixture was dropped into methanol of about 20 times mass at room temperature while stirring to obtain a white precipitate. The precipitate was collected by filtration and dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 5.69 g of a polymer compound F consisting of the following repeating units. Mw of the obtained polymer compound F was 6900, and the degree of dispersion was 1.58.

Comparative Synthesis Example 7 Synthesis of Polymer Compound G In Comparative Synthesis Example 1, 1,3-dithian-5-yl methacrylate was used instead of 10.0 g (42.3 mmol) of 2-methyl-2-adamantyl methacrylate. The polymerization reaction was carried out under the same charging amount and conditions as in Comparative Synthesis Example 1 except that 8.98 g (42.7 mmol) of lato was used.
The obtained reaction mixture was added dropwise with stirring to about 20 times the mass of methanol at room temperature with stirring, and the resulting precipitate was collected by filtration. A solution obtained by dissolving the precipitate in 100.0 g of THF was dropped into methanol of the same mass as above while stirring, and the resulting precipitate was collected by filtration and washed with methanol of the same mass as above to obtain a white precipitate. Obtained. The precipitate was dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 10.22 g of a polymer compound G composed of the following repeating units. Mw of the obtained polymer compound G was 15200, and the degree of dispersion was 1.69.

Comparative Synthesis Example 8 Synthesis of Polymer Compound H In Comparative Synthesis Example 4, 1,3-dithian-5-yl methacrylate was used instead of 4.39 g (18.7 mmol) of 2-methacryloyloxy-2-methyladamantane. The polymerization reaction was carried out under the same charge and conditions as in Comparative Synthesis Example 4 except that 3.93 g (18.7 mmol) was used.
The obtained reaction mixture was dropped into methanol of about 20 times mass at room temperature while stirring to obtain a white precipitate. The precipitate was collected by filtration and dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 5.99 g of a polymer compound H composed of the following repeating units. Mw of the obtained polymer compound H was 12800, and the degree of dispersion was 1.65.

<Examples 12 to 21 and Comparative Examples 1 to 8> Evaluation of Dissolution Properties in Developer by QCM Method 100 parts by mass of the polymer compound obtained in Examples 2 to 11 or Comparative Synthesis Examples 1 to 8 and photoacid 3 parts by mass of TPS-109 (product name, component; nonafluoro-n-butanesulfonate triphenylsulfonium, manufactured by Midori Chemical Co., Ltd.) as a generator, and polymer compounds b, c, d, e, h as solvents , J, A, B, C and G when using a mixed solvent of ethyl lactate, and when using a polymer compound other than those, propylene glycol monomethyl ether acetate / ethyl lactate = 1/1 (volume ratio), Each component was mixed to prepare a photoresist composition having a polymer compound concentration of 12% by mass.
Each of the obtained photoresist compositions was filtered using a filter [made of tetrafluoroethylene resin (PTFE), pore size 0.2 μm], and then a 1-inch size quartz substrate having a gold electrode vacuum-deposited on the surface thereof. Each was coated by a spin coating method to form a photosensitive layer having a thickness of about 300 nm. The quartz substrate on which the photosensitive layer has been formed is pre-baked on a hot plate at 110 ° C. for 90 seconds, then exposed using an ArF excimer laser (wavelength 193 nm) at an exposure amount of 100 mJ / cm ² , and subsequently at 110 ° C. for 90 seconds. Post-exposure bake for seconds.
The quartz substrate was set in a quartz vibrator microbalance device “RQCM” (trade name; manufactured by Maxtek), and developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution for 120 seconds. The change in frequency of the quartz substrate during development is monitored over time, and the obtained change in frequency is converted into a change in film thickness. From the increase in film thickness, the maximum swelling amount and from the change in film thickness are dissolved. The speed was calculated. The results are shown in Table 3.

<Examples 22 to 31 and Comparative Examples 9 to 16> Two-beam Interferometry Exposure Evaluation 100 parts by mass of the polymer compound obtained in Examples 2 to 11 or Comparative Synthesis Examples 1 to 8 and TPS as a photoacid generator -109 (product name, component; nonafluoro-n-butanesulfonic acid triphenylsulfonium, manufactured by Midori Chemical Co., Ltd.) 3 parts by mass, and using as a solvent, polymer compounds b, c, d, e, h, j, A , B, C, and G are mixed using ethyl lactate, and when other polymer compounds are used, they are mixed using a mixed solvent of propylene glycol monomethyl ether acetate / ethyl lactate = 1/1 (volume ratio). A photoresist composition having a polymer compound concentration of 12% by mass was prepared.
Each of the obtained photoresist compositions was filtered using a filter [made of tetrafluoroethylene resin (PTFE), pore size: 0.2 μm]. A cresol novolak resin (PS-6937, manufactured by Gunei Chemical Co., Ltd.) is coated with a 6% by weight propylene glycol monomethyl ether acetate solution by spin coating, and baked on a hot plate at 200 ° C. for 90 seconds to obtain a film thickness of about 100 nm. Each of the filtrates is applied by spin coating on a silicon wafer having a diameter of 10 cm on which an antireflection film (underlying film) is formed, and pre-baked on a hot plate at 130 ° C. for 90 seconds to form a resist having a thickness of about 300 nm. A film was formed.
This resist film was exposed by a two-beam interference method using an ArF excimer laser having a wavelength of 193 nm. Subsequently, the film was post-exposure baked at 130 ° C. for 90 seconds, and then developed with a 2.38% by mass-tetramethylammonium hydroxide aqueous solution for 60 seconds to form a 1: 1 line and space pattern. The developed wafer was cleaved and observed with a scanning electron microscope (SEM), and the pattern shape observation and line width variation (hereinafter referred to as LWR) at an exposure amount obtained by resolving a line and space with a line width of 100 nm at 1: 1. Measured). In the LWR, the line width is detected at a plurality of positions in the measurement monitor, and the dispersion (3σ) of variations in the detected positions is used as an index. The results are shown in Table 4.

<Examples 32-39 and Comparative Examples 17-21> Thermal Stability Evaluation Stability of each polymer compound obtained in Examples 2-5, 8-11 or Comparative Synthesis Examples 1-3, 7, 8 to heat Was confirmed with a micro thermogravimetric measuring device “TGA-50” (trade name; manufactured by Shimadzu Corporation).
The amount of the sample was about 5.0 mg of the polymer compound, and the measurement was performed in the range of 20 to 600 ° C. under the setting of nitrogen gas 50 mL / min and temperature increase 10 ° C./min. From the obtained graph, the starting temperature of weight reduction and the temperature when 5% of the original weight decreased were read. In addition, the weight reduction | restoration here shows that the high molecular compound has decomposed | disassembled with the heat | fever, Generally, it is stable with respect to a heat | fever, so that the temperature when a weight reduction | decrease was shown is high. Can be interpreted. The results are shown in Table 5.

From Table 3 to Table 5, in the case of the polymer compound (8) of the present invention containing the acrylate derivative (1) as a structural unit, the polymer compound not containing the acrylate derivative (1) as a structural unit. In comparison, the dissolution rate in the alkaline developer used in the development process when forming a pattern on the photoresist is very high, and the maximum swelling during development is very small (Examples 12 to 21 and Comparative Example 1). It can be seen that the LWR is improved (see Examples 22 to 31 and Comparative Examples 9 to 16). In addition, the thermal stability is excellent (see Examples 32 to 39 and Comparative Examples 17 to 21), which indicates that it is useful as a chemically amplified resist for manufacturing semiconductor devices.

Reference Example 7 Preparation of Photoresist Composition b 100 parts by mass of the polymer compound b obtained in Example 2, 3.0 parts by mass of triphenylsulfonium nonafluoro-n-butanesulfonate as a photoacid generator, and as a basic compound By mixing 0.27 parts by mass of Nt-butoxycarbonylpyrrolidine and 1962 parts by mass of cyclohexanone as a solvent, a solution in which each component was uniform was obtained. Thereafter, the obtained solution was filtered using a membrane filter having a pore size of 0.2 μm to prepare a photoresist composition b (total solid content concentration of about 5% by mass).
[Refractive index measurement]
The prepared photoresist composition b was spin-coated on a silicon substrate using “CLEAN TRACK ACT8” manufactured by Tokyo Electron Limited, and pre-baked at 100 ° C. for 60 seconds to form a resist film having a thickness of 120 nm. .
The refractive index of the resist film at a wavelength of 193 nm was measured using a spectroscopic ellipsometer (“VUV-VASE”, manufactured by JA Woollam). The results are shown in Table 6.

Reference Examples 8 to 14 Preparation of Photoresist Compositions d and f to k In Reference Example 7, instead of the polymer compound b, the polymer compounds d and f to k obtained in Examples 4 and 6 to 11 were used. Except that it was used, an experiment was conducted in the same manner as in Reference Example 7 to prepare photoresist compositions d and f to k (total solid content concentration of about 5 mass%), respectively, and the refractive index at a wavelength of 193 nm was measured. The results are shown in Table 6.

Reference Examples 15 to 22 Preparation of Photoresist Compositions A to H In Reference Example 7, polymer compounds A to H obtained in Comparative Synthesis Examples 1 to 8 were used in place of polymer compound b. Experiments were conducted in the same manner as in Reference Example 7 to prepare photoresist compositions A to H (total solid content concentration of about 5% by mass) and measure the refractive index at a wavelength of 193 nm. The results are shown in Table 6.

Currently, many resist films that are generally used have a refractive index of about 1.69 to 1.71, and in such a resist film, water (wavelength 193 nm) is used as the immersion liquid. In the case of using a refractive index of 1.44), there is no problem that exposure light becomes difficult to enter the resist film. However, in the future, when a next-generation immersion liquid having a refractive index higher than that of water (an immersion liquid having a refractive index of 1.71 or more) is used, The exposure light is not sufficiently incident on the resist film, and a desired resist pattern cannot be obtained. However, according to the photoresist composition (9) containing the polymer compound (8) of the present invention containing the acrylate derivative (1) as a constituent unit, the next-generation immersion liquid instead of water was used. Also in the immersion exposure process, the exposure light is not reflected at the interface between the immersion liquid and the photoresist film, and can sufficiently enter the photoresist film.

Reference Example 23 Characteristic Curve Measurement Using an 8-inch silicon wafer as a substrate, “CLEAN TRACK ACT8” (manufactured by Tokyo Electron Limited) is used on this substrate, and a 77 nm-thick underlayer antireflection film (“ARC29A”, Formed by Science). On the formed lower antireflection film, the photoresist composition b obtained in Reference Example 7 was spin-coated with “CLEAN TRACK ACT8” (manufactured by Tokyo Electron Ltd.), pre-baked at 100 ° C. for 60 seconds, and the film A resist film having a thickness of 120 nm was formed.
This resist film was exposed with an ArF excimer laser exposure apparatus (“NSR S306C”, manufactured by Nikon Corporation, illumination conditions: NA 0.78 sigma 0.90 / 0.52). This exposure was performed through quartz with no pattern.
Thereafter, post-exposure baking was performed at 130 ° C. for 60 seconds, and development was performed at 23 ° C. for 60 seconds with a 2.38 mass% tetramethylammonium hydroxide aqueous solution. After development, the wafer was washed with water and dried to obtain a characteristic curve measurement wafer.
Then, the film thickness of the resist film at each exposure amount was measured by an automatic film thickness measuring apparatus ( "VM-2010", manufactured by Dainippon Screen Mfg. Co., Ltd.), the exposure amount (mJ / cm ²⁾ and thickness ( Angstrom (Å)) correlation was confirmed. The result is shown in FIG.

<Reference Example 24> Characteristic Curve Measurement In Reference Example 23, measurement was performed in the same manner except that the photoresist composition d obtained in Reference Example 8 was used instead of the photoresist composition b. The result is shown in FIG.

As shown in FIG. 1, the photoresist film formed from the photoresist composition (9) containing the polymer compound (8) containing the acrylate derivative (1) as a constituent unit has a residual film amount by increasing the exposure amount. It was confirmed that all the photoresist films became soluble in the developer at a given exposure, and that the exposure margin (variation of the line width with respect to the change in exposure) was good (reference) See Examples 23 and 24). Therefore, the film formed by the photoresist composition (9) containing the polymer compound (8) containing the acrylic ester derivative (1) as a structural unit can be sufficiently patterned as a photoresist film. It is expected that sufficient contrast can be obtained.
As described above, the photoresist composition (9) containing the polymer compound (8) of the present invention containing the acrylate derivative (1) as a constituent unit can form a photoresist film having high sensitivity. The polymer compound (8) of the present invention obtained by using the acrylate derivative (1) is useful as a chemically amplified resist for manufacturing semiconductor devices.

The polymer compound (8) of the present invention is useful as a raw material for a photoresist composition for an immersion exposure method using an immersion liquid having a refractive index of 1.70 or more, particularly as a raw material for a photoresist composition. .

Claims

The following general formula (1)

(Wherein R 1 represents a hydrogen atom, a methyl group or a trifluoromethyl group. The combination of R 2 , R 3 and R 4 is
1) R 2 , R 3 and R 4 are each independently a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms or a cyclic group having 3 to 6 carbon atoms. Represents an alkyl group. ;
2) R 2 and R 3 are connected to represent an alkylene group having 3 to 6 carbon atoms, and R 4 is a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, or a branched alkyl group having 3 to 6 carbon atoms. Or a cyclic alkyl group having 3 to 6 carbon atoms. Or 3) R 2 represents a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms, and R 3 and R 4 represents an alkylene group having 3 to 6 carbon atoms linked to each other. One of them.
The combination of n, R 5 , R 6 , R 7 , R 8 , R 9 and R 10 is
1) When n = 0, R 5 and R 8 are each independently a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms, or 3 to 3 carbon atoms 6 cyclic alkyl groups are represented. Each of R 6 and R 7 independently represents a hydrogen atom, a linear alkyl group having 1 to 6 carbon atoms, a branched alkyl group having 3 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms; Or R 6 and R 7 are linked to each other to represent an alkylene group having 3 to 6 carbon atoms. Or 2) When n = 1 or 2, R 5 , R 6 , R 7 , R 8 , R 9 and R 10 are each independently a hydrogen atom or a linear alkyl group having 1 to 6 carbon atoms. Represents a branched alkyl group having 3 to 6 carbon atoms or a cyclic alkyl group having 3 to 6 carbon atoms. One of them. )
The high molecular compound obtained by superposing | polymerizing the raw material containing the acrylic acid ester derivative shown by.
The polymer compound according to claim 1, wherein n is 0 or 1, and R 3 is a hydrogen atom.
2. The polymer compound according to claim 1, wherein n is 0 or 1, and R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 are hydrogen atoms.
The polymer compound according to any one of claims 1 to 3, wherein the content of the structural unit based on the acrylate derivative is in the range of 10 to 90 mol%.