KR101782172B1 - Polymer, chemically amplified resist composition, and patterning process using said chemically amplified resist composition - Google Patents

Abstract

An object of the present invention is to provide a photolithography method using photolithography using a high-energy beam such as ArF excimer laser light or EUV as a light source, forming a pattern having excellent resolution, particularly excellent rectangularity of pattern shape, A chemically amplified resist material containing the polymer compound, and a pattern forming method using the chemically amplified resist material.
The present invention provides a polymer compound containing a repeating unit represented by the following formula (1).
≪ Formula 1 >

Description

TECHNICAL FIELD The present invention relates to a polymer compound, a chemically amplified resist material, and a pattern forming method using the chemically amplified resist material. BACKGROUND OF THE INVENTION 1. Field of the Invention [0002]

The present invention relates to (1) a polymer compound, (2) a chemically amplified resist material containing the polymer compound, and (3) a pattern forming method using the chemically amplified resist material. In the present invention, the high energy rays include ultraviolet rays, deep ultraviolet rays, electron rays, EUV, X rays, excimer lasers,? Rays, and synchrotron radiation.

In recent years, miniaturization of pattern rules has been demanded in accordance with the high integration and the high speed of LSI, and as a next generation microfabrication technique, far ultraviolet lithography and vacuum ultraviolet lithography are promising. Among them, photolithography using ArF excimer laser light as a light source is an indispensable technique for ultrafine processing of 0.13 μm or less.

ArF lithography began to be used in part from device fabrication at 130 nm nodes, becoming the dominant lithography technique from 90 nm node devices. 157 nm lithography using the F ₂ laser was promising as a lithography technique for the next 45 nm node. However, since development delay due to various problems has been pointed out, it is necessary to use water such as water, ethylene glycol, glycerin By inserting a liquid having a higher refractive index, the numerical aperture (NA) of the projection lens can be designed to be 1.0 or more, and ArF immersion lithography capable of achieving high resolution is rapidly emerging (see, for example, Non-Patent Document 1) It is in practical use. For this immersion lithography, a resist material which is difficult to elute into water is required.

In ArF lithography, a resist material with high sensitivity that can exhibit sufficient resolution at a low exposure dose is required in order to prevent deterioration of a precise but expensive optical system material. As a measure to be realized, It is most common to choose something that is more transparent. For example, as the base resin, there have been proposed polyacrylic acid and derivatives thereof, norbornene-maleic anhydride copolymer, polynorbornene and ring-opening metathesis polymer, and hydrogenated ring-opening metathesis polymer, and the like. I got some results in terms of points.

In addition, various photoacid generators and additives have been reviewed to achieve high resolution. For example, it is generally known that a high resolution is obtained by adding a basic compound such as an amine as a quencher in order to control diffusion of an acid generated by exposure. In addition, in the case where one of the photoacid generators is an onium salt generating a so-called weak acid, a function of acid diffusion control may be provided by mixing two or more kinds of photoacid generators (Patent Document 1, Patent Document 2). That is, when an onium salt generating a strong acid such as a fluorine-substituted sulfonic acid and a sulfonic acid which is not fluorine-substituted or an onium salt which generates a weak acid such as a carboxylic acid are mixed and used, When the generated strong acid collides with an onium salt having an unreacted weak acid anion, it releases a weak acid by salt exchange and generates an onium salt having a strong acid anion. In this process, since the strong acid is exchanged into the weak acid having a lower catalytic activity, the acid diffusion can be controlled by the inactive appearance of the acid. In the case where the photoacid generator generating a strong acid is an onium salt, the strong acid generated by the high energy irradiation can be replaced with the weak acid, but the weak acid generated by the high energy irradiation may collide with the onium salt generating the unreacted strong acid So that the salt exchange can not be performed. These are due to the phenomenon that the onium cation is more likely to form an ion pair with the anion of the strong acid. However, since the onium salt itself which generates a weak acid has mobility and diffusibility in the resist material, there remains a problem in terms of attaining high resolution such as influence on lithography characteristics and elution into an immersion liquid.

A resin-bound onium salt in which an anion of a weak acid is bonded to a resin has been developed (Patent Document 3, Patent Document 4). This makes it possible to control the migration and diffusion of the weak acid onium salt. However, there still remains a problem to overcome defects such as peeling of the resist pattern, which is often observed in the resist to which the weak acid anion is added, from the substrate.

Japanese Patent Application Laid-Open No. 2010-155824 Japanese Patent Application Laid-Open No. 2008-158339 WO 2010119910 Japanese Patent Application Laid-Open No. 2011-37834

 Journal of photopolymer Science and Technology Vol.17, No.4, p587 (2004)

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method of forming a pattern having excellent resolution, particularly excellent in rectangularity of pattern shape, in photolithography using a high energy beam such as ArF excimer laser light or EUV as a light source A polymer compound capable of obtaining a resist material having suitable adhesiveness to a substrate, a chemically amplified resist material containing the polymer compound, and a pattern forming method using the chemically amplified resist material.

According to the present invention, there is provided a polymer compound containing a repeating unit represented by the following general formula (1).

(Wherein R ¹ represents any ^one of a hydrogen atom, a fluorine atom, a methyl group and a trifluoromethyl group, R ² , R ³ and R ⁴ each independently represents a substituted or unsubstituted, straight, Represents a substituted or unsubstituted aryl group, an aralkyl group and an aryloxoalkyl group having 6 to 18 carbon atoms, or R ² , R ³ and R ^{4 each} independently represent a hydrogen atom, an alkyl group, an alkoxy group, R ⁴ may combine with each other to form a ring with the sulfur atom in the formula, X ¹ represents O or CH ₂ , A ¹ represents a straight, branched or cyclic B ¹ represents an alkylene group having from 1 to 10 carbon atoms or an arylene group having from 6 to 18 carbon atoms which may contain a hetero atom other than fluorine and k ¹ represents an integer of 0 or 1)

The repeating unit represented by the formula (1) has a sulfonium salt structure of a sulfonic acid in which B ¹ is not fluorine-substituted, and has a lactone structure. Therefore, when a polymer compound having such a repeating unit is used as a base resin of a chemically amplified resist material, migration and diffusion of strong acid generated from the acid generator can be appropriately controlled, and the resulting resist pattern is excellent in rectangularity , And the adhesion of the pattern to the substrate is also good. Further, since the elution of the anion component of the sulfonium salt is low, it can be preferably used as an immersion lithography material.

The polymer compound preferably contains a repeating unit having an acid labile group in addition to the repeating unit represented by the formula (1).

The repeating unit represented by the formula (1) contained in the polymer compound of the present invention can function not only as an acid shift and diffusion control function by selection of an acid stable unit but also as a unit for generating an acid .

Further, the present invention provides a chemically amplified resist material characterized by containing (A) the polymer compound, (B) an organic solvent, (C) a photoacid generator, and (D) a basic compound.

As described above, when a chemically amplified resist material containing the polymer compound of the present invention is used, a resist pattern having excellent rectangularity and having good adhesion to a substrate can be obtained.

The present invention also includes a step of applying the chemically amplified resist material onto a substrate, a step of exposing the substrate to a high energy beam through a photomask after the heat treatment, and a step of developing by using a developer A method of forming a pattern is provided.

The present invention also provides a method of manufacturing a semiconductor device, comprising the steps of: applying the chemically amplified resist material onto a substrate; applying a protective film insoluble in water after heat treatment and usable in an alkali developing solution; A step of exposing the resist film to a high energy beam through a photomask, and a step of developing the resist film using a developer.

As described above, according to the pattern forming method of the present invention, a resist pattern having excellent rectangularity and having good adhesion to a substrate can be obtained. Further, since the elution of the anion component of the sulfonium salt is low, it can be preferably used for an immersion lithography material.

A chemically amplified resist material using a sulfonic acid anion having a specific structure of the present invention and a polymer compound containing a sulfonium salt containing a sulfonium cation as a base resin is excellent in resolution, especially rectangular shape in pattern shape. Further, since the repeating unit has a lactone structure, it has excellent adhesion to the substrate of the resin, and is very useful because it is resistant to pattern collapse.

As a result of diligent studies to achieve the above object, the present inventors have found that a resist composition using a resin composition having a repeating unit of a sulfonic acid anion having a specific structure represented by the following formula (1) as a resist base resin, The present invention has been accomplished based on the discovery that it is excellent in the rectangularity of the shape and is excellent in adhesion with the substrate and hence is less liable to peel off the line and space pattern and is very effective for fine processing as a resist material.

Hereinafter, the polymer compound, the chemically amplified resist material and the pattern forming method of the present invention will be described. First, the polymer compound provided by the present invention contains a repeating unit represented by the following formula (1).

≪ Formula 1 >

(Wherein R ¹ represents any ^one of a hydrogen atom, a fluorine atom, a methyl group and a trifluoromethyl group, R ² , R ³ and R ⁴ each independently represents a substituted or unsubstituted, straight, Represents a substituted or unsubstituted aryl group, an aralkyl group and an aryloxoalkyl group having 6 to 18 carbon atoms, or R ² , R ³ and R ^{4 each} independently represent a hydrogen atom, an alkyl group, an alkoxy group, R ⁴ may combine with each other to form a ring with the sulfur atom in the formula, X ¹ represents O or CH ₂ , A ¹ represents a straight, branched or cyclic B ¹ represents an alkylene group having from 1 to 10 carbon atoms or an arylene group having from 6 to 18 carbon atoms which may contain a hetero atom other than fluorine and k ¹ represents an integer of 0 or 1)

Examples of the alkylene group having 6 to 18 carbon atoms or the arylene group having 6 to 18 carbon atoms, which may contain a hetero atom other than fluorine and represented by B ¹ in the above-mentioned formula (1), include the followings. But is not limited thereto. In the present invention, the hetero atom excluding fluorine means nitrogen, oxygen, sulfur atom and the like.

(Wherein the broken line represents the combined hands)

Substituted or unsubstituted linear, branched or cyclic alkyl, alkenyl and oxoalkyl groups of 1 to 10 carbon atoms represented by R ² , R ³ and R ⁴ in the above formula (1) Specific examples of the aryl, aralkyl and aryloxoalkyl groups having 6 to 18 carbon atoms include substituted or unsubstituted alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec- A cyclohexyl group, a cyclohexyl group, a cyclopentyl group, a cyclopropylmethyl group, a 4-methylcyclohexyl group, a cyclohexylmethyl group, a norbornyl group, an adamantyl group, etc. .

Examples of the substituted or unsubstituted alkenyl group include a vinyl group, an allyl group, a propenyl group, a butenyl group, a hexenyl group, and a cyclohexenyl group.

Examples of the substituted or unsubstituted oxoalkyl group include a 2-oxocyclohexyl group, a 2-oxocyclohexyl group, a 2-oxopropyl group, a 2-oxoethyl group, a 2-cyclopentyl- -Oxoethyl group, 2- (4-methylcyclohexyl) -2-oxoethyl group and the like.

Examples of the substituted or unsubstituted aryl group include a phenyl group, a naphthyl group and a thienyl group, and a 4-hydroxyphenyl group, a 4-methoxyphenyl group, a 3-methoxyphenyl group, methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butylphenyl, Alkylphenyl groups such as methylphenyl group, butylphenyl group and 2,4-dimethylphenyl group, alkylnaphthyl groups such as methylnaphthyl group and ethylnaphthyl group, alkoxynaphthyl groups such as methoxynaphthyl group and ethoxynaphthyl group, dimethylnaphthyl group and diethylnaphthyl group And dialkoxynaphthyl groups such as dialkylnaphthyl, dimethoxynaphthyl and diethoxynaphthyl groups.

Examples of the substituted or unsubstituted aralkyl group include a benzyl group, a 1-phenylethyl group, and a 2-phenylethyl group.

Examples of the substituted or unsubstituted aryloxoalkyl group include 2-phenyl-2-oxoethyl group, 2- (1-naphthyl) -2-oxoethyl group, 2- Aryl-2-oxoethyl group and the like.

When two or more of R ² , R ³ and R ⁴ are bonded to each other to form a cyclic structure together with the sulfur atom, the following examples are specifically exemplified, but the present invention is not limited thereto.

(Wherein R < ⁴ > is as defined above)

Specific examples of the sulfonium cation include triphenylsulfonium, 4-hydroxyphenyldiphenylsulfonium, bis (4-hydroxyphenyl) phenylsulfonium, tris (4-hydroxyphenyl) Butoxyphenyldiphenylsulfonium, bis (4-tert-butoxyphenyl) phenylsulfonium, tris (4-tert-butoxyphenyl) Tert-butoxyphenyl) phenylsulfonium, tris (3-tert-butoxyphenyl) sulfonium, 3,4-di-tert-butoxyphenyldiphenylsulfonium, bis Butoxyphenyl) phenylsulfonium, tris (3,4-di-tert-butoxyphenyl) sulfonium, diphenyl (4-thiophenoxyphenyl) sulfonium, 4-tert-butoxycarbonylmethyloxy (4-tert-butoxyphenyl) bis (4-dimethylaminophenyl) sulfonium, tris (4-tert-butoxycarbonylmethyloxyphenyl) sulfonium, ) Sulfonium, 2-naphthyldiphenylsulfonium, (4-hydroxy-3,5-dimethylphenyl) diphenyl (4-n-hexyloxy-3,5-dimethylphenyl) diphenylsulfonium, dimethyl (2-naphthyl) sulfonium, 4-hydroxyphenyldimethylsulfonium, 4-methoxyphenyldimethylsulfonium , Trimethylsulfonium, 2-oxocyclohexylcyclohexylmethylsulfonium, trinaphthylsulfonium, tribenzylsulfonium, diphenylmethylsulfonium, dimethylphenylsulfonium, 2-oxo-2-phenylethylthiacyclopentanium Thienylsulfonium, 4-n-butoxynaphthyl-1-thacyclopentanium, 2-n-butoxynaphthyl-1-thiacyclopentanium, 4-methoxynaphthyl- Thiocyclopentanium, 2-methoxynaphthyl-1-thiacyclopentanium, and the like. More preferred are triphenylsulfonium, 4-tert-butylphenyldiphenylsulfonium, 4-tert-butoxyphenyldiphenylsulfonium, tris (4-tert- butylphenyl) sulfonium, Butoxyphenyl) sulfonium, dimethylphenylsulfonium, and the like.

As the straight, branched or cyclic divalent hydrocarbon group of 1 to 10 carbon atoms represented by A ¹ in the above-mentioned formula (1), the following are specifically exemplified.

(Wherein the broken line represents the combined hands)

Specific examples of the repeating unit represented by the above formula (1) include, but are not limited to, the following.

(Wherein R < ^{1 >} is as defined above)

(Wherein R < ^{1 >} is as defined above)

(Wherein R < ^{1 >} is as defined above)

(Wherein R < ^{1 >} is as defined above)

(Wherein R < ^{1 >} is as defined above)

(Wherein R < ^{1 >} is as defined above)

Here, the monomer for obtaining the repeating unit represented by the formula (1) in the polymer compound of the present invention is a novel substance represented by the following formula (1a).

(Wherein R ¹ represents any ^one of a hydrogen atom, a fluorine atom, a methyl group and a trifluoromethyl group, R ² , R ³ and R ⁴ each independently represents a substituted or unsubstituted, straight, Represents a substituted or unsubstituted aryl group, an aralkyl group and an aryloxoalkyl group having 6 to 18 carbon atoms, or R ² , R ³ and R ^{4 each} independently represent a hydrogen atom, an alkyl group, an alkoxy group, R ⁴ may combine with each other to form a ring with the sulfur atom in the formula, X ¹ represents O or CH ₂ , A ¹ represents a straight, branched or cyclic B ¹ represents an alkylene group having from 1 to 10 carbon atoms or an arylene group having from 6 to 18 carbon atoms which may contain a hetero atom other than fluorine and k ¹ represents an integer of 0 or 1)

Here, the method for obtaining the monomer (1a) is illustrated in the following reaction formula, but it is not limited thereto. Hereinafter, the broken line used in the equation represents a combined hand.

(Wherein R ¹ to R ⁴ , X ¹ , A ¹ , B ¹ and k ¹ are as defined above, and X ² represents a halogen atom, a hydroxyl group, an alkoxy group or a substituent represented by the following formula (10) M ⁺ represents a lithium ion, a sodium ion, a potassium ion, a substituted or unsubstituted ammonium ion, and X < ^3- > represents a halide ion or a methyl sulfate ion)

(Wherein R ¹ , A ¹ and k ¹ are as defined above)

When k ¹ is 1 in the formula (1a), the compound (4) in the above reaction formula can be obtained by another method described below.

(Wherein R ¹ , X ¹ and A ¹ are as defined above, X ⁴ is a halogen atom, X ⁵ is a halogen atom, a hydroxyl group or an alkoxy group, M ^{a +} is a lithium ion, a sodium ion, , Magnesium ion, calcium ion or substituted or unsubstituted ammonium ion)

Step (i) is a step of introducing ester (4) by reaction of hydroxylactone (2) and esterification agent (3). The synthesis method of the hydroxylactone (2) is disclosed in Japanese Patent Application Laid-Open Nos. 2000-159758 and 4539865.

The reaction proceeds easily by a known method, but in the esterifying agent (3) The acid chloride (in case of the formula (3), X ² is a chlorine atom) or an acid anhydride (Formula (3), X ² is the formula ( 10)) or a carboxylic acid (in the formula (3), when X ² is a hydroxyl group).

In the case of using an acid chloride or an acid anhydride, the reaction is carried out in the absence of a solvent or a solvent such as methylene chloride, toluene, hexane, diethyl ether, tetrahydrofuran, acetonitrile, etc., A corresponding acid chloride or acid anhydride such as chloride, acrylic acid anhydride, or methacrylic acid anhydride, and a base such as triethylamine, pyridine, or 4-dimethylaminopyridine are added sequentially or simultaneously, and if necessary, .

When a carboxylic acid is used, the corresponding carboxylic acid such as hydroxylactone (2) and acrylic acid or methacrylic acid in a solvent such as toluene or hexane is heated in the presence of an acid catalyst, and if necessary, Or the like is removed from the system. Examples of the acid catalyst to be used include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and perchloric acid, and organic acids such as p-toluenesulfonic acid and benzenesulfonic acid.

Step (ii) is a step for deprotecting the tert-butyl ester portion of the ester (4) with formic acid to obtain the carboxylic acid (5). The carboxylic acid (5) can be obtained by dissolving the ester (4) with formic acid as a solvent and, if necessary, cooling or heating while stirring.

Step (iii) is a step of deriving the carboxylic acid (5) to the corresponding acid chloride (6). The reaction is preferably carried out by sequentially or simultaneously adding chlorinating agents such as dichloromethane and oxalyl dichloride in a solvent such as methylene chloride, toluene, hexane, diethyl ether, tetrahydrofuran, acetonitrile, etc., .

Step (iv) is a step of obtaining onium salt (8) by nucleophilic substitution reaction of acid chloride (6) and sulfo alcohol (7). The reaction can be carried out according to a conventional method. It is preferable to add acid chloride (6), sulfo alcohol (7) and a base in a solvent in sequence or simultaneously and, if necessary, cooling or heating. Examples of the solvent which can be used in the reaction include water, ethers such as tetrahydrofuran, diethyl ether, diisopropyl ether, di-n-butyl ether and 1,4-dioxane, n- , Aprotic polar solvents such as acetonitrile, dimethylsulfoxide (DMSO) and N, N-dimethylformamide (DMF), chlorinated organic solvents such as methylene chloride, chloroform and carbon tetrachloride . These solvents can be appropriately selected depending on the reaction conditions and can be used singly or in a mixture of two or more. Examples of the base usable for the reaction shown in the step (iv) include amines such as ammonia, triethylamine, pyridine, lutidine, collidine and N, N-dimethylaniline, sodium hydroxide, Hydroxides such as tetramethylammonium hydroxide, and carbonates such as potassium carbonate and sodium hydrogencarbonate. These bases may be used singly or in combination of two or more.

Step (v) is a step of obtaining a sulfonium salt (1a) having a polymerizable anion by ion-exchange reaction between an onium salt (8) and a sulfonium salt (9). The onium salt (8) may be isolated after carrying out the reaction of step (iv) through a usual aqueous post-treatment, or may be used after the reaction is stopped, but not subjected to post treatment.

When the isolated onium salt (8) is used, the onium salt (8) is dissolved in an ether such as water, tetrahydrofuran, diethyl ether, diisopropyl ether, di-n-butyl ether, (DMSO), N, N-dimethylformamide (DMF), etc., chlorinated solvents such as dichloromethane, dichloromethane and the like, chlorinated hydrocarbons such as dichloromethane, A chlorinated organic solvent such as methylene, chloroform, carbon tetrachloride or the like, mixed with the sulfonium salt (9) and, if necessary, cooled or heated to obtain a reaction mixture. The sulfonium salt (1a) having a polymerizable anion can be obtained from the reaction mixture by conventional aqueous work-up, and purification can be carried out according to a conventional method such as distillation, recrystallization and chromatography, if necessary.

In the case where the reaction for synthesizing the onium salt (8) is stopped and the one not specifically subjected to the post treatment is used, the sulfonium salt (9) is added to the mixture in which the synthesis reaction of the onium salt (8) To obtain a reaction mixture. If necessary, water, ethers such as tetrahydrofuran, diethyl ether, diisopropyl ether, di-n-butyl ether and 1,4-dioxane, n-hexane, Chlorinated organic solvents such as methylene chloride, chloroform, and carbon tetrachloride, and the like are added to the reaction mixture, and the organic solvent is added to the reaction mixture It is possible. The sulfonium salt (1a) having a polymerizable anion can be obtained from the reaction mixture by conventional aqueous work-up, and purification can be carried out according to a conventional method such as distillation, recrystallization and chromatography, if necessary.

Steps (vi) and (vii) are other methods for obtaining the ester (4) in the above reaction formula when k ¹ is 1 in the above formula (1a).

Step (vi) is a reaction for obtaining a halo ester (12) by reaction of a hydroxylactone (2) with an esterifying agent (11). As the esterifying agent (11), an acid chloride (when X ⁵ in the formula (11) is a chlorine atom) or a carboxylic acid (in the case of the formula (11) in which X ⁵ is a hydroxyl group) ) Is particularly preferable. In the case of using an acid chloride, the corresponding acid chloride such as hydroxylactone (2), 2-chloroacetic acid chloride, 3-chloropropionic acid chloride or the like in a solvent such as methylene chloride, acetonitrile, toluene or hexane, Ethylamine, pyridine, 4-dimethylaminopyridine and the like are added sequentially or simultaneously at the same time, and cooling or heating is performed if necessary. When a carboxylic acid is used, the corresponding carboxylic acid such as hydroxylactone (2) and 2-chloroacetic acid or 3-chloropropionic acid in a solvent such as toluene or hexane is heated in the presence of an acid catalyst, It is preferable to carry out the removal of the generated water outside the system as required. Examples of the acid catalyst to be used include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and perchloric acid, and organic acids such as p-toluenesulfonic acid and benzenesulfonic acid. The reaction time is preferably from 0.5 to 24 hours in terms of the yield in terms of completion of the reaction by tracing the reaction by gas chromatography (GC) or silica gel thin layer chromatography (TLC). Halo ester (12) can be obtained from the reaction mixture by conventional aqueous work-up, and purification can be carried out according to a conventional method such as distillation, chromatography or recrystallization, if necessary.

Step (vii) is a reaction that leads to the ester (14) by the reaction of the halo ester (12) and the carboxylate compound (13).

The reaction in the step (vii) can be carried out according to a conventional method. As the carboxylate compound (13), a commercially available carboxylate compound such as various carboxylic acid metal salts may be used as it is, or a carboxylate compound may be used in the reaction system from the corresponding carboxylic acid and base such as methacrylic acid and acrylic acid May be used. The amount of the carboxylate compound (13) to be used is preferably 0.5 to 10 moles, particularly 1.0 to 3.0 moles per 1 mole of the haloester (12) as a raw material. If it is used in an amount of less than 0.5 mol, the raw material may remain in a large amount, resulting in a significant reduction in yield. If the amount of the raw material is more than 10 mol, the cost of raw materials may increase and the yield of the cauldron may decrease. Examples of the base which can be used in the production of the carboxylic acid salt compound in the reaction system from the corresponding carboxylic acid and base include amines such as ammonia, triethylamine, pyridine, lutidine, collidine and N, N-dimethylaniline ; Hydroxides such as sodium hydroxide, potassium hydroxide and tetramethylammonium hydroxide; Carbonates such as potassium carbonate and sodium hydrogencarbonate; Metals such as sodium; Metal hydrides such as sodium hydride; Metal alkoxides such as sodium methoxide and potassium t-butoxide; Butyllithium, ethylmagnesium bromide, and the like; Lithium diisopropylamide, and the like, or a mixture of two or more of them may be used. The amount of the base to be used is preferably 0.2 to 10 mol, particularly preferably 0.5 to 2.0 mol based on 1 mol of the corresponding carboxylic acid. If the amount is less than 0.2 mol, a large amount of carboxylic acid becomes useless, which may be disadvantageous in terms of cost. If the amount is more than 10 mol, the yield may be greatly lowered due to an increase in side reaction. The reaction time is preferably from 0.5 to 24 hours, from the viewpoint of the yield, by tracking the reaction by gas chromatography (GC) or silica gel thin layer chromatography (TLC) to complete the reaction. From the reaction mixture, a sulfonium salt (1a) having a polymerizable anion can be obtained by a conventional aqueous work-up, and purification can be carried out according to a conventional method such as distillation, chromatography or recrystallization, if necessary.

The repeating unit represented by the above formula (1) contained in the polymer compound of the present invention has a sulfonium salt structure of a sulfonic acid in which B ¹ is not fluorine-substituted and has a lactone structure. Therefore, when used as a base resin of a chemically amplified resist material, migration and diffusion of strong acid generated from the acid generator can be appropriately controlled, and it is expected that a high adhesion of the resist film to the substrate can be imparted.

In the polymer compound of the present invention, a repeating unit having an acid labile group can be coexisted in addition to the repeating unit represented by the formula (1). As the repeating unit having an acid labile group, there may be mentioned a repeating unit having an acid labile group represented by the following formula (2A).

(Wherein R ¹ is as defined above, and XA represents an acid labile group)

Hereinafter, the forest fire stabilizing unit will be described. The polymer compound further containing the repeating unit represented by the above formula (2A) is decomposed by the action of an acid to generate a carboxylic acid and becomes a polymer compound which becomes alkali-soluble. As the acid stabilizer XA, those represented by the following formulas can be used.

In the above formula, the broken line represents a bonding hand. R ^L01 and R ^L02 represent a hydrogen atom or a straight, branched or cyclic alkyl group of 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. Specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, T-butyl group and the like. R ^L03 represents a monovalent hydrocarbon group which may have a heteroatom such as an oxygen atom having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and may be a linear, branched or cyclic alkyl group, An alkoxy group, an oxo group, an amino group, an alkylamino group and the like. Specific examples of the linear, branched or cyclic alkyl group include the same groups as R ^L01 and R ^L02, and examples of the substituted alkyl group include the following groups.

(Wherein the broken line represents the combined hands)

R ^L01 and R ^L02 , R ^L01 and R ^L03 , and R ^L02 and R ^L03 may form a ring together with a carbon atom or an oxygen atom to which they are bonded and form a ring, R ^L01 and R ^L02 , R ^L01 and R ^L03, or R ^L02 and R ^L03 each represent a straight chain or branched alkylene group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms.

R ^L04 , R ^L05 and R ^L06 each independently represent a straight, branched or cyclic alkyl group of 1 to 15 carbon atoms. Specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, An adamantyl group, a 2-adamantyl group, and the like.

R ^L07 represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms which may be substituted, or an aryl group which may be substituted and has 6 to 20 carbon atoms. The alkyl group which may be substituted is specifically exemplified by methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, Branched or cyclic alkyl groups such as cyclopentyl, cyclohexyl and bicyclo [2.2.1] heptyl groups, and some of these hydrogen atoms may be replaced by hydroxyl, alkoxy, carboxyl, alkoxycarbonyl, oxo, , An alkylamino group, a cyano group, a mercapto group, an alkylthio group, a sulfo group, or a group in which a part of these methylene groups are substituted with an oxygen atom or a sulfur atom. Examples of the aryl group which may be substituted include a phenyl group, a methylphenyl group, a naphthyl group, an anthryl group, a phenanthryl group and a pyrenyl group. In formula (L3), m is 0 or 1, n is 0, 1, 2 or 3, and 2m + n = 2 or 3.

R ^L08 represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms which may be substituted, or an aryl group which may be substituted and has 6 to 20 carbon atoms. Specifically, the same as R ^L07 can be exemplified. Each of R ^L09 to R ^L18 independently represents a hydrogen atom or a monovalent hydrocarbon group of 1 to 15 carbon atoms. Specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, A straight chain, branched or cyclic alkyl group such as a nonyl group, an n-decyl group, a cyclopentyl group, a cyclohexyl group, a cyclopentylmethyl group, a cyclopentylethyl group, a cyclopentylbutyl group, a cyclohexylmethyl group, a cyclohexylethyl group, A cyclic alkyl group and those in which some of the hydrogen atoms are substituted with a hydroxyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, an oxo group, an amino group, an alkylamino group, a cyano group, a mercapto group, an alkylthio group, a sulfo group, have. R ^L09 and R ^L10, R ^L09 and R ^L11, R ^L09 and R ^L12, R ^L10 and R ^L12, R ^L11 and R ^L12, R ^L13 and R ^L14, R ^L15 and R ^L16, or R ^L16 and R ^L17 are each combined may be to form a ring, in which case R ^L09 and R ^L10, R ^L09 and R ^L11, R ^L09 and R ^L12, R ^L10 and R ^L12, R ^L11 and R ^L12, R ^L13 which is involved in the ring formation and R ^L14 , R ^L15 and R ^L16, or R ^L16 and R ^L17 are each a divalent hydrocarbon group of 1 to 15 carbon atoms, and specifically exemplified by excluding one hydrogen atom from those exemplified above for the monovalent hydrocarbon group can do. R ^L09 and R ^L11 , R ^L11 and R ^L17, or R ^L15 and R ^L17 may combine with each other to form a double bond by bonding to adjacent carbon atoms.

R ^L19 represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms which may be substituted, or an aryl group which may be substituted and may have 6 to 20 carbon atoms, and specific examples thereof include the same ones as R ^L07 have.

R ^L20 represents a linear, branched or cyclic alkyl group of 1 to 10 carbon atoms which may be substituted, or an aryl group which may be substituted, which may have a carbon number of 6 to 20, and specific examples thereof include the same groups as R ^L07 have.

X represents a divalent group forming a substituted or unsubstituted cyclopentane ring, cyclohexane ring or norbornane ring which may contain a double bond together with the carbon atom to which it is bonded. R ^L21 and R ^L22 each independently represent a hydrogen atom or a straight, branched or cyclic monovalent hydrocarbon group of 1 to 10 carbon atoms. R ^L21 and R ^L22 may bond to each other to form a ring together with the carbon atom to which they are bonded to form a substituted or unsubstituted cyclopentane ring or a divalent group forming a cyclohexane ring. p represents 1 or 2;

R ^L23 represents a linear, branched or cyclic alkyl group of 1 to 10 carbon atoms which may be substituted, or an aryl group which may be substituted, which may have a carbon number of 6 to 20, and specific examples thereof include the same groups as R ^L07 have.

Y represents a divalent group forming a substituted or unsubstituted cyclopentane ring, cyclohexane ring or norbornane ring together with the carbon atom to which it is bonded. R ^L24 and R ^L25 each independently represent a hydrogen atom or a straight, branched or cyclic monovalent hydrocarbon group of 1 to 10 carbon atoms. R ^L24 and R ^L25 may bond together with the carbon atom to which they are bonded to form a ring, and in this case represents a divalent group forming a substituted or unsubstituted cyclopentane ring or cyclohexane ring. q represents 1 or 2;

R ^L26 represents a linear, branched or cyclic alkyl group of 1 to 10 carbon atoms which may be substituted, or an aryl group which may be substituted, which may have a carbon number of 6 to 20, and specific examples thereof include the same groups as R ^L07 have.

Z represents a divalent group forming a substituted or unsubstituted cyclopentane ring, cyclohexane ring or norbornane ring together with the carbon atom to which it is bonded. R ^L27 and R ^L28 each independently represent a hydrogen atom or a straight, branched or cyclic monovalent hydrocarbon group of 1 to 10 carbon atoms. R ^L27 and R ^L28 may form a ring together with the carbon atom to which they are bonded to form a ring, and in this case represents a divalent group forming a substituted or unsubstituted cyclopentane ring or cyclohexane ring.

Of the acid labile groups represented by the above formula (L1), specific examples of the straight chain or branched groups include the following groups.

(Wherein the broken line represents the combined hands)

Among the acid labile groups represented by the formula (L1), cyclic groups specifically include tetrahydrofuran-2-yl group, 2-methyltetrahydrofuran-2-yl group, tetrahydropyran- 2-yl group and the like.

Examples of the acid labile groups represented by the formula (L2) include tert-butyl group, tert-amyl group, and the following groups.

(Wherein the broken line represents the combined hands)

Examples of the acid labile groups of the above formula (L3) include 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-n-propylcyclopentyl group, 1-isopropylcyclopentyl group, Cyclopentyl group, 1- (4-methoxy-n-butyl) cyclopentyl group, 1- (bicyclo [2.2.1] 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 3-methyl-1-cyclohexylcyclohexyl group, Ethyl-1-cyclopentene-3-yl group, 3-methyl-1-cyclohexene-3-yl group and 3-ethyl- .

As the acid labile group of the above formula (L4), groups represented by the following formulas (L4-1) to (L4-4) are particularly preferable.

In the formulas (L4-1) to (L4-4), the broken line indicates the bonding position and bonding direction. R ^L41 each independently represents a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms which may be substituted, or an aryl group which may be substituted with a carbon atom having 6 to 20 carbon atoms, and specific examples thereof include a methyl group, Butyl group, tert-butyl group, tert-amyl group, n-pentyl group, n-hexyl group, cyclopentyl group, cyclohexyl group and the like.

In the above formulas (L4-1) to (L4-4), an enantiomer or a diastereomer may be present, but the above formulas (L4-1) to (L4-4) All of the isomers are represented. These stereoisomers may be used alone or as a mixture.

For example, the formula (L4-3) is represented as a mixture of one kind or two kinds selected from the groups represented by the following formulas (L4-3-1) and (L4-3-2).

( ^Wherein R ^L41 is as defined above)

The above formula (L4-4) is to represent one or more mixtures selected from the groups represented by the following formulas (L4-4-1) to (L4-4-4).

( ^Wherein R ^L41 is as defined above)

The above formulas (L4-3-1), (L4-3-2) and (L4-4-1) to (L4-4-4) are also representative of a mixture of enantiomers and enantiomers .

Further, the bonding direction of the compounds represented by the formulas (L4-1) to (L4-4), (L4-3-1), (L4-3-2) and (L4-4-1) to Is exo-side with respect to the bicyclo [2.2.1] heptane ring, high reactivity in the acid catalytic elimination reaction is realized (see Japanese Patent Application Laid-Open No. 2000-336121). In the production of a monomer having a tertiary exo-alkyl group having a bicyclo [2.2.1] heptane skeleton as a substituent, an endo-alkyl group represented by the following formulas (L4-1-endo) to (L4-4-endo) . However, in order to realize good reactivity, it is preferable that the exo ratio is 50% or more, and the exo ratio is more preferably 80% or more.

( ^Wherein R ^L41 is as defined above)

Specific examples of the acid labile group of the above formula (L4) include the following groups.

(Wherein the broken line represents the combined hands)

Specific examples of the acid labile group of the above formula (L5) include the following groups.

(Wherein the broken line represents the combined hands)

Specific examples of the acid labile group of the above formula (L6) include the following groups.

(Wherein the broken line represents the combined hands)

Specific examples of the acid labile group of the above formula (L7) include the following groups.

(Wherein the broken line represents the combined hands)

Specific examples of the acid labile group of the above formula (L8) include the following groups.

(Wherein the broken line represents the combined hands)

Specific examples of the repeating unit represented by the above formula (2A) include, but are not limited to, the following.

When the repeating unit represented by the above formula (1) of the present invention coexists with the repeating unit represented by the above formula (2A), the function of controlling the movement and diffusion of the acid by the selection of the stable acid stable unit, It is also possible to function as a generating unit.

In the polymer compound of the present invention, the repeating units represented by the following formulas (2B) to (2E) may coexist in addition to the repeating units represented by the above formulas (1) and (2A).

(Wherein, R ¹ is as defined above and, XB, XC are each independently a single bond or a divalent hydrocarbon group of a linear or branched chain having 1 to 4, YA represents a substituent group having a lactone structure, ZA A fluoroalkyl group having 1 to 15 carbon atoms which may have an oxygen atom or a fluoroalkyl group containing 1 to 15 carbon atoms, k ^1A represents an integer of 1 to 3, R ⁵ , R ⁶ and R ⁷ each independently represents a substituted or unsubstituted, linear or branched alkyl group, alkenyl group or oxoalkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group, aralkyl group or aryloxoalkyl group having 6 to 18 carbon atoms Or two or more of R ⁵ , R ⁶ and R ⁷ may be bonded to each other to form a ring with the sulfur atom in the formula)

Specific examples of the repeating unit represented by the formula (2B) include the following.

Specific examples of the repeating unit represented by the formula (2C) include the following.

Specific examples of the repeating unit represented by the formula (2D) include the following.

Specific examples of the repeating unit represented by the formula (2E) include the following.

(Wherein R < ^{1 >} is as defined above)

In addition to the repeating unit (1) of the present invention, a macromolecular compound in which a stable acid labile unit represented by the formula (2A) and a repeating unit represented by the formulas (2B) to (2E) It is possible to obtain a chemically amplified resist material which is high in resolution and resistant to pattern collapse.

In the synthesis of the polymer compound of the present invention, radical polymerization using an initiator such as 2,2'-azobisisobutyronitrile (abbreviated as AIBN), ion polymerization (anion polymerization) using an alkyllithium or the like Can be used, and these polymerization can be carried out in accordance with the usual method thereof. Among them, the synthesis of the polymer compound of the present invention is preferably carried out by radical polymerization. In this case, polymerization conditions are governed by the type and amount of the initiator, temperature, pressure, concentration, solvent, additives and the like.

The radical polymerization initiator is not particularly limited and examples thereof include AIBN, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl Azo compounds such as 2,2'-azobis (2,4,4-trimethylpentane) and 2,2'-azobis (isobutyric acid) dimethyl, A peroxide compound such as benzoyl peroxide, roile peroxide, benzoyl peroxide and tert-butyl peroxylaurate, a water-soluble polymerization initiator such as potassium persulfate, and a combination of a peroxide such as potassium persulfate or hydrogen peroxide and a reducing agent such as sodium sulfite Redox-based initiators and the like. The amount of the polymerization initiator to be used may be appropriately changed depending on the kind, polymerization conditions and the like, but is usually from 0.001 to 10 mol%, particularly 0.01 to 6 mol%, based on the total amount of the monomers to be polymerized.

In the synthesis of the polymer compound of the present invention, a known chain transfer agent such as dodecylmercaptan or 2-mercaptoethanol may be used in combination for adjusting the molecular weight. In this case, the addition amount of these chain transfer agents is preferably 0.01 to 10 mol% based on the total number of moles of the monomers to be polymerized.

When the polymer compound of the present invention is synthesized, the polymerizable monomer corresponding to the repeating unit represented by the formula (1), (2A) to (2E) is mixed and the initiator and the chain transfer agent are added to perform polymerization.

Here, with respect to the repeating units (1) and (2A) to (2E) in the polymer compound of the present invention,

The total number of moles of the monomer corresponding to the unit of the formula (1)

U1 + U2 + U3 + U4 + U5 + U6 = 1 (100 mol%), where U1, U3, U4, U5 and U6 are the total molar numbers of the monomers corresponding to the units of formulas (2A) to In one case, the introduction ratio of each repeating unit is

0 &lt; U1 < 1, 0 < U2 0.9, 0 U3 0.3, 0 U4 0.7, 0 U5 0.3, 0 U6 0.15, 0 U2 + U3 + U4 + U5 + .

When polymerization is carried out, a solvent may be used if necessary. As the polymerization solvent, it is preferable that the polymerization reaction is not inhibited. Representative examples include esters such as ethyl acetate, n-butyl acetate and? -Butyrolactone, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, Aliphatic or aromatic hydrocarbons such as toluene, xylene, and cyclohexane; alcohols such as isopropyl alcohol and ethylene glycol monomethyl ether; ether solvents such as diethyl ether, dioxane and tetrahydrofuran; These solvents may be used alone or in admixture of two or more. The amount of the polymerization solvent to be used can be appropriately changed according to the polymerization conditions such as the target degree of polymerization (molecular weight), the amount of the initiator added, and the polymerization temperature, and usually 0.1 to 95% Lt; / RTI &gt;

The reaction temperature for the polymerization reaction is appropriately changed depending on the kind of the polymerization initiator or the boiling point of the solvent, but is usually preferably 20 to 200 占 폚, particularly preferably 50 to 140 占 폚. The reaction vessel used in such a polymerization reaction is not particularly limited.

As a method for removing the organic solvent or water as a medium from the solution or dispersion of the polymer thus obtained, any known method can be used. For example, there is a method such as re-precipitation filtration or heating and flow-out under reduced pressure.

The present invention provides a chemically amplified resist material comprising (A) the polymer compound of the present invention, (B) an organic solvent, (C) a photoacid generator, and (D) a basic compound.

The organic solvent (B) used in the present invention is described in detail in Japanese Patent Application Laid-Open No. 2009-269953. Among the organic solvents (B), those having the best solubility of the acid generator in the resist component such as diethylene glycol dimethyl ether, 1-ethoxy-2-propanol, propylene glycol monomethyl ether acetate, cyclohexanone, 4-butyrolactone, A mixed solvent is preferably used.

The amount of the organic solvent to be used is preferably 200 to 5,000 parts by mass, particularly 400 to 3,000 parts by mass based on 100 parts by mass of the base resin.

(C) photoacid generator) that generates an acid by exposure to a high-energy beam for functioning as a chemically amplified resist material. As the component (C) of the photoacid generator, any compound capable of generating an acid by irradiation with high energy radiation may be used. As the preferable photoacid generator, a sulfonium salt, an iodonium salt, a sulfonyldiazomethane, Amide, oxime-O-sulfonate type acid generator, and specific examples thereof are described in paragraphs (0108) to (0116) of Japanese Patent Application Laid-Open No. 2010-002599.

 As the photoacid generator, those represented by the following formula (C) -1 are preferably used.

(Wherein R ⁴⁰⁵ , R ⁴⁰⁶ and R ⁴⁰⁷ each independently represents a hydrogen atom or a straight, branched or cyclic monovalent hydrocarbon group of 1 to 20 carbon atoms which may contain a hetero atom, particularly an alkyl group or an alkoxy group And R ⁴⁰⁸ represents a straight, branched or cyclic monovalent hydrocarbon group of 7 to 30 carbon atoms which may contain a hetero atom)

The amount of the photoacid generator to be added to the chemically amplified resist composition of the present invention may be any amount as long as it does not hinder the effects of the present invention. The amount of the photoacid generator may be 0 to 40 parts by mass, Particularly 0.1 to 40 parts by mass, more preferably 0.1 to 20 parts by mass. When the ratio of the photoacid generator is within this range, it is preferable because deterioration of resolution and problems of foreign matter at development / resist peeling do not occur. The photoacid generators may be used alone or in combination of two or more. Further, it is also possible to control the transmittance of the resist film with the addition amount of the photoacid generator having a low transmittance at the exposure wavelength.

Further, (D) a basic compound may be added to the chemically amplified resist material of the present invention. Examples of such basic compounds (D) include primary, secondary and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen- Nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, carbamates, ammonium salts and the like, and specific examples thereof are described in Japanese Patent Application Laid-Open No. 2009-269953 have.

In this case, the basic compound may be used singly or in combination of two or more. The amount of the basic compound may be any amount as long as it does not hinder the effect of the repeating unit represented by the formula (1) 0.001 to 12 parts by mass, particularly preferably 0.01 to 8 parts by mass, based on 100 parts by mass of the resin is preferable.

The chemical amplification resist material of the present invention may further contain at least one of an organic acid derivative and / or a fluorine-substituted alcohol, a dissolution inhibitor having a weight average molecular weight of 3,000 or less, and a surfactant.

Addition of an organic acid derivative and / or a fluorine-substituted alcohol and a compound having a weight average molecular weight of 3,000 or less (dissolution inhibitor) is optional, but the compounds described in JP-A-2009-269953 can be referred to.

As the surfactant, reference may be made to the component (E) defined in Japanese Patent Application Laid-Open No. 2009-269953. Further, Japanese Patent Application Laid-Open Nos. 2008-122932, 2010-134012, 2010-107695, 2009-276363, 2009-192784, 2009- 191151 and JP-A-2009-98638, and conventional surfactants and alkali-soluble surfactants can be used.

The amount of the surfactant to be added is in the range of 0.001 to 20 parts by mass, preferably 0.01 to 10 parts by mass based on 100 parts by mass of the base resin of the resist material. These are detailed in Japanese Patent Application Laid-Open No. 2007-297590.

Next, the present invention is characterized by including a step of applying the above-described chemically amplified resist material onto a substrate, a step of exposing the substrate to a high energy beam through a photomask after the heat treatment, and a step of developing by using a developer The method comprising the steps of:

The present invention also provides a method of manufacturing a semiconductor device, comprising the steps of: applying the chemical amplification resist material described above onto a substrate; applying a protective film insoluble in water after heat treatment and soluble in an alkali developing solution; A step of exposing the resist film to a high energy beam through a photomask, and a step of developing using a developer.

More specifically, in order to form a pattern using the resist composition of the invention can be performed by employing the well-known lithography technology, for example, an integrated circuit substrate for producing (Si, SiO _2, SiN, SiON, TiN, WSi, (Cr, CrO, CrON, MoSi, or the like) for mask circuit fabrication to a thickness of 0.05 to 2.0 mu m by a method such as spin coating, To 150 ° C for 1 to 10 minutes, preferably 80 to 140 ° C for 1 to 5 minutes. Then plug the mask for forming a pattern for the purpose on the resist film, a far ultraviolet ray, excimer laser, X-rays, the exposure dose for high-energy radiation such as electron beam 1 to 200 mJ / cm ^2, preferably 10 to 100 mJ / cm &lt; ² &gt;. Alternatively, the electron beam is directly drawn without passing through a mask for pattern formation. Subsequently, the substrate is exposed on a hot plate at 60 to 150 ° C for 1 to 5 minutes, preferably at 80 to 140 ° C for 1 to 3 minutes, and then subjected to post burying (PEB). In addition, immersion (0.1 to 5 mass%, preferably 2 to 3 mass%) of a developer of an aqueous alkaline solution such as tetramethylammonium hydroxide (TMAH) for 0.1 to 3 minutes, preferably 0.5 to 2 minutes dip method, a puddle method, a spray method, or the like, and a desired pattern is formed on the substrate.

The unexposed portions are dissolved by an ordinary method such as a dip method, a puddle method or a spray method for 0.1 to 3 minutes, preferably 0.5 to 2 minutes by using a developing solution of an organic solvent. It is also possible to form a negative pattern. As the developing solution at this time, it is preferable to use at least one developer selected from the group consisting of 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutylketone, methylcyclohexanone, Acetophenone, methyl acetophenone ketone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butenyl acetate, acetic acid isoamyl, phenyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, But are not limited to, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl ethyl ketone, methyl ethyl ketone, methyl ethyl ketone, methyl ethyl ketone, methyl ethyl ketone, Aromatic esters of benzyl propionate, ethyl phenylacetate and 2-phenylethyl acetate can be preferably used.

Further, the resist material of the present invention can reduce the pattern size after development by various contraction methods. For example, the hole size can be reduced by known methods such as thermal flow, RELACS, SAFIRE, and WASOOM. In particular, when a hydrogenated ROMP polymer (cycloolefin ring-opening metathesis polymer hydrogenation product) having a low polymer Tg or the like is blended, the hole size can be effectively reduced by the thermal flow.

Further, the chemically amplified resist material of the present invention is most suitable for fine patterning by ultraviolet or excimer laser, X-ray, and electron beam of 250 to 190 nm in particular in a high energy beam. Within the above range, a desired pattern can be obtained, which is preferable.

In addition to the usual exposure method, the immersion method may also be used for the exposure. In the immersion lithography, an immersion medium (preferably water) is inserted between the resist film after the pre-baking and the projection lens (between the substrate and the projection lens) to expose it. In ArF immersion lithography, pure water is mainly used as the immersion medium. Combining with a projection lens with an NA of 1.0 or greater is an important technology for sustaining ArF lithography beyond the 65 nm node and is being accelerated in development. In this case, it is also possible to use a water-insoluble protective film.

The above-mentioned water-insoluble protective film is used for preventing elution from the resist film and for increasing the surface activity of the film surface. One type is an organic solvent type in which an organic solvent that does not dissolve the resist film does not dissolve before the alkali development, and the other type is soluble in an alkali developing solution. The alkali soluble type is used to remove the resist film soluble portion and remove the protective film.

The latter is based on a polymer compound having a 1,1,1,3,3,3-hexafluoro-2-propanol residue which is insoluble in water and soluble in an alkaline developing solution, and contains an alcoholic solvent having 4 or more carbon atoms, To (12), and a mixed solvent thereof.

A surfactant which is insoluble in water and soluble in an alkali developing solution may be prepared by dissolving the surfactant in an alcoholic solvent having 4 or more carbon atoms, an ether solvent having 8 to 12 carbon atoms, or a mixed solvent thereof.

As a means of the pattern formation method, pure rinse (post-soak) may be performed after formation of the photoresist film to extract the acid generator or the like from the surface of the film or to remove the particles from the film surface. Alternatively, (Post-soak) may be performed.

[Example]

Hereinafter, the present invention will be described in detail by way of Synthesis Examples, Comparative Synthesis Examples, Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following examples, Me represents a methyl group.

(Synthesis Example 1) Synthesis of Polymer-1

In a nitrogen flask, 4.94 g of triphenylsulfonium = 2- (6-methacryloyloxy-2-oxohexahydro-3,5-methano-2H-cyclopenta [b] 19.0 g of methacrylic acid = 1-isopropylcyclopentyl, 6.61 g of methacrylic acid = 2-oxotetrahydrofuran-3-yl, 12.09 g of methacrylic acid = 5-oxo 4 , 8-dioxa-tricyclo [4.2.1.0 ^3,7] non-2-yl, 2.20 g of V-601 (Wako Pure yakku, Ltd.), 2-mercaptoethanol GBL (gamma -butyrolactone of 0.45 g to 68 g Lactone) to prepare a monomer-polymerization initiator solution. 24 g of GBL was taken in a separate flask in a nitrogen atmosphere and heated to 80 DEG C with stirring, and then the monomer solution was added dropwise over 4 hours. After completion of the dropwise addition, stirring was continued for 2 hours while maintaining the temperature of the polymerization solution at 80 占 폚, followed by cooling to room temperature. The obtained polymerization solution was added dropwise to 640 g of a water-methanol solution (weight ratio 3: 7) which was stirred vigorously, and the precipitated copolymer was filtered off. The copolymer was washed twice with 240 g of a water-methanol solution (weight ratio 3: 7), and then vacuum-dried at 50 ° C for 20 hours to obtain 30.3 g of a white powdery copolymer. The copolymer was analyzed by &lt; ¹³ &gt; C-NMR, and the copolymerization ratio was 2/50/20/28 mol% in that order.

(Synthesis Examples 2 to 7, Comparative Synthesis Examples 1 to 4) Polymer-2 to polymer-7, Synthesis of Polymers A to D

The polymeric compound shown below was prepared by the same procedure as in Synthesis Example 1 except that the kind of each monomer and the blending ratio were changed.

Preparation of chemically amplified resist materials (Examples 1-1 to 1-7, Comparative Examples 1-1 to 1-4)

The polymer compound shown in the above Synthesis Example was used and 0.01 mass% of the following surfactant A (manufactured by Omnova) was added to the composition shown in Table 1 below, with the following photoacid generator, quencher, and alkali-soluble surfactant (SF-1) , And the resist material was filtered through a filter made of Teflon (registered trademark) of 0.2 占 퐉 to prepare resist solutions (R-01 to R11), respectively.

In Table 1, the photoacid generator, the quencher, the solvent, and the alkali-soluble surfactant (SF-1) used as a resist material together with the polymer compound shown in the above Synthesis Example are as follows.

P-1 to P-7: The polymer-1 to polymer-7

P-A to P-D: Polymer-A to Polymer-D

PAG-1: 4-t-butylphenyldiphenylsulfonium = 2- (adamantane-1-carbonyloxy) -1,1,3,3,3-pentafluoropropane-1-sulfonate

PAG-2: N-nonafluorobutane sulfonyloxy-1,8-naphthalene dicarboxyimide

Q-1: 1-Benzyloxycarbonyl-2-phenylbenzimidazole

Q-2: Triphenylsulfonium = 10-camphorsulfonate

PGMEA: Propylene glycol monomethyl ether acetate

GBL:? -Butyrolactone

Alkali-soluble Surfactant (SF-1): The compound represented by the following formula (the compound described in JP-A-2008-122932)

Surfactant A:

(2,2,2-trifluoroethoxymethyl) oxetane, tetrahydrofuran, 2,2-dimethyl-1,3-propanediol copolymer (Omnova) )

ArF  Exposure Patterning  evaluation( Example  2-1 to Example  2-7, Comparative Example  2-1 to Comparative Example  2-4)

(100 nm film thickness) substrate prepared by applying an antireflection film solution (ARC-29A, manufactured by Nissan Chemical Industries, Ltd.) on a silicon substrate and baking at 200 캜 for 60 seconds, And baked at 100 DEG C for 60 seconds using a hot plate to prepare a resist film having a thickness of 120 nm. This was subjected to liquid immersion exposure using an ArF excimer laser scanner (NSR-S610C, NA = 1.30, dipole, Cr mask manufactured by Nikon Corporation) and baked at 80 占 폚 for 60 seconds to give 2.38% And development was carried out with an aqueous solution of methylammonium hydroxide for 60 seconds.

In the evaluation of the resist shape, the exposure amount for resolving the line-and-space of 40 nm group at 1: 1 was defined as the optimum exposure amount (Eop, mJ / cm ² ). The pattern shape and roughness (LWR) at the optimum exposure amount were observed and evaluated by an electron microscope.

Evaluation criteria of the pattern shape were as follows.

Rectangle: The line side wall is vertical, and the dimensional change from the bottom (near the substrate) to the top is small and good.

Taper: A shape whose line dimension decreases from the bottom to the top.

The elution amount of the resist component into the immersion water was evaluated by first placing a Teflon (registered trademark) ring having an inner diameter of 10 cm with an inner diameter of 10 cm on the wafer on which a resist film was formed by the above method, carefully pouring 10 ml of pure water into it, The resist film and pure water were brought into contact with each other for 60 seconds. Thereafter, pure water was recovered, and the concentration of anion component (mol / cm ² 초) of the sulfonium salt in purified water was measured by an LC-MS analyzer (Agilent Technologies, Ltd.).

The adhesion of the resist pattern to the substrate was observed with an electron microscope to observe the presence or absence of peeling defects.

The evaluation results of the respective resist materials are shown in Table 2.

From the results shown in Table 2, it can be seen that when a polymer compound having a sulfonium salt of a specific structure of the present invention is used as a base resin for a resist material, the pattern is excellent in rectangularity, the anion component of the sulfonium salt is low in elution, Was small, and the adhesion of the pattern to the substrate was good. In view of the above, the resist material of the present invention is preferable as an immersion lithography material.

The present invention is not limited to the above embodiments. The above-described embodiments are illustrative and any of those having substantially the same constitution as the technical idea described in the claims of the present invention and exhibiting the same operational effects are included in the technical scope of the present invention.

Claims (5)

A polymer compound containing a repeating unit represented by the following formula (1).
&Lt; Formula 1 >

(Wherein R ¹ represents any ^one of a hydrogen atom, a fluorine atom, a methyl group and a trifluoromethyl group, R ² , R ³ and R ⁴ each independently represents a substituted or unsubstituted, straight, Represents a substituted or unsubstituted aryl group, an aralkyl group and an aryloxoalkyl group having 6 to 18 carbon atoms, or R ² , R ³ and R ^{4 each} independently represent a hydrogen atom, an alkyl group, an alkoxy group, R ⁴ may combine with each other to form a ring with the sulfur atom in the formula, X ¹ represents O or CH ₂ , A ¹ represents a straight, branched or cyclic B ¹ represents an alkylene group having from 1 to 10 carbon atoms or an arylene group having from 6 to 18 carbon atoms which may contain a hetero atom other than fluorine and k ¹ represents an integer of 0 or 1) The polymer compound according to claim 1, which further comprises a repeating unit having an acid labile group in addition to the repeating unit represented by the formula (1). (A) a polymeric compound according to any one of claims 1 and 2, (B) an organic solvent, (C) a photoacid generator, and (D) a basic compound. A step of applying the chemically amplified resist material according to claim 3 onto a substrate, a step of exposing the substrate to a high energy beam through a photomask after the heat treatment, and a step of developing using a developing solution Way. A step of applying a chemical amplification resist material according to claim 3 on a substrate; a step of applying a protective film which is insoluble in water after heat treatment and usable in an alkali developing solution; and water is inserted between the substrate and the projection lens, A step of exposing the resist film to a high energy beam through a resist film; and a step of developing the resist film with a developer.