JP2003186196A - Radiation-sensitive resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition having a high resolution and a high radiation transmittance as a chemically amplified resist sensitive to an actinic radiation such as KrF excimer laser, ArF excimer laser, F<SB>2</SB>excimer laser or far UV typified by EUV (extreme-ultraviolet radiation). <P>SOLUTION: The radiation-sensitive resin composition is characterized in containing (A) a polymer component comprising a repeating unit derived from a tetrahydrofuranyl-containing (meth)acrylate, a repeating unit derived from a hydroxystyrene or the like and a repeating unit containing an acid-dissociable group and (B) a radiation-sensitive acid generator. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to ultraviolet rays such as g rays and i rays, (extreme) far ultraviolet rays such as KrF excimer laser, ArF excimer laser, F2 excimer laser, and EUV, X-rays such as synchrotron radiation, and electrons. The present invention relates to a radiation-sensitive resin composition used as a chemically amplified resist suitable for microfabrication by various kinds of radiation such as charged particles such as rays.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit devices, a photolithography technique capable of microfabrication at a level of 0.20 .mu.m or less is recently required in order to obtain a higher degree of integration. It is said that. However, in the conventional photolithography process, near-ultraviolet rays such as i-rays are generally used as radiation, and it is said that the near-ultraviolet rays are extremely difficult to perform microfabrication at the subquarter micron level. Therefore,
Utilization of shorter wavelength radiation has been studied to enable fine processing at a level of 0.20 μm or less. Examples of such short-wavelength radiation include far-ultraviolet rays such as an emission line spectrum of a mercury lamp and an excimer laser,
Examples thereof include X-rays and electron beams. Of these, KrF excimer laser (wavelength 248 nm), A
rF excimer laser (wavelength 193 nm) or F ₂
Excimer laser (wavelength 157 nm), EUV (wavelength 1
Extreme ultraviolet rays such as 3 nm) are attracting attention. As the radiation-sensitive resin composition suitable for the radiation of the short wavelength, a component having an acid dissociative functional group and a radiation-sensitive acid generator that generates an acid by irradiation with radiation (hereinafter, referred to as “exposure”) A number of compositions utilizing the chemical amplification effect between the two (hereinafter referred to as "chemical amplification type radiation-sensitive composition") have been proposed. Examples of the chemically amplified radiation-sensitive composition include a resin having a t-butyl ester group of a carboxylic acid or a t-butyl carbonate group of a phenol and a radiation-sensitive acid generator as disclosed in JP-B-2-27660. A composition containing is proposed. In this composition, the t-butyl ester group or t-butyl carbonate group present in the resin is dissociated by the action of the acid generated by the exposure, and the resin contains an acidic group consisting of a carboxyl group or a phenolic hydroxyl group. It is formed by utilizing the phenomenon that the exposed region of the resist film becomes easily soluble in an alkali developing solution as a result.

By the way, in recent years, the photolithography process has been rapidly miniaturized, and particularly in the KrF photolithography process, the demand for the critical resolution has reached half or less of the light source wavelength. Therefore, the demands on the characteristics required for photoresists are becoming more and more strict, and in particular, there is an urgent need to improve resolution performance (resolution, exposure margin, etc.), radiation transmittance, and dry etching resistance. . The chemically amplified resist becomes easily soluble in an alkali developing solution because the protective group in the resin is dissociated by the action of the acid generated by exposure to generate an acidic group such as a carboxyl group or a phenolic hydroxyl group. However, on the boundary between the exposed area and the unexposed area, the dissociation of the protective group is incomplete, and the difference in solubility between the exposed area and the unexposed area in the alkaline developer tends to be small, and thus the resolution is high. Performance (resolution, exposure margin, etc.) is reduced. Therefore, by cutting a hydrophilic monomer having a high radiation transmittance such as tetrahydrofurfuryl (meth) acrylate into the resin, it is possible to improve the solubility of the exposed area by making the resin have an appropriate hydrophilicity, and Image performance can be improved.

[0004]

The object of the present invention is to provide a chemical amplification type resist sensitive to actinic radiation, for example, KrF excimer laser, ArF excimer laser, F ₂ excimer laser or EUV, which is a chemical amplification type resist. It is intended to provide a radiation-sensitive resin composition having high resolution and high radiation transmittance.

[0005]

Means for Solving the Problems The present invention provides, as means for solving the above problems, (A) a repeating unit represented by the following general formula (1), a repeating unit represented by the general formula (2) and the following: Provided is a radiation-sensitive resin composition comprising a polymer component containing a repeating unit represented by the general formula (3) and (B) a radiation-sensitive acid generator.

[0006]

[Chemical 4]

[In the general formula (1), R ₁ represents a hydrogen atom or a methyl group. L is an integer of 0 to 4. ]

[0008]

[Chemical 5]

[In the general formula (2), R ₂ represents a hydrogen atom or a methyl group, and R ₃ represents a monovalent organic group. Further, n is an integer of 1 to 3 and m is an integer of 0 to 3. ]

[0010]

[Chemical 6]

[In the general formula (3), R ₄ represents a hydrogen atom or a methyl group, R ₆ represents a monovalent organic group,
₇ and R ₈ independently represent a monovalent acid-dissociable group.
Further, q is an integer of 1 to 3, and p is an integer of 0 to 3. ]

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to embodiments. — (A) Polymer Component— The polymer component used as the component (A) (hereinafter, referred to as “polymer component (A)”) is a repeating unit represented by the above general formula (1) (hereinafter, “polymer component (A)”). Repeating unit (1) ")
And a repeating unit represented by the general formula (2) (hereinafter referred to as “repeating unit (2)”) and a repeating unit represented by the general formula (3) (hereinafter referred to as “repeating unit (3)”) And must be included. However, the content of these repeating units is not particularly limited, and a mixture of three homopolymers of each of these three repeating units, a copolymer containing three repeating units, and different among these three repeating units. Examples thereof include a mixture of two or more kinds of copolymers containing two kinds of repeating units, and an arbitrary copolymer of these homopolymers and copolymers. That is, as an example of the polymer component (A), Example 1) A form in which the polymer component (A) contains a copolymer having a repeating unit (1), a repeating unit (2) and a repeating unit (3). Example 2) A mixture of two or more kinds of polymers different from each other, containing one or two kinds of repeating units selected from the repeating unit (1), the repeating unit (2) and the repeating unit (3), The repeating units (1) to (3) are each a structural unit of at least one polymer; and the like. Among these, those containing a copolymer containing the above-mentioned three kinds of repeating units are preferable. As a typical example of Example 2, a copolymer having (a1) repeating unit (1) and repeating unit (2) and a copolymer having (a2) repeating unit (2) and repeating unit (3) And a polymer mixture containing and.

The polymer component (A) in the present invention has a repeating unit (1) having a high radiation transmittance and a hydrophilic property, and at the same time, a repeating unit (A) having an acid dissociable protective group having a high dry etching resistance ( 3). Therefore, high resolution, high transparency, and dry etching resistance can be achieved at the same time.

In the general formula (2), 1 represented by R ₃
As the valent organic group, for example, a methyl group, an ethyl group, n
-C1-12 linear or branched alkyl group such as -propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group; methoxy Group, ethoxy group, n-propoxy group,
Examples thereof include linear or branched alkoxyl groups having 1 to 12 carbon atoms such as i-propoxy group, n-butoxy group, 2-methylpropoxy group, 1-methylpropoxy group and t-butoxy group. As the monovalent organic group represented by R ₆ in the general formula (3), those exemplified for the above R ₃ can be exemplified. In any case, a methyl group, an ethyl group, an n-butyl group and a t-butyl group are preferable. In the general formula (3), R ₇ and R ₈ are acid dissociable groups, and specifically, substituted methyl group, 1-substituted ethyl group, 1-branched alkyl group, triorganosilyl group, triorganogermyl group. , An alkoxycarbonyl group, an acyl group or a cyclic acid-dissociable group. R ₇ and R ₈ are independent of each other, and when plural R ₇ are present,
They may be the same or different.

Examples of the substituted methyl group include methoxymethyl group, methylthiomethyl group, ethoxymethyl group, ethylthiomethyl group, methoxyethoxymethyl group,
Benzyloxymethyl group, benzylthiomethyl group, phenacyl group, bromophenacyl group, methoxyphenacyl group, methylthiophenacyl group, α-methylphenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, Bromobenzyl group,
Nitrobenzyl group, methoxybenzyl group, methylthiobenzyl group, ethoxybenzyl group, ethylthiobenzyl group, piperonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, n-propoxycarbonylmethyl group, i-propoxycarbonylmethyl group, n- Examples thereof include butoxycarbonylmethyl group, t-butoxycarbonylmethyl group, adamantylmethyl group and the like.

As the 1-substituted ethyl group, for example, 1-methoxyethyl group, 1-methylthioethyl group, 1,1-dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, 1 , 1-diethoxyethyl group, 1-ethoxypropyl group, 1-propoxyethyl group, 1-cyclohexyloxyethyl group, 1-phenoxyethyl group, 1-phenylthioethyl group, 1,1-diphenoxyethyl group, 1 -Benzyloxyethyl group, 1-
Benzylthioethyl group, 1-cyclopropylethyl group,
1-phenylethyl group, 1,1-diphenylethyl group,
1-methoxycarbonylethyl group, 1-ethoxycarbonylethyl group, 1-n-propoxycarbonylethyl group, 1-isopropoxycarbonylethyl group, 1-n-
Examples thereof include butoxycarbonylethyl group and 1-t-butoxycarbonylethyl group.

Further, as the 1-branched alkyl group,
Examples thereof include i-propyl group, sec-butyl group, t-butyl group, 1,1-dimethylpropyl group, 1-methylbutyl group and 1,1-dimethylbutyl group. Examples of the triorganosilyl group include trimethylsilyl group, ethyldimethylsilyl group, methyldiethylsilyl group, triethylsilyl group, i-propyldimethylsilyl group, methyldi-i-propylsilyl group, tri-i-propylsilyl group. Group, t-butyldimethylsilyl group, methyldi-t-butylsilyl group, tri-t-
Examples thereof include tricarbylsilyl groups such as a butylsilyl group, a phenyldimethylsilyl group, a methyldiphenylsilyl group and a triphenylsilyl group.

Examples of the triorganogermyl group include trimethylgermyl group, ethyldimethylgermyl group, methyldiethylgermyl group, triethylgermyl group, isopropyldimethylgermyl group and methyldi-
i-propylgermyl group, tri-i-propylgermyl group, t-butyldimethylgermyl group, methyldi-t-butylgermyl group, tri-t-butylgermyl group, phenyldimethylgermyl group, methyldiphenylgermyl group,
There may be mentioned tricarbylgermyl groups such as triphenylgermyl group. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, an i-propoxycarbonyl group, a t-butoxycarbonyl group, and the like.

Examples of the acyl group include acetyl group, propionyl group, butyryl group, heptanoyl group, hexanoyl group, valeryl group, pivaloyl group, isovaleryl group, lauroyl group, myristoyl group, palmitoyl group, stearoyl group, oxalyl group. Group, malonyl group,
Succinyl group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoil group, sebacyl group,
Acryloyl group, propioroyl group, methacryloyl group, crotonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconoyl group, camphoroyl group, benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatropoyl group Group, atropoyl group, cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group, isonicotinoyl group, p-toluenesulfonyl group, mesyl group and the like.

Examples of the cyclic acid-dissociable group include cyclopropyl group, cyclopentyl group, 1-methylcyclopentyl group, 1-ethylcyclopentyl group, cyclohexyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group. , 4-methoxycyclohexyl group, cyclohexenyl group, tetrahydropyranyl group, tetrahydrofuranyl group, tetrahydrothiopyranyl group,
Tetrahydrothiofuranyl group, 3-bromotetrahydropyranyl group, 4-methoxytetrahydropyranyl group, 4
-Methoxytetrahydrothiopyranyl group, 3-tetrahydrothiophene-1,1-dioxide group, norbornyl group, methylnorbornyl group, ethylnorbornyl group, isobornyl group, tricyclodecanyl group, dicyclopentenyl group, adamantyl Group, 2-methyl-2-adamantyl group, 2-ethyl-2-adamantyl group and the like.

Among these monovalent acid-dissociable groups, t-butyl group, benzyl group, 1-methoxyethyl group, 1-ethoxyethyl group, trimethylsilyl group, t-butoxycarbonyl group, t-butoxycarbonylmethyl group. , A tetrahydropyranyl group, a tetrahydrofuranyl group, a tetrahydrothiopyranyl group, a tetrahydrothiofuranyl group, 2-
A methyl-2-adamantyl group and the like are preferable.

The proportion of the repeating unit (1) in the polymer component (A) is usually 1 to 30 mol%, preferably 1 to 20 mol%, more preferably 1 to 16 mol%. If the proportion of the repeating unit (1) is too small, the transparency and resolution of the resulting composition may be insufficient, and if it is too large, the dry etching resistance of the resist film may be insufficient. The ratio of repeating units (2) is usually 30
˜90 mol%, preferably 45 to 85 mol%, more preferably 55 to 75 mol%. If the proportion of the repeating unit (2) is too small, the adhesion of the formed resist coating to the substrate may be poor, and if it is too large, the contrast of the resist coating after development may be low. Repeating unit (3)
Is usually 5 to 60 mol%, preferably 7 to 40
Mol%, more preferably 8 to 30 mol%. If the proportion of the repeating unit (3) is too small, the dry etching resistance of the formed resist coating may be insufficient, and if it is too large, the adhesion of the formed resist coating to the substrate may be poor.

The polystyrene equivalent weight average molecular weight (hereinafter referred to as "M") of each polymer constituting the polymer component (A) measured by gel permeation chromatography (GPC).
"w") is preferably 1,000 to 150,000.
It is 0, more preferably 3,000 to 100,000. The ratio (Mw / Mn) of Mw of each polymer to the polystyrene reduced number average molecular weight (hereinafter referred to as “Mn”) measured by GPC is usually 1 to 10, preferably 1 to 5.

The method for synthesizing the various polymers constituting the polymer component (A) is not particularly limited, but examples thereof include the following methods (1) to (3). It is selected from a monomer constituting the repeating unit (1) such as tetrahydrofurfuryl (meth) acrylate and a monomer constituting the repeating unit (3) such as a styrene derivative substituted with an acid-labile group or (meth) acrylate. At least one and acetoxystyrene are used to obtain a copolymer by known radical polymerization or anionic polymerization, and the obtained copolymer is hydrolyzed in the presence of a base or an acid in an organic solvent to obtain a repeating unit. A method for obtaining a copolymer having (2) and a repeating unit (1) and / or a repeating unit (3). Using at least one selected from the monomer constituting the repeating unit (1), vinylphenol or α-methylvinylphenol (monomer constituting the repeating unit (2)) and the monomer constituting the repeating unit (3),
Having at least one repeating unit selected from repeating unit (1), repeating unit (2) and repeating unit (3) by known radical polymerization or anionic polymerization (co)
A method of obtaining a polymer. Using a styrene derivative substituted with an acid-labile group such as t-butoxystyrene, polymerization is carried out by known radical polymerization or anionic polymerization, and during or after polymerization, hydrolysis is carried out in the same manner as described above to obtain poly (p- Hydroxystyrene), and the resulting polymer is reacted with a hydroxyl group-protecting base agent such as ethyl vinyl ether in the presence of an acid or a base in an organic solvent to have a repeating unit (2) and a repeating unit (3). A method for obtaining a copolymer. A styrene derivative substituted with an acid-dissociable group such as t-butoxystyrene is used to polymerize by known radical polymerization or anionic polymerization, and then hydrolyzed in the same manner as described above to partially decompose the acid-dissociable group. Alternatively, a method of obtaining a polymer having a repeating unit (2) or a copolymer having a repeating unit (2) and a repeating unit (3) with all hydroxyl groups.

The radical polymerization can be carried out, for example, as follows. Under a nitrogen atmosphere, in a suitable organic solvent, in the presence of a radical polymerization initiator, a monomer and optionally other monomer are stirred, for example, at 50 to 200 ° C.
It is carried out by heating. Examples of the radical polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis- (2,4-dimethylvaleronitrile) and 2,2'-azobis- (4-methoxy-2). , 4-
Dimethylvaleronitrile) 2,2'-azobismethylbutyronitrile, 2,2'-azobiscyclohexanecarbonitrile, cyanomethylethylazoformamide,
Azo compounds such as 2,2′-azobis (methyl 2,4-dimethylpropionate) and 2,2′-azobiscyanovaleric acid; benzoyl peroxide, lauroyl peroxide, 1,1′-bis- (t- There may be mentioned organic peroxides such as butylperoxy) cyclohexane, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-ethylhexanoate and hydrogen peroxide. Further, 2,2,6,6-tetramethyl-1-piperidinyloxy, iodine, mercaptan, styrene dimer and the like can be added as a polymerization aid.

The anionic polymerization can be carried out as follows, for example. It is carried out in a suitable organic solvent under a nitrogen atmosphere, in the presence of an anionic polymerization initiator, by maintaining the monomer with stirring at a temperature of, for example, -100 ° C to 50 ° C. As the anionic polymerization initiator, for example, n-butyl lithium, s-butyl lithium, t-butyl lithium, ethyl lithium, ethyl sodium, 1,1
-Diphenylhexyl lithium, 1,1-diphenyl-
An organic alkali metal such as 3-methylpentyllithium is used.

Further, in the synthesis of the above-mentioned polymer, it is possible to carry out the polymerization reaction by heating without using a polymerization initiator.

Examples of the acid used in the above hydrolysis and reaction with the protective base include p-toluenesulfonic acid and its hydrate, methanesulfonic acid, trifluoromethanesulfonic acid, malonic acid, oxalic acid, 1 Organic acids such as 1,1,1-fluoroacetic acid; inorganic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, hydrobromic acid; or pyridinium p-toluenesulfonate, ammonium p-toluenesulfonate, 4-methylpyridinium p-toluenesulfonate Such salts may be mentioned. Further, as the base, inorganic bases such as potassium hydroxide, sodium hydroxide, sodium carbonate, potassium carbonate; triethylamine, N
Examples include organic bases such as -methyl-2-pyrrolidone, piperidine, and tetramethylammonium hydroxide.

Suitable organic solvents used in the above polymerization and hydrolysis include acetone, methyl ethyl ketone,
Ketones such as methyl amyl ketone; diethyl ether,
Ethers such as tetrahydrofuran (THF); alcohols such as methanol, ethanol, propanol, etc .;
Aliphatic hydrocarbons such as hexane, heptane, octane;
Aromatic hydrocarbons such as benzene, toluene, xylene;
Chloroform, bromoform, methylene chloride, methylene bromide, carbon tetrachloride, and other halogenated alkyls; ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, esters such as cellosolves; dimethylformamide And aprotic polar solvents such as dimethyl sulfoxide, hexamethylphosphoramide, and the like. Of these, particularly preferred are acetone, methyl amyl ketone, methyl ethyl ketone, tetrahydrofuran, methanol, ethanol, propanol, ethyl acetate, butyl acetate, ethyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and the like. You can

The reaction temperature in the above polymerization varies depending on the initiator species. When alkyl lithium is used in the anionic polymerization, it is preferably −100 to 50 ° C., more preferably −78 to 30 ° C. When an azo initiator or a peroxide initiator is used in radical polymerization, a temperature at which the half-life of the initiator is about 10 minutes to 30 hours is preferable, and more preferably, the half-life of the initiator is about 30 minutes to 10 hours. Is the temperature. The reaction time varies depending on the type of the initiator and the reaction temperature, but the reaction time at which the initiator is consumed by 50% or more is desirable, and in many cases it is about 0.5 to 24 hours.

-(B) Radiation-sensitive acid generator-The component (B) in the present invention is a radiation-sensitive acid generator (hereinafter referred to as "acid generator (B)") which generates an acid upon exposure. Become. Examples of the acid generator (B) include onium salt compounds, sulfone compounds, sulfonic acid ester compounds, sulfonimide compounds, diazomethane compounds, disulfonylmethane compounds and the like. Below, the example of these acid generators (B) is shown.

Onium salt compounds: Examples of onium salt compounds include iodonium salts, sulfonium salts (including tetrahydrothiophenium salts), phosphonium salts, diazonium salts, ammonium salts, pyridinium salts and the like. . Specific examples of the onium salt compound include bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate and bis (4-t
-Butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium pyrenesulfonate, bis (4-t-butylphenyl) iodonium n-dodecylbenzenesulfonate, bis (4-t-butylphenyl) ) Iodonium p
-Toluene sulfonate, bis (4-t-butylphenyl) iodonium benzene sulfonate, bis (4-t
-Butylphenyl) iodonium 10-camphorsulfonate, bis (4-t-butylphenyl) iodonium n-octanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butyl) Phenyl) iodonium 2-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) iodonium 4-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) iodonium 2,4-difluorobenzenesulfonate, diphenyliodonium trifluor Rmethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium pyrenesulfonate, diphenyliodonium n-dodecylbenzenesulfate Sulfonate, diphenyliodonium p
-Toluene sulfonate, diphenyl iodonium benzene sulfonate, diphenyl iodonium 10-camphor sulfonate, diphenyl iodonium n-octane sulfonate, diphenyl iodonium perfluoro-n-octane sulfonate, diphenyl iodonium 2-trifluoromethylbenzene sulfonate, diphenyl iodonium 4-trifluoromethyl Benzenesulfonate, diphenyliodonium 2,4-difluorobenzenesulfonate,

Triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium pyrenesulfonate, triphenylsulfonium n
-Dodecyl benzene sulfonate, triphenyl sulfonium p-toluene sulfonate, triphenyl sulfonium benzene sulfonate, triphenyl sulfonium 10-camphor sulfonate, triphenyl sulfonium n-octane sulfonate, triphenyl sulfonium perfluoro-n-octane sulfonate, triphenyl sulfonium 2 -Trifluoromethylbenzenesulfonate, triphenylsulfonium 4-trifluorobenzenesulfonate, triphenylsulfonium 2,4-difluorobenzenesulfonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium 1-naphthalenesulfonate, 4-
t-butylphenyl diphenylsulfonium trifluoromethanesulfonate, 4-t-butylphenyl diphenylsulfonium nonafluoro-n-butanesulfonate, 4-t-butylphenyl diphenylsulfonium pyrenesulfonate, 4-t-butylphenyl diphenylsulfonium n -Dodecylbenzene sulfonate, 4-t-butylphenyl-diphenylsulfonium p-toluenesulfonate, 4-t-butylphenyl-
Diphenylsulfonium benzene sulfonate, 4-t
-Butylphenyl diphenylsulfonium 10-camphor sulfonate, 4-t-butylphenyl diphenylsulfonium n-octane sulfonate, 4-t-
Butylphenyl / diphenylsulfonium 2-trifluoromethylbenzenesulfonate, 4-t-butylphenyl / diphenylsulfonium 4-trifluoromethylbenzenesulfonate, 4-t-butylphenyl / diphenylsulfonium 2,4-difluorobenzenesulfonate, 4-t -Butoxyphenyl diphenylsulfonium nonafluoro-n-butanesulfonate, 4-hydroxyphenylbenzyl methylsulfonium p-
Toluenesulfonate cyclohexyl-2-oxocyclohexyl methylsulfonium trifluoromethanesulfonate, dicyclohexyl-2-oxocyclohexylsulfonium trifluoromethanesulfonate, 2
-Oxocyclohexyldimethylsulfonium trifluoromethanesulfonate, 1-naphthyldimethylsulfonium trifluoromethanesulfonate, 1-naphthyldiethylsulfonium trifluoromethanesulfonate, 1- (4-cyanonaphthyl) dimethylsulfonium trifluoromethanesulfonate, 1- (4-nitronaphthyl) dimethyl Sulfonium trifluoromethanesulfonate, 1- (4-methylnaphthyl) dimethylsulfonium trifluoromethanesulfonate, 1- (4-cyanonaphthyl) diethylsulfonium trifluoromethanesulfonate, 1- (4-nitronaphthyl) diethylsulfonium trifluoromethanesulfonate, 1-
(4-methylnaphthyl) diethylsulfonium trifluoromethanesulfonate, 1- (4-hydroxynaphthyl) dimethylsulfonium trifluoromethanesulfonate,

1- (4-hydroxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate,
1- (4-hydroxynaphthyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1-
(4-hydroxynaphthyl) tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- (4
-Methoxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-methoxynaphthyl) tetrahydrothiophenium nonafluoro-n-
Butanesulfonate, 1- (4-methoxynaphthyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-ethoxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate,
1- (4-ethoxynaphthyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (4
-Ethoxynaphthyl) tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- (4-n-
Butoxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium nonafluoro-n
-Butane sulfonate, 1- (4-n-butoxynaphthyl) tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- (4-methoxymethoxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-methoxymethoxy Naphthyl)
Tetrahydrothiophenium nonafluoro-n-butane sulfonate, 1- (4-methoxymethoxynaphthyl)
Tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- (4-ethoxymethoxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-ethoxymethoxynaphthyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (4-ethoxymethoxynaphthyl) tetrahydrothiophenium perfluoro-n-octane sulfonate,

1- [4- (1-methoxyethoxy) naphthyl] tetrahydrothiophenium trifluoromethanesulfonate, 1- [4- (1-methoxyethoxy) naphthyl] tetrahydrothiophenium nonafluoro-n
-Butanesulfonate, 1- [4- (1-methoxyethoxy) naphthyl] tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- [4- (2-methoxyethoxy) naphthyl] tetrahydrothiophenium trifluoromethanesulfonate, 1- [4- (2-
Methoxyethoxy) naphthyl] tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- [4
-(2-Methoxyethoxy) naphthyl] tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- (4-methoxycarbonyloxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-methoxycarbonyloxynaphthyl)
Tetrahydrothiophenium nonafluoro-n-butane sulfonate, 1- (4-methoxycarbonyloxynaphthyl) tetrahydrothiophenium perfluoro-n
-Octane sulfonate, 1- (4-ethoxycarbonyloxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-ethoxycarbonyloxynaphthyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (4-ethoxy Carbonyloxynaphthyl) tetrahydrothiophenium perfluoro-n-octane sulfonate, 1-
(4-n-propoxycarbonyloxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-propoxycarbonyloxynaphthyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (4-n-propoxy Carbonyloxynaphthyl) tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- (4-i-propoxycarbonyloxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4
-I-propoxycarbonyloxynaphthyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (4-i-propoxycarbonyloxynaphthyl) tetrahydrothiophenium perfluoro-n-
Octane sulfonate,

1- (4-n-butoxycarbonyloxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxycarbonyloxynaphthyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- ( 4-n-butoxycarbonyloxynaphthyl) tetrahydrothiophenium perfluoro-n-octane sulfonate, 1-
(4-t-Butoxycarbonyloxynaphthyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-t-butoxycarbonyloxynaphthyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (4-t-butoxy Carbonyloxynaphthyl) tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- [4- (2-tetrahydrofuranyloxy) naphthyl] tetrahydrothiophenium trifluoromethanesulfonate, 1-
[4- (2-Tetrahydrofuranyloxy) naphthyl]
Tetrahydrothiophenium nonafluoro-n-butane sulfonate, 1- [4- (2-tetrahydrofuranyloxy) naphthyl] tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- [4- (2-
Tetrahydropyranyloxy) naphthyl] tetrahydrothiophenium trifluoromethanesulfonate, 1-
[4- (2-Tetrahydropyranyloxy) naphthyl]
Tetrahydrothiophenium nonafluoro-n-butane sulfonate, 1- [4- (2-tetrahydropyranyloxy) naphthyl] tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- (4-benzyloxynaphthyl) tetrahydrothio Phenium trifluoromethanesulfonate, 1- (4-benzyloxynaphthyl) tetrahydrothiophenium nonafluoro-
n-Butane sulfonate, 1- (4-benzyloxynaphthyl) tetrahydrothiophenium perfluoro-n
-Octanesulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (1-naphthylacetomethyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (1-naphthylacetomethyl) ) Tetrahydrothiophenium perfluoro-n-octane sulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydro Thiophenium nonafluoro-n-butane sulfonate, 1- (3,5-dimethyl-
4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octane sulfonate and the like can be mentioned.

Sulfone compound: Examples of the sulfone compound include β-ketosulfone, β-sulfonylsulfone, and α-diazo compounds thereof. Specific examples of the sulfone compound include phenacylphenyl sulfone, mesitylphenacyl sulfone, bis (phenylsulfonyl) methane, and 4-trisphenacyl sulfone.

Sulfonic acid ester compound: Examples of the sulfonic acid ester compound include alkyl sulfonic acid ester, haloalkyl sulfonic acid ester, aryl sulfonic acid ester, imino sulfonate and the like. Specific examples of the sulfonate compound include benzoin tosylate, pyrogallol tris (trifluoromethane sulfonate), pyrogallol tris (nonafluoro-n-butane sulfonate), pyrogallol tris (methane sulfonate), nitrobenzyl-
9,10-diethoxyanthracene-2-sulfonate, α-methylolbenzoin tosylate, α-methylolbenzoin n-octanesulfonate, α-methylolbenzoin trifluoromethanesulfonate, α-
Methylol benzoin n-dodecane sulfonate etc. can be mentioned.

Sulfonimide compound: As the sulfonimide compound, for example, the following formula (4):

[0040]

[Chemical 7]

(In the formula, V represents a divalent group such as an alkylene group, an arylene group or an alkoxylene group, and R ₉ represents a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group or a halogen-substituted aryl group. A group represented by the formula).

Specific examples of the sulfonimide compound include:
N- (trifluoromethanesulfonyloxy) succinimide, N- (trifluoromethanesulfonyloxy)
Phthalimide, N- (trifluoromethanesulfonyloxy) diphenylmaleimide, N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-
5-ene-2,3-dicarboximide, N- (trifluoromethanesulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (trifluoro Rmethanesulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (trifluoromethanesulfonyloxy) naphthylimide, N- (10-
Camphorsulfonyloxy) succinimide, N-
(10-camphorsulfonyloxy) phthalimide,
N- (10-camphorsulfonyloxy) diphenylmaleimide, N- (10-camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3
-Dicarboximide, N- (10-camphorsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (1
0-camphorsulfonyloxy) bicyclo [2.2.
1] heptane-5,6-oxy-2,3-dicarboximide, N- (10-camphorsulfonyloxy) naphthylimide,

N- (p-toluenesulfonyloxy) succinimide, N- (p-toluenesulfonyloxy)
Phthalimide, N- (p-toluenesulfonyloxy)
Diphenylmaleimide, N- (p-toluenesulfonyloxy) bicyclo [2.2.1] hept-5-ene-
2,3-dicarboximide, N- (p-toluenesulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N-
(P-Toluenesulfonyloxy) bicyclo [2.2.
1] Heptane-5,6-oxy-2,3-dicarboximide, N- (p-toluenesulfonyloxy) naphthylimide, N- (2-trifluoromethylbenzenesulfonyloxy) succinimide, N- (2-tri Fluoromethylbenzenesulfonyloxy) phthalimide, N
-(2-trifluoromethylbenzenesulfonyloxy) diphenylmaleimide, N- (2-trifluoromethylbenzenesulfonyloxy) bicyclo [2.2.
1] hept-5-ene-2,3-dicarboximide,
N- (2-trifluoromethylbenzenesulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-
Ene-2,3-dicarboximide, N- (2-trifluoromethylbenzenesulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (2 -Trifluoromethylbenzenesulfonyloxy) naphthylimide,

N- (4-trifluoromethylbenzenesulfonyloxy) succinimide, N- (4-trifluoromethylbenzenesulfonyloxy) phthalimide,
N- (4-trifluoromethylbenzenesulfonyloxy) diphenylmaleimide, N- (4-trifluoromethylbenzenesulfonyloxy) bicyclo [2.2.
1] hept-5-ene-2,3-dicarboximide,
N- (4-trifluoromethylbenzenesulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-
Ene-2,3-dicarboximide, N- (4-trifluoromethylbenzenesulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (4 -Trifluoromethylbenzenesulfonyloxy) naphthylimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) phthalimide, N- (nonafluoro-n-butanesulfonyloxy) diphenylmaleimide , N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.
2.1] Hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-
Ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.
1] heptane-5,6-oxy-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) naphthylimide,

N- (pentafluorobenzenesulfonyloxy) succinimide, N- (pentafluorobenzenesulfonyloxy) phthalimide, N- (pentafluorobenzenesulfonyloxy) diphenylmaleimide, N- (pentafluorobenzenesulfonyloxy)
Bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (pentafluorobenzenesulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2 , 3-dicarboximide, N-
(Pentafluorobenzenesulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (pentafluorobenzenesulfonyloxy) naphthylimide, N- (perfluoro-
n-octanesulfonyloxy) succinimide, N-
(Perfluoro-n-octanesulfonyloxy) phthalimide, N- (perfluoro-n-octanesulfonyloxy) diphenylmaleimide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.
1] hept-5-ene-2,3-dicarboximide,
N- (perfluoro-n-octanesulfonyloxy)
-7-Oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro-
n-octanesulfonyloxy) bicyclo [2.2.
1] Heptane-5,6-oxy-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) naphthylimide, N-{(5-methyl-5-carboxymethanebicyclo [2.2] .1] hepta-2-yl) sulfonyloxy} succinimide and the like. Diazomethane compound: As a diazomethane compound,
For example, the following formula (5)

[0046]

[Chemical 8]

(In the formula, R ₁₀ and R ₁₁ each independently represent a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group and a halogen-substituted aryl group.)

Examples thereof include compounds represented by:
Specific examples of the diazomethane compound include bis (trifluoromethanesulfonyl) diazomethane, bis (cyclohexanesulfonyl) diazomethane, bis (benzenesulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, methanesulfonyl-p-toluenesulfonyldiazomethane, cyclohexanesulfonyl. −
1,1-dimethylethylsulfonyldiazomethane, bis (1,1-dimethylethanesulfonyl) diazomethane,
Bis (3,3-dimethyl-1,5-dioxaspiro [5.5] dodecane-8-sulfonyl) diazomethane,
Bis (1,4-dioxaspiro [4.5] decane-7-
Examples thereof include sulfonyl) diazomethane.

Disulfonylmethane compound: Examples of the disulfonylmethane compound include compounds represented by the following formula (6):

[0050]

[Chemical 9]

(In the formula, R ₁₂ and R ₁₃ are, independently of each other, a linear or branched monovalent aliphatic hydrocarbon group, a cycloalkyl group, an aryl group, an aralkyl group or a monovalent monovalent group having a hetero atom. Represents another organic group, X and Y each independently represent an aryl group, a hydrogen atom, a linear or branched monovalent aliphatic hydrocarbon group or another monovalent organic group having a hetero atom. And at least one of X and Y is an aryl group, or X and Y are linked to each other to form a monocyclic or polycyclic ring having at least one unsaturated bond, or X and Y are Connected to each other and the following formula

[0052]

[Chemical 10]

(Wherein X'and Y'independently represent a hydrogen atom, a halogen atom, a linear or branched alkyl group, a cycloalkyl group, an aryl group or an aralkyl group, or the same or different. X'and Y'bonded to a carbon atom are linked to each other to form a carbon monocyclic structure, and a plurality of X'and Y'may be the same or different from each other, and r is 2 to 10 Is an integer of 1.) forming a group represented by. )

Examples thereof include compounds represented by:

As the acid generator (B), onium salt compounds and sulfonimide compounds are preferable, and particularly,
Bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium p-
Toluenesulfonate, bis (4-t-butylphenyl) iodonium 10-camphorsulfonate, bis (4-t-butylphenyl) iodonium 2-trifluoromethylbenzenesulfonate, bis (4-t-butylphenyl) iodonium 4-trifluoro Methylbenzene sulfonate, bis (4-t-butylphenyl) iodonium 2,4-difluorobenzenesulfonate,
Triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium perfluoro-n-butanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium 10-camphorsulfonate, triphenylsulfonium 2-
Trifluoromethylbenzenesulfonate, triphenylsulfonium 4-trifluorobenzenesulfonate, triphenylsulfonium 2,4-difluoromethylbenzenesulfonate, N- (trifluoromethanesulfonyloxy) succinimide, N- (trifluoromethanesulfonyloxy) bicyclo [2. 2.1] Hept-5-ene-2,3-dicarboximide, N- (1
0-camphorsulfonyloxy) succinimide, N
-(10-camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide and N-{(5-methyl-5-carboxymethanebicyclo [2.2.1]]. It is preferable to use at least one selected from the group of hept-2-yl) sulfonyloxy} succinimide.

In the present invention, the amount of the acid generator (B) used is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 15 parts by weight, per 100 parts by weight of the resin component (A).
Parts by weight. In the present invention, the acid generator (B) may be used alone or in combination of two or more.

-Other components-Acid diffusion control agent: the radiation-sensitive resin composition of the present invention,
It is preferable to add an acid diffusion control agent which controls the diffusion phenomenon of the acid generated from the acid generator (B) by exposure in the resist film and suppresses an undesired chemical reaction in the non-exposed region. By using such an acid diffusion control agent, the storage stability of the composition is improved, the resolution as a resist is improved, and the retention time (PED) from exposure to heat treatment after exposure varies. The change in the line width of the resist pattern can be suppressed, and the process stability becomes extremely excellent. The acid diffusion controller is preferably a nitrogen-containing organic compound whose basicity does not change due to exposure or heat treatment during the resist pattern forming step.

Examples of such nitrogen-containing organic compounds include those represented by the following general formula (7)

[0059]

[Chemical 11]

[In the general formula (7), each R ₁₄ independently represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, and these groups are substituted with a functional group such as a hydroxyl group. Good. ]

A compound (hereinafter referred to as "nitrogen-containing compound (I)"), a diamino compound having two nitrogen atoms in the same molecule (hereinafter referred to as "nitrogen-containing compound (II)"), Examples thereof include diamino polymers having 3 or more nitrogen atoms (hereinafter referred to as "nitrogen-containing compound (III)"), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds and the like.

As the nitrogen-containing compound (I), for example, n
-Hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine and other monoalkylamines; di-n-butylamine, di-n-pentylamine, di-n-hexylamine, di- Dialkylamines such as n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine , Tri-n-hexylamine, tri-n-heptylamine,
Tri-n-octylamine, tri-n-nonylamine,
Trialkylamines such as tri-n-decylamine; alkanolamines such as ethanolamine, diethanolamine, triethanolamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4
-Aromatic amines such as nitroaniline, diphenylamine, triphenylamine, 1-naphthylamine and the like can be mentioned.

Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetrakis (2
-Hydroxypropyl) ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,
4'-diaminodiphenylamine, 2,2'-bis (4
-Aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4
-Aminophenyl) -2- (3-hydroxyphenyl)
Propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4
-Aminophenyl) -1-methylethyl] benzene,
1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene and the like can be mentioned. Examples of the nitrogen-containing compound (III) include polyethyleneimine, polyallylamine, and a polymer of dimethylaminoethylacrylamide.

Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-
Examples thereof include dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone and N-methylpyrrolidone. Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea and tributylthiourea. be able to. Examples of the nitrogen-containing heterocyclic compound include imidazole, benzimidazole, 4-methylimidazole, 4-methyl-2-
Imidazoles such as phenylimidazole and 2-phenylbenzimidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, N-methyl-4 In addition to pyridines such as phenylpyridine, nicotine, nicotinic acid, nicotinic acid amide, quinoline, 8-oxyquinoline and acridine, pyrazine, pyrazole, pyridazine, quinozalin, purine,
Pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine,
1,4-diazabicyclo [2.2.2] octane and the like can be mentioned.

As the nitrogen-containing organic compound, a base precursor having an acid dissociable group can also be used. Examples of the base precursor include N- (t-butoxycarbonyl) piperidine, N- (t-butoxycarbonyl) imidazole, N- (t-butoxycarbonyl) benzimidazole, N- (t-butoxycarbonyl) -2. -Phenylbenzimidazole, N- (t-butoxycarbonyl) di-n-octylamine, N- (t-butoxycarbonyl) diethanolamine, N- (t-butoxycarbonyl) dicyclohexylamine, N- (t-butoxycarbonyl) diphenylamine Etc. can be mentioned.

Of these nitrogen-containing organic compounds, the nitrogen-containing compound (I), the nitrogen-containing compound (II), the nitrogen-containing heterocyclic compound and the like are preferable. The acid diffusion control agent may be used alone or 2
A mixture of two or more species can be used. The amount of the acid diffusion controller is preferably 15 parts by weight or less, more preferably 0.001 parts by weight, per 100 parts by weight of the polymer component (A).
10 to 10 parts by weight, particularly preferably 0.005 to 5 parts by weight. In this case, if the amount of the acid diffusion controller is more than 15 parts by weight, the sensitivity of the resist and the developability of the exposed area tend to be lowered. The amount of the acid diffusion control agent added was 0.
If the amount is less than 001 parts by weight, the pattern shape and dimensional fidelity as a resist may decrease depending on the process conditions.

Alkali-soluble resin: The radiation-sensitive resin composition of the present invention may optionally contain an alkali-soluble resin. Examples of the alkali-soluble resin include poly (m-hydroxystyrene), poly (p-hydroxystyrene), and partially hydrogenated poly (p-).
Hydroxystyrene), p-hydroxystyrene / m-
Examples thereof include hydroxystyrene copolymer, p-hydroxystyrene / styrene copolymer, novolac resin, polyvinyl alcohol, polyacrylic acid and the like. The Mw of the alkali-soluble resin is usually 1,000-1,000.
10,000, preferably 2000-100,000. These alkali-soluble resins can be used alone or in admixture of two or more. The content of the alkali-soluble resin is preferably 30 parts by weight or less per 100 parts by weight of the polymer component (A).

Surfactant: The radiation-sensitive resin composition of the present invention may be blended with a surfactant having an effect of improving the coating property, striation, developability as a resist and the like of the composition. . Examples of such a surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenol ether, polyoxyethylene n-nonylphenol ether, polyethylene glycol dilaurate, polyethylene. Examples thereof include glycol distearate, and commercially available products include, for example, Ftop EF301, EF303, EF352 (manufactured by Tochem Products), Megafax F171, F173.
(Manufactured by Dainippon Ink and Chemicals, Inc.), Florard FC4
30, FC431 (Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC10
1, SC102, SC103, SC104, SC10
5, SC106 (manufactured by Asahi Glass Co., Ltd.), KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 9
5 (manufactured by Kyoeisha Chemical Co., Ltd.) and the like. These surfactants may be used alone or in admixture of two or more. The blending amount of the surfactant is preferably 2 parts by weight or less per 100 parts by weight of the polymer component (A).

Sensitizer: The radiation-sensitive resin composition of the present invention may contain a sensitizer. Examples of preferable sensitizers include carbazoles, benzophenones, rose bengals, anthracenes, and the like. The compounding amount of the sensitizer is 100% of the polymer component (A).
It is preferably 50 parts by weight or less per part by weight. -Additives other than the above: Further, by blending a dye and / or a pigment, the latent image in the exposed area can be visualized, and the effect of halation during exposure can be mitigated. The adhesiveness with can be further improved. Further, as other additives, an antihalation agent such as 4-hydroxy-4′-methylchalcone, a shape improving agent, a storage stabilizer, an antifoaming agent and the like can be added.

-Solvent- When the radiation-sensitive resin composition of the present invention is used,
After being uniformly dissolved in a solvent so that the concentration of the total solid content is usually 0.1 to 50% by weight, preferably 1 to 40% by weight, for example, by filtering with a filter having a pore size of about 0.2 μm. , A composition solution. Examples of the solvent used for preparing the composition solution include ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate,
Ethylene glycol monoalkyl ether acetates such as ethylene glycol mono-n-butyl ether acetate; Propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-n-butyl ether and other propylene glycol mono Alkyl ethers; propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol di-n-propyl ether,
Propylene glycol dialkyl ethers such as propylene glycol di-n-butyl ether; propylene glycol such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol mono-n-butyl ether acetate Monoalkyl ether acetates;

Lactic acid esters such as methyl lactate, ethyl lactate, n-propyl lactate, i-propyl lactate; n-amyl formate, i-amyl formate, ethyl acetate, n-propyl acetate, i-propyl acetate, acetic acid n-butyl, i-butyl acetate, n-amyl acetate, i-amyl acetate, i-propionate
-Propyl, n-butyl propionate, propionate i
-Aliphatic carboxylic acid esters such as butyl; ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate , Ethyl 3-methoxypropionate,
Methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3
-Methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, methyl acetoacetate, ethyl acetoacetate, methyl pyruvate, ethyl pyruvate and other esters; aromatic hydrocarbons such as toluene and xylene Methyl ethyl ketone, methyl n-propyl ketone,
Ketones such as methyl n-butyl ketone, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone; N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methyl Amides such as pyrrolidone; γ-
Lactones such as butyrolacun can be mentioned. These solvents may be used alone or in admixture of two or more.

Formation of Resist Pattern When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the composition solution prepared as described above is subjected to spin coating, cast coating, roll coating, etc. By a suitable coating means, for example, by coating on a substrate such as a silicon wafer, a wafer covered with aluminum, etc., a resist film is formed, and depending on the case, 70 ° C.
After heat treatment (hereinafter referred to as “PB”) at a temperature of about 160 ° C., exposure is performed through a predetermined mask pattern. As the radiation used at that time, for example, an F ₂ excimer laser (wavelength 157 nm) or an ArF excimer laser (wavelength 1 depending on the type of the acid generator (D) is used.
93nm) or KrF excimer laser (wavelength 248n
Far ultraviolet rays such as m), X-rays such as synchrotron radiation, and charged particle beams such as electron beams are appropriately selected and used. In addition, the exposure conditions such as the exposure amount, the composition of the radiation-sensitive resin composition,
It is appropriately selected according to the type of each additive.

In the present invention, in order to stably form a highly precise fine pattern, after exposure, the temperature is 70 to 160 ° C.
It is preferable to perform heat treatment (hereinafter referred to as “PEB”) at the temperature of 30 seconds or more. In this case, if the PEB temperature is lower than 70 ° C., there is a possibility that the variations in sensitivity will spread depending on the type of substrate. Then, with an alkaline developer, it is usually at 10 to 50 ° C. for 10 to 200 seconds, preferably at 15 to 30 ° C. for 15 to 100 seconds, particularly preferably 20 to
A predetermined resist pattern is formed by developing at 25 ° C. for 15 to 90 seconds.

Examples of the alkali developer include alkali metal hydroxide, aqueous ammonia, mono-, di- or tri-alkylamines, mono-, di- or tri-alkanolamines, and heterocyclic amines. , Tetraalkylammonium hydroxides, choline, 1,8
-Diazabicyclo- [5.4.0] -7-undecene,
Alkaline compounds such as 1,5-diazabicyclo- [4.3.0] -5-nonene are usually used in a concentration of 1 to 10% by weight, preferably 1 to 5% by weight, particularly preferably 1 to 3% by weight. An alkaline aqueous solution dissolved so that is used is used.
In addition, a water-soluble organic solvent such as methanol or ethanol, or a surfactant can be appropriately added to the developer containing the alkaline aqueous solution. In forming the resist pattern, a protective film may be provided on the resist film in order to prevent the influence of basic impurities contained in the ambient atmosphere.

[0075]

EXAMPLES The embodiments of the present invention will be described more specifically below with reference to examples. However, the present invention is not limited to these examples. Synthesis Example 1 p-acetoxystyrene 87 g, styrene 7 g, p-t
-Butoxystyrene 36 g, tetrahydrofurfuryl acrylate 32 g, azobisisobutyronitrile 7 g,
1 g of t-dodecyl mercaptan was dissolved in 160 g of propylene glycol monomethyl ether, and then the reaction temperature was kept at 70 ° C. under a nitrogen atmosphere to carry out polymerization for 16 hours. After the polymerization, the reaction solution was dropped into a large amount of n-hexane to solidify and purify the produced polymer. Then, 150 g of propylene glycol monomethyl ether was added again to this polymer, and then 300 g of methanol, 100 g of triethylamine and 18 g of water were added, and the hydrolysis reaction was carried out for 8 hours while refluxing at the boiling point. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, the obtained polymer was dissolved in acetone, and then dropped into a large amount of water to coagulate, and the produced white powder was filtered, and the resulting mixture was filtered under reduced pressure.
Dry overnight at 0 ° C. The polymer obtained had an Mw of 13,
000, Mw / Mn is 1.7, and as a result of ¹³ C-NMR analysis, p-hydroxystyrene, styrene, and pt-
The copolymerization molar ratio of butoxystyrene and tetrahydrofurfuryl acrylate was 54: 6: 20: 20. This polymer is referred to as a polymer (a-1).

Polymer (a-1) and Synthesis Examples 1 to 1 below
The Mw and Mn of each polymer obtained in 9 were measured by Tosoh Corporation.
GPC column (G2000H)_XL  Two, G30
00H _XL  1 piece, G4000H_XL  Flow rate
1.0 ml / min, dissolution solvent Tetrahydrofura
Under the conditions of column temperature of 40 ℃.
Gel permeation chromatography
-(GPC).

Synthesis Example 2 p-acetoxystyrene 98 g, tetrahydrofurfuryl acrylate 63 g, azobisisobutyronitrile 7
1 g of g, t-dodecyl mercaptan was dissolved in 160 g of propylene glycol monomethyl ether, and then the reaction temperature was kept at 70 ° C. under a nitrogen atmosphere to carry out polymerization for 16 hours. After the polymerization, the reaction solution was dropped into a large amount of n-hexane to solidify and purify the produced polymer. Then, 150 g of propylene glycol monomethyl ether was added to this polymer again, and then methanol 300 was added.
g, triethylamine 120 g, and water 20 g were added, and the hydrolysis reaction was carried out for 8 hours while refluxing at the boiling point. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, the obtained polymer was dissolved in acetone, and then dropped into a large amount of water to coagulate, and the produced white powder was filtered, and the mixture was filtered under reduced pressure at 50 ° C. overnight. Dried. The obtained polymer is
Mw is 13,000, Mw / Mn is 1.7, and ¹³ C
-As a result of NMR analysis, the copolymerization molar ratio of p-hydroxystyrene and tetrahydrofurfuryl acrylate was 5
It was 8:62. This polymer is referred to as polymer (a1-1)
And

Synthesis Example 3 101 g of p-acetoxystyrene, 5 g of styrene, p-
After dissolving 42 g of t-butoxystyrene, 6 g of azobisisobutyronitrile and 1 g of t-dodecyl mercaptan in 160 g of propylene glycol monomethyl ether, the reaction temperature was kept at 70 ° C. under a nitrogen atmosphere, and
Polymerized for hours. After the polymerization, the reaction solution was dropped into a large amount of n-hexane to solidify and purify the produced polymer. Then, 150 g of propylene glycol monomethyl ether was added again to this polymer, and then methanol 3 was added.
00g, triethylamine 80g, water 15g,
The hydrolysis reaction was carried out for 8 hours while refluxing at the boiling point. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, the obtained polymer was dissolved in acetone, and then dropped into a large amount of water to coagulate, and the produced white powder was filtered, and the mixture was filtered under reduced pressure at 50 ° C. overnight. Dried. The obtained polymer is
Mw is 16,000, Mw / Mn is 1.7, and ¹³ C
As a result of NMR analysis, the copolymerization molar ratio of p-hydroxystyrene, styrene and pt-butoxystyrene was 7
It was 2: 5: 23. This polymer is referred to as the polymer (a2-
1).

Synthesis Example 4 p-acetoxystyrene 113 g, pt-butoxystyrene 18 g, tetrahydrofurfuryl acrylate 3
1 g, azobisisobutyronitrile 7 g, and t-dodecyl mercaptan 1 g were dissolved in 160 g of propylene glycol monomethyl ether, and then the reaction temperature was maintained at 70 ° C. in a nitrogen atmosphere, and polymerization was performed for 16 hours. After the polymerization, the reaction solution was dropped into a large amount of n-hexane to solidify and purify the produced polymer. Thereafter, 150 g of propylene glycol monomethyl ether was added to the polymer again, 300 g of methanol, 135 g of triethylamine, and 24 g of water were further added, and the hydrolysis reaction was carried out for 8 hours while refluxing at the boiling point. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, the obtained polymer was dissolved in acetone, and then dropped into a large amount of water to coagulate, and the produced white powder was filtered, and the mixture was filtered under reduced pressure at 50 ° C. overnight. Dried. The obtained polymer has Mw of 13,300, M
w / Mn is 1.7, and as a result of ¹³ C-NMR analysis, p
-Hydroxystyrene / pt-butoxystyrene / tetrahydrofurfuryl acrylate copolymerization molar ratio is
It was 70:10:20. This polymer is referred to as polymer (a
-2).

Synthesis Example 5 176 g of pt-butoxystyrene was subjected to anionic polymerization in 500 ml of tetrahydrofuran at -78 ° C with n-butyllithium as a catalyst. After the polymerization, the reaction solution was coagulated in methanol to give white poly (p-
150 g of t-butoxystyrene) was obtained. Then, this poly (pt-butoxystyrene) was added to dioxane 600.
It was dissolved in g, diluted hydrochloric acid was added, and a hydrolysis reaction was carried out at 70 ° C. for 2 hours. Then, the reaction solution was dropped into a large amount of water to solidify the polymer. Then, the operation of dissolving this polymer in acetone and coagulating it in a large amount of water was repeated, and then the produced white powder was filtered and dried under reduced pressure at 50 ° C. overnight. The obtained polymer has Mw of 10,400,
Mw / Mn was 1.10, and as a result of ¹³ C-NMR analysis, it had a structure in which only part of the t-butyl group in poly (pt-butoxystyrene) was hydrolyzed, and pt- It was confirmed that the copolymerization molar ratio of butoxystyrene and p-hydroxystyrene was 32:68. This polymer is referred to as a polymer (a2-2).

Synthesis Example 6 25 g of a p-hydroxystyrene / pt-butoxystyrene / tetrahydrofurfuryl acrylate copolymer having a copolymerization molar ratio of 75/10/15 was added to 10 g of n-butyl acetate.
After dissolving in 0 g and bubbling with nitrogen gas for 30 minutes, 2.8 g of ethyl vinyl ether and 0.85 g of p-toluenesulfonic acid pyridinium salt as a catalyst were added and reacted at room temperature for 12 hours. Then, the reaction solution was dropped into a 1% by weight aqueous ammonia solution to precipitate a polymer, which was then filtered and dried overnight in a vacuum dryer at 50 ° C. The obtained polymer has Mw of 13,000 and M
w / Mn is 1.01, and as a result of ¹³ C-NMR analysis,
23% by mole of hydrogen atoms of the phenolic hydroxyl group in the repeating unit derived from p-hydroxystyrene had an ethoxyxyethyl group and 10% by mole had a structure substituted with a t-butyl group. This polymer is referred to as polymer (a-
3).

Synthesis Example 7 100 g of p-acetoxystyrene, 23 g of pt-butoxystyrene, 39 of methyladamantyl acrylate
g, 6 g of azobisisobutyronitrile, and 1 g of t-dodecyl mercaptan were dissolved in 160 g of propylene glycol monomethyl ether, and then the reaction temperature was kept at 70 ° C. under a nitrogen atmosphere to carry out polymerization for 16 hours. After polymerization,
The reaction solution was dropped into a large amount of n-hexane to solidify and purify the produced polymer. After that, 150 g of propylene glycol monomethyl ether was added to this polymer again, and then 300 g of methanol, 115 g of triethylamine and 21 g of water were added, and the hydrolysis reaction was carried out for 8 hours while refluxing at the boiling point. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, the obtained polymer was dissolved in acetone, and then dropped into a large amount of water to coagulate, and the produced white powder was filtered, and the mixture was filtered under reduced pressure at 50 ° C. overnight. Dried. The obtained polymer has Mw of 14,000 and M
w / Mn was 1.8, and as a result of ¹³ C-NMR analysis, p
-Hydroxystyrene / pt-butoxystyrene / methyladamantyl acrylate copolymerization molar ratio is 6
It was 7:14:19. This polymer is referred to as the polymer (a2
-3).

Synthetic Example 8 100 g of p-acetoxystyrene, 25 g of t-butyl acrylate, 18 g of styrene, 6 g of azobisisobutyronitrile, 1 g of t-dodecyl mercaptan were dissolved in 230 g of propylene glycol monomethyl ether, and under nitrogen atmosphere, Polymerization was carried out for 16 hours while maintaining the reaction temperature at 70 ° C. After the polymerization, the reaction solution was dropped into a large amount of n-hexane to solidify and purify the produced polymer. Then, 150 g of propylene glycol monomethyl ether was added again to this polymer, and then 300 g of methanol,
80 g of triethylamine and 15 g of water were added, and a hydrolysis reaction was carried out for 8 hours while refluxing at the boiling point. After the reaction, the solvent and triethylamine were distilled off under reduced pressure, the obtained polymer was dissolved in acetone, and then dropped into a large amount of water to coagulate, and the produced white powder was filtered, and the resulting mixture was filtered under reduced pressure.
Dry overnight at 0 ° C. The polymer obtained had an Mw of 11,
As a result of ¹³ C-NMR analysis, the copolymerization molar ratio of p-hydroxystyrene, t-butyl acrylate and styrene was 61:19:20. This polymer is referred to as a polymer (a2-4).

Synthesis Example 9 p-Hydroxystyrene / p with a copolymerization molar ratio of 90/10
After dissolving 25 g of -t-butoxystyrene copolymer in 100 g of n-butyl acetate and bubbling with nitrogen gas for 30 minutes, 3.3 g of ethyl vinyl ether,
1 g of p-toluenesulfonic acid pyridinium salt as a catalyst
Was added and reacted at room temperature for 12 hours. Then, the reaction solution was dropped into a 1% by weight aqueous ammonia solution to precipitate a polymer, which was then filtered and dried overnight in a vacuum dryer at 50 ° C. The obtained polymer has a Mw of 13,000,
Mw / Mn was 1.01, and as a result of ¹³ C-NMR analysis, 23 mol% of hydrogen atoms of the phenolic hydroxyl group in the repeating unit derived from p-hydroxystyrene were ethoxyxyethyl groups and 10 mol% were t. It had a structure substituted with a -butyl group. This polymer is referred to as polymer (a
2-4).

Examples 1 to 9 and Comparative Examples 1 to 2 The components shown in Table 1 (where parts are based on weight) were mixed to form a uniform solution, which was then filtered through a membrane filter having a pore size of 0.2 μm. A composition solution was prepared. afterwards,
After spin coating each composition solution on a silicon wafer, PB was performed under the conditions shown in Table 1 to form resist coatings having a thickness of 0.5 μm in Examples 1 to 9 and Comparative Examples 1 and 2. Then, Examples 1-7 and Comparative Examples 1-2
Nikon Corporation Stepper NSR2205 EX12B (numerical aperture 0.5
5), and in Examples 8 to 9, Hitachi Ltd.
Using an electron beam drawing apparatus for direct drawing HL700 (accelerating voltage 30 KeV) improved to an accelerating voltage of 50 KeV, exposure was performed under the conditions shown in Table 1, and then PEB was performed under the conditions shown in Table 1. Then, using a 2.38 wt% tetramethylammonium hydroxide aqueous solution, development was performed by a paddle method at 23 ° C. for 1 minute, followed by washing with pure water and drying to form a resist pattern. The evaluation result of each resist is
It shows in Table 1.

The evaluation of each resist was carried out in the following manner. Sensitivity: The resist film formed on the silicon wafer is exposed to light, PEB is immediately performed, and alkali development is performed.
When washed with water and dried to form a resist pattern,
The exposure amount for forming a line-and-space pattern (1L1S) having a line width of 0.22 μm with a line width of 1: 1 was taken as the optimum exposure amount, and the sensitivity was evaluated by this optimum exposure amount. Resolution: The minimum dimension (μm) of the line-and-space pattern (1L1S) that is resolved when exposed with the optimum exposure amount is defined as the resolution. Exposure margin: A line-and-space pattern (1L1S) having a line width of 0.13 μm is formed, and a range of the exposure amount at which a pattern having a pattern size of 0.13 μm ± 10% can be obtained is less than 7% of the optimum exposure amount. In some cases, "x" was given, and 7% or more and less than 10% was given "o", and 10% or more was given as "◎".

The acid generator (B), the acid diffusion controlling agent and the solvent in Table 1 are as follows. Acid generator (B): B-1: N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide B-2: bis (cyclohexylsulfonyl) diazomethane B-3: Bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate B-4: Triphenylsulfonium trifluoromethanesulfonate Acid diffusion control agent: C-1: 2-phenylbenzimidazole C-2: Triethanolamine C- 3: N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine solvent: D-1: ethyl lactate D-2: propylene glycol monomethyl ether acetate D-3: 3-ethoxyethyl propionate

[0088]

[Table 1]

[0089]

The radiation-sensitive resin composition of the present invention has a pattern as a chemically amplified resist sensitive to actinic radiation such as KrF excimer laser, ArF excimer laser, F ₂ excimer laser or EUV. High sensitivity without sacrificing the basic physical properties of the resist such as shape, dry etching resistance and heat resistance.
It can be used very suitably in the field of microfabrication represented by the manufacture of integrated circuit devices, which have high resolution and high transmittance to radiation and are expected to become more miniaturized in the future.

Continued front page    F term (reference) 2H025 AA02 AB16 AC04 AC06 AC08                       AD03 BE00 BE10 BG00 CB14                       CB17 CB41                 4J100 AB07Q AL08P BA03Q BA04Q                       BC53P CA04 JA37 JA38

Claims (3)

[Claims] 1. A polymer containing (A) a repeating unit represented by the following general formula (1), a repeating unit represented by the general formula (2) and a repeating unit represented by the following general formula (3). A radiation-sensitive resin composition comprising a component and (B) a radiation-sensitive acid generator. [Chemical 1] [In the general formula (1), R ₁ represents a hydrogen atom or a methyl group. L is an integer of 0 to 4. ] [Chemical 2] [In the general formula (2), R ₂ represents a hydrogen atom or a methyl group, and R ₃ represents a monovalent organic group. N is 1 to 3
Is an integer of 0, and m is an integer of 0 to 3. ] [Chemical 3] [In the general formula (3), R ₄ represents a hydrogen atom or a methyl group, R ₆ represents a monovalent organic group, R ₇ and R ₈
Each independently represent a monovalent acid-dissociable group. Q is 1 to
3 is an integer of 3, and p is an integer of 0 to 3. ] 2. The polymer component of component (A) is represented by the repeating unit represented by the general formula (1), the repeating unit represented by the general formula (2) and the general formula (3). Characterized in that it is a mixture of two or more polymers containing one or two repeating units selected from repeating units,
The composition of claim 1. 3. A mixture of polymers comprising: (a1) a copolymer having a repeating unit represented by the general formula (1) and a repeating unit represented by the general formula (2); The composition according to claim 3, which is a mixture of a repeating unit represented by the general formula (2) and a copolymer having the repeating unit represented by the general formula (3).