KR20140077848A - Process for refining crude resin, resin for resist composition, method of producing resist composition, resist composition and method of forming resist pattern - Google Patents

Abstract

The objective of the present invention is to suppress defects in the formation of resist patterns to which a solvent development process is applied. Provided is a method for refining a resin for a resist in which solubility to an organic solvent decreases by the action of acid and a crude resin for a resist which is used for a resist composition containing an acid generator generating acid by exposure. A method for refining a crude resin includes a process (1) of preparing a crude resin solution by mixing a crude resin with a solvent containing an organic solvent (C) which can be used for a developer and a process (2) of obtaining residual liquid containing a resin for a resist by filtering a crude resin solution prepared by the process (1).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist composition, a method for preparing the resist composition, a method for preparing the resist composition,

The present invention relates to a method for purifying a crude resin, a resin for a resist, a method for producing a resist composition, a resist composition and a method for forming a resist pattern.

In the lithography technique, for example, a resist film made of a resist material is formed on a substrate, and the resist film is subjected to selective exposure and development processing, thereby forming a resist pattern of a predetermined shape on the resist film. A resist material in which the exposure portion of the resist film changes in properties to be dissolved in the developing solution in a positive type and a resist portion in which the exposure portion is not dissolved in a developing solution is referred to as a negative type.

BACKGROUND ART [0002] In recent years, in the production of semiconductor devices and liquid crystal display devices, patterns are being rapidly miniaturized by advances in lithography techniques.

As a method of micronization, the exposure light source is generally shortened in wavelength (high energy). Specifically, conventionally, ultraviolet rays represented by g-line and i-line have been used, but now semiconductor devices using KrF excimer laser or ArF excimer laser are mass-produced.

The resist material is required to have lithography characteristics such as sensitivity to the exposure light source and resolution to reproduce a fine pattern.

A chemically amplified resist composition containing a base component whose solubility in a developing solution changes by the action of an acid and an acid generator component which generates an acid by exposure is used as a resist material satisfying such a demand. For example, when the developer is an alkali developing solution (alkali developing process), the positive chemically amplified resist composition includes a resin component (base resin) that increases solubility in an alkali developing solution by the action of an acid, Is generally used. When a resist film formed using such a resist composition is subjected to selective exposure at the time of forming a resist pattern, acid is generated from the acid generator component in the exposed portion, and the solubility of the base resin in the alkali developer is increased by the action of the acid, It becomes soluble in an additional alkali developing solution. For this reason, by the alkali development, a positive pattern in which the unexposed portion remains as a pattern is formed.

Herein, the base resin having a high polarity of the resin due to the action of an acid is used to increase solubility in an alkali developing solution, while solubility in an organic solvent is reduced. Therefore, when a solvent developing process using a developing solution (organic developing solution) containing an organic solvent is applied instead of an alkali developing process, the solubility in the organic developing solution relatively decreases in the exposed portion of the resist film, A negative resist pattern is formed in which the unexposed portion of the film is dissolved or removed by an organic developer to leave an exposed pattern as a pattern. Thus, the solvent developing process for forming a negative resist pattern is referred to as a negative developing process (see, for example, Patent Document 1).

Presently, as a base resin of a chemically amplified resist composition used in ArF excimer laser lithography and the like, a resin (acrylic resin) having a structural unit derived from a (meth) acrylate ester as a main chain is excellent in transparency at around 193 nm (For example, refer to Patent Document 2).

In the present invention, the term "(meth) acrylic acid ester" means either or both of an acrylate ester having a hydrogen atom bonded to the α-position and a methacrylate ester having a methyl group bonded to the α-position. The term "(meth) acrylate" means either or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position. The term "(meth) acrylic acid" means either or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position.

Such a resin for resist may be obtained by, for example, (1) a method of purifying a polymer obtained by dropping the reaction solution into a poor solvent, followed by washing with an organic solvent or water, or 2) a solution prepared by dissolving a polymer precipitated from the reaction solution in a solvent for resist is treated with a purification method in which a solution is filtered using a specific filter (see, for example, Patent Document 3). Such purification results in elimination of impurities such as high-polarity components that coexist with the polymer, and the occurrence of defects is suppressed in forming a resist pattern to which an alkali development process is applied, and it is difficult for defects to occur during development.

Japanese Patent Application Laid-Open No. 2008-281974 Japanese Patent Application Laid-Open No. 2003-241385 Japanese Patent Application Laid-Open No. 2005-189789

However, in the formation of a resist pattern to which a solvent developing process using an organic developing solution is applied as a developing solution while pattern miniaturization is proceeding, the suppression of the occurrence of defects is insufficient.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to suppress the occurrence of defects in forming a resist pattern to which a solvent developing process is applied.

A first aspect of the present invention for solving the above problems is a resist composition for use in a resist composition containing a resin for resist in which the solubility in an organic solvent is reduced by the action of an acid and an acid generator for generating an acid by exposure, (1) for preparing a crude resin solution by mixing the above-mentioned crude resin with a solvent containing an organic solvent (C) which can be used as a developer, and a step (1) for preparing a crude resin solution, And a step (2) of filtering the crude resin solution to obtain a filtrate containing the resin for resist.

A second aspect of the present invention is a resist resin obtained by the method for purifying a crude resin according to the first aspect of the present invention.

A third aspect of the present invention is a method for producing a resist composition, which comprises mixing the resist resin of the second aspect of the present invention with an acid generator which generates an acid by exposure.

A fourth aspect of the present invention is a resist composition characterized by containing the resist resin of the second aspect of the present invention.

A fifth aspect of the present invention is a method for manufacturing a resist pattern, comprising the steps of forming a resist film on a support using the resist composition of the fourth aspect of the present invention, exposing the resist film, and developing the resist film by a negative type development using a developer containing an organic solvent And patterning the resist pattern to form a resist pattern.

According to the method for purifying crude resin of the present invention, it is possible to provide a resist resin suitable for a resist composition capable of forming a resist pattern in which the occurrence of defects is suppressed in forming a resist pattern to which a solvent developing process is applied.

According to the resist composition containing the resin for resist and the method of forming a resist pattern using the resist composition, a resist pattern in which the occurrence of defects is suppressed can be formed in forming a resist pattern to which a solvent developing process is applied.

In the present specification and claims, the term " aliphatic " is defined as meaning a group, compound, or the like having no aromaticity as a relative concept to an aromatic.

The term " alkyl group " includes monovalent saturated hydrocarbon groups which are linear, branched and cyclic unless otherwise specified. The same applies to the alkyl group in the alkoxy group.

The "alkylene group" is intended to include a divalent saturated hydrocarbon group which is linear, branched and cyclic unless otherwise specified.

The "halogenated alkyl group" is a group in which a part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

The "fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which a part or all of the hydrogen atoms of the alkyl group or alkylene group are substituted with fluorine atoms.

"Constituent unit" means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).

Includes the case where the hydrogen atom (-H) is substituted with a monovalent group and the case where a methylene group (-CH ₂ -) is substituted with a divalent group when describing "may have a substituent".

&Quot; Exposure " is a concept including the entire irradiation of radiation.

The term "structural unit derived from an acrylate ester" means a structural unit in which an ethylenic double bond of an acrylate ester is cleaved and constituted.

"Acrylic acid ester" is a compound in which the hydrogen atom at the carboxyl terminal end of acrylic acid (CH ₂ ═CH-COOH) is substituted with an organic group.

The acrylic acid ester may have a hydrogen atom bonded to the carbon atom at the? -Position thereof substituted with a substituent. The substituent (R ^{? 0} ) for substituting a hydrogen atom bonded to the carbon atom at the? ^-Position is an atom or a group other than a hydrogen atom, and examples thereof include an alkyl group having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms . Also, itaconic acid diesters in which a substituent (R ^{? 0} ) is substituted with a substituent containing an ester bond, or an? -Hydroxyacrylic ester in which a substituent (R ^{? 0} ) is substituted with a hydroxyalkyl group or a group do. The carbon atom at the? -Position of the acrylate ester is a carbon atom to which a carbonyl group of acrylic acid is bonded, unless otherwise specified.

Hereinafter, an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the? -Position is substituted with a substituent is referred to as? -Substituted acrylate ester. In addition, the term "(α-substituted) acrylate ester" includes an acrylate ester and an α-substituted acrylate ester.

The term "structural unit derived from acrylamide" means a structural unit in which an ethylenic double bond of acrylamide is cleaved and constituted.

The acrylamide may have a hydrogen atom bonded to the carbon atom at the? -Position, or may be substituted with a substituent at one or both of the hydrogen atoms of the amino group of the acrylamide. The carbon atom at the? -Position of acrylamide is a carbon atom to which a carbonyl group of acrylamide is bonded, unless otherwise specified.

The substituent substituting the hydrogen atom bonded to the carbon atom at the? -Position of the acrylamide is the same as the substituent (substituent (R ^{? 0} )) at the ^{? -Position} in the? -Substituted acrylate ester.

The term "structural unit derived from hydroxystyrene or hydroxystyrene derivative" means a structural unit in which an ethylenic double bond of hydroxystyrene or hydroxystyrene derivative is cleaved and constituted.

The term " hydroxystyrene derivative " is intended to include those in which hydrogen atoms at the alpha -position of hydroxystyrene are substituted with other substituents such as alkyl groups and halogenated alkyl groups, and derivatives thereof. Examples of these derivatives include those in which the hydrogen atom of the hydroxyl group of the hydroxystyrene, which hydrogen atom at the? -Position may be substituted with a substituent, is replaced with an organic group; those in which a substituent other than a hydroxyl group is bonded to a benzene ring of hydroxystyrene in which a hydrogen atom at the? -position may be substituted with a substituent, and the like. The? Position (carbon atom at?) Refers to a carbon atom to which a benzene ring is bonded unless otherwise specified.

Examples of the substituent for substituting the hydrogen atom at the? -Position of hydroxystyrene include the same substituents as those at the? -Position in the? -Substituted acrylate ester.

The "structural unit derived from a vinylbenzoic acid or a vinylbenzoic acid derivative" means a structural unit in which an ethylenic double bond of a vinylbenzoic acid or a vinylbenzoic acid derivative is cleaved and constituted.

The term " vinylbenzoic acid derivative " includes not only those in which the hydrogen atom at the? -Position of vinylbenzoic acid is substituted with another substituent such as an alkyl group, a halogenated alkyl group, and derivatives thereof. Examples of these derivatives include those in which the hydrogen atom of the carboxyl group of vinylbenzoic acid, which hydrogen atom at the? -Position may be substituted with a substituent, is replaced with an organic group; and a benzene ring of a vinylbenzoic acid in which a hydrogen atom at a position may be substituted with a substituent is bonded to a substituent other than a hydroxyl group and a carboxy group. The? Position (carbon atom at?) Refers to a carbon atom to which a benzene ring is bonded unless otherwise specified.

The term " styrene " includes the concept that hydrogen atoms at the [alpha] -position of styrene and styrene are substituted with other substituents such as an alkyl group and a halogenated alkyl group.

"Constituent unit derived from styrene" and "constituent unit derived from styrene derivative" refer to a constituent unit in which an ethylene double bond of styrene or styrene derivative is formed by cleavage.

The alkyl group as the substituent at the? -Position is preferably a linear or branched alkyl group, and more specifically, an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, -Butyl group, pentyl group, isopentyl group, neopentyl group).

Specific examples of the halogenated alkyl group as the substituent at the? -Position include groups in which a part or all of the hydrogen atoms of the "alkyl group as the substituent at the? -Position" are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable.

Specific examples of the hydroxyalkyl group as the substituent at the? -Position include groups in which a part or all of the hydrogen atoms of the "alkyl group as a substituent at the? -Position" are substituted with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

≪ Purification method of crude resin >

The method for purifying a crude resin as the first aspect of the present invention is a method for purifying a crude resin which is used in a resist composition containing a resin for resist in which the solubility in an organic solvent is reduced by the action of an acid and an acid generator for generating an acid by exposure, And refining the crude resin of the resin for use.

In the present invention, " crude resin " refers to a resin used in a resist composition, which has been uncured after completion of the polymerization reaction.

When the resist resin and the resist composition containing the acid generator are exposed to radiation, an acid is generated from the acid generator and the solubility of the resist resin in the organic solvent is reduced by the action of the acid. For this reason, in the formation of a resist pattern to which a solvent developing process is applied, when the resist film obtained using the resist composition is subjected to selective exposure, the solubility of the resist film in a developing solution (organic developing solution) On the other hand, since the solubility of the unexposed portion in the organic developing solution does not change, the unexposed portion is removed by the negative development using the organic developing solution to form a resist pattern.

The method for purifying a crude resin of the present invention comprises a step (1) of mixing a crude resin with a solvent containing an organic solvent (C) which can be used for a developer to prepare a crude resin solution, and a step (1) (2) of filtering the solution to obtain a filtrate containing the resist resin.

[Step (1)]

In step (1), a crude resin solution is prepared by mixing a crude resin with a solvent containing an organic solvent (C) (hereinafter, also referred to as "component (C)") At this time, what is insoluble in the solvent containing the component (C) is not dissolved in the solvent. As a result, impurities ((particularly polar oligomers), unreacted materials, and the like contained in the crude resin) contained in the crude resin are removed in the step (2), and therefore, in the resist pattern formation using the solvent development process , The occurrence of defects is suppressed.

In the step (1), a component (C) is added to a resin solution (hereinafter, this resin solution is referred to as " resin solution (X) ") obtained by mixing crude resin with an organic solvent. The crude resin solution is referred to as " crude resin solution (Y) "). By preparing the resin solution (X) before obtaining the crude resin solution (Y), handleability of resin preparation and purification efficiency are improved.

As a method for preparing the crude resin solution (Y), specifically, (1) a method of adding a component (C) (preferably an organic solvent (C1) described below) to the resin solution (X) A method of adding a component (C) and a mixed solvent of an organic solvent (preferably a mixed solvent of an organic solvent (C1) described later and an organic solvent other than the above) to the component (X) .

The content of the crude resin in the resin solution (X) is preferably 5% by mass or more, more preferably 6 to 30% by mass, and further preferably 7 to 25% by mass. In particular, in the case of (1) above, the content of the crude resin in the resin solution (X) is preferably 5 to 10% by mass. In the case of (2) above, the content of the crude resin in the resin solution (X) is preferably 5 to 25% by mass, more preferably 10 to 25% by mass. If the content of the crude resin is more than the lower limit value, the purification efficiency becomes better, and if the content is lower than the upper limit, the uniformity of the resin solution X becomes higher.

The organic solvent as the solvent of the resin solution (X) may be appropriately selected from one or more of known solvents conventionally used as a solvent for resists. Lactones such as? -Butyrolactone; Cyclic ketones such as cyclopentanone, cyclohexanone, cycloheptanone, and 4-methylcycloheptanone; Chain ketones such as acetone, methyl ethyl ketone, methyl n-pentyl ketone, methyl isopentyl ketone and 2-heptanone; Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol and dipropylene glycol; A compound having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; a monomethyl ether, monoethyl ether, Monoalkyl ethers such as monopropyl ether and monobutyl ether, and compounds having an ether bond such as monophenyl ether [among these, derivatives of alkylene glycol monoalkyl (e.g., propylene glycol monomethyl ether acetate (PGMEA) Ether acetate, and propylene glycol monomethyl ether (PGME). The alkyl group or alkylene group in the derivative preferably has 1 to 5 carbon atoms. Cyclic ethers such as dioxane, esters such as methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate and ethyl ethoxypropionate; Aniline, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene Aromatic organic solvents; Dimethyl sulfoxide (DMSO) and the like.

The organic solvent as the solvent of the resin solution (X) is preferably selected to be different from the organic solvent (C) component (particularly the organic solvent (C1)) described later. It is preferable to select the same one as the organic solvent (S) (at least one of the (S) components contained in the resist composition is a mixed solvent). By selecting the same organic solvent as that of the component (S), handling efficiency of the resin and purification efficiency are enhanced. In addition, removal of the component (C) at the time of concentration or the like becomes easy.

The component (C) may be any one capable of dissolving the crude resin, and may be appropriately selected from known organic solvents. Specific examples thereof include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents and ether solvents, hydrocarbon solvents and the like.

The ketone-based solvent is an organic solvent containing C-C (= O) -C in the structure. The ester solvent is an organic solvent containing C-C (= O) -O-C in the structure. The alcoholic solvent is an organic solvent containing an alcoholic hydroxyl group in the structure, and the " alcoholic hydroxyl group " means a hydroxyl group bonded to the carbon atom of the aliphatic hydrocarbon group. The nitrile solvent is an organic solvent containing a nitrile group in the structure. The amide-based solvent is an organic solvent containing an amide group in its structure. The ether solvent is an organic solvent containing C-O-C in the structure.

In the organic solvent, an organic solvent containing a plurality of functional groups characterizing each of the solvents is also present in the structure, but in this case, it corresponds to any solvent species including the functional group of the organic solvent. For example, diethylene glycol monomethyl ether corresponds to all of the alcohol solvents and ether solvents in the above-mentioned classification.

The hydrocarbon solvent is a hydrocarbon solvent which is made of a hydrocarbon which may be halogenated and has no substituent other than a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.

Examples of the ketone-based solvent include cyclic ketones and chain ketones, and examples thereof include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, But are not limited to, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetyl acetone, acetonyl acetone, ionone, diacetonyl alcohol, acetylcarbinol, Acetophenone, methylnaphthal ketone, isophorone, propylene carbonate, and methyl amyl ketone (2-heptanone). Among them, ketone-based solvents are preferably chain ketones and most preferably methylamyl ketone (2-heptanone).

Examples of the ester-based solvent include, for example,? -Butyrolactone, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, isoamyl ethyl, methoxyacetyl ethyl, ethoxyacetyl ethyl, propyleneglycol monomethyl Ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol Monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl Ethyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, propylene glycol monomethyl ether acetate, Acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2- Methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate , Butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, Methyl propionate, ethyl propionate, ethyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl- 3-ethoxypropionate, propyl-3-methoxypropionate, and the like. Among them, it is most preferable to use butyl acetate as the ester-based solvent.

Examples of the alcoholic solvent include alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert- butyl alcohol, isobutyl alcohol, n- Monohydric alcohols such as heptyl alcohol, n-octyl alcohol, n-decanol and 3-methoxy-1-butanol; Glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol; Ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monoethyl ether, methoxymethyl butanol, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, propylene And glycol ether solvents including hydroxyl groups such as glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether and propylene glycol monophenyl ether. Of these, glycol ether-based solvents are preferred.

The nitrile-based solvent includes, for example, acetonitrile, propionitrile, valeronitrile, butyronitrile, and the like.

Examples of the amide-based solvent include N, N-dimethyl-acetamide, N, N-dimethylformamide, Imidazolidinone, and the like.

Examples of the ether-based solvent include a glycol ether-based solvent containing the hydroxyl group; Glycol ether solvents which do not contain a hydroxyl group such as propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol dimethyl ether and diethylene glycol diethyl ether; Dioxane, tetrahydrofuran, anisole, perfluoro-2-butyltetrahydrofuran, perfluorotetrahydrofuran, 1,4-dioxane and the like. Among them, a glycol ether-based solvent such as a glycol ether-based solvent containing a hydroxyl group and a glycol ether-based solvent containing no hydroxyl group is preferable.

Examples of the hydrocarbon-based solvent include aliphatic hydrocarbon solvents such as pentane, hexane, octane, decane, 2,2,4-trimethylpentane, 2,2,3-trimethylhexane, perfluorohexane and perfluoroheptane ; Aromatic hydrocarbon solvents such as toluene, xylene, ethylbenzene, propylbenzene, 1-methylpropylbenzene, 2-methylpropylbenzene, dimethylbenzene, diethylbenzene, ethylmethylbenzene, trimethylbenzene, ethyldimethylbenzene and dipropylbenzene . Of these, aromatic hydrocarbon solvents are preferred.

Among them, a polar solvent is preferable as the component (C), and a ketone solvent, an ester solvent and a nitrile solvent are preferable. Among them, the component (C) is particularly preferably one or more selected from the group consisting of a ketone solvent and an ester solvent. Of the ketone solvents, chain ketones are preferred.

In the case of the method (2) for preparing the crude resin solution (Y), the organic solvent other than the component (C) in the component (C) and the mixed solvent of the organic solvent other than the component (C) (S) contained in the resist composition (in the case where the (S) component is a mixed solvent, any one or more of them) is preferably selected from the same ones as the organic solvent as the solvent . Specifically, lactones and derivatives of polyhydric alcohols are preferable. Derivatives of polyhydric alcohols are more preferable. Of these, alkylene glycol monoalkyl ether acetates are more preferable, and PGMEA is particularly preferable.

The organic solvent other than the component (C) may be the same as or different from the organic solvent as the solvent of the resin solution (X), and is preferably the same in terms of compatibility. In addition, by selecting the same organic solvent as the organic solvent as the solvent of the resin solution (X), handling efficiency of the resin and refinement efficiency are enhanced. The mixing ratio of the component (C) and the organic solvent other than the component (C) in the mixed solvent is preferably 90/10 to 10/90 in terms of the mass ratio expressed by "organic solvent other than the component (C) / component (C) More preferably 70/30 to 30/70, and even more preferably 60/40 to 40/60.

When such a mass ratio is within the above-mentioned preferable range, the handling efficiency of the crude resin and the purification efficiency are enhanced. Particularly, when the mass ratio is more than the lower limit, the impurities contained in the crude resin are more easily removed, and when the mass ratio is not more than the upper limit, the removal of the solvent is facilitated when the purification resin is separated.

(Crude resin solution)

The content of the crude resin in the crude resin solution (Y) is preferably 2% by mass or more, more preferably 3 to 10% by mass, and further preferably 4 to 8% by mass. When the content of the crude resin in the crude resin solution (Y) is not less than the lower limit value, the purification efficiency becomes better, and when the content is lower than the preferable upper limit value, the liquid stability of the crude resin solution (Y) is enhanced.

The solvent of the crude resin solution (Y) is preferably a mixed solvent of the component (C) and an organic solvent other than the above-mentioned components, and is preferably a mixed solvent of the component (C) and the component (S) Is more preferable. The component (C) is preferably the same as the organic solvent (the organic solvent is referred to as " organic solvent (C1) ") contained in the developer used for the negative type development when the resist pattern is formed using the resist composition.

The proportion of the component (C) in the solvent of the crude resin solution (Y) is preferably 10% by mass or more, more preferably 20 to 80% by mass, and still more preferably 30 to 70% by mass.

When the ratio of the component (C) in the solvent is within the above-mentioned preferable range, the handleability of the crude resin and the purification efficiency are enhanced. In particular, when the lower limit is more than the lower limit, the impurities contained in the crude resin are more easily removed, and when the upper limit is not more than the upper limit, the removal of the solvent is facilitated when the purification resin is separated.

When the solvent of the crude resin solution (Y) is a mixed solvent of the component (C) and an organic solvent other than the component (C), a mixture of the component (C) contained in the solvent of the crude resin solution The ratio is preferably 90/10 to 10/90, more preferably 70/30 to 30/70, and most preferably 60/40 to 30/70, in terms of the mass ratio expressed by "organic solvent other than the component (C) / component (C) More preferably 40/60.

The method of preparing the crude resin solution (Y) is not limited to the above-described embodiment. For example, the crude resin (solid phase) may be used as it is to dissolve it in the mixed solvent of the component (C) do.

[Step (2)]

In the step (2), the crude resin solution (Y) prepared in the step (1) is filtered to obtain a filtrate containing the resist resin.

Filtration of the crude resin solution (Y) can be carried out by a conventionally known method and is preferably carried out through a filter having a filtration membrane. The filtration membrane is not particularly limited as long as it is used for filtration applications of conventional photoresist compositions, and examples thereof include fluororesins such as PTFE (polytetrafluoroethylene); Polyolefin resins such as polypropylene and polyethylene; Polyamide resins such as nylon 6, nylon 66 and the like. Among them, it is preferable to remove unreacted materials such as polyethylene, polypropylene, nylon (nylon 66, nylon 6), oligomers produced as a by-product in the polymerization reaction, polymers having a low molecular weight or polymers (impurities) having a higher molecular weight than the aimed mass average molecular weight Is excellent and the effect of suppressing the generation of defects and the property of elution of the foreign materials (the preservation stability of the resist composition) are excellent.

The pore size of the filter is preferably 0.02 to 0.1 탆, more preferably 0.02 to 0.05 탆, from the viewpoint of effectively removing the impurities. If the pore size of the filter is less than 0.02 탆, the filtration rate may be slowed down and the productivity may be lowered. If it is larger than 0.1 占 퐉, it may be impossible to effectively remove the by-produced oligomer or low-molecular-weight polymer in the polymerization reaction, or the polymer having a higher molecular weight than the desired mass-average molecular weight.

It is particularly preferable that the crude resin solution (Y) is filtered through a filter having a filtration membrane in two stages. This makes it possible to effectively remove impurities such as polymers and oligomers, and thus has an effect of suppressing the generation of defects and a property of elongation of the foreign materials (storage stability of the resist composition).

As a specific example of the two-stage filtration process, a nylon filter is used as the first filtration process to filter the diluted resin solution, and as a second filtration process, the filtrate obtained in the first filtration process is further passed through a filter made of polypropylene , And a series of steps of filtration using a filtration method. A filter made of polyethylene may be used in the second filtration step.

By filtration in the step (2), a filtrate containing a resist resin is obtained.

Thereafter, an operation for precipitating a resin, for example, is performed from the filtrate, followed by filtration, drying and the like to obtain a resist resin (refined product). Alternatively, if necessary, the filtrate may be used as it is.

[Step (3)]

The method for purifying the crude resin of the present invention is not limited to the embodiment described above. For example, in addition to the steps (1) and (2), the step (3) of concentrating the filtrate obtained in the step (2) You can have it. By concentrating the filtrate, the component (C) can be removed from the resin solution (tablet resin solution) for preparing the resist composition, and the efficiency of preparation of the resist composition is enhanced. Further, by removing the component (C) and then preparing a resist composition, the applicability of the resist composition is improved.

Concentration of the filtrate can be carried out by a conventionally known method. By removing a part of the solvent from the filtrate, a resist resin solution adjusted to a desired resin concentration is obtained.

The resin solution for resist obtained may be used as it is. Alternatively, the solvent of the resin solution for resist may be completely removed and used as a solid resin.

<< Resin Resin >>

The resin for resist, which is the second aspect of the present invention, is obtained by the above-described method for purifying crude resin of the present invention. The resin for resist is a resin which is free of impurities contained in the crude resin and is suitable for a resist composition.

Such resins for resists are those having reduced solubility in an organic solvent due to the action of an acid, and are preferably organic compounds having film-forming ability. It is also preferable that the molecular weight is 1000 or more.

As the molecular weight of the resin in the present invention, the mass average molecular weight in terms of polystyrene by GPC (gel permeation chromatography) is used.

The resist resin of the present invention is preferably a polymer compound (A1) (hereinafter also referred to as "component (A1)") having a structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid.

As the component (A1), a polymer compound having a constituent unit (a2) containing a lactone-containing cyclic group, -SO ₂ -containing cyclic group or a carbonate-containing cyclic group in addition to the structural unit (a1) is preferable.

In addition to the constituent unit (a1), the constituent unit (a1) containing the polar group-containing aliphatic hydrocarbon group in addition to the constituent unit (a1) and the constituent unit (a2) Or a structural unit (a2)) is preferable.

(Constituent unit (a1))

The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid.

The "acid-decomposable group" is an acid-decomposable group capable of cleaving at least part of the bond of the structure of the acid-decomposable group by the action of an acid.

Examples of the acid-decomposable group whose polarity is increased by the action of an acid include groups which are decomposed by the action of an acid to generate a polar group.

Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO ₃ H). Among them, a polar group containing -OH (hereinafter referred to as &quot; OH-containing polar group &quot;) in the structure is preferable, a carboxyl group or a hydroxyl group is more preferable, and a carboxyl group is particularly preferable.

As the acid decomposable group, more specifically, a group in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

The term "acid-dissociable group" as used herein means (i) a group having an acid dissociable property capable of cleaving a bond between an acid-cleavable group and an atom adjacent to the acid-cleavable group through the action of an acid, or (ii) Refers to both of groups in which a bond between an acid-cleavable group and an atom adjacent to the acid-cleavable group can be cleaved by further occurrence of a decarboxylic acid reaction after cleavage of a part of the bonds.

It is necessary that the acid-cleavable group constituting the acid-decomposable group be a group having a lower polarity than the polar group generated by dissociation of the acid-cleavable group, whereby when the acid-cleavable group is dissociated by the action of an acid, Polarity is increased. As a result, the polarity of the entire component (A1) increases. As the polarity increases, the solubility of the developer relative to the developer is changed. When the developer is an alkaline developer, the solubility is increased. When the developer is an organic developer, the solubility is decreased.

The acid-dissociable group is not particularly limited, and the acid dissociable groups of the base resin for chemically amplified resists can be used.

Examples of the acid-dissociable group for protecting the carboxyl group or the hydroxyl group in the polar group include an acid dissociable group represented by the following formula (a1-r-1) (hereinafter referred to as "acetal-type acid dissociable group").

[Wherein Ra ' ¹ and Ra' ² are a hydrogen atom or an alkyl group, Ra ' ³ is a hydrocarbon group, and Ra' ³ may be bonded to any one of Ra ' ¹ and Ra' ² to form a ring.]

In formula (a1-r-1), at least one of Ra ' ¹ and Ra' ² is preferably a hydrogen atom, and more preferably both hydrogen atoms.

When Ra ' ¹ or Ra' ² is an alkyl group, examples of the alkyl group include the same alkyl groups as the substituents which may be bonded to the carbon atom at the α-position in the explanation of the α-substituted acrylate ester. Is preferred. Specifically, straight-chain or branched alkyl groups are preferred. More specifically, examples thereof include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl and neopentyl. And a methyl group is particularly preferable.

In the formula (a1-r-1), examples of the hydrocarbon group of Ra ' ³ include a straight chain or branched chain alkyl group and a cyclic hydrocarbon group.

The straight-chain alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include methyl, ethyl, n-propyl, n-butyl and n-pentyl. Among them, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specific examples thereof include isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl and 2,2-dimethylbutyl. desirable.

When Ra ' ³ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and the polycyclic group may be a monocyclic group.

The monocyclic alicyclic hydrocarbon group is preferably a group in which one hydrogen atom is removed from the monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane, cyclohexane, and the like.

The polycyclic alicyclic hydrocarbon group is preferably a group excluding one hydrogen atom from the polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobor Trichlorosilane, tetrachlorododecane, tetracyclododecane, and the like.

When the cyclic hydrocarbon group of Ra ' ³ is an aromatic hydrocarbon group, specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene and phenanthrene; And aromatic heterocyclic rings in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.

Specific examples of the aromatic hydrocarbon group include groups in which one hydrogen atom is removed from the aromatic hydrocarbon ring (aryl group); A group in which one of the hydrogen atoms of the aryl group is substituted with an alkylene group (e.g., a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, Arylalkyl groups), and the like. The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

When Ra ' ³ is bonded to any one of Ra' ¹ and Ra ' ² to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

Examples of the acid-dissociable group for protecting the carboxyl group in the polar group include an acid dissociable group represented by the following general formula (a1-r-2). Among the acid-cleavable groups represented by the following formula (a1-r-2), those constituted by an alkyl group are referred to as &quot; tertiary alkyl ester-type acid- cleavable group &quot;

Wherein Ra ' ⁴ to Ra' ⁶ are each a hydrocarbon group, and Ra ' ⁵ and Ra' ⁶ may be bonded to each other to form a ring.

Examples of the hydrocarbon group of Ra ' ⁴ to Ra' ⁶ include the same groups as those of Ra ' ³ above.

Ra ' ⁴ is preferably an alkyl group having 1 to 5 carbon atoms. When Ra ' ⁵ and Ra' ⁶ are bonded to each other to form a ring, there may be mentioned groups represented by the following general formula (a1-r2-1). On the other hand, when Ra ' ⁴ to Ra' ⁶ are not bonded to each other and are independent hydrocarbon groups, there may be mentioned groups represented by the following general formula (a1-r2-2).

[Wherein, Ra represents a hydrocarbon group, each is ¹² ~ Ra ^'14' group, Ra to form an aliphatic cyclic group together with the carbon atom of ¹⁰ combines' ¹⁰ is an alkyl group, Ra of 1 to 10 carbon atoms, ¹¹ is Ra independently .]

Equation (a1-r2-1) of, Ra is preferably an as "alkyl group having a carbon number of 1 to 10 of ¹⁰ the formula (a1-r-1) Ra of from" ³ straight chain or branched chain alkyl group of all. Equation (a1-r2-1) of, Ra 'is Ra ^{11' 10} The aliphatic ring formed together with carbon atoms bonded tableware formula (a1-r-1) Ra ' group is preferably any of an alkyl group of ³ in cyclic Do.

Equation (a1-r2-2) of, Ra ', and Ra ^{12' 14} are each independently preferably an alkyl group of 1 to 10 carbon atoms, wherein the alkyl group is formulas Ra ^'3 of the straight-on (a1-r-1) More preferably a group represented by a straight chain or branched chain alkyl group, more preferably a straight chain alkyl group having 1 to 5 carbon atoms, particularly preferably a methyl group or an ethyl group.

Is formula (a1-r2-2) of, Ra is ^"13 expression (a1-r-1) Ra of the" alkyl group having a straight chain, branched chain or cyclic hydrocarbon group exemplified as the ^group which is preferred. Among them, it is more preferable that R &lt; ³ &gt;

Specific examples of the group represented by the formula (a1-r2-1) are shown below. In the present specification, * in the formulas represents the number of bonds.

Specific examples of the groups represented by the above formula (a1-r2-2) are shown below.

Examples of the acid-dissociable group for protecting the hydroxyl group in the polar group include an acid-dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as a "tertiary alkyloxycarbonyl acid dissociable group" .

Wherein Ra ' ⁷ to Ra' ⁹ each represent an alkyl group.

In the formula (a1-r-3), each of Ra ' ⁷ to Ra' ⁹ is preferably an alkyl group having 1 to 5 carbon atoms, more preferably 1 to 3.

The total number of carbon atoms of each alkyl group is preferably from 3 to 7, more preferably from 3 to 5, and most preferably from 3 to 4.

Examples of the structural unit (a1) include a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the [alpha] -position may be substituted with a substituent, and having an acid-decomposable group whose polarity is increased by the action of an acid; As the structural unit derived from acrylamide, a structural unit comprising an acid-decomposable group whose polarity is increased by the action of an acid; A constituent unit in which at least a part of the hydrogen atoms in the hydroxyl group of the constituent unit derived from a hydroxystyrene or hydroxystyrene derivative is protected by a substituent comprising the acid-decomposable group; Structural units in which at least a part of hydrogen atoms in -C (= O) -OH of the constituent unit derived from vinylbenzoic acid or vinylbenzoic acid derivative is protected by a substituent containing the acid-decomposable group.

As the structural unit (a1), a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the [alpha] position may be substituted with a substituent is preferable.

Specific examples of such a structural unit (a1) include structural units represented by the following general formula (a1-1) or (a1-2).

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ¹ is a divalent hydrocarbon group which may have an ether bond, n _a1 is 0 to 2, and Ra ¹ is an acid dissociable group represented by the formula (a1-r-1) or (a1-r-2). Wa ¹ is a monovalent hydrocarbon group, n _a2 +1, n _a2 is 1 ~ 3, Ra ² is an acid-dissociable group represented by the formula (a1-r-1) or (a1-r-3). ]

In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms for R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, Butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group and neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which a part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms is substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable.

R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group because of industrial availability.

The hydrocarbon group of Va &lt; ¹ &gt; may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is preferably saturated.

More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group or an aliphatic hydrocarbon group containing a ring in the structure.

Also, Va ¹ may have an ether bond (-O-) between the carbon atoms of the above-mentioned divalent hydrocarbon group. The number of ether bonds present in Va ¹ may be one or two or more.

The straight-chain or branched-chain aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

The aliphatic hydrocarbon group in a straight chain is preferably an alkylene group of a straight chain, particularly a methylene group [-CH ₂ -], an ethylene group _{[- (CH 2) 2 -} ], a trimethylene group [- (CH _{2) 3} -], tetramethylene group [- (CH ₂ ) ₄ -], pentamethylene group [- (CH ₂ ) ₅ -] and the like.

Aliphatic hydrocarbon group of the branched chain is preferably an alkylene group of a branch chain, and specifically _{-CH (CH 3) -, -CH} (CH 2 CH 3) -, -C (CH 3) 2 -, -C (CH ₃ ) an alkylmethylene group such as - (CH ₂ CH ₃ ) -, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ ) -, or -C (CH ₂ CH ₃ ) ₂ -; _{-CH (CH 3) CH 2 -} , -CH (CH 3) CH (CH 3) -, -C (CH 3) 2 CH 2 -, -CH (CH 2 CH 3) CH 2 -, -C (CH ₂ CH _{3) 2} -CH ₂ - alkyl group such as ethylene; _{-CH (CH 3) CH 2 CH} 2 -, -CH 2 CH (CH 3) CH 2 - alkyl trimethylene group and the like; And alkyl alkylene groups such as alkyltetramethylene groups such as -CH (CH ₃ ) CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ ) CH ₂ CH ₂ - and the like. The alkyl group in the alkyl alkylene group is preferably a straight chain alkyl group having 1 to 5 carbon atoms.

As the aliphatic hydrocarbon group containing a ring in the structure, an alicyclic hydrocarbon group (a group in which two hydrogen atoms are removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a straight chain or branched chain aliphatic hydrocarbon group, And a group in which a hydrocarbon group is introduced in the middle of a straight chain or branched chain aliphatic hydrocarbon group. Examples of the straight chain or branched chain aliphatic hydrocarbon group include the same ones as described above.

The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.

The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms are removed from the monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane, cyclohexane, and the like.

The polycyclic alicyclic hydrocarbon group is preferably a group excluding two hydrogen atoms from the polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobor Trichlorosilane, tetrachlorododecane, tetracyclododecane, and the like.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.

The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, 10 is most preferable. Provided that the number of carbon atoms does not include the number of carbon atoms in the substituent group.

Specific examples of the aromatic ring of the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene and phenanthrene; And aromatic heterocyclic rings in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.

Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms are removed from the aromatic hydrocarbon ring (arylene group); A group in which one of the hydrogen atoms of the group (aryl group) excluding one hydrogen atom from the aromatic hydrocarbon ring is substituted with an alkylene group (e.g., a benzyl group, a phenethyl group, a 1-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, and other arylalkyl groups). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

The formula (a1-2) wherein n valent group _a2 +1 hydrocarbons from Wa ¹ is an aliphatic hydrocarbon contribution, contribution is an aromatic hydrocarbon. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, and may be saturated or unsaturated, and usually saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, a ring-containing aliphatic hydrocarbon group, or a combination of a straight chain or branched chain aliphatic hydrocarbon group and a ring-containing aliphatic hydrocarbon group .

The n _a2 + 1 is preferably 2 to 4, more preferably 2 or 3.

Specific examples of the structural unit represented by the formula (a1-1) are shown below. In the following formulas, R ^{? Represents} a hydrogen atom, a methyl group or a trifluoromethyl group.

Specific examples of the structural unit represented by the formula (a1-2) are shown below.

The constituent unit (a1) of the component (A1) may be one kind or two or more kinds.

The proportion of the structural unit (a1) in the component (A1) is preferably from 10 to 80 mol%, more preferably from 15 to 75 mol%, still preferably from 20 to 70 mol%, based on the total structural units constituting the component (A1) Is more preferable.

When the ratio of the constituent unit (a1) is set to the lower limit value or more, a resist pattern can easily be obtained when the component (A1) is incorporated in the resist composition, and lithography characteristics such as sensitivity, resolution and LWR are improved. In addition, by keeping the value below the upper limit value, balance with other constituent units can be obtained.

(The constituent unit (a2))

The structural unit (a2) is a structural unit containing a lactone-containing cyclic group, -SO ₂ -containing cyclic group or a carbonate-containing cyclic group.

The lactone-containing cyclic group, -SO ₂ -containing cyclic group or carbonate-containing cyclic group of the constituent unit (a2) is effective in enhancing the adhesion of the resist film to the substrate when the component (A1) is used for forming a resist film.

When the structural unit (a1) includes a lactone-containing cyclic group, -SO ₂ -containing cyclic group or a carbonate-containing cyclic group in its structure, the structural unit also corresponds to the structural unit (a2) Such a structural unit corresponds to the structural unit (a1) and does not correspond to the structural unit (a2).

The "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -O-C (═O) - in the ring skeleton. A lactone ring is referred to as a first ring, and a lactone ring is referred to as a monocyclic group, and in the case of a ring structure having another ring structure, it is referred to as a polycyclic group regardless of its structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.

The lactone-containing cyclic group in the structural unit (a2) is not particularly limited, and any cyclic group can be used. Specific examples thereof include groups represented by the following general formulas (a2-r-1) to (a2-r-7).

[Wherein, Ra ^'21 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR ", -OC (= O ) R", a hydroxyalkyl group or a cyano group; R "is a hydrogen atom or an alkyl group; A" is an alkylene group, an oxygen atom or a sulfur atom having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-) An integer of 0 to 2, and m 'is 0 or 1.]

In the above general formula (a2-r-1) ~ (a2-r-7), the alkyl group in Ra ^'21 is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably a straight chain or branched chain. Specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl and hexyl. Among them, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.

Ra 'The alkoxy group in ²¹ is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably a straight chain or branched chain. Specifically, there may be mentioned an alkyl group and an oxygen atom (-O-) heard as the alkyl group in the Ra ^'21 is connected.

Ra 'halogen atoms of ²¹ may be a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a fluorine atom is preferable.

Ra 'with a halogenated alkyl group of from ²¹ wherein Ra' may be a group in which some or all of the hydrogen atoms of the alkyl group in the ²¹ halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

In the Ra 'at -COOR ^{21 ", -OC (= O)} R", R " is a hydrogen atom or an alkyl group;

The alkyl group in R "may be any of linear, branched and cyclic, and the number of carbon atoms is preferably from 1 to 15.

When R "is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, particularly preferably a methyl group or an ethyl group.

When R "is a cyclic alkyl group, the number of carbon atoms is preferably from 3 to 15, more preferably from 4 to 12, and most preferably from 5 to 10. Specifically, it may be substituted with a fluorine atom or a fluorinated alkyl group Examples of the monocycloalkane include a monocycloalkane which may not be substituted, a polycycloalkane such as a bicycloalkane, a tricycloalkane, a tetracycloalkane, etc., and a group in which at least one hydrogen atom is removed, etc. More specifically, Hexane and the like, and groups in which at least one hydrogen atom is removed from a polycycloalkane such as adamantane, norbornane, isoborane, tricyclodecane, and tetracyclododecane.

Ra may be a group, a hydroxy alkyl group of ²¹ carbon atoms is 1 to 6 is preferable, and specifically, the Ra 'is substituted by at least one is the hydroxyl group of the hydrogen atoms of the alkyl group in ^21.

Among the alkylene groups of 1 to 5 carbon atoms in A "in the general formulas (a2-r-2), (a2-r-3) and (a2-r-5), linear or branched alkylene groups When the alkylene group includes an oxygen atom or a sulfur atom, specific examples thereof include the terminal of the alkylene group or the carbon atom of the alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group and an isopropylene group. -O- or -S- interposed therebetween, and examples thereof include -O-CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S- CH ₂ -. A "is preferably an alkylene group of 1 to 5 carbon atoms or -O-, more preferably an alkylene group of 1 to 5 carbon atoms, and most preferably a methylene group.

Specific examples of the groups represented by the general formulas (a2-r-1) to (a2-r-7) are described below.

The "-SO ₂ -containing cyclic group" refers to a cyclic group containing a ring containing -SO ₂ - in its ring skeleton, and more specifically, the sulfur atom (S) in -SO ₂ - It is a circulating machine that forms part of the skeleton. In the ring skeleton, a ring containing -SO ₂ - is referred to as a first ring, and in the case of the ring, a monocyclic group and a ring having another ring structure are referred to as a polycyclic group regardless of the structure thereof. The -SO ₂ -containing cyclic group may be monocyclic or polycyclic.

The -SO ₂ -containing cyclic group is particularly preferably a cyclic group containing -O-SO ₂ - in its ring skeleton, that is, a sultone ring in which -OS-in -O-SO ₂ - forms part of a cyclic skeleton Is preferably a cyclic group.

Specific examples of the -SO ₂ -containing cyclic group include the groups represented by the following general formulas (a5-r-1) to (a5-r-4).

(Wherein Ra ^'51 is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR ", -OC (= O) R", a hydroxyalkyl group or a cyano group; R "is a hydrogen atom or an alkyl group; A" is an alkylene group, an oxygen atom or a sulfur atom having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom; and n 'is an integer of 0 to 2.

In the general formulas (a5-r-1) to (a5-r-4), A " A ".

(A2-r-1) to (a2-r) in the above Ra ^{'51 can be used} as the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR " -7) it is the same as those in the description of any of the Ra ^'21.

Specific examples of the groups represented by the general formulas (a5-r-1) to (a5-r-4) are described below. "Ac" in the formula represents an acetyl group.

The "carbonate-containing cyclic group" refers to a cyclic group containing a ring (carbonate ring) containing -O-C (═O) -O- in the ring skeleton. A carbonate ring is referred to as a first ring and a monocyclic group in the case of a carbonate ring and a polycyclic group in the case of having another ring structure, regardless of the structure thereof. The carbonate-containing cyclic group may be monocyclic or polycyclic.

The carbonate ring-containing cyclic group is not particularly limited and any arbitrary group can be used. Specific examples thereof include groups represented by the following general formulas (ax3-r-1) to (ax3-r-3).

Wherein each Ra ' ^x31 is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR ", -OC (= O) R", a hydroxyalkyl group or a cyano group; R "is a hydrogen atom or an alkyl group; A" is an alkylene group, an oxygen atom or a sulfur atom having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom; and q 'is 0 or 1.

Among the above-mentioned general formulas (ax3-r-1) to (ax3-r-3), A "is a group represented by the general formula (a2-r-2), (a2- A ".

(A2-r-1) to (a2-r) in the above Ra ^'31 are the same as the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR " -7) it is the same as those in the description of any of the Ra ^'21.

Specific examples of the groups represented by the general formulas (ax3-r-1) to (ax3-r-3) are described below.

As the structural unit (a2), a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the? -Position may be substituted with a substituent is preferable.

Such a structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ²¹ is a single bond or a divalent linking group. La ²¹ represents -O-, -COO-, -CON (R ') -, -OCO-, -CONHCO- or -CONHCS-, and R' represents a hydrogen atom or a methyl group. Provided that when La ²¹ is -O-, then Ya ²¹ is not -CO-. Ra ²¹ is a lactone-containing cyclic group, a carbonate-containing cyclic group or a -SO ₂ -containing cyclic group.]

In the formula (a2-1), R is the same as defined above.

The bivalent linking group of Ya ²¹ is not particularly limited, but may be a bivalent hydrocarbon group which may have a substituent or a divalent linking group containing a heteroatom.

In Ya ²¹ , the hydrocarbon group as a divalent linking group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually saturated.

Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group or an aliphatic hydrocarbon group containing a ring in the structure.

The straight-chain or branched-chain aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

The aliphatic hydrocarbon group in a straight chain is preferably an alkylene group of a straight chain, particularly a methylene group [-CH ₂ -], an ethylene group _{[- (CH 2) 2 -} ], a trimethylene group [- (CH _{2) 3} -], tetramethylene group [- (CH ₂ ) ₄ -], pentamethylene group [- (CH ₂ ) ₅ -] and the like.

Aliphatic hydrocarbon group of the branched chain is preferably an alkylene group of a branch chain, and specifically _{-CH (CH 3) -, -CH} (CH 2 CH 3) -, -C (CH 3) 2 -, -C (CH ₃ ) an alkylmethylene group such as - (CH ₂ CH ₃ ) -, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ ) -, or -C (CH ₂ CH ₃ ) ₂ -; _{-CH (CH 3) CH 2 -} , -CH (CH 3) CH (CH 3) -, -C (CH 3) 2 CH 2 -, -CH (CH 2 CH 3) CH 2 -, -C (CH ₂ CH _{3) 2} -CH ₂ - alkyl group such as ethylene; _{-CH (CH 3) CH 2 CH} 2 -, -CH 2 CH (CH 3) CH 2 - alkyl trimethylene group and the like; And alkyl alkylene groups such as alkyltetramethylene groups such as -CH (CH ₃ ) CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ ) CH ₂ CH ₂ - and the like. The alkyl group in the alkyl alkylene group is preferably a straight chain alkyl group having 1 to 5 carbon atoms.

The straight chain or branched chain aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and a carbonyl group.

Examples of the aliphatic hydrocarbon group having a ring in the structure include a cyclic aliphatic hydrocarbon group (a group excluding two hydrogen atoms from an aliphatic hydrocarbon ring) which may contain a hetero atom-containing substituent in the ring structure, a cyclic aliphatic hydrocarbon group A group bonded to the terminal of the chain or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the straight chain or branched chain aliphatic hydrocarbon group. Examples of the straight chain or branched chain aliphatic hydrocarbon group include the same ones as described above.

The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.

The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms are removed from the monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane, cyclohexane, and the like. The polycyclic alicyclic hydrocarbon group is preferably a group excluding two hydrogen atoms from the polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobor Trichlorosilane, tetrachlorododecane, tetracyclododecane, and the like.

The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group.

The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.

The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, a n-butoxy group or a tert- The ethoxy group is most preferred.

Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.

Examples of the halogenated alkyl group as the substituent include groups in which a part or all of the hydrogen atoms of the alkyl group are substituted with the halogen atom.

The cyclic aliphatic hydrocarbon group may be substituted with a substituent group in which a part of the carbon atoms constituting the cyclic structure includes a hetero atom. The substituent containing the hetero atom is preferably -O-, -C (= O) -O-, -S-, -S (= O) _2- or -S (= O) ₂ -O-.

The aromatic hydrocarbon group as the divalent hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 &lt; [pi] &gt; electrons, and may be a monocyclic or polycyclic system. The carbon number of the aromatic ring is preferably from 5 to 30, more preferably from 5 to 20, still more preferably from 6 to 15, and particularly preferably from 6 to 12. Provided that the number of carbon atoms does not include the number of carbon atoms in the substituent group. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; And aromatic heterocyclic rings in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.

Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms are removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); A group in which two hydrogen atoms are removed from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.); A group in which one of the hydrogen atoms of the group (aryl group or heteroaryl group) excluding one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g., a benzyl group, a phenethyl group, a 1-naphthyl group A group in which one hydrogen atom is further removed from an aryl group in an arylalkyl group such as a methyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group and a 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aryl group or the heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

In the aromatic hydrocarbon group, the hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.

The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.

Examples of the alkoxy group, the halogen atom and the halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

When Y ^{&lt; a} &gt; is a divalent linking group containing a heteroatom, preferable examples of the linking group include -O-, -C (= O) -O-, -C (= O) -, -OC -, -C (= O) -NH-, -NH-, -NH-C (= NH) - (H may be substituted with a substituent such as an alkyl group or an acyl group) = O) ₂ -, -S (= O) ₂ -O-, -Y ²¹ -OY ²² -, -Y ²¹ -O-, -Y ²¹ -C ^{21 -C (= O) -O]} m "-Y 22 -, -Y 21 -OC (= O) -Y 22 - or _{^{-Y 21 -S (= O) 2}} -OY 22 - group represented by the formula Middle, Y ²¹ And Y ²² are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m "is an integer of 0 to 3.].

The divalent linking group containing the hetero atom may be -C (= O) -NH-, -C (= O) -NH-C (= O) -, -NH-, -NH-C , This H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.

Formula ^{-Y 21 -OY 22 -, -Y 21} -O-, -Y 21 -C (= O) -O-, - [Y 21 -C (= O) -O] m "-Y 22 -, ^{-Y 21 -OC (= O) -Y} 22 - or _{^{-Y 21 -S (= O) 2}} -OY 22 - of, Y ²¹ and Y ²² are groups each independently 2, which may be substituted monovalent hydrocarbon group. Examples of the bivalent hydrocarbon group include the same groups as those described above for the divalent linking group (bivalent hydrocarbon group which may have a substituent).

Y ²¹ is preferably a straight-chain aliphatic hydrocarbon group, more preferably a straight-chain alkylene group, more preferably a straight-chain alkylene group having 1 to 5 carbon atoms, particularly preferably a methylene group or an ethylene group.

Y ²² is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a straight-chain alkyl group having 1 to 5 carbon atoms, more preferably a straight-chain alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

In the group represented by the formula - [Y ²¹ -C (═O) -O] _{m "} -Y ²² -, m" is an integer of 0 to 3, preferably 0 to 2, more preferably 0 or 1 , And 1 is particularly preferable. The group represented by the formula - [Y ²¹ -C (═O) -O] _{m "} -Y ²² - is particularly preferably a group represented by the formula -Y ²¹ -C (═O) -OY ²² - A 'is an integer of from 1 to 10, and an integer of from 1 to 8 is preferably an integer of from 1 to 10, preferably a group represented by the formula - (CH ₂ ) _a' -C (= O) -O- (CH ₂ ) _{b '} B 'is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably an integer of 1 to 4, more preferably an integer of 1 to 5, More preferably 1, more preferably 1 or 2, and most preferably 1.

Ya ²¹ is preferably a single bond, an ester bond [-C (= O) -O-], an ether bond (-O-), a linear or branched alkylene group or a combination thereof.

In the formula (a2-1), Ra ²¹ is a lactone-containing cyclic group, -SO ₂ - containing cyclic group or a carbonate-containing cyclic group.

Examples of the lactone-containing cyclic group, -SO ₂ -containing cyclic group and carbonate-containing cyclic group at Ra ²¹ include groups represented by the general formulas (a2-r-1) to (a2-r-7) (a3-r-1) to (a5-r-4), and groups represented by formulas (ax3-r-1) to (ax3-r-3), respectively.

Among them, a lactone-containing cyclic group or -SO ₂ -containing cyclic group is preferable, and the groups represented by the general formulas (a2-r-1), (a2-r-2) or (a5-r-1) Do. (R-lc-1-17), (r-lc-2-1) to (r- 1-1) and (r-sl-1-18), respectively.

The constituent unit (a2) of the component (A1) may be one kind or two or more kinds.

When the component (A1) has the structural unit (a2), the proportion of the structural unit (a2) is preferably from 1 to 80 mol%, more preferably from 10 to 80 mol%, based on the total structural units constituting the component (A1) , More preferably 70 mol%, still more preferably 10 mol% to 65 mol%, and particularly preferably 10 mol% to 60 mol%.

By making the ratio of the constituent unit (a2) to the lower limit value or more, the effect of incorporating the constituent unit (a2) can be sufficiently obtained. By making the ratio lower than the upper limit value, balance with other constituent units can be obtained, And the pattern shape is improved.

(The constituent unit (a3))

The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (except for the structural unit (a1) or structural unit (a2) described above).

When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A1) increases. It is believed that the component (A1) contributes to improvement in resolution when used for forming a resist film.

Examples of the polar group include a hydroxyl group, a cyano group, a carboxyl group, a hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group is substituted with a fluorine atom, and particularly, a hydroxyl group is preferable.

Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) or a cyclic aliphatic hydrocarbon group (a cyclic group). The cyclic group may be a monocyclic group or a cyclic group, and may be appropriately selected from among those proposed for a resin for a resist composition for an ArF excimer laser. The cyclic group is preferably a polycyclic group, and more preferably 7 to 30 carbon atoms.

Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of the hydrogen atoms of the hydroxyl group, cyano group, carboxyl group or alkyl group is substituted with a fluorine atom is more preferable. Examples of the polycyclic group include groups excluding two or more hydrogen atoms in a bicycloalkane, a tricycloalkane, a tetracycloalkane, and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isoborane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, a group excluding two or more hydrogen atoms from adamantane, a group excluding two or more hydrogen atoms from norbornane, and a group excluding two or more hydrogen atoms from tetracyclododecane are industrially preferable.

The structural unit (a3) is not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any structural unit (a3) can be used.

As the structural unit (a3), a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the? -Position may be substituted with a substituent is preferably a structural unit containing a polar group-containing aliphatic hydrocarbon group.

When the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the structural unit (a3) is preferably a structural unit derived from a hydroxyethyl ester of acrylic acid, and the hydrocarbon group is preferably a polycyclic (A3-1), a structural unit represented by the formula (a3-2), and a structural unit represented by the formula (a3-3) are preferable.

Wherein R is as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, 1 is an integer of 1 to 5, s is It is an integer from 1 to 3.]

In formula (a3-1), j is preferably 1 or 2, more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3-position and the 5-position of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.

j is preferably 1, and it is particularly preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.

In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5-position or the 6-position of the norbornyl group.

In formula (a3-3), t 'is preferably 1. l is preferably 1. s is preferably 1. It is preferable that the 2-norboronyl group or 3-norbornyl group is bonded to the terminal of the carboxyl group of acrylic acid. It is preferable that the fluorinated alkyl alcohol is bonded to the 5th or 6th position of the norbornyl group.

The constituent unit (a3) of the component (A1) may be one kind or two or more kinds.

When the component (A1) has the structural unit (a3), it is preferably from 5 to 50 mol%, more preferably from 5 to 40 mol% based on the total of all the structural units constituting the component (A1) More preferably 5 to 30 mol%.

By making the ratio of the constituent unit (a3) to be equal to or more than the lower limit value, the effect of containing the constituent unit (a3) can be sufficiently obtained. When the proportion is below the upper limit value, balance with other constituent units can be easily obtained.

(Other constituent units)

(A1) may contain, in addition to the structural units (a1) to (a3), other structural units which do not correspond to these structural units.

The other structural unit is not particularly limited as long as it is a structural unit that can not be classified as the above-mentioned structural unit, and is used for a resist resin for ArF excimer laser or KrF excimer laser (preferably ArF excimer laser) (A4) shown below and a structural unit (a5) for generating an acid upon exposure, and the like can be given.

Constituent unit (a4):

The structural unit (a4) is a structural unit containing an acid-labile aliphatic cyclic group.

When the component (A1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved when the component (A1) is used for forming a resist film. In addition, the hydrophobicity of the component (A1) increases. It is considered that the improvement of the hydrophobicity contributes to the improvement of the resolution and the resist pattern shape particularly in the case of organic solvent development.

The &quot; acid-unlike cyclic group &quot; in the structural unit (a4) is a structural unit in which the acid is generated in the resist composition (when an acid is generated from the acid generator or the like) The remaining is the circular tableware.

As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing an acid-labile aliphatic cyclic group is preferable. Examples of the cyclic group include the same ones as those exemplified above for the structural unit (a1), and a resist composition such as ArF excimer laser or KrF excimer laser (preferably ArF excimer laser) A large number of conventionally known ones can be used.

Particularly, at least one member selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group and a norbornyl group is preferable from the standpoint of industrial availability and the like. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

Specific examples of the structural unit (a4) include structural units represented by the following general formulas (a4-1) to (a4-7).

[Wherein R ^? Is as defined above].

The constituent unit (a4) of the component (A1) may be one kind or two or more kinds.

When the component (A1) has the structural unit (a4), the proportion of the structural unit (a4) is preferably from 1 to 30 mol%, more preferably from 3 to 30 mol% based on the total structural units constituting the component (A1) More preferably 20 mol%.

When the proportion of the structural unit (a4) is at least the lower limit value, the effect of incorporating the structural unit (a4) can be sufficiently obtained. When the proportion is smaller than the upper limit value, balance with other structural units can be easily obtained.

As the resist resin, it is preferable that the component (A1) is a polymer having at least the constituent unit (a1).

Examples of the component (A1) include a copolymer having at least one structural unit selected from the structural units (a2) to (a5) in addition to the structural unit (a1). Among them, a copolymer having at least one structural unit selected from the structural unit (a2) and the structural unit (a3) in addition to the structural unit (a1) is more preferable.

Such a copolymer may be a copolymer comprising a repeating structure of the constituent units (a1) and (a2), a repeating structure of the constituent units (a1) and (a3); A copolymer consisting of repeating units of the structural units (a1), (a2) and (a3); And a repeating structure of the structural units (a1), (a2), (a3) and (a4). Of these, the repeating units of the structural units (a1), (a2) Is particularly preferred.

The mass average molecular weight (Mw) (based on polystyrene conversion by gel permeation chromatography (GPC)) of the component (A1) is not particularly limited and is preferably from 1,000 to 50,000, more preferably from 1,500 to 30,000, Is most preferable. If it is not more than the upper limit of the above range, the resist resin is sufficiently soluble in a resist solvent. If the lower limit of the above range is exceeded, the dry etching resistance and the cross-sectional shape of the resist pattern are favorable.

The dispersion degree (Mw / Mn) is not particularly limited and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5. Mn represents the number average molecular weight.

The component (A1) can be obtained by polymerizing a monomer which derives each constituent unit by, for example, known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate .

The chain transfer agent such as HS-CH ₂ -CH ₂ -CH ₂ -C (CF ₃ ) ₂ -OH is used in combination with the component (A1) ₃ ) ₂ -OH group may be introduced. As described above, a copolymer into which a hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group is substituted with a fluorine atom is introduced is effective for reduction of development defects and reduction of LER (line edge roughness: uneven irregularity of line side wall) Valid.

The monomer for deriving each constituent unit may be a commercially available monomer, or a monomer synthesized using a known method may be used.

The resist resin of the present invention, that is, the resin obtained by the method of purifying the crude resin of the present invention described above is suitable for a resist composition, and particularly, in forming a resist pattern in a solvent development process, It is suitable for a resist composition capable of forming a pattern. In addition, the component (A1) is particularly suitable as a base resin for a resist composition.

&Lt; Method of producing resist composition &

A third aspect of the present invention is a method for producing a resist composition by mixing the aforementioned resin for resist of the present invention and an acid generator for generating an acid upon exposure.

For example, a resist composition is prepared by dissolving the resist resin, the acid generator, and, if necessary, other components in a solvent for resist.

As the resist resin, the filtrate obtained in the step (2) in the method of purifying the crude resin of the present invention may be used as it is, or a solid resin separated from the filtrate may be used. Alternatively, the resin solution for resist after the concentration obtained in the step (3) may be used as it is, or the solvent of the resin solution for resist may be completely removed to use a solid resin.

&Quot; Resist composition &

The resist composition according to the fourth aspect of the present invention comprises a resin for resist (hereinafter referred to as "component (A)") whose solubility in an organic solvent is reduced by the action of an acid and an acid generator Quot; component (B) &quot;).

When a resist film is formed using such a resist composition and selectively exposed to the resist film, an acid is generated in the exposed portion and the solubility of the component (A) in the developer is changed by the action of the acid, while in the unexposed portion Since the solubility of the component A in the developer does not change, a difference in solubility in the developer occurs between the exposed portion and the unexposed portion. Therefore, when the resist film is developed, when the resist composition is a positive type, the exposed portion is dissolved and removed to form a positive resist pattern. When the resist composition is negative, the unexposed portion is dissolved and removed to form a negative resist pattern .

In the present specification, a resist composition for forming a positive resist pattern by dissolving and removing an exposed portion is referred to as a positive resist composition, and a negative resist composition for forming a negative resist pattern through dissolution and removal of an unexposed portion is referred to as a negative resist composition.

The resist composition of the present invention may be a positive resist composition or a negative resist composition.

The resist composition of the present invention may be used for an alkali development process using an alkali developer for development processing at the time of forming a resist pattern, and for a solvent development process using a developer (organic developer) containing an organic solvent for the development process do. Among them, the resist composition of the present invention is particularly preferably used for forming a resist pattern by applying a solvent developing process.

&Lt; Resin for Resin Reducing Solubility to Organic Solvent by the Action of Acid: Component (A) &gt;

The resist composition of the present invention has an acid-generating ability to generate an acid upon exposure, and in addition to the component (B), the component (A) may also generate an acid by exposure. When the component (A) also generates an acid by exposure, the component (A) becomes a &quot; resin which generates an acid upon exposure and has a reduced solubility in an organic solvent by the action of an acid &quot;. As the component (A), a resin having a structural unit (a5) capable of generating an acid upon exposure and having reduced solubility in an organic solvent by the action of an acid can be used. As the structural unit (a5), known ones can be used.

In the case where the resist composition of the present invention is a "negative resist composition for alkali developing process" in which a negative resist pattern is formed in an alkali developing process or in a solvent developing process, (A-2) (hereinafter referred to as "component (A-2)") is preferably used as the component (A) do. When an acid is generated from the component (B) by exposure to light, the acid acts to cross-link the component (A-2) and the crosslinking agent component, and as a result, the solubility in an alkali developing solution decreases The solubility is increased). Therefore, in the formation of a resist pattern, when the resist film obtained by applying the resist composition on a support is selectively exposed, the exposed portion is changed to an insoluble (soluble in an organic developer) to an alkaline developer, The resist pattern is not changed while being soluble (poorly soluble in an organic developing solution). Therefore, a negative resist pattern is formed by developing with an alkaline developing solution. At this time, a positive type resist pattern is formed by developing with an organic developing solution.

(Hereinafter referred to as &quot; alkali-soluble resin &quot;) that is soluble in a component (A-2), that is, an alkali developing solution, includes, for example,? - (hydroxyalkyl) acrylic acid , Or a unit derived from at least one selected from alkyl esters of? - (hydroxyalkyl) acrylic acid (preferably alkyl esters having 1 to 5 carbon atoms); An acrylic resin or a polycycloolefin resin in which a hydrogen atom bonded to a carbon atom at an alpha position having a sulfonamide group, which is disclosed in U.S. Patent No. 6949325, may be substituted with a substituent; Acrylic resins containing a fluorinated alcohol and hydrogen atoms bonded to carbon atoms at the? Position may be substituted with substituents, as disclosed in U.S. Patent Nos. 6949325, 2005-336452, and 2006-317803; A polycycloolefin resin having a fluorinated alcohol disclosed in Japanese Patent Application Laid-Open No. 2006-259582 and the like are preferable because a good resist pattern with little swelling can be formed.

Further, in the above-mentioned? - (hydroxyalkyl) acrylic acid, acrylic acid in which a hydrogen atom bonded to the carbon atom at the? -Position to which a carboxy group binds and an acrylic acid in which a hydrogen atom bonded to the carbon atom at the? Hydroxyalkylacrylic acid in which a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) is bonded to a carbon atom at a position of the? -Hydroxyalkylacrylic acid.

As the crosslinking agent component, for example, an amino-based crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, or a melamine-based crosslinking agent is usually used, which is preferable because a good resist pattern with less swelling can be formed. The blending amount of the crosslinking agent component is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the alkali-soluble resin.

In the case where the resist composition of the present invention is a &quot; positive resist composition for alkali developing process &quot; in which a positive pattern is formed in an alkali developing process, or a &quot; negative resist for solvent developing process &quot; (A-1) "(hereinafter referred to as" component (A-1) ") whose polarity is increased by the action of an acid is used as the component (A). By using the component (A-1), since the polarity of the resin changes before and after the exposure, a good development contrast can be obtained not only in the alkali development process but also in the solvent development process.

In the case of applying the alkali development process, the component (A-1) is poorly soluble in an alkali developing solution before exposure, and when an acid is generated by exposure, the polarity increases due to the action of the acid and the solubility in an alkali developing solution Increase. Therefore, in the formation of a resist pattern, when the resist composition obtained by applying the resist composition on a support is selectively exposed to light, the exposed portion changes from being poorly soluble to soluble in an alkaline developer, while the unexposed portion is a non- Since it does not change, a positive pattern is formed by alkali development.

On the other hand, when the solvent developing process is applied, the component (A-1) has high solubility in an organic developing solution before exposure, and when an acid is generated by exposure, the polarity increases due to the action of the acid, . Therefore, in the formation of a resist pattern, when the resist composition obtained by applying the resist composition on a support is selectively exposed to light, the exposed portion changes from soluble to poorly soluble in the organic developer, while the unexposed portion remains soluble Therefore, by developing with an organic developer, a contrast can be provided between the exposed portion and the unexposed portion, and a negative pattern is formed.

&Lt; Resin for Resin Reducing Solubility to Organic Solvent by the Action of Acid: Component (A) &gt;

The component (A) used in the resist composition of the present invention is a resist resin obtained by the above-described method for purifying a crude resin of the present invention, and is preferably a component (A-1).

When the component (A) is the component (A-1), the component (A-1) is preferably the component (A1) described above.

In the resist composition, the component (A) may be used alone or in combination of two or more.

When the component (A1) is used as the component (A), the proportion of the component (A1) in the component (A) is preferably 25 mass% or more, more preferably 50 mass% , More preferably 75 mass%, further preferably 100 mass%. When the above ratio is 25 mass% or more, lithographic properties such as mask reproducibility (MEEF), circularity, roughness reduction, and DOF (focal depth width) characteristics are further improved.

The content of the component (A) in the resist composition of the present invention may be adjusted depending on the thickness of the resist film to be formed.

&Lt; Acid generating agent: component (B) &gt;

The component (B) is not particularly limited, and those that have been proposed so far as acid generators for chemically amplified resists can be used.

Such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisaryl sulfonyl diazomethanes, poly (bis-sulfonyl) diazomethanes, etc. Diazomethane-based acid generators, nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, disulfone-based acid generators, and the like. Among them, it is preferable to use an onium salt-based acid generator.

Examples of the onium salt-based acid generators include compounds represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)") and compounds represented by the general formula (b-2) (hereinafter also referred to as "component (b-2)") or a compound represented by formula (b-3)

Wherein R ¹⁰¹ and R ¹⁰⁴ to R ¹⁰⁸ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a straight chain alkenyl group which may have a substituent. R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ¹⁰¹ to V ¹⁰³ are each independently a single bond, an alkylene group or a fluorinated alkylene group. L ¹⁰¹ to L ¹⁰² each independently represent a single bond or an oxygen atom. L ¹⁰³ to L ¹⁰⁵ each independently represent a single bond, -CO- or -SO ₂ -. M ' ^{m +} is an ^{m &lt}; 2 & ^{gt ;} onium cation.

{Negative ion part}

The negative ion part of the component (b-1)

In formula (b-1), R ¹⁰¹ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a straight chain alkenyl group which may have a substituent.

(A cyclic group which may have a substituent)

The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually saturated.

The aromatic hydrocarbon group in R &lt; ¹⁰¹ &gt; is a hydrocarbon group having an aromatic ring. The number of carbon atoms of the aromatic hydrocarbon group is preferably from 3 to 30, more preferably from 5 to 30, still more preferably from 5 to 20, particularly preferably from 6 to 15, most preferably from 6 to 10. Provided that the number of carbon atoms does not include the number of carbon atoms in the substituent group.

Specific examples of the aromatic ring of the aromatic hydrocarbon group in R ¹⁰¹ include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocyclic rings in which a part of carbon atoms constituting these aromatic rings are substituted with a hetero atom . Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.

Specific examples of the aromatic hydrocarbon group in R ¹⁰¹ include a group in which one hydrogen atom is removed from the aromatic ring (aryl group: phenyl group, naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (For example, benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl and 2-naphthylethyl). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

The cyclic aliphatic hydrocarbon group for R &lt; ¹⁰¹ &gt; includes an aliphatic hydrocarbon group containing a ring in its structure.

In this structure, the aliphatic hydrocarbon group containing a ring includes an alicyclic hydrocarbon group (a group in which one hydrogen atom is removed from the aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a straight chain or branched aliphatic hydrocarbon group, And a group in which a hydrocarbon group is introduced in the middle of a straight chain or branched chain aliphatic hydrocarbon group.

The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.

The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group in which at least one hydrogen atom is removed from the monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane, cyclohexane, and the like. The polycyclic alicyclic hydrocarbon group is preferably a group in which at least one hydrogen atom is removed from the polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, iso Borane, tricyclodecane, tetracyclododecane and the like.

Among them, the cyclic aliphatic hydrocarbon group for R &lt; ¹⁰¹ &gt; is preferably a group excluding one or more hydrogen atoms from the monocycloalkane or polycycloalkane, more preferably a group excluding one hydrogen atom from the polycycloalkane, , A norbornyl group is particularly preferable, and an adamantyl group is most preferable.

The straight-chain or branched-chain aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, further preferably 1 to 4, and most preferably 1 to 3 carbon atoms.

The aliphatic hydrocarbon group in a straight chain is preferably an alkylene group of a straight chain, particularly a methylene group [-CH ₂ -], an ethylene group _{[- (CH 2) 2 -} ], a trimethylene group [- (CH _{2) 3} -], tetramethylene group [- (CH ₂ ) ₄ -], pentamethylene group [- (CH ₂ ) ₅ -] and the like.

Aliphatic hydrocarbon group of the branched chain is preferably an alkylene group of a branch chain, and specifically _{-CH (CH 3) -, -CH} (CH 2 CH 3) -, -C (CH 3) 2 -, -C (CH ₃ ) an alkylmethylene group such as - (CH ₂ CH ₃ ) -, -C (CH ₃ ) (CH ₂ CH ₂ CH ₃ ) -, or -C (CH ₂ CH ₃ ) ₂ -; _{-CH (CH 3) CH 2 -} , -CH (CH 3) CH (CH 3) -, -C (CH 3) 2 CH 2 -, -CH (CH 2 CH 3) CH 2 -, -C (CH ₂ CH _{3) 2} -CH ₂ - alkyl group such as ethylene; _{-CH (CH 3) CH 2 CH} 2 -, -CH 2 CH (CH 3) CH 2 - alkyl trimethylene group and the like; And alkyl alkylene groups such as alkyltetramethylene groups such as -CH (CH ₃ ) CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ ) CH ₂ CH ₂ - and the like. The alkyl group in the alkyl alkylene group is preferably a straight chain alkyl group having 1 to 5 carbon atoms.

The cyclic hydrocarbon group for R &lt; ¹⁰¹ &gt; may include a hetero atom such as a heterocycle. Specifically, the lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7) and the lactone-containing cyclic group represented by the general formulas (a5-r-1) to A -SO ₂ -containing polycyclic group, and other heterocyclic groups which may be mentioned below.

Examples of the substituent in the cyclic hydrocarbon group of R &lt; ¹⁰¹ &gt; include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group and a nitro group.

The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group.

The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso- propoxy group, a n-butoxy group or a tert- The ethoxy group is most preferred.

Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.

Examples of the halogenated alkyl group as a substituent include an alkyl group having 1 to 5 carbon atoms such as a group in which some or all of hydrogen atoms such as methyl, ethyl, propyl, n-butyl and tert-butyl groups are substituted with the halogen atom .

The carbonyl group as a substituent is a group substituting a methylene group (-CH ₂ -) constituting a cyclic hydrocarbon group.

(A linear alkyl group which may have a substituent)

The alkyl group on the chain represented by R &lt; ¹⁰¹ &gt; may be either straight chain or branched chain.

The straight-chain alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15, and most preferably 1 to 10 carbon atoms. Specific examples include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decanyl, undecyl, dodecyl, Hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, henicosyl group, and docosyl group, and the like.

The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples thereof include 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, Butyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group and 4-methylpentyl group.

(A straight chain alkenyl group which may have a substituent)

The straight chain or branched chain of R ¹⁰¹ may be straight chain or branched chain, preferably 2 to 10 carbon atoms, more preferably 2 to 5, still more preferably 2 to 4, and particularly preferably 3 Do. Examples of the straight chain alkenyl group include a vinyl group, a propenyl group (allyl group), and a butyryl group. Examples of the branched chain alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group and a 2-methylpropenyl group.

As the chain alkenyl group, a vinyl group or a propenyl group is more preferable, and a vinyl group is particularly preferable.

Examples of the substituent in the alkyl group or the alkenyl group on the chain of R ¹⁰¹ include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group and a cyclic group in the R ¹⁰¹ .

Among them, R ¹⁰¹ is preferably a cyclic group which may have a substituent, more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, a group excluding one or more hydrogen atoms from a phenyl group, a naphthyl group, or a polycycloalkane; Lactone-containing cyclic groups represented by the above general formulas (a2-r-1) to (a2-r-7); -SO ₂ -containing cyclic groups represented by the above-mentioned general formulas (a5-r-1) to (a5-r-4) are preferable.

In the formula (b-1), Y ¹⁰¹ is a divalent linking group containing a single bond or an oxygen atom.

If the Y ¹⁰¹ 2-valent connecting group containing an oxygen atom, wherein Y ¹⁰¹ is may contain atoms other than oxygen atoms. Examples of the atom other than the oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom.

Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: -O-), an ester bond (-C (= O) -O-), an oxycarbonyl group (-OC , A non-hydrocarbon-based oxygen atom-containing linking group such as an amide bond (-C (= O) -NH-), a carbonyl group (-C (= O) -) and a carbonate bond (-OC (= O) -O-); And combinations of the non-hydrocarbon-based oxygen atom-containing linking group and the alkylene group. In addition to the above combination, a sulfonyl group (-SO ₂ -) may be connected. Examples of the combination include a linking group represented by the following formulas (y-al-1) to (y-al-7).

Wherein V ' ¹⁰¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' ¹⁰² is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

The divalent saturated hydrocarbon group at V ' ¹⁰² is preferably an alkylene group having 1 to 30 carbon atoms.

The alkylene group at V ' ¹⁰¹ and V' ¹⁰² may be a straight chain alkylene group or a branched chain alkylene group, preferably a straight chain alkylene group.

Specific examples of the alkylene group at V ' ¹⁰¹ and V' ¹⁰² include a methylene group [-CH ₂ -]; _{-CH (CH 3) -, -CH} (CH 2 CH 3) -, -C (CH 3) 2 -, -C (CH 3) (CH 2 CH 3) -, -C (CH 3) (CH 2 CH ₂ CH ₃ ) -, -C (CH ₂ CH ₃ ) ₂ -; Ethylene group [-CH ₂ CH ₂ -]; _{-CH (CH 3) CH 2 -} , -CH (CH 3) CH (CH 3) -, -C (CH 3) 2 CH 2 -, -CH (CH 2 CH 3) CH 2 - such as the ethylene-alkyl ; A trimethylene group (n-propylene group) [- CH ₂ CH ₂ CH ₂ -]; _{-CH (CH 3) CH 2 CH} 2 -, -CH 2 CH (CH 3) CH 2 - alkyl trimethylene group and the like; A tetramethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ -]; An alkyltetramethylene group such as -CH (CH ₃ ) CH ₂ CH ₂ CH ₂ -, -CH ₂ CH (CH ₃ ) CH ₂ CH ₂ -; A pentamethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -] and the like.

Also, a part of the methylene groups in the alkylene group at V ' ¹⁰¹ or V' ¹⁰² may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a divalent group excluding one hydrogen atom from the cyclic aliphatic hydrocarbon group of Ra ' ³ in the formula (a1-r-1), and a cyclohexylene group, a 1,5-adamantyl group More preferably a phenylene group or a 2,6-adamantylene group.

Y ¹⁰¹ is preferably a divalent linking group including an ester linkage or an ether linkage, and a linking group represented by the above formulas (y-al-1) to (y-al-5) is preferable.

In the formula (b-1), V ¹⁰¹ is a single bond, an alkylene group or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group in V ¹⁰¹ preferably have 1 to 4 carbon atoms. ^Examples of the fluorinated alkylene group in V ¹⁰¹ include groups in which some or all of the hydrogen atoms of the alkylene group in V ¹⁰¹ are substituted with fluorine atoms. Among them, V ¹⁰¹ is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

In the formula (b-1), R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R ¹⁰² is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom.

Specific examples of the anion moiety of the component (b-1) include, for example, when Y ¹⁰¹ is a single bond, a fluorinated alkyl sulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion Can be; When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, an anion represented by any one of the following formulas (an-1) to (an-3) may be mentioned.

Wherein R ¹⁰¹ is an aliphatic cyclic group which may have a substituent, a group respectively represented by the above formulas (r-hr-1) to (r-hr-6), or a chain alkyl group which may have a substituent; R " ¹⁰² represents an aliphatic cyclic group which may have a substituent, a lactone-containing cyclic group represented by any one of the general formulas (a2-r-1) to (a2- ~ (a5-r-4) each represent a -SO ₂ - containing cyclic group, and; R " ¹⁰³ is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent; v" is independently an integer of 0 to 3, and q " Each independently represents an integer of 1 to 20, t "is an integer of 1 to 3, and n" is 0 or 1.]

R ^"101, R" ¹⁰² and R "aliphatic ring which may have a ¹⁰³ substituents of the dish is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in the R ^101. As the substituent of the cyclic in R ¹⁰¹ an aliphatic May be the same as the substituent which may be substituted with a hydrocarbon group.

R "aromatic ring group which may have a substituent in ¹⁰³ is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in the R ^101. As the substituent may be substituted with a group of the aromatic hydrocarbon in R ¹⁰¹ And the like.

R alkenyl chain which may have a substituent in "the alkyl group of the chain which may have a substituent in ¹⁰¹ is caused, it is preferable. R exemplified as the alkyl group of the chain in the R ^{101" 103} groups in the R ¹⁰¹ Is preferably a group exemplified as a chain alkenyl group.

The negative ion part of component (b-2)

In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, 1) there may be mentioned the same ones as in R ^101. Provided that R ¹⁰⁴ and R ¹⁰⁵ may combine with each other to form a ring.

R ¹⁰⁴ and R ¹⁰⁵ are preferably a linear alkyl group which may have a substituent, more preferably a linear or branched alkyl group or a linear or branched fluorinated alkyl group.

The number of carbon atoms of the above chain alkyl group is preferably from 1 to 10, more preferably from 1 to 7, and still more preferably from 1 to 3. The number of carbon atoms of the alkyl group on the chain of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible within the above range of the number of carbon atoms and solubility in a resist solvent. It is preferable that the number of hydrogen atoms substituted with fluorine atoms in the chain alkyl group for R ¹⁰⁴ and R ¹⁰⁵ is larger because the strength of the acid is increased and the transparency to high energy light or electron beam of 200 nm or more is improved. The ratio of the fluorine atoms in the alkyl group on the chain, that is, the fluoride ratio is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all the hydrogen atoms are fluorine-substituted perfluoroalkyl groups.

In the formula (b-2), V ¹⁰² and V ¹⁰³ are each independently a single bond, an alkylene group or a fluorinated alkylene group, and the same groups as those of V ¹⁰¹ in the formula (b-1)

In the formula (b-2), L ¹⁰¹ to L ¹⁰² each independently represent a single bond or an oxygen atom.

The anion portion of the component (b-3)

In formula (b-3), R ¹⁰⁶ to R ¹⁰⁸ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, 1) there may be mentioned the same ones as in R ^101.

L ¹⁰³ to L ¹⁰⁵ each independently represent a single bond, -CO- or -SO ₂ -.

{Cation part}

Formula (b-1), (b -2) and (b-3) of the, M ^{'m +,} m is a monovalent onium cations, the sulfonium cations, it is possible to fit the iodonium cation represented by the general formula of the following ( ca-1) to (ca-4) are particularly preferable.

R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, and R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ , R ²¹¹ to R ²¹² may bond together to form a ring with the sulfur atom in the formula. R ²⁰⁸ ~ R ²⁰⁹ independently represent a hydrogen atom or an alkyl group having a carbon number of 1 ~ 5, R ²¹⁰ is an aryl group, an alkyl group or -SO _2, which may have a substituent, respectively and containing a cyclic group, L is ²⁰¹ - ^Y201 is independently an arylene group, an alkylene group or an alkenylene group, x is 1 or 2, and ^W201 is (x + 1) Represents a connector.]

The aryl group for R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² includes an unsubstituted aryl group having 6 to 20 carbon atoms, preferably a phenyl group or a naphthyl group.

The alkyl group represented by R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

~ R ²⁰¹ R ^207, and alkenyl group in R ²¹¹ ~ R ²¹² is preferably a carbon number of 2-10.

Examples of the substituent which R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, (ca-r-7), respectively.

: Wherein R ' ²⁰¹ each independently represents a hydrogen atom, a cyclic group which may have a substituent, a straight chain alkyl group or a straight chain alkenyl group.

The cyclic group which may have a substituent of R ' ²⁰¹ , the chain alkyl which may have a substituent, or the chain alkenyl which may have a substituent may be the same as those of R ¹⁰¹ in the above-mentioned formula (b-1) , A cyclic group which may have a substituent or a chain alkyl group which may have a substituent may be the same as the acid-cleavable group represented by the above-mentioned formula (a1-r-2).

R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ , and R ²¹¹ to R ²¹² are bonded to each other to form a ring together with the sulfur atom in the formula, a hetero atom such as a sulfur atom, an oxygen atom and a nitrogen atom, a carbonyl group, May be bonded through a functional group such as SO-, -SO ₂ -, -SO ₃ -, -COO-, -CONH- or -N (R _N ) - (wherein R _N is an alkyl group having 1 to 5 carbon atoms) . As the formed ring, one ring included in the ring skeleton is preferably a 3-membered to 10-membered ring including a sulfur atom, and particularly preferably a 5- to 7-membered ring. Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thienthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthene ring, Phenanthine ring, tetrahydrothiophenium ring, tetrahydrothiopyranium ring and the like can be given.

Each of R ²⁰⁸ to R ²⁰⁹ independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. When the alkyl group is composed of an alkyl group, they may be bonded to each other to form a ring.

R ²¹⁰ is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO ₂ -containing cyclic group which may have a substituent.

As the aryl group for R ²¹⁰ , an unsubstituted aryl group having 6 to 20 carbon atoms may be mentioned, and a phenyl group or a naphthyl group is preferable.

The alkyl group in R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

The alkenyl group for R ²¹⁰ preferably has 2 to 10 carbon atoms.

The -SO ₂ -containing cyclic group which may have a substituent at R ²¹⁰ includes the same ones as the above-mentioned "-SO ₂ -containing cyclic group", and among them, the group represented by the general formula (a5-r-1) is preferable Do.

Y ²⁰¹ each independently represent an arylene group, an alkylene group or an alkenylene group.

The arylene group for Y ²⁰¹ is a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group for R ¹⁰¹ in the above-mentioned formula (b-1).

The alkylene group and alkenylene group in Y ²⁰¹ are the same as the aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ in the aforementioned general formula (a1-1).

In the above formula (ca-4), x is 1 or 2.

W ²⁰¹ is (x + 1), that is, a divalent or trivalent linking group.

The divalent linking group for W ²⁰¹ is preferably a divalent hydrocarbon group which may have a substituent, and may be the same hydrocarbon group as Ya ²¹ in the general formula (a2-1). The divalent linking group in W ²⁰¹ may be any of linear, branched and cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.

Trivalent connecting group in W is ^201, and the like group which combines the divalent connecting group is a divalent linking group to more hydrogen atoms from a group, the divalent connecting group other than one at the ²⁰¹ W. The trivalent linking group in W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following formulas (ca-1-1) to (ca-1-67).

G1 represents an integer of 1 to 5, g2 represents an integer of 0 to 20, and g3 represents an integer of 0 to 20.] [wherein, g1, g2 and g3 represent repeating numbers,

Wherein R " ²⁰¹ is a hydrogen atom or a substituent, and the substituent is the same as the substituent which R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have.]

Specific examples of preferred cations represented by the above formula (ca-2) include diphenyliodonium cations and bis (4-tert-butylphenyl) iodonium cations.

Specific examples of suitable cations represented by the above formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

Specific examples of suitable cations represented by the above formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2).

Among them, the cation moiety [( ^{M'm +} ) _{1 / m} ] is preferably the cation represented by the formula (ca-1), and the cation represented by the formula (ca-1-1) Is more preferable.

As the component (B), the aforementioned acid generators may be used alone, or two or more of them may be used in combination.

When the resist composition contains the component (B), the content of the component (B) is preferably 0.5 to 60 parts by mass, more preferably 1 to 50 parts by mass, and more preferably 1 to 40 parts by mass relative to 100 parts by mass of the component (A) More preferable. By setting the content of the component (B) within the above range, pattern formation is sufficiently performed. Further, when each component of the resist composition is dissolved in an organic solvent, a homogeneous solution can be obtained, which is preferable because the storage stability is improved.

&Lt; Other components &gt;

[Component (D)] [

The resist composition of the present invention may further contain an acid diffusion controller component (hereinafter referred to as "component (D)") in addition to the component (A) and the component (B).

The component (D) acts as a catalyst (acid diffusion control agent) for trapping an acid generated by exposure from the component (B) or the like.

The component (D) may be a photodegradable base (D1) (hereinafter, referred to as "component (D1)") which is decomposed by exposure to lose acid diffusion controllability, The compound (D2) (hereinafter referred to as the &quot; component (D2) &quot;).

· For component (D1)

(D1), the contrast between the exposed portion and the unexposed portion can be improved when the resist pattern is formed.

The component (D1) is not particularly limited as long as it is decomposed by exposure to lose acid diffusion controllability, and a compound represented by the following general formula (d1-1) (hereinafter referred to as "component (d1-1) The compound represented by the general formula (d1-2) (hereinafter referred to as the "component (d1-2)") and the compound represented by the following general formula (d1-3) Is preferably at least one compound selected from the group consisting of

The components (d1-1) to (d1-3) are decomposed in the exposed part and lose acid diffusion controllability (basicity), so they do not act as a catalyst and act as a catalyst in the unexposed part.

Wherein, ¹ ~ Rd Rd ⁴ is an alkenyl group which may have a branched alkyl group, or a substituent in the chain which may have a ring group, substituents may have a substituent. It is to be noted that the fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd ² in the formula (d1-2). Yd ¹ is a single bond or a divalent linking group. m is an integer of 1 or more, and M ^&lt; ^{m +} &^gt;

{(d1-1) component}

.. Anion portion

Formula (d1-1) of, R ^{1 101} of Rd is an alkenyl group which may have a branched alkyl group, or a substituent in the chain which may have a ring group, substituents may have a substituent, the formula (b-1) And the like.

Among them, Rd ¹ is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkyl group which may have a substituent. The substituent which these groups may have is preferably a hydroxyl group, a fluorine atom or a fluorinated alkyl group.

The aromatic hydrocarbon group is more preferably a phenyl group or a naphthyl group.

The aliphatic cyclic group is more preferably a group excluding at least one hydrogen atom from a polycycloalkane such as adamantane, norbornane, isoborane, tricyclodecane, tetracyclododecane and the like.

The straight chain alkyl group preferably has 1 to 10 carbon atoms and specifically includes straight chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, An alkyl group; Methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methyl Pentyl group, 2-methylpentyl group, 3-methylpentyl group and 4-methylpentyl group.

When the above chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms of the fluorinated alkyl group is preferably from 1 to 11, more preferably from 1 to 8, still more preferably from 1 to 4. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of the atom other than the fluorine atom include an oxygen atom, a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom.

Rd ¹ is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted by fluorine atoms and the fluorinated alkyl group in which all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms Of a perfluoroalkyl group).

Preferred examples of the anion moiety of the component (d1-1) are shown below.

...

In the formula (d1-1), M ^{m +} is an organic cation of m valent.

Examples of the organic cation represented by M ^{m +} are the same as the cation represented by the above general formulas (ca-1) to (ca-4) 67) are more preferable.

The component (d1-1) may be used singly or in combination of two or more.

{(d1-2) component}

.. Anion portion

Formula (d1-2) of, R ¹⁰¹ of Rd ² is an alkenyl group which may have a branched-chain alkyl group which may have a ring group, substituents may have a substituent, or a substituent group, the formula (b-1) And the like.

Provided that a fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd ² (not fluorine-substituted). As a result, the anion of the component (d1-2) becomes an appropriate weak acid anion, and the kinetin function as the component (D) improves.

Rd ² is preferably a linear alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. Examples of the aliphatic cyclic group include groups excluding at least one hydrogen atom from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have a substituent); It is more preferable that it is a group excluding at least one hydrogen atom from a camphor or the like.

The hydrocarbon group of Rd ² may have a substituent, and the substituent may be the same as the substituent which the hydrocarbon group (aromatic hydrocarbon group, aliphatic hydrocarbon group) in Rd ¹ of the formula (d1-1) may have.

Preferred examples of the anion moiety of the component (d1-2) are shown below.

...

In the formula (d1-2), M ^{m +} is an organic cation of ^m and is the same as M ^{m +} in the formula (d1-1).

The component (d1-2) may be used singly or in combination of two or more.

{(d1-3) component}

.. Anion portion

Formula (d1-3) of, Rd ³ is an alkenyl group which may have a branched alkyl group, or a substituent in the chain which may have a ring group, substituents may have a substituent, R ¹⁰¹ in the formula (b-1) And is preferably a cyclic group containing a fluorine atom, a straight chain alkyl group or a straight chain alkenyl group. Among them, a fluorinated alkyl group is preferable, and the same as the fluorinated alkyl group of Rd ¹ is more preferable.

Formula (d1-3) of, Rd ⁴ is an alkenyl group which may have a branched alkyl group, or a substituent in the chain which may have a ring group, substituents may have a substituent, R ¹⁰¹ in the formula (b-1) And the like.

Among them, an alkyl group, an alkoxy group, an alkenyl group, and a cyclic group which may have a substituent are preferable.

The alkyl group in Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, Pentyl group, isopentyl group, neopentyl group and the like. Part of the hydrogen atoms of the alkyl group Rd is ⁴ may be substituted by a hydroxyl group, a cyano group or the like.

The alkoxy group in Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, tert-butoxy group. Among them, a methoxy group and an ethoxy group are preferable.

The alkenyl group in Rd ⁴ may be the same as R ¹⁰¹ in the above formula (b-1), preferably a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group or a 2-methylpropenyl group. These groups may further have, as a substituent, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

The cyclic group in Rd ⁴ is the same as R ¹⁰¹ in the above formula (b-1), and cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane , An aromatic group such as a phenyl group or a naphthyl group is preferable. When Rd ⁴ is an alicyclic group, the resist composition is well dissolved in the organic solvent, and the lithography characteristics are improved. When Rd ⁴ is an aromatic group, in the lithography using EUV or the like as an exposure light source, the resist composition has excellent light absorption efficiency, and sensitivity and lithography characteristics are improved.

Formula (d1-3) of, Yd ¹ is a single bond or a divalent connecting group.

The divalent linking group in Yd ¹ is not particularly limited, and examples thereof include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, and a divalent linking group containing a hetero atom. Each of these may be the same as the divalent linking group containing a divalent hydrocarbon group or a heteroatom which may have a substituent, in the description of the divalent linking group of Ya ²¹ in the formula (a2-1).

Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, more preferably a methylene group or an ethylene group.

Preferred examples of the anion moiety of the component (d1-3) are shown below.

...

In the formula (d1-3), M ^{+ m} is equal to M ^{m +} m of a monovalent organic cation, the formula (d1-1).

(d1-3) may be used singly or in combination of two or more.

As the component (D1), any one of the above components (d1-1) to (d1-3) may be used, or two or more components may be used in combination.

The content of the component (D1) is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and further preferably 1 to 8 parts by mass with respect to 100 parts by mass of the component (A).

When the content of the component (D1) is lower than or equal to the preferable lower limit value, particularly good lithography characteristics and resist pattern shape can be obtained. On the other hand, if it is less than the upper limit value, the sensitivity can be kept good and the throughput is also excellent.

(Production method of component (D1)) [

The method for producing the above components (d1-1) and (d1-2) is not particularly limited and can be produced by a known method.

The method for producing the component (d1-3) is not particularly limited, and it is produced in the same manner as described in, for example, US2002-0149916.

· For the (D2) component

The acid diffusion control agent component may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") which does not correspond to the above-mentioned component (D1).

The component (D2) is not particularly limited as long as it functions as an acid diffusion control agent and does not correspond to the component (D1), and any known component may be used. Of these, aliphatic amines, especially secondary aliphatic amines and tertiary aliphatic amines, are preferred.

The aliphatic amine is an amine having at least one aliphatic group, and the aliphatic group preferably has 1 to 12 carbon atoms.

Examples of the aliphatic amine include amines (alkylamine or alkyl alcohol amine) or cyclic amines in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or a hydroxyalkyl group having 12 or less carbon atoms.

Specific examples of alkyl amines and alkyl alcohol amines include monoalkyl amines such as n-hexyl amine, n-heptyl amine, n-octyl amine, n-nonyl amine, and n-decyl amine; Dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine and dicyclohexylamine; N-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-octylamine, trialkylamines such as n-nonylamine, tri-n-decylamine and tri-n-dodecylamine; And alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine and tri-n-octanolamine. Of these, trialkylamines having 5 to 10 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

The cyclic amine includes, for example, a heterocyclic compound containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).

Specific examples of the aliphatic monocyclic amines include piperidine and piperazine.

The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, and specifically includes 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7 Undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.

Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} Amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} Tris [2- {2- (2-hydroxyethoxy) ethoxy} ethyl] amine, triethanolamine triacetate and the like, and triethanolamine triacetate is preferable.

As the component (D2), an aromatic amine may be used.

Examples of the aromatic amine include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, .

(D2) may be used alone or in combination of two or more.

(D2) is usually used in a range of 0.01 to 5 parts by mass based on 100 parts by mass of the component (A). By setting the concentration in the above range, the shape of the resist pattern, the stability over time, and the like are improved.

[Component (E)] [

The resist composition of the present invention may contain, as optional components, at least one member selected from the group consisting of organic carboxylic acid and phosphorous oxo acid and derivatives thereof for the purpose of preventing deterioration of sensitivity, improving resist pattern shape, (E) (hereinafter referred to as &quot; component (E) &quot;).

As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.

Phosphoric acid, phosphonic acid, phosphinic acid and the like can be given as examples of phosphorous acid, and phosphonic acid is particularly preferable.

Examples of the derivative of phosphorous oxo acid include esters obtained by substituting a hydrogen atom of the oxo acid with a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 15 carbon atoms, and the like. .

Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.

Examples of phosphonic acid derivatives include phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.

Examples of phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid.

The component (E) may be used alone or in combination of two or more.

The component (E) is usually used in a range of 0.01 to 5 parts by mass based on 100 parts by mass of the component (A).

[Component (F)] [

The resist composition of the present invention may contain a fluorine additive (hereinafter referred to as "component (F)") in order to impart water repellency to the resist film.

As the component (F), for example, Japanese Patent Application Laid-Open Nos. 2010-002870, 2010-032994, 2010-277043, 2011-13569, and 2011-128226 Described fluorinated polymer compound can be used.

More specifically, as the component (F), a polymer having the structural unit (f1) represented by the following formula (f1-1) may be mentioned. The polymer is preferably a polymer (homopolymer) composed only of the constituent unit (f1) represented by the following formula (f1-1); A copolymer of the structural unit (f1) and the structural unit (a1); The constituent unit (f1), the constituent unit derived from acrylic acid or methacrylic acid, and the copolymer of the constituent unit (a1) are preferable. As the structural unit (a1) copolymerized with the structural unit (f1), a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate is preferable.

[Wherein, R is as defined above and, Rf ¹⁰² and Rf ¹⁰³ each independently represents an alkyl group or halogenated alkyl group having 1 to 5 carbon atoms of hydrogen atom, a halogen atom, a 1 to 5 carbon atoms, Rf ¹⁰² and Rf ¹⁰³ is the same May be different or different. nf ¹ is an integer of 1 to 5, and Rf ¹⁰¹ is an organic group containing a fluorine atom.]

In formula (f1-1), R bonded to the carbon atom at the? -Position is the same as described above. R is preferably a hydrogen atom or a methyl group.

In the formula (f1-1), examples of the halogen atom of Rf ¹⁰² and Rf ¹⁰³ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. Examples of the alkyl group having 1 to 5 carbon atoms represented by Rf ¹⁰² and Rf ¹⁰³ include the same alkyl groups having 1 to 5 carbon atoms as R described above, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms represented by Rf ¹⁰² and Rf ¹⁰³ include groups in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable. Among them, Rf ¹⁰² and Rf ¹⁰³ are preferably a hydrogen atom, a fluorine atom or an alkyl group having 1 to 5 carbon atoms, and are preferably a hydrogen atom, a fluorine atom, a methyl group or an ethyl group.

In the formula (f1-1), nf ¹ is an integer of 1 to 5, preferably an integer of 1 to 3, more preferably 1 or 2.

In the formula (f1-1), Rf ¹⁰¹ is an organic group containing fluorine atom, is preferably a hydrocarbon group containing a fluorine atom.

The hydrocarbon group containing a fluorine atom may be any of linear, branched or cyclic. The number of carbon atoms is preferably from 1 to 20, more preferably from 1 to 15, and particularly preferably from 1 to 10.

The hydrocarbon group containing a fluorine atom preferably has at least 25% of the hydrogen atoms in the hydrocarbon group fluorinated, more preferably at least 50% fluorinated, more preferably at least 60% fluorinated, Is particularly preferable since the hydrophobicity of the resist film at the time of exposure is increased.

Of these, ¹⁰¹ roneun Rf group is a fluorinated hydrocarbon group having 1 to 5 carbon atoms as a particularly preferred, and _{trifluoromethyl, -CH 2 -CF 3, -CH 2} -CF 2 -CF 3, -CH (CF 3) 2, -CH the _{2 -CH 2 -CF 3, -CH 2} -CH 2 -CF 2 -CF 2 -CF 2 -CF 3 is most preferred.

The weight average molecular weight (Mw) of the component (F) is preferably 1000 to 50000, more preferably 5000 to 40000, and most preferably 10000 to 30000 in terms of polystyrene conversion by gel permeation chromatography. If it is not more than the upper limit of the above range, there is sufficient solubility in a resist solvent for use as a resist, and if it is not lower than the lower limit of this range, dry etching resistance and cross-sectional shape of the resist pattern are good.

The dispersion degree (Mw / Mn) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

The component (F) may be used singly or in combination of two or more.

The component (F) is used in a proportion of 0.5 to 10 parts by mass based on 100 parts by mass of the component (A).

The resist composition of the present invention may further contain additives suitably miscible with it, for example, an additive resin for improving the performance of a resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, a halation inhibitor, .

[Component (S)] [

The resist composition of the present invention can be produced by dissolving a resist material in an organic solvent (hereinafter referred to as "component (S)").

As the component (S), any one that can dissolve each component to be used to form a homogeneous solution may be used, and any one or two or more kinds of solvents conventionally known as solvents for chemically amplified resists may be appropriately selected and used.

Lactones such as? -Butyrolactone; Ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone and 2-heptanone; Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol and dipropylene glycol; A compound having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; a monomethyl ether, monoethyl ether, Monoalkyl ethers such as monopropyl ether and monobutyl ether, and compounds having an ether bond such as monophenyl ether (among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether PGME) is preferred; Cyclic ethers such as dioxane, esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate and ethyl ethoxypropionate; Aniline, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene Aromatic organic solvent, dimethyl sulfoxide (DMSO), and the like.

These organic solvents may be used alone or in combination of two or more.

Among them, PGMEA, PGME,? -Butyrolactone, EL, and cyclohexanone are preferable.

A mixed solvent in which PGMEA and a polar solvent are mixed is also preferable. The compounding ratio (mass ratio) may be suitably determined in consideration of the compatibility of the PGMEA and the polar solvent, and is preferably within the range of 1: 9 to 9: 1, more preferably 2: 8 to 8: 2 .

More specifically, when EL or cyclohexanone is blended as a polar solvent, the mass ratio of PGMEA: EL or cyclohexanone is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2 . When PGME is blended as a polar solvent, the mass ratio of PGMEA: PGME is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, even more preferably 3: 7 to 7: 3. Mixed solvents of PGMEA, PGME and cyclohexanone are also preferred.

As the (S) component, a mixed solvent of at least one selected from PGMEA and EL and? -Butyrolactone is also preferable. In this case, as the mixing ratio, the mass ratio of the former and the latter is preferably 70:30 to 95: 5.

The amount of the component (S) to be used is not particularly limited and is appropriately set in accordance with the coating film thickness at a concentration that can be applied to a substrate or the like. In general, the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

&Lt; Method of forming resist pattern &

The resist pattern forming method of the present invention includes a step of forming a resist film on the support by using the resist composition of the present invention described above, a step of exposing the resist film, and a step of patterning the resist film by a negative type development using a developer containing an organic solvent And a step of forming a resist pattern.

The resist pattern forming method of the present invention can be carried out, for example, as follows.

First, a resist composition of the present invention as described above is coated on a support by a spinner or the like and baked (post-application baked (PAB)) treatment is performed at a temperature of 80 to 150 ° C for 40 to 120 seconds, For 90 seconds to form a resist film. Next, the resist film is subjected to exposure through a mask (mask pattern) having a predetermined pattern formed thereon by using an exposure apparatus such as an ArF exposure apparatus, an electron beam lithography apparatus, an EUV exposure apparatus, or the like, (Post exposure bake (PEB)) treatment is performed at a temperature of 80 to 150 ° C for 40 to 120 seconds, preferably 60 to 90 seconds, for example, after performing selective exposure by drawing by electron beam direct irradiation or the like. Conduct. The resist film is subjected to a negative type developing treatment using an organic developing solution and then rinsed with a rinsing solution containing an organic solvent and dried.

A treatment for removing the developer or rinsing liquid adhering to the pattern by the supercritical fluid may be performed after the developing treatment or the rinsing treatment.

In some cases, a baking (post-baking) treatment may be performed to remove residual organic solvent after development, rinsing, or treatment with a supercritical fluid.

The support is not particularly limited and conventionally known ones may be used, and examples thereof include a substrate for electronic components and a substrate having a predetermined wiring pattern formed thereon. More specifically, examples thereof include substrates made of metals such as silicon wafers, copper, chromium, iron and aluminum, and glass substrates. As the material of the wiring pattern, copper, aluminum, nickel, gold, or the like can be used, for example.

As the support, an inorganic and / or organic film may be provided on the substrate as described above. The inorganic film may be an inorganic antireflection film (inorganic BARC). Examples of the organic film include an organic antireflection film (organic BARC) and an organic film such as a lower organic film in a multilayer resist method.

Here, the multi-layer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate and patterning of the lower organic film is performed using the resist pattern formed on the upper resist film as a mask And it is considered that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, since the necessary thickness can be secured by the lower organic film, the resist film can be made thinner, and a fine pattern with a high aspect ratio can be formed.

In the multilayer resist method, a three-layered or multi-layered structure in which an upper layer resist film and a lower layer organic film are formed into a two-layer structure (two-layer resist method) and an intermediate layer (metal thin film or the like) (3-layer resist method).

The wavelength to be used for exposure is not particularly limited and may be selected from the group consisting of ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam) . &Lt; / RTI &gt; The resist composition is highly useful as KrF excimer laser, ArF excimer laser, EB or EUV, and is particularly useful for ArF excimer laser, EB or EUV.

The exposure method of the resist film may be ordinary exposure (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography.

The liquid immersion exposure is an exposure method in which an exposure (immersion exposure) is performed in such a state that a space between a resist film and a lens in the lowermost position of the exposure apparatus is filled with a solvent (immersion medium) having a refractive index larger than that of air.

As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the exposed resist film is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.

Examples of the solvent having a refractive index higher than that of air and lower than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicone-based solvent, and a hydrocarbon-based solvent.

Specific examples of the fluorine-based inert liquid include liquids containing a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component And has a boiling point of preferably 70 to 180 ° C, more preferably 80 to 160 ° C. If the fluorine-based inert liquid has a boiling point in the above range, it is preferable that the medium used for immersion after the end of exposure can be removed by a simple method.

As the fluorine-based inert liquid, a perfluoroalkyl compound in which the hydrogen atoms of the alkyl group are all substituted with fluorine atoms is preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.

Specific examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ° C), and the perfluoroalkylamine compounds include perfluorotributylamine (Boiling point 174 DEG C).

As the immersion medium, water is preferably used in terms of cost, safety, environmental problems, versatility, and the like.

In the negative type development, the organic solvent (organic solvent (C1)) contained in the developing solution may be any solvent which can dissolve the component (A) (resist for exposure before exposure) and may be appropriately selected from known organic solvents. Specific examples thereof include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents and ether solvents, hydrocarbon solvents and the like. Specific examples of these organic solvents include the same ones as those exemplified above as the component (C).

Among them, a polar solvent is preferable as the organic solvent contained in the developer. Among them, a ketone solvent, an ester solvent and a nitrile solvent are preferable, and it is particularly preferable to use at least one selected from the group consisting of a ketone solvent and an ester solvent. The ester-based solvent is preferably butyl acetate. The ketone-based solvent is preferably 2-heptanone (methyl amyl ketone).

Any one of these organic solvents may be used alone, or two or more of them may be mixed and used.

In the purification method according to the present invention, the component (C) used in the step (1) is an organic solvent (C1) contained in the developer used in the resist pattern forming method using the resist composition containing the resist resin obtained by the above- ). This improves the purification efficiency of the purification method. For example, when the organic solvent (C1) contained in the developing solution used for the negative type development is singly used, the component (C) used in the step (1) is preferably the organic solvent (C1) (C) used in the step (1) is at least one of the above two or more kinds, or a mixture of two or more kinds of the above organic solvents (C1) It is preferable that the organic solvent is a mixed organic solvent of the same kind as the solvent or a mixed organic solvent which is the same as the mixed organic solvent of the two or more kinds.

As the organic solvent to be used as a developer for negative development, it is preferable to use an organic solvent not containing a halogen atom from the viewpoint of cost reduction of the solvent used for development. The content of the organic solvent which does not contain a halogen atom in the total mass of the organic developing solution is preferably 60% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, and even more preferably 100% by mass.

The boiling point of the organic solvent used in the organic developing solution is preferably 50 占 폚 or more and less than 250 占 폚.

The organic solvent used in the organic developing solution preferably has an ignition point of 200 DEG C or higher.

If necessary, known additives may be added to the organic developer. As the additive, for example, a surfactant can be mentioned. The surfactant is not particularly limited and, for example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used.

Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Aitakitai Co., Ltd.), Plurad FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), Megafac F171, F173, (Manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (manufactured by Troy Chemical Co., Ltd.), F176, F189 and R08 (manufactured by DIC Corporation), Sulfuron S- And fluorine-based surfactants or silicone-based surfactants. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicone surfactant.

The surfactant may be a fluoroaliphatic compound derived from a fluoroaliphatic compound produced by a telomerization method (also referred to as a telomer method) or an oligomerization method (also referred to as an oligomer method) A surfactant using a polymer having a group can be used. The fluoroaliphatic compound can be synthesized by the method described in Japanese Patent Application Laid-Open No. 2002-90991.

Polymers having a fluoroaliphatic group are preferably copolymers of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate and are distributed irregularly Or may be block-copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group and a poly (oxybutylene) group, and a poly (oxyethylene, oxypropylene and oxyethylene block Or may be a unit having an alkylene chain having a different chain length within the same chain length, such as a poly (oxyethylene / oxypropylene block linking group) group. The copolymer of the (fluoroaliphatic) group-containing monomer and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, (Poly (oxyalkylene)) acrylate (or methacrylate) copolymerized at the same time with the above-mentioned copolymer.

Examples of commercially available surfactants include Megapac F178, F-470, F-473, F-475, F-476 and F-472 (manufactured by DIC Corporation). (Or methacrylate) having a C6F13 group and (poly (oxyalkylene)) acrylate (or methacrylate), a copolymer of an acrylate (or methacrylate) having a C6F13 group and a (Methacrylate) having a C8F17 group and a (poly (oxyalkylene)) acrylate (or methacrylate) acrylate (or methacrylate) (Methacrylate), (poly (oxyethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) Or methacrylate), and the like.

The surfactant is preferably a nonionic surfactant, more preferably a fluorine surfactant or a silicon surfactant.

When the surfactant is blended, the blending amount thereof is usually 0.001 to 5 mass%, preferably 0.005 to 2 mass%, more preferably 0.01 to 0.5 mass%, based on the whole amount of the organic developing solution.

The developing process using an organic developing solution can be carried out by a known developing method. In this method, for example, a method of immersing a support in a developing solution for a predetermined time (dip method) , A method of spraying a developer onto the surface of a support (spray method), a method of continuously extracting a developer while scanning a developer-introducing nozzle at a constant speed on a support rotating at a constant speed (dynamic dispensing method), etc. .

After the development treatment, rinse treatment may be performed using a rinsing liquid containing an organic solvent before drying. By performing the rinsing treatment, a good pattern can be formed.

As the organic solvent to be used for the rinsing liquid, for example, organic solvent which is used as the organic solvent for the organic developing solution can be appropriately selected and used which hardly dissolves the resist pattern. Usually, at least one solvent selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, a nitrile solvent, an alcohol solvent, an amide solvent and an ether solvent is used. Among them, at least one selected from a hydrocarbon-based solvent, a ketone-based solvent, an ester-based solvent, an alcohol-based solvent and an amide-based solvent is preferable and at least one selected from an alcoholic solvent and an ester- Alcohol-based solvents are particularly preferred.

The alcoholic solvent used in the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be any one of linear, branched and cyclic. Specific examples thereof include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, Octanol, benzyl alcohol, and the like. Among them, 1-hexanol, 2-heptanol and 2-hexanol are preferable, and 1-hexanol or 2-hexanol is more preferable.

Any one organic solvent to be used for the rinsing liquid may be used alone or in combination of two or more kinds. It may be mixed with an organic solvent or water other than the above. However, considering the developing characteristics, the amount of water in the rinsing liquid is preferably 30 mass% or less, more preferably 10 mass% or less, more preferably 5 mass% or less, and most preferably 3 mass% Or less is particularly preferable.

A known additive may be added to the rinse liquid if necessary. Examples of the additive include surfactants. As the surfactant, the same ones as described above are exemplified. Nonionic surfactants are preferable, and fluorine surfactants or silicone surfactants are more preferable. When the surfactant is blended, the blending amount thereof is usually 0.001 to 5 mass%, preferably 0.005 to 2 mass%, more preferably 0.01 to 0.5 mass%, based on the whole amount of the rinsing liquid.

The rinsing treatment (rinsing treatment) using the rinsing liquid can be carried out by a known rinsing method. The above-mentioned method includes, for example, a method (rotation coating method) of continuously extracting the rinsing liquid on a support rotating at a constant speed, A method of dipping the support in a rinsing liquid for a predetermined time (dip method), and a method of spraying a rinsing liquid onto the surface of the support (spraying method).

According to the above-mentioned resist composition and the resist pattern forming method using the resist composition, it is possible to form a resist pattern in which the occurrence of defects is suppressed in forming a resist pattern to which a solvent developing process is applied.

[ Example ]

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

In the present embodiment, the compound represented by the formula (1) is also referred to as the &quot; compound (1) &quot;

<Purification of crude resin>

The resin for resist shown below was obtained by the purification method of each example to be described later.

For each resin, the copolymer composition ratio (ratio of each constituent unit in the structural formula (molar ratio)) was determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz ¹³ C-NMR). Further, the internal standard of ¹³ C-NMR in the analysis by NMR is tetramethylsilane (TMS). Mw and Mw / Mn are the mass average molecular weight and the molecular weight dispersion in terms of standard polystyrene obtained by GPC measurement.

Resist Resin (A) -1-1 to (A) -1-2:

The copolymerization composition ratio 1 / m / n / o / p = 10/30/40/10/10 (molar ratio), Mw = 7000 and Mw / Mn = 1.56.

Resist Resin (A) -1-3 to (A) -1-4:

The copolymerization composition ratio 1 / m / n / o / p = 30/10/40/10/10 (molar ratio), Mw = 7000 and Mw / Mn = 1.58.

Resist Resin (A) -2-1 to (A) -2-4:

The copolymerization composition ratio 1 / m / n / o / p = 20/20/30/20/10 (molar ratio), Mw = 7000 and Mw / Mn = 1.56.

Resist Resin (A) -3-1 to (A) -3-4:

Copolymer composition ratio l / m / n = 40/40/20 (molar ratio), Mw = 7300, Mw / Mn = 1.55.

(Example 1)

Step (1):

The crude resin (uncured) of the resin (A) -1-1 was dissolved in propylene glycol monomethyl ether acetate (PGMEA) to prepare a resin solution having a crude resin concentration of 20 mass%. Then, PGMEA was further added to the resin solution (crude resin concentration: about 7.7 mass%), and then butyl acetate was added to the mixture to prepare a crude resin solution having a crude resin concentration of 4 mass% (acetic acid Butyl was 50 mass%) was prepared.

Step (2):

The crude resin solution obtained in the step (1) was filtered with a nylon filter having a pore size of 0.02 占 퐉 to obtain a filtrate.

Step (3):

The filtrate obtained in the step (2) was heated and concentrated under a condition of 40 캜 using a rotary evaporator to obtain a resin solution (resin concentration: about 25% by mass) containing the resist resin (A) -1-1.

(Example 2)

A procedure was carried out in the same manner as in Example 1 except that methyl amyl ketone (MAK) was used instead of butyl acetate in the step (1) of Example 1 (the ratio of MAK in the solvent of the crude resin solution was 50 mass% ) To obtain a resin solution (resin concentration: about 25% by mass) containing the resist resin (A) -1-2.

(Example 3)

An operation was carried out in the same manner as in Example 1 except that the crude resin of Resin (A) -2-1 was used instead of the crude resin of Resin (A) -1-1 in the step (1) of Example 1 The proportion of butyl acetate in the solvent of the crude resin solution was 50 mass%) to obtain a resin solution (resin concentration: about 25 mass%) containing the resist resin (A) -2-1.

(Example 4)

The procedure was carried out in the same manner as in Example 3 except that MAK was used instead of butyl acetate in the step (1) of Example 3 (the ratio of MAK in the solvent of the crude resin solution was 50 mass%), (Resin concentration of about 25% by mass) containing (A) -2-2.

(Example 5)

An operation was performed in the same manner as in Example 1 except that the crude resin of Resin (A) -3-1 was used instead of the resin of Resin (A) -1-1 in the step (1) of Example 1 The proportion of butyl acetate in the solvent of the crude resin solution was 50 mass%) to obtain a resin solution (resin concentration of about 25 mass%) containing the resist resin (A) -3-1.

(Example 6)

The procedure was carried out in the same manner as in Example 5 except that MAK was used in place of butyl acetate in the step (1) of Example 5 (the ratio of MAK in the solvent of the crude resin solution was 50% by mass) (Resin concentration: about 25% by mass) containing (A) -3-2.

(Comparative Example 1)

The crude resin (uncured) of the resin (A) -1-3 was dissolved in PGMEA to prepare a resin solution having a crude resin concentration of 20 mass%.

Then, the resin solution was added dropwise to n-heptane to carry out an operation of precipitating the resin.

Then, the precipitated resin precipitated was filtered with a nylon filter having a pore size of 0.02 탆 and washed with water to obtain a resist resin (A) -1-3 (refined product) in solid form.

(Comparative Example 2)

Comparative Examples 1 and 2 were obtained in the same manner as in Comparative Example 1 except that the crude resin (untreated resin) of Resin (A) -2-3 was used in place of the crude resin (uncorrected) of Resin (A) The operation was carried out in the same manner to obtain a solid resist resin (A) -2-3 (a refined product).

(Comparative Example 3)

Comparative Example 1 was repeated except that the crude resin (untreated resin) of Resin (A) -3-3 was used in place of the crude resin (untreated resin) of Resin (A) -1-3. (A) -3-3 (refined product) in the form of a solid resist.

(Comparative Examples 4 to 6)

Resin (A) -1-4, resin (A) -2-4, resin (A) -3-4 The crude resin (untreated) was used as it is.

&Lt; Preparation of resist composition &gt;

(Examples 7 to 12 and Comparative Examples 7 to 12)

Each of the components shown in Table 1 was mixed and dissolved by using the resin for resist obtained in the above &lt; refining of crude resin &gt; to prepare resist compositions of the respective examples.

In Table 1, the respective abbreviations have the following meanings respectively. The values in [] are the compounding amount (parts by mass).

(A) -1: The resin (A) -1-1.

(A) -2: The resin (A) -1-2.

(A) -3: The resin (A) -2-1.

(A) -4: The resin (A) -2-2.

(A) -5: the resin (A) -3-1.

(A) -6: the resin (A) -3-2.

(A) -7: the resin (A) -1-3.

(A) -8: the resin (A) -2-3.

(A) -9: the resin (A) -3-3.

(A) -10: the resin (A) -1-4.

(A) -11: the resin (A) -2-4.

(A) -12: the resin (A) -3-4.

(B) -1: A compound represented by the following formula (B) -1.

(B) -2: A compound represented by the following formula (B) -2.

(D) -1: A compound represented by the following formula (D) -1.

(D) -2: A compound represented by the following formula (D) -2.

(D) -3: a compound represented by the following formula (D) -3.

(F) -1: A fluorinated polymer compound represented by the following formula (F) -1. The mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 23,000 and the molecular weight dispersion degree (Mw / Mn) was 1.78. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) obtained by carbon 13 nuclear magnetic resonance spectrum (600 MHz ¹³ C-NMR) is l / m = 77/23.

(E) -1: Salicylic acid.

(S) -1: mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / cyclohexanone = 45/30/25 (mass ratio).

<Evaluation>

The storage stability of the resist composition and the evaluation of pattern defects were evaluated using the resist composition obtained in the &lt; Preparation of resist composition &gt;

[Storage stability of resist composition]

A bottle of 1 liter capacity was filled with 100 mL of the resist composition immediately after preparation and stored for 2 months under the conditions of room temperature (23 DEG C) and freezing (-20 DEG C).

After the above-mentioned preservation, the number (foreign particles / cm ³ ) of foreign substances present in the resist composition in the bottle was measured using a liquid particle counter (product name: KS-41; The results are shown in Tables 2 and 3.

Refers to a granular material having a size (long diameter) of 0.135 mu m or more.

In the case where the number of foreign matter after storage for 2 months increased to 100 times or more as compared with the room temperature sample at the storage start time (initial), the storage stability was judged to be defective.

In the table, &quot; Cell NG &quot; indicates that measurement is impossible because a large amount of particles are detected.

From the results shown in Tables 2 and 3, it can be seen that the resist compositions of Comparative Examples 10 to 12 containing the untreated resin are inferior in storage stability.

[Pattern defect]

A space and line resist pattern was formed by using each example of the resist composition as follows.

An organic antireflection film composition "ARC95" (trade name, manufactured by Brewer Science) was applied onto a 12-inch silicon wafer using a spinner and baked on a hot plate at 205 ° C. for 60 seconds and dried to form an organic antireflection film having a film thickness of 90 nm did.

Each of the resist compositions of Example was coated on the organic antireflection film using a spinner and subjected to prebaking (PAB) treatment for 60 seconds at a heating temperature shown in Table 4 on a hot plate and dried to form a resist film having a film thickness of 90 nm.

Next, with respect to the resist film, a liquid immersion ArF exposure apparatus NSR-S609B (manufactured by Nikon Corporation; NA (numerical aperture) = 1.07, immersion medium: water] was selectively irradiated with an ArF excimer laser (193 nm) through a photomask.

Thereafter, a post-exposure baking (PEB) treatment was performed at a heating temperature shown in Table 4 for 60 seconds.

Subsequently, solvent development was carried out for 13 seconds using butyl acetate (BA) or methyl amyl ketone (MAK) as a developer at room temperature.

As a result, a space and line (SL) pattern having a space width of 60 nm and a pitch of 150 nm was formed in all examples.

With respect to the obtained SL pattern, the total number of defects (total number of defects) in the wafer was measured using a surface defect observation apparatus (KLA Tencor Corporation, product name: KLA2371). The wafers provided for these measurements were each divided into two for each example, and the average value was adopted.

The results of this measurement are divided into modes by a review SEM to determine the number of remodelings (Blob) attached to the pattern, the number of points where the lines are bridged and disconnected (Short), and the number of locations where the pattern is twisted Table 4 shows the number (Deformation).

Further, if the pattern twist (phenomenon in which the line partially curves) occurs over a part or all of the line pattern, the resist pattern shape becomes defective.

From the results shown in Table 4, it is understood that the resist compositions of Examples 7 to 12, to which the present invention is applied, are superior to the resist compositions of Comparative Examples 7 to 12 in that the occurrence of defects is suppressed in the resist pattern formation using the solvent development process .

Claims (8)

A method for purifying a crude resin of a resist resin for use in a resist composition containing a resin for a resist in which solubility in an organic solvent is reduced by the action of an acid and an acid generator for generating an acid upon exposure,
(1) of mixing the crude resin with a solvent containing an organic solvent (C) usable in a developing solution to prepare a crude resin solution,
(2) of filtering the crude resin solution prepared in the step (1) to obtain a filtrate containing the resist resin. The method according to claim 1,
Wherein the ratio of the organic solvent (C) in the solvent of the crude resin solution prepared in the step (1) is 10% by mass or more. The method according to claim 1,
And a step (3) of concentrating the filtrate obtained in the step (2). The method according to claim 1,
Wherein the organic solvent (C) is at least one selected from the group consisting of a ketone solvent and an ester solvent. A resist resin obtained by the method for purifying crude resin according to any one of claims 1 to 4. A process for producing a resist composition, which comprises mixing the resist resin according to claim 5 and an acid generator for generating an acid by exposure. A resist composition comprising the resist resin according to claim 5. A step of forming a resist film by using the resist composition according to claim 7 on a support, a step of exposing the resist film, and a step of patterning the resist film by a negative type development using a developer containing an organic solvent to form a resist pattern Thereby forming a resist pattern.