KR102206690B1 - Resist composition and method of forming resist pattern - Google Patents

Abstract

(assignment)
Provision of a resist composition capable of forming a resist pattern with reduced roughness.
(Solution) A polymer compound having a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and having a lactone-containing cyclic group including an electron withdrawing group at the side chain terminal And an acid generator comprising a compound represented by general formula (b1). In formula (b1), R ¹⁰¹ is a cyclic group, a chain alkyl group, or a chain alkenyl group which may have a substituent. q'' is an integer of 1-20. M ^{m +} is an m-valent organic cation.
[Formula 1]

Description

Resist composition and resist pattern formation method TECHNICAL FIELD [RESIST COMPOSITION AND METHOD OF FORMING RESIST PATTERN}

The present invention relates to a resist composition and a method of forming a resist pattern.

In the lithography technique, for example, a process of forming a resist pattern of a predetermined shape on the resist film by forming a resist film made of a resist material on a substrate, selectively exposing the resist film, and performing a development treatment. This is carried out. A resist material in which the exposed portion of the resist film changes to a property that dissolves in the developer is called a positive type, and a resist material in which the exposed portion changes to a property that does not dissolve in the developer is called a negative type.

BACKGROUND ART In the manufacture of semiconductor devices and liquid crystal display devices in recent years, pattern miniaturization is rapidly progressing due to advances in lithography technology. As a method of miniaturization, a shorter wavelength (higher energy) of an exposure light source is generally performed. Specifically, conventionally, ultraviolet rays typified by g-rays and i-rays have been used, but mass production of semiconductor devices using a KrF excimer laser or an ArF excimer laser has been started. Moreover, EUV (extreme ultraviolet rays), EB (electron rays), X-rays, etc. of shorter wavelength (higher energy) than these excimer lasers are also being examined.

Resist materials are required to have lithographic properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns of fine dimensions.

As a resist material that satisfies such requirements, conventionally, a chemically amplified resist composition containing a base component whose solubility in a developer is changed by the action of an acid and an acid generator component that generates an acid by exposure has been used. .

For example, when the developer is an alkali developer (alkaline developing process), a positive chemically amplified resist composition includes a resin component (base resin) whose solubility in an alkaline developer increases by the action of an acid, and acid generation. Those containing the first component are generally used. When a resist film formed using such a resist composition is subjected to selective exposure during formation of a resist pattern, an acid is generated from the acid generator component in the exposed portion, and the polarity of the base resin increases due to the action of the acid. The exposed portion becomes soluble in the alkaline developer. Therefore, by alkali development, a positive pattern in which an unexposed portion remains as a pattern is formed.

On the other hand, when such a chemically amplified resist composition is applied to a solvent development process using a developer containing an organic solvent (organic developer), when the polarity of the base resin increases, solubility in an organic developer decreases. The unexposed portion of the resist film is dissolved and removed with an organic developer, thereby forming a negative resist pattern in which the exposed portion remains as a pattern. The solvent developing process for forming a negative resist pattern in this way is sometimes referred to as a negative developing process (see, for example, Patent Document 1).

The base resin used in the chemically amplified resist composition generally has a plurality of structural units in order to improve lithography properties and the like.

For example, in the case of a resin component whose solubility in an alkali developer is increased by the action of an acid, a constituent unit containing an acid-decomposable group that is decomposed by the action of an acid generated from an acid generator or the like to increase polarity is used, In addition, a structural unit containing a lactone-containing cyclic group, a structural unit containing a polar group such as a hydroxyl group, and the like are used in combination (see, for example, Patent Document 2).

In recent years, with the progress of further miniaturization of patterns, the demand for a polymer compound useful as a base resin for a resist composition is increasing.

Among them, for example, a polymer compound using a polycyclic ester containing an electron withdrawing substituent and a lactone skeleton as a monomer, and a resist composition containing the polymer compound have been proposed (see Patent Document 3).

Japanese Unexamined Patent Publication No. 2009-025723 Japanese Unexamined Patent Publication No. 2003-241385 Japanese Patent Application Publication No. 2008-231059

As the lithography technology is further advanced and the application field is being expanded, there is a further demand for improvement in various lithographic properties such as higher sensitivity and improved roughness in forming a resist pattern. However, in the resist composition described in Patent Document 3, for example, further improvement of the roughness in particular of the resist pattern is required.

The present invention has been made in view of the above circumstances, and has as a subject a resist composition capable of forming a resist pattern with reduced roughness.

A first aspect of the present invention for solving the above problems is a resist composition comprising a base component (A) whose solubility in a developer is changed by the action of an acid and an acid generator component (B) that generates an acid by exposure As, the base component (A) contains a polymer compound (A1) having a structural unit (a0) represented by the following general formula (a0-1), and the acid generator component (B) is represented by the following general formula ( It is a resist composition comprising an acid generator (B1) comprising a compound represented by b1).

[Formula 1]

[In the formula, 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 ⁰ is a divalent hydrocarbon group which may have a substituent. n _a0 is an integer of 0-2. Ra ¹ and Ra ² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or an alkylthio group, or Ra ¹ and Ra ² are bonded to each other to form an oxygen atom (-O-) or a sulfur atom It may be a C1-C6 alkylene group, an ether bond, or a thioether bond which may contain (-S-). Ra' ⁰¹ is an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms that may have a halogen atom protected by a protecting group or may have a halogen atom, and a carboxyl group forming a salt Or a substituted oxycarbonyl group. When two or more Ra' ⁰¹ are present, a plurality of Ra' ⁰¹ may be the same as or different from each other. X is a substituent selected from the group consisting of a halogen atom, a carboxyl group, an alkoxycarbonyl group, an acyl group, a nitro group, and a cyano group. When two or more Xs are present, a plurality of Xs may be the same or different from each other. p ₀ is an integer of 0-8. q ₀ is an integer of 1 to 9.]

[Formula 2]

[In the formula, R ¹⁰¹ is 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. q'' is an integer of 1-20. m is an integer of 1 or more, and M ^{m +} is an m-valent organic cation.]

The second aspect of the present invention provides a step of forming a resist film on a support using the resist composition of the first aspect of the present invention, a step of exposing the resist film, and developing the resist film after the exposure to form a resist pattern. It is a method of forming a resist pattern comprising a step.

According to the resist composition and the resist pattern forming method of the present invention, a resist pattern with reduced roughness can be formed.

In the present specification and claims, the term "aliphatic" is a relative concept with respect to aromatics, and is defined to mean a group, compound, etc. that do not have aromaticity.

Unless otherwise specified, the "alkyl group" shall include a linear, branched, and cyclic monovalent saturated hydrocarbon group. The alkyl group in the alkoxy group is also the same.

The "alkylene group" shall include a linear, branched and cyclic divalent saturated hydrocarbon group unless otherwise specified.

The "halogenated alkyl group" is a group in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms, 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 the "fluorinated alkylene group" refers to a group in which some or all of the hydrogen atoms of the alkyl group or the alkylene group are substituted with fluorine atoms.

The "constituent unit" means a monomer unit (monomer unit) constituting a high molecular compound (resin, polymer, copolymer).

In the case of describing as "you may have a substituent", both a case where a hydrogen atom (-H) is substituted with a monovalent group and a case where a methylene group (-CH ₂ -) is substituted with a divalent group are included.

"Exposure" is a concept including the whole irradiation of radiation.

The "constituent unit derived from an acrylic acid ester" means a structural unit formed by cleaving an ethylenic double bond of an acrylic acid ester.

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

In the acrylic acid ester, a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent. The substituent (R ^α0 ) that replaces the hydrogen atom bonded to the carbon atom at the α-position is an atom or group other than a hydrogen atom, and examples thereof include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, etc. have. Further, the substituent (R ^α0) is an itaconic diester substituted with a substituent containing an ester bond or a substituent (R ^α0) a hydroxy group or by including an α-hydroxy acrylic ester is substituted with the formula the hydroxyl group do. In addition, the carbon atom at the α-position of the acrylic acid ester is a carbon atom to which the carbonyl group of acrylic acid is bonded, unless otherwise noted.

Hereinafter, an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylic acid ester. Moreover, an acrylic acid ester and an α-substituted acrylic acid ester are encompassed and referred to as "(α-substituted) acrylic acid ester" in some cases.

The "constituent unit derived from acrylamide" means a structural unit constituted by cleavage of an ethylenic double bond of acrylamide.

In acrylamide, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, or one or both of the hydrogen atoms of the amino group of the acrylamide may be substituted with a substituent. In addition, the carbon atom at the α-position of the acrylamide is a carbon atom to which the carbonyl group of the acrylamide is bonded, unless otherwise noted.

Examples of the substituent for substituting the hydrogen atom bonded to the carbon atom at the α-position of the acrylamide include those exemplified as the substituent at the α-position in the α-substituted acrylic acid ester (substituent group (R ^α0 )).

The "constituent unit derived from a hydroxystyrene or a hydroxystyrene derivative" means a structural unit formed by cleaving an ethylenic double bond of a hydroxystyrene or a hydroxystyrene derivative.

The term "hydroxystyrene derivative" is a concept including those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. As their derivatives, the hydrogen atom of the hydroxyl group of hydroxystyrene in which the hydrogen atom at the α-position may be substituted with a substituent is substituted with an organic group; in the benzene ring of hydroxystyrene in which the hydrogen atom at the α-position may be substituted with a substituent, And those in which a substituent other than a hydroxyl group is bonded. In addition, the α-position (carbon atom in the α-position) refers to a carbon atom to which a benzene ring is bonded, unless otherwise noted.

Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same as those exemplified as the substituent at the α-position in the α-substituted acrylate ester.

The "constituent unit derived from a vinylbenzoic acid or a vinylbenzoic acid derivative" means a structural unit constituted by cleavage of an ethylenic double bond of a vinylbenzoic acid or a vinylbenzoic acid derivative.

The term "vinylbenzoic acid derivative" is a concept in which a hydrogen atom at the α-position of vinylbenzoic acid is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. As their derivatives, the hydrogen atom of the carboxyl group of vinylbenzoic acid in which the hydrogen atom at the α-position may be substituted with an organic group is substituted with an organic group; in the benzene ring of the vinylbenzoic acid in which the hydrogen atom at the α-position may be substituted with a substituent, a hydroxyl group and And those in which a substituent other than a carboxyl group is bonded. In addition, the α-position (carbon atom in the α-position) refers to a carbon atom to which a benzene ring is bonded, unless otherwise noted.

The term "styrene" is a concept including styrene and those in which the hydrogen atom at the α-position of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group.

The "constituent units derived from styrene" and "constituent units derived from a styrene derivative" mean a structural unit constituted by cleavage of an ethylenic double bond of styrene or a styrene derivative.

The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, and specifically, an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, iso Butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group), and the like.

Further, specific examples of the halogenated alkyl group as the substituent at the α-position include a group in which some or all of the hydrogen atoms of the “alkyl group as the substituent at the α-position” 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.

Further, the hydroxyalkyl group as the substituent at the α-position is specifically, a group in which a part or all of the hydrogen atoms of the “alkyl group as the substituent at the α-position” is substituted with a hydroxyl group. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

≪Resist composition≫

The resist composition of the first aspect of the present invention includes a base component (A) whose solubility in a developer is changed by the action of an acid (hereinafter, also referred to as ``component (A)'') and acid generation that generates an acid by exposure. It contains the first component (B) (hereinafter also referred to as "component (B)").

When a resist film is formed using such a resist composition and selective exposure is performed on 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. In the miner part, the solubility of the component (A) in the developer does not change, so that a difference in solubility in the developer solution occurs between the exposed part and the unexposed part. Therefore, when the resist film is developed, when the resist composition is positive, the exposed portion is dissolved and removed to form a positive resist pattern, and when the resist composition is negative, the unexposed portion is dissolved and removed to form a negative resist pattern. Is formed.

In the present specification, the resist composition in which the exposed portion is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and the resist composition in which the unexposed portion is dissolved and removed to form a negative resist pattern is referred to as a negative resist composition.

The resist composition of this embodiment may be a positive resist composition or a negative resist composition.

In addition, the resist composition of the present embodiment may be for an alkali developing process using an alkali developer for developing treatment at the time of forming a resist pattern, and for a solvent developing process using a developer (organic developer) containing an organic solvent for the developing treatment. May be.

<(A) component>

In the present invention, the "substrate component" is an organic compound having a film-forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved, and it is easy to form a nano-level resist pattern.

Organic compounds used as the base component are roughly classified into non-polymers and polymers.

As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, in the case of a "low molecular weight compound", a non-polymer having a molecular weight of 500 or more and less than 4000 is indicated.

As the polymer, one having a molecular weight of 1000 or more is usually used. Hereinafter, in the case of "resin" or "polymer compound", a polymer having a molecular weight of 1000 or more is indicated.

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

When the resist composition of the present embodiment is a ``negative resist composition for an alkali developing process'' that forms a negative resist pattern in an alkali developing process, or a ``solvent development process that forms a positive resist pattern in a solvent developing process'' For positive resist composition”, as the component (A), a base component (A-2) soluble in an alkali developer (hereinafter, referred to as “component (A-2)”) is preferably used, and a crosslinking agent The ingredients are blended. In such a resist composition, when an acid is generated from the component (B) by exposure, the acid acts and crosslinking occurs between the component (A-2) and the crosslinking agent component, and as a result, the solubility in an alkali developer decreases (organic developer Solubility to increase). 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 poorly soluble in an alkaline developer (soluble in an organic developer), while the unexposed portion is changed to alkali. Since it does not change while being soluble in a developer (slightly soluble in an organic developer), a negative resist pattern is formed by developing with an alkaline developer. Further, by developing with an organic developer at this time, a positive resist pattern is formed.

As the component (A-2), a resin that is soluble in an alkali developer (hereinafter, referred to as "alkali-soluble resin") is used.

As the alkali-soluble resin, for example, an alkyl ester of α-(hydroxyalkyl)acrylic acid or α-(hydroxyalkyl)acrylic acid disclosed in Japanese Laid-Open Patent Publication No. 2000-206694 (preferably, having 1 to A resin having a unit derived from at least one selected from the alkyl ester of 5); As disclosed in U.S. Patent No. 6949325, an acrylic resin in which a hydrogen atom bonded to a carbon atom at the α-position having a sulfonamide group may be substituted with a substituent; or Polycycloolefin resin; As disclosed in U.S. Patent Publication No. 6949325, JP 2005-336452 A, and JP 2006-317803, a fluorinated alcohol is contained, and the hydrogen atom bonded to the carbon atom at the α-position is a substituent. Acrylic resins which may be substituted; polycycloolefin resins having fluorinated alcohols disclosed in Japanese Patent Application Laid-Open No. 2006-259582, etc., are preferable because they can form a good resist pattern with little swelling.

In addition, the α-(hydroxyalkyl) acrylic acid is an acrylic acid in which a hydrogen atom is bonded to a carbon atom at the α-position to which a carboxyl group is bonded among acrylic acids in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, One or both of the α-hydroxyalkylacrylic acids to which a hydroxyalkyl group (preferably a C1-C5 hydroxyalkyl group) is bonded to the carbon atom at the α-position is shown.

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

When the resist composition of the present embodiment is a ``positive resist composition for an alkali developing process'' that forms a positive resist pattern in an alkali developing process, or a ``solvent development process that forms a negative resist pattern in a solvent developing process'' For negative resist composition”, as the component (A), preferably, the base component (A-1) whose polarity increases due to the action of an acid (hereinafter referred to as “component (A-1)”) Is used. By using the component (A-1), since the polarity of the base component changes before and after exposure, good development contrast can be obtained not only in the alkali developing process but also in the solvent developing process.

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

On the other hand, in the case of applying a solvent development process, the component (A-1) has high solubility in an organic developer before exposure, and when an acid is generated by exposure, the polarity increases due to the action of the acid, and the organic developer Solubility to is reduced. Therefore, in the formation of a resist pattern, when selectively exposing the resist film obtained by coating the resist composition on a support, the exposed portion changes from soluble to poorly soluble in an organic developer, while the unexposed portion remains soluble. Since it does not change, by developing with an organic developer, a contrast can be provided between the exposed portion and the unexposed portion, thereby forming a negative resist pattern.

The component (A) used in the resist composition of the present embodiment contains a polymer compound (A1) having a structural unit (a0) represented by the general formula (a0-1) (hereinafter referred to as ``component (A1)''). will be.

As the component (A), at least the component (A1) is used, and other high molecular compounds and/or low molecular compounds may be used together with the component (A1).

In the resist composition of this aspect, it is preferable that the component (A) is the component (A-1). That is, the resist composition of the present embodiment is a ``positive resist composition for an alkali developing process'' that forms a positive resist pattern in an alkali developing process, or a ``solvent development process that forms a negative resist pattern in a solvent development process'' It is preferably a negative resist composition”. Moreover, it is preferable that the component (A-1) contains the component (A1).

[(A1) component]

The component (A1) is a polymer compound having a structural unit (a0) represented by General Formula (a0-1).

(Constituent unit (a0))

The structural unit (a0) is a structural unit represented by the following general formula (a0-1). In forming a resist pattern, the use of a polymer compound having a structural unit (a0) as a base resin is effective for high sensitivity.

[Formula 3]

[In the formula, 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 ⁰ is a divalent hydrocarbon group which may have a substituent. n _a0 is an integer of 0-2. Ra ¹ and Ra ² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or an alkylthio group, or Ra ¹ and Ra ² are bonded to each other to form an oxygen atom (-O-) or a sulfur atom It may be a C1-C6 alkylene group, an ether bond, or a thioether bond which may contain (-S-). Ra' ⁰¹ is an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms that may have a halogen atom protected by a protecting group or may have a halogen atom, and a carboxyl group forming a salt Or a substituted oxycarbonyl group. When two or more Ra' ⁰¹ are present, a plurality of Ra' ⁰¹ may be the same as or different from each other. X is a substituent selected from the group consisting of a halogen atom, a carboxyl group, an alkoxycarbonyl group, an acyl group, a nitro group, and a cyano group. When two or more Xs are present, a plurality of Xs may be the same or different from each other. p ₀ is an integer of 0-8. q ₀ is an integer of 1 to 9.]

In the formula (a0-1), the alkyl group having 1 to 5 carbon atoms in 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, Isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, and the like.

The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the "alkyl group having 1 to 5 carbon atoms in R" 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.

As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is particularly preferable from the ease of industrial availability.

In the formula (a0-1), Va ⁰ is a divalent hydrocarbon group which may have a substituent.

The hydrocarbon group of Va ⁰ 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 for Va ⁰ may be saturated or unsaturated, and is preferably saturated.

As the aliphatic hydrocarbon group for Va ⁰ , more specifically, a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure, and the like can be mentioned.

Va ⁰ may have a substituent. Include those having a case which is substituted with a divalent, ether bond between the carbon atoms of the divalent hydrocarbon group of ⁰ Va group (-O-) - for example, a methylene group (-CH ₂₎ in the hydrocarbon groups Va ⁰ I can. In this case, the number of ether bonds present in Va ⁰ may be one or two. In addition, a case where the hydrogen atom (-H) in the hydrocarbon groups are substituted with ⁰ Va monovalent, fluorinated alkyl group with a hydrogen atom (-H) in the hydrocarbon groups of Va ⁰ is a fluorine atom or having 1 to 5 carbon atoms What has been substituted is mentioned. In this case, Va ⁰ is -CH ₂ CHF-, -CH(CH ₂ CH ₃ )CF ₂ -, -CH(CH ₂ CH ₃ )C(CF ₃ )F-, -CH(CH ₃ )CF ₂ -Etc. are preferable.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, still more preferably 1 to 4, and most preferably 1 to 3.

As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], and a trimethylene group [-( CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.

The branched-chain aliphatic hydrocarbon group is preferably a branched-chain alkylene group, specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, Alkyl methylene groups, such as -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -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 ) Alkyl ethylene group, such as ₂ -CH ₂ -; Alkyl trimethylene group such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ )CH ₂ CH ₂ CH ₂ - and the like can be mentioned alkyl groups such as alkyl groups, such as tetramethylene _{-, -CH 2 CH (CH 3} ) CH 2 CH 2. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

As the aliphatic hydrocarbon group containing a ring in the above structure, an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the terminal of a linear or branched aliphatic hydrocarbon group And groups in which the alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those similar to those described above.

The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and 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 two hydrogen atoms have been removed from a monocycloalkane is preferable. As the monocycloalkane, those having 3 to 6 carbon atoms are preferable, and specifically, cyclopentane, cyclohexane, etc. are mentioned.

As the polycyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a polycycloalkane is preferable, and the polycycloalkane is preferably a C7 to C12 group. Specifically, adamantane, norbornane, iso Bornane, tricyclodecane, tetracyclododecane, etc. are mentioned.

The aromatic hydrocarbon group for Va ⁰ 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 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. Examples of the hetero atom 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.

As an aromatic hydrocarbon group, specifically, a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or the aromatic heterocyclic ring (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings (for example, biphenyl, flue A group in which two hydrogen atoms have been removed from an orene, etc.); a group in which one of the hydrogen atoms of the group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) is substituted with an alkylene group (example For example, one additional hydrogen atom was removed from the aryl group in the arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group. Group) and the like. The number of carbon atoms of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

In said formula (a0-1), n _a0 is an integer of 0-2, 0 or 1 is preferable, and 0 is more preferable.

In the formula (a0-1), Ra ¹ and Ra ² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or an alkylthio group, or Ra ¹ and Ra ² are bonded to each other to form oxygen It may be a C1-C6 alkylene group, an ether bond, or a thioether bond which may contain an atom (-O-) or a sulfur atom (-S-).

The alkyl group having 1 to 5 carbon atoms for Ra ¹ and Ra ² 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, an isopropyl group, and n -Butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. are mentioned.

The alkoxy group for Ra ¹ and Ra ² is preferably a linear or branched chain, and specifically, the alkyl group exemplified as the alkyl group for Ra ¹ and Ra ² is connected to an oxygen atom (-O-). Can be raised.

The alkylthio group in Ra ¹ and Ra ² preferably has 1 to 4 carbon atoms, and specifically, a methylthio group, an ethylthio group, an n-propylthio group, an iso-propylthio group, an n-butylthio group, tert-butylthio group is mentioned.

In addition, in Ra ¹ and Ra ² , Ra ¹ and Ra ² are bonded to each other to include an oxygen atom (-O-) or a sulfur atom (-S-), an alkylene group having 1 to 6 carbon atoms, an ether bond ( -O-) or a thioether bond (-S-) may be used.

As an alkylene group having 1 to 6 carbon atoms formed by bonding of Ra ¹ and Ra ² to each other, a linear or branched alkylene group is preferable, and a methylene group, ethylene group, n-propylene group, isopropylene group, etc. Can be mentioned. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which -O- or -S- is interposed between the terminal of the alkylene group or between carbon atoms, for example -O- CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S-CH ₂ -, etc. are mentioned. The group formed by bonding of Ra ¹ and Ra ² to each other is preferably an alkylene group having 1 to 6 carbon atoms or -O-, more preferably an alkylene group having 1 to 6 carbon atoms, furthermore an alkylene group having 1 to 5 carbon atoms It is preferred, and a methylene group is particularly preferred.

In the above formula (a0-1), Ra' ⁰¹ is an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, and a hydroxy group moiety may be protected with a protecting group or having 1 to 6 carbon atoms which may have a halogen atom. It is a hydroxyalkyl group, a carboxyl group forming a salt, or a substituted oxycarbonyl group.

Examples of the C1-C6 alkyl group for Ra' ⁰¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group , A pentyl group, a hexyl group, and the like. Among these, an alkyl group having 1 to 5 carbon atoms is preferable, an alkyl group having 1 to 4 carbon atoms is more preferable, an alkyl group having 1 to 3 carbon atoms is still more preferable, and a methyl group or an ethyl group It is particularly preferred, and a methyl group is most preferred. Examples of the halogen atom that may have an alkyl group having 1 to 6 carbon atoms for Ra′ ⁰¹ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group having 1 to 6 carbon atoms having a halogen atom include a chloroalkyl group such as a chloromethyl group; a fluoroalkyl group such as a trifluoromethyl group, a 2,2,2-trifluoroethyl group, or a pentafluoroethyl group ( Preferably, a C1-C3 fluoroalkyl group) etc. are mentioned.

Examples of the hydroxyalkyl group having 1 to 6 carbon atoms in Ra′ ⁰¹ include hydroxymethyl group, 2-hydroxyethyl group, 1-hydroxyethyl group, 3-hydroxypropyl group, and 2-hydroxypropyl. Group, 4-hydroxybutyl group, 6-hydroxyhexyl group, etc. are mentioned. Examples of the halogen atom that may have a hydroxyalkyl group having 1 to 6 carbon atoms for Ra′ ⁰¹ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable. Examples of the hydroxyalkyl group having 1 to 6 carbon atoms having a halogen atom include difluorohydroxymethyl group, 1,1-difluoro-2-hydroxyethyl group, and 2,2-difluoro-2- Hydroxyethyl group, 1,1,2,2-tetrafluoro-2-hydroxyethyl group, etc. are mentioned. Among the hydroxyalkyl groups having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 3 carbon atoms which may have a halogen atom is preferred, and a hydroxyalkyl group having 1 or 2 (preferably 1) carbon atoms, Alternatively, a hydroxyalkyl group having a halogen atom having 1 or 2 carbon atoms (preferably 1 carbon atom) is more preferable.

As a protecting group that protects the hydroxy group portion of a hydroxyalkyl group having 1 to 6 carbon atoms which may have a halogen atom, for example, an ether bond or acetal together with an oxygen atom constituting a hydroxy group such as a methyl group or a methoxymethyl group Groups that form bonds; groups that form ester bonds together with oxygen atoms constituting hydroxy groups such as an acetyl group and a benzoyl group, etc. are mentioned.

Examples of the carboxyl group (salt of a carboxyl group) forming a salt in Ra′ ⁰¹ include alkali metal salts, alkaline earth metal salts, and transition metal salts.

Examples of the substituted oxycarbonyl group for Ra′ ⁰¹ include an alkoxycarbonyl group in which an alkoxy group having 1 to 4 carbon atoms and a carbonyl group are bonded (specifically, a methoxycarbonyl group, an ethoxycarbonyl group, an isopropyloxycarbonyl group, n-pro Alkyloxycarbonyl groups, such as a foxycarbonyl group; Alkenyloxycarbonyl groups, such as a vinyloxycarbonyl group and an allyloxycarbonyl group); Cycloalkyloxycarbonyl groups, such as a cyclohexyloxycarbonyl group, Aryloxycarbonyl groups, such as a phenyloxycarbonyl group, etc. are mentioned.

In the structural unit represented by the above formula (a0-1), when two or more Ra' ⁰¹ are present, a plurality of Ra' ⁰¹ may be the same or different from each other.

Ra' ⁰¹ is, among the above, a C1-C6 alkyl group which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms which may have a halogen atom protected by a protecting group, or substituted oxy. A carbonyl group is preferred.

Among the alkyl groups having 1 to 6 carbon atoms which may have a halogen atom, an alkyl group having 1 to 3 carbon atoms or a halogenated alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group and a trifluoromethyl group are particularly preferable.

Among the hydroxyalkyl groups having 1 to 6 carbon atoms in which the hydroxy group moiety may be protected with a protecting group and may have a halogen atom, a hydroxyalkyl group having 1 to 3 carbon atoms in which the hydroxy group moiety may be protected with a protecting group, or, A hydroxyalkyl group having a halogen atom in which the hydroxy group portion may be protected by a protecting group is preferable, and a hydroxymethyl group in which the hydroxymethyl group and the hydroxy group portion may be protected by a protecting group such as an acetoxymethyl group is more preferable.

In the formula (a0-1), X is a substituent selected from the group consisting of a halogen atom, a carboxyl group, an alkoxycarbonyl group, an acyl group, a nitro group, and a cyano group.

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

Examples of the alkoxycarbonyl group for X include a methoxycarbonyl group.

As an acyl group for X, an acetyl group etc. are mentioned, for example.

In the structural unit represented by the above formula (a0-1), when two or more Xs are present, a plurality of Xs may be the same or different from each other.

Among the above, X is a halogen atom (preferably a fluorine atom), a carboxyl group, an alkoxycarbonyl group (preferably a methoxycarbonyl group), an acyl group (preferably an acetyl group), a cyano group, from the viewpoint of a high electron withdrawing property. A nitro group is preferred, and a cyano group is particularly preferred.

In said formula (a0-1), p ₀ is an integer of 0-8, Preferably it is an integer of 0-6, More preferably, it is an integer of 0-3.

In said formula (a0-1), q ₀ is an integer of 1-9, Preferably it is an integer of 1-5, More preferably, it is 1 or 2.

In the above formula (a0-1), when Ra ¹ and Ra ² are not bonded to each other, X is at the 1 position, the 2 position and the 3 position of the 6-oxabicyclo[3.2.1 ^1,5 ]octane ring, It may be bonded to any of the 4, 5, or 8 positions, and among them, it is preferably bonded to the 1 position (the α position of the lactone) or the 2 position, and among them, the 1 position (the α position of the lactone) It is particularly preferable to bind to the position of.

In addition, when Ra ¹ and Ra ² are bonded to each other, X is a 3-oxatricyclo[4.2.1.0 ^4,8 ]nonane ring at 1 position, 4 position, 5 position, 6 position, 7 position, 8 It may be bonded to any position such as the position or the 9 position, among which 3-oxatricyclo[4.2.1.0 ^4,8 ] is bonded to the position 1 or 9 (or a position corresponding to these) of the nonane ring It is preferable that it exists, and it is especially preferable that it couple|bonds with the position of 1 position (or the position corresponding to this; α position of a lactone) among them.

The specific example of the structural unit (a0) is shown below. In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group. X is the same as X in the above formula (a0-1).

[Formula 4]

[Formula 5]

The structural unit (a0) of the component (A1) may be one or two or more.

The proportion of the structural unit (a0) in the component (A1) is preferably 5 to 70 mol%, more preferably 10 to 60 mol%, and 10 to the total of all structural units constituting the component (A1). -50 mol% is more preferable, and 10-40 mol% is particularly preferable.

By making the ratio of the structural unit (a0) less than or equal to a preferred upper limit, it is easy to obtain a resist pattern having a good shape while maintaining high sensitivity. On the other hand, by setting it as more than a preferable lower limit, while the sensitivity is raised, lithography characteristics, such as resolution and exposure margin (EL margin), are also improved.

(Other constituent units)

In addition to the structural unit (a0), the component (A1) may further have other structural units.

The other structural unit is not particularly limited as long as it is a structural unit that is not classified into the structural unit (a0) described above, and is for resists such as for ArF excimer lasers and KrF excimer lasers (preferably for ArF excimer lasers). A large number of conventionally known ones used for resins can be used, and examples thereof include structural units (a1) to (a4) shown below, structural units that generate an acid by exposure, and the like.

Constituent unit (a1):

In the resist composition of the present embodiment, it is preferable that the component (A1) has a structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid in addition to the structural unit (a0).

When the resist composition of the present embodiment contains a polymer compound having a structural unit (a0) and a structural unit (a1), when the resist film formed using the resist composition is exposed, in the resist film, the structural unit (a1) is At least part of the bonds in the structure are cleaved by the action of the acid, and the polarity increases. In this way, since the polarity of the component (A1) changes before and after exposure, by using the component (A1), a good development contrast can be obtained not only in the alkali developing process but also in the solvent developing process. And the resist composition of this aspect becomes a positive type in an alkali developing process, and becomes a negative type in a solvent developing process.

The "acid decomposable group" is a group having acid decomposability in which at least a part of the bonds in the structure of the acid decomposable group can be cleaved by the action of an acid.

As an acid-decomposable group whose polarity increases by the action of an acid, for example, a group which is decomposed by the action of an acid to generate a polar group is mentioned.

As a polar group, a carboxyl group, a hydroxyl group, an amino group, a sulfo group (-SO ₃ H), etc. are mentioned, for example. Among these, a polar group containing -OH in the structure (hereinafter, sometimes referred to as "OH-containing polar group") 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 by an acid dissociable group (for example, a group in which the hydrogen atom of the OH-containing polar group is protected by an acid dissociable group) is mentioned.

Here, the term "acid dissociable group" means (i) a group having an acid dissociable property capable of cleaving a bond between the acid dissociable group and an atom adjacent to the acid dissociable group by the action of an acid, or (ii) It refers to both groups of groups capable of cleaving a bond between the acid dissociable group and an atom adjacent to the acid dissociable group by causing a decarboxylation reaction after cleavage of some of the bonds due to the action of an acid.

The acid dissociable group constituting the acid decomposable group needs to be a group having a lower polarity than the polar group generated by dissociation of the acid dissociable group. Accordingly, when the acid dissociable group is dissociated by the action of an acid, the acid dissociation Polar groups with higher polarity than genitals occur, increasing the polarity. As a result, the polarity of the entire component (A1) increases. As the polarity increases, the solubility in the developer is relatively changed, so that the solubility increases when the developer is an alkaline developer, and the solubility decreases when the developer is an organic developer.

Examples of the acid dissociable group include those that have been proposed as acid dissociable groups of base resins for chemically amplified resists so far.

It is proposed as an acid dissociable group of a base resin for a chemically amplified resist, specifically, ``acetal type acid dissociable group'', ``tertiary alkyl ester type acid dissociable group'', and ``tertiary Alkyloxycarbonyl acid dissociable group" is mentioned.

·Acetal type acid dissociation:

Among the polar groups, an acid dissociable group that protects a carboxyl group or a hydroxyl group is, for example, an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an ``acetal acid dissociable group'') Can be mentioned.

[Formula 6]

[In the formula, 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 of Ra' ¹ and Ra' ² to form a ring.]

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

When Ra' ¹ or Ra' ² is an alkyl group, examples of the alkyl group include the same alkyl groups exemplified as substituents which may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylate ester, and the number of carbon atoms is 1 The alkyl group of -5 is preferable. Specifically, a linear or branched alkyl group is preferably mentioned. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. may be mentioned, and a methyl group or an ethyl group It is more preferable and a methyl group is especially preferable.

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

The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2. Specifically, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. are mentioned. Among these, 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 chain type alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specifically, isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc. are mentioned, and isopropyl group It is desirable.

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

As the aliphatic hydrocarbon group which is a monocyclic group, a group in which one hydrogen atom has been removed from a monocycloalkane is preferable. As the monocycloalkane, one having 3 to 6 carbon atoms is preferable, and specific examples thereof include cyclopentane and cyclohexane.

As the aliphatic hydrocarbon group which is a polycyclic group, a group in which one hydrogen atom has been removed from a polycycloalkane is preferable, and as the polycycloalkane, a one having 7 to 12 carbon atoms is preferable. Specifically, adamantane, norbornane, iso Bornane, tricyclodecane, tetracyclododecane, etc. are mentioned.

When the cyclic hydrocarbon group of Ra' ³ becomes an aromatic hydrocarbon group, the aromatic 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 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. Examples of the hetero atom 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.

As the aromatic hydrocarbon group for Ra' ³ , specifically, a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); an aromatic compound containing two or more aromatic rings (Example For example, a group in which one hydrogen atom has been removed from biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or the aromatic heterocycle is substituted with an alkylene group (eg, benzyl group, phenethyl group, 1 -Arylalkyl groups, such as a naphthyl methyl group, a 2-naphthyl methyl group, a 1-naphthyl ethyl group, and a 2-naphthyl ethyl group), etc. are mentioned. The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or the aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

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

-Tertiary alkyl ester type acid dissociable group:

Among the polar groups, examples of the acid-dissociable group protecting the carboxyl group include an acid-dissociable group represented by the following general formula (a1-r-2). In addition, what is constituted by an alkyl group among the acid dissociable groups represented by the following formula (a1-r-2) is hereinafter sometimes referred to as a "tertiary alkyl ester type acid dissociable group" for convenience.

[Formula 7]

[In the formula, 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 for Ra' ⁴ to Ra' ⁶ include those similar to those of Ra' ³ .

It is preferable that Ra' ⁴ is a C1-C5 alkyl group. When Ra' ⁵ and Ra' ⁶ are bonded to each other to form a ring, a group represented by the following general formula (a1-r2-1) is mentioned. On the other hand, when Ra' ⁴ to Ra' ⁶ are not bonded to each other and are independent hydrocarbon groups, a group represented by the following general formula (a1-r2-2) is mentioned.

[Formula 8]

[In the formula, Ra' ¹⁰ represents an alkyl group having 1 to 10 carbon atoms, Ra' ¹¹ represents a group forming an aliphatic cyclic group together with the carbon atom to which Ra' ¹⁰ is bonded, and Ra' ¹² to Ra' ¹⁴ each independently represent a hydrocarbon group. .]

In the formula (a1-r2-1), the alkyl group having 1 to 10 carbon atoms of Ra′ ¹⁰ is a group exemplified as a linear or branched alkyl group of Ra′ ^{3 in} the formula (a1-r-1). desirable. In formula (a1-r2-1), the aliphatic cyclic group formed by Ra' ¹¹ with the carbon atom to which Ra' ¹⁰ is bonded is a monocyclic group or polycyclic group of Ra' ³ in formula (a1-r-1) The group exemplified as the group aliphatic hydrocarbon group is preferable.

In formula (a1-r2-2), Ra' ¹² and Ra' ¹⁴ are each independently preferably an alkyl group having 1 to 10 carbon atoms, and the alkyl group is Ra' ^{3 in the} formula (a1-r-1) The group exemplified as a linear or branched alkyl group of is more preferable, a linear alkyl group having 1 to 5 carbon atoms is still more preferable, and a methyl group or an ethyl group is particularly preferable.

Ra' ¹³ in formula (a1-r2-2) is a linear or branched alkyl group, monocyclic group or polycyclic group exemplified as the hydrocarbon group of Ra' ³ in formula (a1-r-1) It is preferably an aliphatic hydrocarbon group. Among these, the group exemplified as an aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group of Ra′ ³ is more preferable.

Specific examples of the group represented by the above formula (a1-r2-1) are given below. * Represents a bonding hand (hereinafter, the same in this specification).

[Formula 9]

[Formula 10]

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

[Formula 11]

-Tertiary alkyloxycarbonyl acid dissociable group:

Among the polar groups, the acid dissociable group protecting the hydroxyl group is, for example, an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter, referred to as ``tertiary alkyloxycarbonyl acid dissociable group'' for convenience). There are cases).

[Formula 12]

[In the formula, Ra' ⁷ to Ra' ⁹ are each an alkyl group.]

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

Moreover, it is preferable that it is 3-7, and, as for the total carbon number of each alkyl group, it is more preferable that it is 3-5, and it is most preferable that it is 3-4.

As the structural unit (a1), a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, a structural unit derived from acrylamide, a structural unit derived from a hydroxystyrene or a hydroxystyrene derivative Hydrogen in -C(=O)-OH of a structural unit in which at least part of the hydrogen atoms in the hydroxyl group of the unit is protected by a substituent containing the acid decomposable group, a structural unit derived from a vinylbenzoic acid or a vinylbenzoic acid derivative And structural units in which at least part of the atoms are protected by a substituent containing the acid-decomposable group.

As the structural unit (a1), among the above, a structural unit derived from an acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent is preferable.

As a preferable specific example of such a structural unit (a1), the structural unit represented by the following general formula (a1-1) or (a1-2) is mentioned.

[Formula 13]

[In the formula, 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 above formula (a1-r-1) or (a1-r-2). Wa ¹ is an n _a2 +1 valent hydrocarbon group, n _a2 is 1 to 3, and Ra ² is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-3).]

In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl group, ethyl group, propyl group, isopropyl Group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, and the like. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms 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.

As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is most preferable from the ease of industrial availability.

In the formula (a1-1), the divalent hydrocarbon group which may have an ether bond of Va ¹ is the same as the case where Va ⁰ in the formula (a0-1) becomes a divalent hydrocarbon group that may have an ether bond as a substituent. Do.

In the formula (a1-2), the n _a2 +1 valent hydrocarbon group in Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, and is preferably saturated. As the aliphatic hydrocarbon group, a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure are combined There is one qi.

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

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

[Formula 14]

[Formula 15]

[Formula 16]

[Formula 17]

[Formula 18]

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

[Formula 19]

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

When the component (A1) has a structural unit (a1), the ratio of the structural unit (a1) in the component (A1) is preferably 1 to 50 mol% with respect to the total of all structural units constituting the component (A1), , 5 to 45 mol% is more preferable, and 5 to 40 mol% is still more preferable.

By making the ratio of the structural unit (a1) more than the lower limit, a resist pattern can be easily obtained, and lithography properties such as sensitivity, resolution, roughness improvement, or EL margin are also improved. Moreover, by setting it as below an upper limit, balance with other structural units can be achieved.

Constituent unit (a2):

In the resist composition of the present embodiment, the component (A1) further contains a lactone-containing cyclic group, -SO ₂ -containing cyclic group, or carbonate-containing cyclic group in addition to the structural unit (a0) and the structural unit (a1). It is preferable to have a structural unit (a2) (however, excluding the structural unit (a0)).

The lactone-containing cyclic group, -SO ₂ -containing cyclic group, or carbonate-containing cyclic group of the structural unit (a2) is effective in enhancing the adhesion of the resist film to the substrate when the component (A1) is used for formation of the resist film. will be. In addition, by having the structural unit (a2), in an alkali developing process, the solubility of the resist film in an alkali developing solution increases during development.

The "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -O-C(=O)- in the cyclic skeleton. The lactone ring is counted as the first ring, and when only the lactone ring is a monocyclic group, when it has a further other ring structure, it is called 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 one can be used. Specifically, groups represented by the following general formulas (a2-r-1) to (a2-r-7) are mentioned.

[Formula 20]

[In the formula, Ra' ²¹ 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, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or an -SO ₂ -containing cyclic group; A'' is an oxygen atom (-O-) or a sulfur atom (-S-) It is an optionally C1-C5 alkylene group, an oxygen atom, or a sulfur atom, n'is an integer of 0-2, and m'is 0 or 1.]

In the general formulas (a2-r-1) to (a2-r-7), the alkyl group for Ra' ²¹ is preferably an alkyl group having 1 to 6 carbon atoms. It is preferable that the alkyl group is linear or branched. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a hexyl group, and the like are mentioned. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.

The alkoxy group for Ra' ²¹ is preferably an alkoxy group having 1 to 6 carbon atoms. It is preferable that the alkoxy group is linear or branched. Specifically, a group in which an alkyl group and an oxygen atom (-O-) exemplified as the alkyl group in the above Ra′ ²¹ are connected is mentioned.

Examples of the halogen atom for Ra' ²¹ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.

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

In -COOR'' and -OC(=O)R'' in Ra′ ²¹ , R'' are all hydrogen atoms, alkyl groups, lactone-containing cyclic groups, carbonate-containing cyclic groups, or -SO ₂ -containing rings It's a sentence.

As the alkyl group for R'', any of linear, branched and cyclic may be used, and the number of carbon atoms is preferably 1 to 15.

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

When R″ is a cyclic alkyl group, it is preferably 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane. A group from which one or more hydrogen atoms have been removed can be exemplified. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane and cyclohexane; a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane And groups in which one or more hydrogen atoms have been removed from.

Examples of the lactone-containing cyclic group for R'' include the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7).

The carbonate-containing cyclic group for R'' is the same as the carbonate-containing cyclic group described later, and specifically, groups represented by general formulas (ax3-r-1) to (ax3-r-3) are exemplified. .

-SO ₂ of the R '' - containing a cyclic group, which will be described later -SO ₂ - the same as that containing cyclic group, and specifically by the following formula (a5-r-1) ~ (a5-r-4) The groups represented respectively are mentioned.

The hydroxyalkyl group for Ra' ²¹ preferably has 1 to 6 carbon atoms, and specifically, a group in which at least one hydrogen atom of the alkyl group for Ra' ²¹ is substituted with a hydroxyl group is exemplified.

In the general formulas (a2-r-2), (a2-r-3) and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A'' is a linear or branched chain A type alkylene group is preferable, and a methylene group, an ethylene group, an n-propylene group, an isopropylene group, etc. are mentioned. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which -O- or -S- is interposed between the end of the alkylene group or between carbon atoms, for example -O- CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S-CH ₂ -, etc. are mentioned. As A", a C1-C5 alkylene group or -O- is preferable, a C1-C5 alkylene group is more preferable, and a methylene group is most preferable.

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

[Formula 21]

[Formula 22]

"-SO ₂ -containing cyclic group" refers to a cyclic group containing a ring containing -SO ₂ -in the ring skeleton, and specifically, the sulfur atom (S) in -SO ₂ -is a cyclic group It is a cyclic group forming part of the cyclic skeleton of. The ring containing -SO ₂ -in the ring skeleton is counted as the first ring, and in the case of only the ring, it is called a monocyclic group, and in the case of having another ring structure further, it is called a polycyclic group regardless of its structure. The -SO ₂ -containing cyclic group may be a monocyclic group or a polycyclic group.

-SO ₂ -containing cyclic group is, in particular, a cyclic group containing -O-SO ₂ -in its cyclic skeleton, that is, -OS- in -O-SO ₂ -is a sultone forming part of the cyclic skeleton It is preferably a cyclic group containing a ring.

As the -SO ₂ -containing cyclic group, more specifically, groups represented by the following general formulas (a5-r-1) to (a5-r-4) are exemplified.

[Formula 23]

[In the formula, 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, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or an -SO ₂ -containing cyclic group; A'' is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom. , An oxygen atom or a sulfur atom, and n'is an integer of 0-2.]

In the general formulas (a5-r-1) to (a5-r-4), A'' is the general formula (a2-r-2), (a2-r-3), (a2-r-5) It is the same as in A''.

The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'' and hydroxyalkyl group for Ra′ ⁵¹ are each of the general formulas (a2-r-1) to The same thing as those exemplified in the description of Ra' ²¹ in (a2-r-7) can be mentioned.

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

[Formula 24]

[Formula 25]

[Formula 26]

The "carbonate-containing cyclic group" refers to a cyclic group containing a ring (carbonate ring) containing -O-C(=O)-O- in the cyclic skeleton. The carbonate ring is counted as the first ring, and in the case of only the carbonate ring, it is referred to as a monocyclic group, and when it has a further other ring structure, it is referred to as a polycyclic group regardless of its structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.

The carbonate ring-containing cyclic group is not particularly limited, and any one can be used. Specifically, groups represented by the following general formulas (ax3-r-1) to (ax3-r-3) are exemplified.

[Formula 27]

[In the formula, Ra' ^x31 Are 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, An alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or an -SO ₂ -containing cyclic group; A'' is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom , p'is an integer of 0 to 3, and q'is 0 or 1.]

In the general formulas (ax3-r-1) to (ax3-r-3), A'' is the general formula (a2-r-2), (a2-r-3), (a2-r-5) It is the same as in A''.

The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'' and hydroxyalkyl group for Ra′ ³¹ are each of the general formulas (a2-r-1) to The same thing as those exemplified in the description of Ra' ²¹ in (a2-r-7) can be mentioned.

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

[Formula 28]

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

It is preferable that such a structural unit (a2) is a structural unit represented by the following general formula (a2-1).

[Chemical Formula 29]

[In the formula, 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 is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO- or -CONHCS-, and R'represents a hydrogen atom or a methyl group. However, when La ²¹ is -O-, Ya ²¹ does not become -CO-. Ra ²¹ is a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO ₂ -containing cyclic group.]

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

Although it does not specifically limit as a divalent linking group of Ya ²¹ , A divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, etc. are mentioned as a preferable thing.

・Divalent hydrocarbon group which may have a substituent:

When Ya ²¹ is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

-Aliphatic hydrocarbon group in Ya ²¹

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

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.

···Linear or branched aliphatic hydrocarbon group

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, still more preferably 1 to 4, and most preferably 1 to 3.

As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], and a trimethylene group [-( CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.

The branched-chain aliphatic hydrocarbon group is preferably a branched-chain alkylene group, specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, Alkyl methylene groups, such as -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -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 ) Alkyl ethylene group, such as ₂ -CH ₂ -; Alkyl trimethylene group such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ )CH ₂ CH ₂ CH ₂ - and the like can be mentioned alkyl groups such as alkyl groups, such as tetramethylene _{-, -CH 2 CH (CH 3} ) CH 2 CH 2. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

The linear or branched 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, and a carbonyl group substituted with a fluorine atom.

Aliphatic hydrocarbon group containing a ring in the structure

Examples of the aliphatic hydrocarbon group containing a ring in its structure include a cyclic aliphatic hydrocarbon group (a group from which two hydrogen atoms have been removed from the aliphatic hydrocarbon ring), which may contain a substituent containing a hetero atom in the ring structure, and the cyclic aliphatic A group in which a hydrocarbon group is bonded to the terminal of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of the linear or branched aliphatic hydrocarbon group may be mentioned. Examples of the linear or branched aliphatic hydrocarbon group include those similar to those described above.

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

The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a monocycloalkane is preferable. As the monocycloalkane, those having 3 to 6 carbon atoms are preferable, and specifically, cyclopentane, cyclohexane, etc. are mentioned. As the polycyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a polycycloalkane is preferable, and the polycycloalkane is preferably a C7 to C12 group. Specifically, adamantane, norbornane, iso Bornane, tricyclodecane, tetracyclododecane, etc. are mentioned.

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.

As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert-butoxy group is preferable, and a methoxy group And an ethoxy group are most preferable.

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 a group in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms.

In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing the hetero atom, -O-, -C(=O)-O-, -S-, -S(=O) ₂ -, -S(=O) ₂ -O- are preferable. .

· · Aromatic hydrocarbon group in Ya ²¹

The aromatic 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 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. However, the carbon number does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. Examples of the hetero atom 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.

As an aromatic hydrocarbon group, specifically, a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings (for example, biphenyl, flue A group in which two hydrogen atoms have been removed from an orene, etc.); a group in which one of the hydrogen atoms of the group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) is substituted with an alkylene group For example, one additional hydrogen atom was removed from the aryl group in the arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group. Group) and the like. The number of carbon atoms of the alkylene group bonded to the aryl group or 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, the hydrogen atom bonded to the 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, halogen atom, and halogenated alkyl group as the substituent include those exemplified as a substituent for substituting a hydrogen atom possessed by the cyclic aliphatic hydrocarbon group.

-Divalent linking group containing hetero atom:

When Ya ²¹ is a divalent linking group containing a hetero atom, preferred as the linking group, -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O -, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(= O) ₂ -, -S(=O) ₂ -O-, general formula -Y ²¹ -OY ²² -, -Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C(= O)-OY ²¹ -, -[Y ²¹ -C(=O)-O] _m'' -Y ²² -, -Y ²¹ -OC(=O)-Y ²² -or -Y ²¹ -S(=O ) Group represented by ₂ -OY ^22- [In the formula, 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. ] And the like.

The divalent linking group containing the hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)- In the case, the 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, and particularly preferably 1 to 5.

General formula -Y ²¹ -OY ²² -, -Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C(=O)-OY ²¹ -, -[Y ²¹ -C(=O )-O] _m'' -Y ²² -, -Y ²¹ -OC(=O)-Y ²² -or -Y ²¹ -S(=O) ₂ -OY ²² -, Y ²¹ and Y ²² are each independently It is a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include those similar to the (divalent hydrocarbon group which may have a substituent) exemplified in the description as the above divalent linking group.

As Y ²¹ , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is still more preferable, and a methylene group or an ethylene group is particularly preferable.

As Y ²² , a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group, or an alkylmethylene group is more preferable. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear 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 an integer of 0 to 2, and 0 or 1 is It is more preferable and 1 is especially preferable. That is, as a group represented by the formula -[Y ²¹ -C(=O)-O] _m" -Y ²² -, a group represented by the formula -Y ²¹ -C(=O)-OY ²² -is particularly preferable. Among them, a group represented by the formula -(CH ₂ ) _a'- C(=O)-O-(CH ₂ ) _b' -is preferable. In the formula, a'is an integer of 1 to 10, an integer of 1 to 8 is preferable, an integer of 1 to 5 is more preferable, 1 or 2 is still more preferable, and 1 is most preferable. b'is an integer of 1-10, the integer of 1-8 is preferable, the integer of 1-5 is more preferable, 1 or 2 is still more preferable, and 1 is the most preferable.

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, an -SO ₂ -containing cyclic group, or a carbonate-containing cyclic group.

As the lactone-containing cyclic group, -SO ₂ -containing cyclic group, and carbonate-containing cyclic group in Ra ²¹ , respectively, groups represented by the aforementioned general formulas (a2-r-1) to (a2-r-7) , Groups each represented by general formulas (a5-r-1) to (a5-r-4), and groups each represented by general formulas (ax3-r-1) to (ax3-r-3) are preferably mentioned.

Among them, a lactone-containing cyclic group or an -SO ₂ -containing cyclic group is preferable, and a group represented by the general formula (a2-r-1), (a2-r-2) or (a5-r-1) is more desirable. Specifically, the above formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-sl Any group represented by -1-1) and (r-sl-1-18) is more preferable.

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

When the component (A1) has a structural unit (a2), the proportion of the structural unit (a2) is preferably 1 to 80 mol% with respect to the total of all the structural units constituting the component (A1), and 10 to It is more preferable that it is 70 mol%, it is more preferable that it is 10 to 65 mol%, and 10-60 mol% is especially preferable.

By making the ratio of the structural unit (a2) more than a preferable lower limit, the effect of containing the constitutional unit (a2) is sufficiently obtained. On the other hand, by making the ratio of the constitutional unit (a2) or less, the balance with other constitutional units can be achieved, and various The lithography characteristics and pattern shape become good.

Constituent unit (a3):

The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (however, except for those corresponding to any of the structural units (a0), (a1) or (a2) described above).

When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) increases, and it contributes to the improvement of resolution.

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

Examples of the aliphatic hydrocarbon group include a C 1 to C 10 linear or branched hydrocarbon group (preferably an alkylene group) or a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group, and for example, in resins for resist compositions for ArF excimer lasers, it can be appropriately selected and used from among many proposed ones. The cyclic group is preferably a polycyclic group, and more preferably 7 to 30 carbon atoms.

Among them, a structural unit derived from an acrylic acid ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a hydroxyl group, a cyano group, a carboxyl group, or a part of the hydrogen atom of the alkyl group is substituted with a fluorine atom is more preferable. Examples of the polycyclic group include a group in which two or more hydrogen atoms have been removed from a bicycloalkane, tricycloalkane, tetracycloalkane, or the like. Specifically, a group in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane may be mentioned. Among these polycyclic groups, a group in which two or more hydrogen atoms have been removed from adamantane, a group in which two or more hydrogen atoms have been removed from norbornane, and a group in which two or more hydrogen atoms have been removed 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 one can be used.

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

As the structural unit (a3), 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, a structural unit derived from hydroxyethyl ester of acrylic acid is preferable, and When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the formula (a3-2), and the structural unit represented by the formula (a3-3) are mentioned as preferable examples.

[Formula 30]

[In the formula, R is the same as 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, l is an integer of 1 to 5, and s is It is an integer of 1-3.]

In formula (a3-1), it is preferable that j is 1 or 2, and it is more preferable that it is 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions 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.

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

In formula (a3-2), it is preferable that k is 1. It is preferable that the cyano group is bonded to the 5 or 6 position of the norbornyl group.

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

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

When the component (A1) has a structural unit (a3), it is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, and 5 to the total of all the structural units constituting the component (A1). -35 mol% is more preferable.

By making the ratio of the structural unit (a3) more than a preferable lower limit, the effect of containing the constitutional unit (a3) is sufficiently obtained, and on the other hand, by making it less than or equal to a preferable upper limit, it becomes easy to balance with other constitutional units.

Constituent unit (a4):

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

When the component (A1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. Moreover, the hydrophobicity of the component (A) increases. It is considered that the improvement of hydrophobicity contributes to improvement of resolution, resist pattern shape, etc., especially in the case of a solvent developing process.

The "acid non-dissociable cyclic group" in the structural unit (a4) is when an acid is generated in the resist composition by exposure (for example, when an acid is generated from the component (B) described below), the acid acts. Even if it does not dissociate, it is a cyclic group which remains in the said structural unit as it is.

As the structural unit (a4), for example, a structural unit derived from an acrylic acid ester containing an acid non-dissociable aliphatic cyclic group, etc. are preferable. The cyclic group is used for a resin component of a resist composition such as an ArF excimer laser or a KrF excimer laser (preferably for an ArF excimer laser), and many conventionally known ones can be used.

Particularly, if at least one species selected from tricyclodecyl group, adamantyl group, tetracyclododecyl group, isobornyl group, and norbornyl group is preferred, it is easy to obtain industrially. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

As the structural unit (a4), the structural units respectively represented by the following general formulas (a4-1) to (a4-7) can be illustrated.

[Formula 31]

[In the formula, R ^α is the same as above.]

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

When the component (A1) has a structural unit (a4), the proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all structural units constituting the component (A1), and 3 to 20 mol% is more preferable.

By making the ratio of the structural unit (a4) more than a preferable lower limit, the effect of containing the constitutional unit (a4) is sufficiently obtained, and on the other hand, by making it less than or equal to a preferable upper limit, it becomes easy to balance with other constitutional units.

In the resist composition of the present embodiment, the component (A) contains a polymer compound (A1) having a structural unit (a0), and as the component (A1), specifically, the structural unit (a0) and the structural unit ( A polymer compound etc. which consist of a repeating structure of a1) and a structural unit (a2) can be illustrated.

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 1000 to 50000, more preferably 1500 to 30000, and 2000 to 20000 is most preferred.

If the Mw of the component (A1) is less than or equal to the preferred upper limit of this range, there is sufficient solubility in a resist solvent for use as a resist, and if it is greater than or equal to the preferred lower limit of this range, the dry etching resistance and resist pattern cross-sectional shape are good. .

The dispersion degree (Mw/Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 4.0, and most preferably 1.0 to 3.0. In addition, Mn represents a number average molecular weight.

(A1) component may be used individually by 1 type, and may use 2 or more types together.

The ratio of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and 100 with respect to the total mass of the component (A). It may be mass%. When the ratio is 25% by mass or more, it becomes easy to form a resist pattern excellent in various lithographic properties such as high sensitivity and improved roughness.

In the resist composition of the present embodiment, as a component (A), a base component that does not correspond to the component (A1) and whose solubility in a developer is changed by the action of an acid (hereinafter referred to as "component (A2)") is used. You may use it together.

The component (A2) is not particularly limited, and a number of those conventionally known as substrate components for chemically amplified resist compositions (e.g., for ArF excimer lasers and KrF excimer lasers (preferably for ArF excimer lasers) And the like base resin). Component (A2) may be used individually by 1 type, and may be used in combination of 2 or more types.

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

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

<(B) component>

The component (B) is an acid generator component that generates an acid by exposure.

[(B1) component]

The component (B) used in the resist composition of the present embodiment includes an acid generator (B1) composed of a compound represented by the general formula (b1) (hereinafter referred to as "component (B1)").

[Formula 32]

[In the formula, R ¹⁰¹ is 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. q'' is an integer of 1-20. m is an integer of 1 or more, and M ^{m +} is an m-valent organic cation.]

Anion part of component (B1):

In the above formula (b1), R ¹⁰¹ is 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.

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. Moreover, the aliphatic hydrocarbon group may be saturated or unsaturated, and it is preferable that it is usually saturated.

The aromatic hydrocarbon group for R ¹⁰¹ is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the carbon number does not include the number of carbon atoms in the substituent.

As the aromatic ring of the aromatic hydrocarbon group for R ¹⁰¹ , specifically, benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heteroatoms in which some of the carbon atoms constituting these aromatic rings are substituted with hetero atoms. Rings, etc. are mentioned. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom.

As the aromatic hydrocarbon group for R ¹⁰¹ , specifically, a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), and one of the hydrogen atoms of the aromatic ring is alkylene. A group substituted with a group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, and a 2-naphthylethyl group, etc.) etc. are mentioned. The number of carbon atoms in 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 ¹⁰¹ includes an aliphatic hydrocarbon group containing a ring in the structure.

As the aliphatic hydrocarbon group containing a ring in this structure, an alicyclic hydrocarbon group (a group in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the terminal of a linear or branched aliphatic hydrocarbon group And groups in which the alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.

The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and 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 has been removed from a monocycloalkane is preferable. As the monocycloalkane, those having 3 to 6 carbon atoms are preferable, and specifically, cyclopentane, cyclohexane, etc. are mentioned. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane is preferably a C7 to C12 group, specifically adamantane, norbornane, Isobornane, tricyclodecane, tetracyclododecane, etc. are mentioned.

Among them, the cyclic aliphatic hydrocarbon group for R ¹⁰¹ is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, and a group in which one hydrogen atom has been removed from a polycycloalkane is more preferable. An adamantyl group and a norbornyl group are particularly preferred, and an adamantyl group is most preferred.

The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and 1 to 3 most desirable.

As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], and a trimethylene group [-( CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.

The branched-chain aliphatic hydrocarbon group is preferably a branched-chain alkylene group, specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, Alkyl methylene groups, such as -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -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 ) Alkyl ethylene group, such as ₂ -CH ₂ -; Alkyl trimethylene group such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ )CH ₂ CH ₂ CH ₂ - and the like can be mentioned alkyl groups such as alkyl groups, such as tetramethylene _{-, -CH 2 CH (CH 3} ) CH 2 CH 2. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

As a substituent in the cyclic hydrocarbon group of R ¹⁰¹ , for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group (-C(=O)-), an ether bond (-O-), Ester bond (-C(=O)-O-), a nitro group, etc. are mentioned.

As the alkyl group as a substituent, a C1-C5 alkyl group is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are more preferable.

As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group is more preferable, and a methoxy group And an ethoxy group are most preferable.

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

As a substituent, a carbonyl group (-C(=O)-), an ether bond (-O-), and an ester bond (-C(=O)-O-) are methylene groups constituting a cyclic hydrocarbon group (-CH _2- ) Is a group that replaces.

Examples of the cyclic hydrocarbon group for R ¹⁰¹ include "an aliphatic hydrocarbon group containing a ring in the structure and having a substituent" exemplified below.

[Formula 33]

Moreover, the cyclic hydrocarbon group for R ¹⁰¹ may contain a hetero atom like a hetero ring or the like. Specifically, lactone-containing cyclic groups each represented by the above general formulas (a2-r-1) to (a2-r-7), respectively, by the above general formulas (a5-r-1) to (a5-r-4) The represented -SO ₂ -containing cyclic group and other heterocyclic groups exemplified below are mentioned.

[Formula 34]

Chain-type alkyl group which may have a substituent:

The linear alkyl group for R ¹⁰¹ may be either linear or branched.

As a linear alkyl group, it is preferable that it is C1-C20, it is more preferable that it is 1-15, and 1-10 are most preferable. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group , Tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group, and the like.

As a branched chain alkyl group, it is preferable that it has 3-20 carbon atoms, it is more preferable that it is 3-15, and 3-10 are most preferable. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2 -Ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, etc. are mentioned.

Chain alkenyl group which may have a substituent:

The chain alkenyl group of R ¹⁰¹ may be linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5, and still more preferably 2 to 4, 3 is particularly preferred. As a linear alkenyl group, a vinyl group, a propenyl group (allyl group), a butynyl group, etc. are mentioned, for example. Examples of the branched chain alkenyl group include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, and 2-methylpropenyl group.

As the chain alkenyl group, among the above, a vinyl group and a propenyl group are more preferable, and a vinyl group is particularly preferable.

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group (-C(=O)-), and an ether bond (-O-). , An ester bond (-C(=O)-O-), a nitro group, an amino group, and the cyclic group in R ¹⁰¹ can be mentioned.

As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group is more preferable, and a methoxy group And an ethoxy group are most preferable.

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

As a substituent, a carbonyl group (-C(=O)-), an ether bond (-O-), and an ester bond (-C(=O)-O-) are a methylene group constituting a chain alkyl group or an alkenyl group (- It is a group which substitutes for CH ₂ -).

Among these, R ¹⁰¹ is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, a group in which at least one hydrogen atom has been removed from a phenyl group which may have a substituent, a naphthyl group which may have a substituent, and a polycycloalkane which may have a substituent; the formulas (a2-r-1) to (a2) The lactone-containing cyclic groups each represented by -r-7), the -SO ₂ -containing cyclic groups each represented by the general formulas (a5-r-1) to (a5-r-4) are preferable.

In the formula (b1), q'' is an integer of 1 to 20, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, still more preferably an integer of 1 to 3, It is particularly preferably 1.

A preferred specific example of the anionic moiety of the component (B1) is shown below.

[Formula 35]

Cation part of component (B1):

In formula (b1), M ^{m +} is an m-valent organic cation, preferably an onium cation, and specifically, preferably a sulfonium cation, an iodonium cation, and the like.

The cation moiety [(M ^{m +} ) _1/m ] of the component (B1) is preferably an organic cation represented by the following general formulas (ca-1) to (ca-4).

[Formula 36]

[In the formula, R ²⁰¹ to R ²⁰⁷ , and R ²¹¹ to R ²¹² each independently represent an aryl group, alkyl group or alkenyl group which may have a substituent, and R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ , R ²¹¹ to R ²¹² may be bonded to each other to form a ring together with the sulfur atom in the formula. R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ²¹⁰ is an aryl group, an alkyl group, an alkenyl group, or an -SO ₂ -containing cyclic group which may have a substituent, and L ²⁰¹ is Represents -C(=O)- or -C(=O)-O-, Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group, x is 1 or 2, and W ²⁰¹ is (x+1 ) Represents a linking group.]

Examples of the aryl group for R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.

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

The alkenyl group for R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² is preferably 2 to 10 carbon atoms.

Examples of the substituents R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have include, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, the following formula (ca-r-1) The groups each represented by-(ca-r-7) are mentioned.

[Formula 37]

[In the formula, ^R'201 is each independently a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group, or a chain alkenyl group.]

The cyclic group which may have a substituent of R′ ²⁰¹ , a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent is the same as R ¹⁰¹ in the above formula (b1). In addition, examples of the cyclic group which may have a substituent or the chain alkyl group which may have a substituent include those similar to the acid dissociable group represented by the above-described formula (a1-r-2).

When 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 with a sulfur atom in the formula, a hetero atom such as a sulfur atom, an oxygen atom, or a nitrogen atom, a carbonyl group,- You may bond through a functional group, such as SO-, -SO ₂ -, -SO _{3 -} , -COO-, -CONH-, or -N(R _N )- (the R _N is a C1-C5 alkyl group). As the ring to be formed, it is preferable that one ring containing a sulfur atom in the formula in its ring skeleton is a 3 to 10 membered ring including a sulfur atom, and particularly preferably a 5 to 7 membered ring. Specific examples of the ring to be formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthene ring, A thianthrene ring, a phenoxatiin ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.

Each of R ²⁰⁸ to R ²⁰⁹ independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and 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 an -SO ₂ -containing cyclic group which may have a substituent.

Examples of the aryl group for R ²¹⁰ include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.

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

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

Examples of the -SO ₂ -containing cyclic group for R ²¹⁰ which may have a substituent include those similar to the "-SO ₂ -containing cyclic group" of Ra ^{21 in} the aforementioned general formula (a2-1), A group represented by the aforementioned general formula (a5-r-1) is preferable.

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

The arylene group for Y ²⁰¹ includes a group in which one hydrogen atom has been removed from the aryl group exemplified as the aromatic hydrocarbon group for R ¹⁰¹ in the aforementioned formula (b1).

^Examples of the alkylene group and alkenylene group for Y ²⁰¹ include the same aliphatic hydrocarbon group as the divalent hydrocarbon group for Va ⁰ in the aforementioned general formula (a0-1).

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

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

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

Connection of the trivalent group is ²⁰¹ W, and ²⁰¹ W the group 1 to remove the hydrogen atom from the divalent linking group in, in addition to the divalent linking group, and the like which combines the divalent connecting group. The trivalent linking group for W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

As a preferable cation represented by formula (ca-1), specifically, the cation represented by following formula (ca-1-1)-(ca-1-67) is mentioned, respectively.

[Formula 38]

[Formula 39]

[Formula 40]

[In the formula, g1, g2, g3 represents the number of repetitions, g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.]

[Formula 41]

[In the formula, R″ ²⁰¹ is a hydrogen atom or a substituent, and the substituent is the same as exemplified as the substituent which R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have.]

As a preferable cation represented by the above formula (ca-2), specifically, diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, etc. are mentioned.

As a preferable cation represented by the above formula (ca-3), specifically, a cation represented by the following formulas (ca-3-1) to (ca-3-6) may be mentioned.

[Formula 42]

As a preferred cation represented by the above formula (ca-4), specifically, a cation represented by the following formulas (ca-4-1) to (ca-4-2) may be mentioned.

[Formula 43]

Among the above, the cation part [(M' ^{m +} ) _1/m ] Is preferably an organic cation represented by the general formula (ca-1), and more preferably a cation represented by each of the formulas (ca-1-1) to (ca-1-67).

As for the component (B1), one type of acid generator described above may be used alone, or two or more types may be used in combination.

In the resist composition of the present embodiment, the content of the component (B1) is preferably 1 to 30 parts by mass, more preferably 2 to 20 parts by mass, and still more preferably 2 to 15 parts by mass per 100 parts by mass of the component (A).

When the content of the component (B1) is more than a preferable lower limit, lithography properties such as reduction in roughness are further improved when a resist composition is formed. Moreover, it becomes easy to obtain a resist pattern of a good shape. When the content of the component (B1) is less than or equal to a preferred upper limit, a uniform solution is obtained and storage stability becomes good, which is preferable.

In the component (B), the proportion of the component (B1) is preferably 2% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and 50 with respect to the total mass of the component (B). Particularly preferred is mass% or more, and may be 100 mass%. Most preferably, it is 100 mass%. When the ratio of the component (B1) to the component (B) is not less than the preferred lower limit, when a resist composition is used, it is easy to achieve a particularly low roughness, and a better resist pattern with lithography characteristics is formed.

[Component (B2)]

The component (B) may contain, other than the component (B1), an acid generator component that generates an acid by exposure (hereinafter, referred to as "component (B2)").

The component (B2) is not particularly limited, and one proposed so far as an acid generator for chemically amplified resists can be used.

Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly(bissulfonyl)diazomethane Diazomethane-based acid generators such as Ryu, nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators, etc. are mentioned. Among them, it is preferable to use an onium salt-based acid generator.

As an onium salt-based acid generator, for example, a compound represented by the following general formula (b-1) (hereinafter, also referred to as a "component (b-1)"), a compound represented by the general formula (b-2) (hereinafter , "(B-2) component"), or a compound represented by general formula (b-3) (hereinafter, also referred to as "(b-3) component") can be used.

[Formula 44]

[In the formula, R ¹⁰³ , 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 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. Each of V ¹⁰¹ to V ¹⁰³ is independently a single bond, an alkylene group, or a fluorinated alkylene group. L ¹⁰¹ to L ¹⁰² are each independently a single bond or an oxygen atom. L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, -CO-, or -SO ₂ -. m is an integer equal to or greater than 1, M ^{'m +} m is a monovalent onium cation.]

{Noon part}

·(B-1) Anion part of component

In formula (b-1), R ¹⁰³ is 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.

As such R ¹⁰³ , the cyclic group which may have a substituent, the chain alkyl group which may have a substituent, or the chain alkenyl group which may have a substituent in R ¹⁰¹ in the above formula (b1) are the same. Can be mentioned.

Among these, R ¹⁰³ is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, a group in which at least one hydrogen atom has been removed from a phenyl group, a naphthyl group, or a polycycloalkane, a lactone-containing cyclic group represented by the formulas (a2-r-1) to (a2-r-7), and the general -SO ₂ -containing cyclic groups each represented by formulas (a5-r-1) to (a5-r-4) are preferable.

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

When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, the Y ¹⁰¹ may contain atoms other than an oxygen atom. As an atom other than an oxygen atom, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, etc. are mentioned, for example.

As a divalent linking group containing an oxygen atom, for example, an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-) ), amide bond (-C(=O)-NH-), carbonyl group (-C(=O)-), carbonate bond (-OC(=O)-O-), etc. The combination of the non-hydrogen-based oxygen atom-containing linking group and an alkylene group, etc. are mentioned. A sulfonyl group (-SO ₂ -) may be further linked to the combination. As the said combination, the linking groups each represented by following formula (y-al-1)-(y-al-7) are mentioned, for example.

[Formula 45]

[In the formula, ^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.]

V 'group is a divalent saturated hydrocarbon in the ^102, is preferably an alkylene group of 1 to 30 carbon atoms.

V ^'101 and V' alkylene group in ^102, may be either a linear alkylene group and the alkylene group may be a branched, is preferably an alkylene group of a linear.

V as an alkylene group in the ^"101 and V" ^102, specifically, a methylene group _{[-CH 2 -]; - CH} (CH 3) -, -CH (CH 2 CH 3) -, -C (CH 3) Alkyl methylene groups such as 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 ) Alkylethylene group such as CH ₂ -; trimethylene group (n-propylene group) [-CH ₂ CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ ) Alkyltrimethylene group such as CH ₂ -; Tetramethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH Alkyl tetramethylene groups, such as ₂ CH ₂ -; pentamethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -], etc. are mentioned.

In addition, or may V 'or ¹⁰¹ V' ¹⁰² portion of the methylene groups in the alkylene in the group is substituted by a divalent aliphatic cyclic group with a carbon number of 5-10. The aliphatic cyclic group is preferably a divalent group in which one further hydrogen atom has been removed from the aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group in Ra′ ³ in the formula (a1-r-1), and cyclohexylene A group, a 1,5-adamantylene group, or a 2,6-adamantylene group is more preferable.

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

In formula (b-1), V ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group. It is preferable that the alkylene group and the fluorinated alkylene group for V ¹⁰¹ have 1 to 4 carbon atoms. A fluorinated alkylene group in the V ¹⁰¹ is, a part or all of the hydrogen atoms of the alkylene group of the ¹⁰¹ V may be substituted with a fluorine atom. Among them, V ¹⁰¹ is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

In formula (b-1), R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. It is preferable that R ¹⁰² is a fluorine atom or a C1-C5 perfluoroalkyl group, and it is more preferable that it is a fluorine atom.

As a specific example of the anion moiety of the component (b-1), for example, when Y ¹⁰¹ becomes a single bond, a fluorinated alkyl sulfo such as trifluoromethanesulfonate anion or perfluorobutanesulfonate anion. Nate anion is mentioned; When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, an anion represented by the following formula (an-1) (however, v''=0, n''=0, t The case where''=1 is excluded), the anion represented by Formula (an-2), and the anion represented by Formula (an-3) are mentioned.

[Chemical Formula 46]

[In the formula, R'' ¹⁰¹ represents an aliphatic cyclic group which may have a substituent, a group represented by the above formulas (r-hr-1) to (r-hr-6), or a chain type which may have a substituent It is an alkyl group; R'' ¹⁰² is an aliphatic cyclic group which may have a substituent, a lactone-containing cyclic group each represented by the formulas (a2-r-1) to (a2-r-7), or the general formula (a5- r-1) to (a5-r-4) is an -SO ₂ -containing cyclic group, respectively; R'' ¹⁰³ is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent It is a chain alkenyl group which may have; v'' is each independently an integer of 0 to 3, q'' is each independently an integer of 1 to 20, and t'' is an integer of 1 to 3, n'' is 0 or 1.]

The aliphatic cyclic group which may have a substituent of R'' ¹⁰¹ , R'' ¹⁰² and R'' ¹⁰³ is preferably a group exemplified as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ in the above formula (b1). Examples of the substituent include the same substituents which may be substituted for the cyclic aliphatic hydrocarbon group for R ¹⁰¹ .

The aromatic cyclic group which may have a substituent for R'' ¹⁰³ is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group for R ¹⁰¹ . Examples of the substituent include the same substituents which may be substituted for the aromatic hydrocarbon group in R ¹⁰¹ .

The chain alkyl group which may have a substituent for R'' ¹⁰¹ is preferably a group exemplified as the chain alkyl group for R ¹⁰¹ . The chain alkenyl group which may have a substituent for R'' ¹⁰³ is preferably a group exemplified as the chain alkenyl group for R ¹⁰¹ .

·(B-2) Anion part of component

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, each And the same as R ¹⁰¹ in formula (b1). However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.

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

The number of carbon atoms of the chain alkyl group is preferably 1 to 10, more preferably 1 to 7, more preferably 1 to 3 carbon atoms. The number of carbon atoms in the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably smaller for reasons such as good solubility in a resist solvent within the above carbon number range. In addition, in the chain alkyl group of R ¹⁰⁴ and R ^105, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and the higher the transparency to high-energy light or electron beams of 200 nm or less. It is preferable because it becomes. The proportion of fluorine atoms in the chain alkyl group, that is, the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

In 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 as those of V ¹⁰¹ in the formula (b-1) can be exemplified.

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

·(B-3) Anion part of component

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, each And the same as R ¹⁰¹ in formula (b1).

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

{Cation Department}

Formula (b-1), (b -2) and (b-3) of the, M ^{'m +} may be preferably an m-valent cation is an onium, sulfonium cation, iodonium cation. As (M' ^{m +} ) _{1/ m} , specifically, the same organic cation as each represented by the general formulas (ca-1) to (ca-4) is preferably mentioned, and the formula (ca-1 -1)-(ca-1-67) cation; diphenyliodonium cation, bis (4-tert-butylphenyl) iodonium cation; formula (ca-3-1)-(ca Specific examples include cation represented by -3-6) and cation represented by formulas (ca-4-1) to (ca-4-2), respectively.

Among the above, a cation moiety _{^{[(M 'm +) 1}} / m] is preferably the following general formula the organic cation represented by (ca-1) and formula (ca-1-1) ~ (ca -1-67) The cation represented by each is more preferable.

As for the component (B), the above-described acid generator may be used singly or in combination of two or more.

When the resist composition of the present embodiment contains the component (B2), the content of the component (B2) is preferably 30 parts by mass or less, more preferably 0.5 to 20 parts by mass, and 0.5 to 100 parts by mass of the component (A). More preferably-15 parts by mass.

Pattern formation is sufficiently performed by setting the content of the component (B2) in the above preferable range. Moreover, when each component of a resist composition is dissolved in an organic solvent, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<Other ingredients>

[(D) component]

In addition to the components (A) and (B), the resist composition of the present embodiment may further contain an acid diffusion control agent component (hereinafter, referred to as "component (D)").

The component (D) acts as a quencher (acid diffusion control agent) that traps acid generated by exposure from the component (B) or the like.

As the component (D), for example, a photodegradable base (D1) that is decomposed by exposure to lose controllability of acid diffusion (hereinafter referred to as "component (D1)"), or the component (D1) Nitrogen-containing organic compounds (D2) (hereinafter referred to as "component (D2)") are mentioned.

(About the (D1) component)

By setting it as a resist composition containing the component (D1), when forming a resist pattern, the contrast of an exposed part and an unexposed part can be improved.

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

The components (d1-1) to (d1-3) do not act as a quencher because they are decomposed in the exposed portion to lose acid diffusion controllability (basicity), but act as a quencher in the unexposed portion.

[Chemical Formula 47]

[In the formula, Rd ¹ to Rd ⁴ are 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. However, it is assumed that no fluorine atom is 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 greater than or equal to 1, and M ^{m +} is each independently an m-valent organic cation.]

・(D1-1) component

(d1-1) Anion part of component:

In formula (d1-1), Rd ¹ is 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, and R ¹⁰¹ in the above formula (b1) The same can be mentioned.

Among these, 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. As the substituent which these groups may have, a hydroxyl group, a fluorine atom, or a fluorinated alkyl group is preferable.

As the aromatic hydrocarbon group, a phenyl group or a naphthyl group is more preferable.

The aliphatic cyclic group is more preferably a group in which at least one hydrogen atom has been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc. Of a linear alkyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2- Branched-chain alkyl groups, such as ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group, are mentioned.

When the chain alkyl group is a fluorinated alkyl group having a fluorine atom as a substituent, the number of carbon atoms of the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and still more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than a fluorine atom. As an atom other than a fluorine atom, an oxygen atom, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, etc. are mentioned, for example.

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

The preferred specific examples of the anionic moiety of the component (d1-1) are shown below.

[Formula 48]

(d1-1) Cation part of component:

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

As the organic cation of M ^{m +} , the same cation represented by the general formulas (ca-1) to (ca-4) is preferably mentioned, and the cation represented by the general formula (ca-1) It is more preferable that it is the same as the above, and the cation represented by the above formulas (ca-1-1) to (ca-1-67) is mentioned as a specific one.

The component (d1-1) may be used individually by 1 type, or may be used in combination of 2 or more types.

・(D1-2) component

(d1-2) Anion part of component:

In formula (d1-2), Rd ² is 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, and R in the formula (b1) ^The same thing as ¹⁰¹ can be mentioned.

However, it is assumed that the fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd ² (the fluorine atom is not substituted). Accordingly, the anion of the component (d1-2) becomes an appropriate weak acid anion, and the quenching ability as the component (D) is improved.

Rd ² is preferably an aliphatic cyclic group which may have a substituent, and a group in which at least one hydrogen atom has been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (substituent group You may have); It is more preferable that it is a group in which one or more hydrogen atoms have been removed from a camper or the like.

The hydrocarbon group of Rd ² may have a substituent, and examples of the substituent include the same substituents that the hydrocarbon group (aromatic hydrocarbon group, aliphatic hydrocarbon group) in Rd ¹ of the formula (d1-1) may have. have.

The preferred specific examples of the anion moiety of the component (d1-2) are shown below.

[Chemical Formula 49]

(d1-2) Cation part of component:

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

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

・(D1-3) component

(d1-3) Anion part of component:

In formula (d1-3), Rd ³ is 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, and R ¹⁰¹ in the above formula (b1) The same can be mentioned, and a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group is preferable. Among them, a fluorinated alkyl group is preferable, and the same is more preferable as the fluorinated alkyl group of Rd ¹ .

In formula (d1-3), Rd ⁴ is 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, and R in the above formula (b1) ^The same thing as ¹⁰¹ can be mentioned.

Especially, it is preferable that they are an alkyl group, an alkoxy group, an alkenyl group, and a cyclic group which may have a substituent.

The alkyl group for Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. are mentioned. Some of the hydrogen atoms of the alkyl group of Rd ⁴ may be substituted with a hydroxyl group or a cyano group.

The alkoxy group for Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms, and as an alkoxy group having 1 to 5 carbon atoms, specifically, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, or n- Butoxy group and tert-butoxy group. Among them, a methoxy group and an ethoxy group are preferable.

Examples of the alkenyl group for Rd ⁴ include the same as R ¹⁰¹ in the formula (b1), and a vinyl group, a propenyl group (allyl group), 1-methylpropenyl group, and 2-methylpropenyl group are preferable. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

The cyclic group for Rd ⁴ is the same as R ¹⁰¹ in the above formula (b1), and includes cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane. An alicyclic group in which at least one hydrogen atom has been removed from a cycloalkane such as a cycloalkane, or 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 satisfactorily dissolved in an organic solvent, thereby improving lithography characteristics. Further, when Rd ⁴ is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition has excellent light absorption efficiency and good sensitivity and lithography characteristics.

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

Although it does not specifically limit as a divalent linking group for Yd ¹ , The divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a divalent linking group containing a hetero atom, etc. are mentioned. These are the same as the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom as exemplified in the description of the divalent linking group of Ya ²¹ in the formula (a2-1), respectively. .

Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. As the alkylene group, it is more preferable that it is a linear or branched alkylene group, and it is still more preferable that it is a methylene group or an ethylene group.

A preferred specific example of the anionic moiety of the component (d1-3) is shown below.

[Formula 50]

[Formula 51]

(d1-3) Cation part of component:

In formula (d1-3), M ^{m +} is an m-valent organic cation, and it is the same as M ^{m +} in said formula (d1-1).

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

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

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 still more preferably 1 to 8 parts by mass based on 100 parts by mass of the component (A).

When the content of the component (D1) is more than a preferable lower limit, particularly favorable lithography properties and resist pattern shape are obtained. On the other hand, if it is less than or equal to a preferable upper limit, the sensitivity can be maintained satisfactorily, and the throughput is also excellent.

··(D1) method of manufacturing component

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

In addition, the manufacturing method of the component (d1-3) is not particularly limited, and is manufactured, for example, in the same manner as the method described in US2012-0149916.

(About component (D2))

As the acid diffusion control agent component, a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") not corresponding to the component (D1) may be used.

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

The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms.

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

Specific examples of the alkylamine and the alkyl alcohol amine include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; diethylamine, di-n- Dialkylamines such as propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri- Trees such as n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine, etc. Alkyl amine; Alkyl alcohol amines, such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine, are mentioned. Among these, trialkylamines having 5 to 10 carbon atoms are more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

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

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

The aliphatic polycyclic amine is preferably having 6 to 10 carbon atoms, and specifically, 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo[2.2.2]octane, etc. are mentioned.

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

Moreover, you may use an aromatic amine as a component (D2).

As aromatic amines, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, etc. Can be mentioned.

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

The component (D2) is usually used in the range of 0.01 to 5 parts by mass per 100 parts by mass of the component (A). By setting it as the said range, the shape of a resist pattern, stability over time after exposure, etc. are improved.

When the resist composition of the present embodiment contains the component (D), among the above, it is preferable to contain a photodegradable base (D1) that is decomposed by exposure to lose controllability of acid diffusion, and the component (d1-2) is It is more preferable to contain.

[(E) component]

In the resist composition of the present embodiment, for the purpose of preventing deterioration in sensitivity, improving the shape of the resist pattern, and stability over time after exposure, as an optional component, from the group consisting of an organic carboxylic acid and phosphorus oxoic acid and derivatives thereof. At least one selected compound (E) (hereinafter referred to as "component (E)") can be contained.

As an organic carboxylic acid, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc. are preferable, for example.

Phosphoric acid, phosphonic acid, phosphinic acid, etc. are mentioned as oxo acid of phosphorus, Among these, phosphonic acid is especially preferable.

Examples of phosphorus oxo acid derivatives include esters in which a hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and 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. Can be mentioned.

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

Phosphonic acid esters, such as a phosphonic acid dimethyl ester, a phosphonic acid-di-n-butyl ester, a phenylphosphonic acid, a phosphonic acid diphenyl ester, and a phosphonic acid dibenzyl ester, etc. are mentioned as a phosphonic acid derivative.

As a derivative of phosphinic acid, phosphinic acid ester, phenylphosphinic acid, etc. are mentioned.

(E) component may be used individually by 1 type, and may use 2 or more types together.

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

[(F) component]

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

(F) As a component, for example, JP 2010-002870 A, JP 2010-032994 A, JP 2010-277043 A, JP 2011-13569 A, JP The fluorinated polymer compound described in Publication No. 2011-128226 can be used.

More specifically, as the component (F), a polymer having a structural unit (f1) represented by the following formula (f1-1) is exemplified. As the polymer, a polymer (homopolymer) consisting only of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1); the structural unit (f1) And a structural unit derived from acrylic acid or methacrylic acid, and a copolymer of the structural unit (a1). Here, as the structural unit (a1) copolymerized with the structural unit (f1), a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate is preferable.

[Formula 52]

[In the formula, R is the same as above, Rf ¹⁰² and Rf ¹⁰³ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf ¹⁰² and Rf ¹⁰³ are They may be the same 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 α-position is the same as described above. As R, a hydrogen atom or a methyl group is preferable.

In formula (f1-1), examples of the halogen atom for 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 for Rf ¹⁰² and Rf ^{103 include} the same alkyl group having 1 to 5 carbon atoms for R, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms for Rf ¹⁰² and Rf ¹⁰³ include a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms 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. Among these, as Rf ¹⁰² and Rf ¹⁰³ , a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group is preferable.

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

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

The hydrocarbon group containing a fluorine atom may be linear, branched, or cyclic, preferably having 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and having 1 to 10 carbon atoms. It is particularly preferred.

In addition, the hydrocarbon group containing a fluorine atom is preferably 25% or more of the hydrogen atoms in the hydrocarbon group fluorinated, more preferably 50% or more is fluorinated, and 60% or more is fluorinated. Since the hydrophobicity of the resist film during exposure increases, it is particularly preferable.

Among them, Rf ¹⁰¹ is particularly preferably a fluorinated hydrocarbon group having 1 to 5 carbon atoms, and a trifluoromethyl group, -CH ₂ -CF ₃ , -CH ₂ -CF ₂ -CF ₃ , -CH(CF ₃ ) ₂ ,- Most preferred are CH ₂ -CH ₂ -CF ₃ , -CH ₂ -CH ₂ -CF ₂ -CF ₂ -CF ₂ -CF ₃ .

The mass average molecular weight (Mw) (based on polystyrene conversion by gel permeation chromatography) of the component (F) is preferably from 1000 to 50000, more preferably from 5000 to 40000, and most preferably from 10000 to 30000. If it is less than the upper limit of this range, there is sufficient solubility in a resist solvent for use as a resist, and if it is more than the lower limit of this range, dry etching resistance and a resist pattern cross-sectional shape 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 alone or in combination of two or more.

It is used in a ratio of preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (F) and the component (A).

In the resist composition of the present embodiment, as desired, additives that are miscible, for example, additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, etc. are suitably added, It can be added and contained.

[(S) component]

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

As the (S) component, any component that can be used as a solvent by dissolving each component to be used and forming a uniform solution is appropriately selected from one or two or more solvents known conventionally as solvents for chemically amplified resists. Can be used.

For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; ethylene glycol, Polyhydric alcohols such as diethylene glycol, propylene glycol and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, the polyhydric alcohols Or derivatives of polyhydric alcohols such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether of the compound having an ester bond, or compounds having an ether bond such as monophenyl ether. , Propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; Cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, and butyl acetate , Methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, and other esters; anisole, ethylbenzyl ether, cresylmethyl ether, diphenyl ether, dibenzyl ether, phenetol, butylphenyl ether, ethylbenzene , Aromatic organic solvents such as diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO).

These organic solvents may be used alone or as a mixed solvent of two or more.

Among them, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferable.

Moreover, a mixed solvent in which PGMEA and a polar solvent were mixed is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility of PGMEA and the polar solvent, but it is preferably in the range of 1:9 to 9:1, more preferably 2:8 to 8:2. desirable.

More specifically, in the case of blending EL or cyclohexanone 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: It is 2. In addition, in the case of blending PGME as a polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, still more preferably 3:7 to It is 7:3. Further, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferable.

In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-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 used amount of the component (S) is not particularly limited, and is a concentration applicable to a substrate or the like, and is appropriately set according to the coating film thickness. In general, it is used so that the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

According to the resist composition of the present invention, a resist pattern with reduced roughness can be formed.

The resist composition of the present invention contains a polymer compound (A1) having a structural unit (a0) containing a lactone-containing cyclic group having an electron-attracting substituent (X). By using the component (A1), when forming a resist pattern, a decrease in sensitivity is suppressed, and good sensitivity is maintained. In addition, by having the structural unit (a0), the solubility of the component (A1) in the organic solvent is increased, and it can be stably dissolved in the solvent for resist.

Further, the resist composition of the present invention contains an acid generator (B1) composed of a compound having a specific anionic moiety. Since the component (B1) of the acid generated by exposure is mono-diffuse, the roughness of the sidewalls of the resist pattern and the like can be reduced. In addition, the acid dissociable group can be easily dissociated from the base resin by using the component (B1). In addition, in the alkali developing process, dissolution inhibition is hardly caused by the alkali developing solution.

In the resist composition of the present invention, by combining the component (A1) having the structural unit (a0) and the component (B1) having a specific anion moiety, a remarkable effect of reducing roughness is obtained when forming a resist pattern. Lose.

Further, according to the resist composition of the present invention, a resist pattern with reduced roughness can be formed while maintaining better sensitivity. In addition, in forming a resist pattern using the resist composition of the present invention, the exposure margin (EL margin), which is an index of the amount of change in the pattern size accompanying the fluctuation of the exposure amount, is also good, which makes it difficult to achieve coexistence with reduction of roughness.

≪Method of forming a resist pattern≫

The method of forming a resist pattern of the second aspect of the present invention comprises a step of forming a resist film on a support using the resist composition of the first aspect of the present invention, a step of exposing the resist film, and developing the resist film after the exposure. And a process of forming a resist pattern.

The resist pattern formation method of this embodiment can be implemented as follows, for example.

First, on a support, the resist composition according to the first aspect is applied with a spinner or the like, and a bake (post-applied bake (PAB)) treatment is performed, for example, under a temperature condition of 80 to 150°C for 40 to 120 seconds, Preferably, it is carried out for 60 to 90 seconds to form a resist film.

Next, for the resist film, an exposure device such as an ArF exposure device, an electron beam drawing device, or an EUV exposure device is used, and an exposure or a mask pattern is interposed with a mask (mask pattern) in which a predetermined pattern is formed. After selective exposure by drawing or the like by direct irradiation of an electron beam that is not applied, a bake (post exposure bake (PEB)) treatment is performed, for example, at a temperature of 80 to 150°C for 40 to 120 seconds, preferably 60 to Conduct for 90 seconds.

Next, the resist film is developed. In the case of an alkali developing process, the developing treatment is performed using an alkali developer, and in the case of a solvent developing process, a developing solution containing an organic solvent (organic developer) is used.

After the development treatment, preferably, a rinse treatment is performed. In the case of an alkali developing process, water rinse using pure water is preferable for the rinse treatment, and in the case of a solvent developing process, it is preferable to use a rinse liquid containing an organic solvent.

In the case of the solvent developing process, after the above developing treatment or rinsing treatment, a treatment in which the developer or rinsing liquid adhered on the pattern is removed with a supercritical fluid may be performed.

Drying is performed after developing treatment or after rinsing treatment. Moreover, in some cases, a baking treatment (post baking) may be performed after the development treatment. In this way, a resist pattern can be obtained.

It does not specifically limit as a support body, A conventionally well-known thing can be used, For example, the board|substrate for electronic components, the thing with a predetermined wiring pattern formed on it, etc. can be illustrated. More specifically, a silicon wafer, a metal substrate such as copper, chromium, iron, aluminum, or a glass substrate may be mentioned. As the material of the wiring pattern, for example, copper, aluminum, nickel, gold, or the like can be used.

In addition, as a support, an inorganic and/or organic film may be formed on a substrate as described above. Examples of the inorganic film include an inorganic antireflection film (inorganic BARC). Examples of the organic film include organic films such as an organic antireflection film (organic BARC) and an underlayer organic film in a multilayer resist method.

Here, the multilayer resist method means forming at least one layer of an organic film (lower layer organic film) and at least one layer of a resist film (upper layer resist film) on a substrate, and using a resist pattern formed on the upper resist film as a mask. Thus, it is a method of performing patterning of the lower organic film, and is believed to be capable of forming a high aspect ratio pattern. That is, according to the multilayer resist method, since the required thickness can be secured by the lower organic film, the resist film can be made thin, and fine patterns with a high aspect ratio can be formed.

In the multilayer resist method, basically, a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and one or more intermediate layers (metal thin film, etc.) are formed between the upper resist film and the lower organic film. It is divided into a method of forming a multilayer structure of three or more layers (three-layer resist method).

The wavelength used for exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet light), EB (electron ray), X-ray, and lead X It can be carried out using radiation such as lines. The above resist composition is highly useful for 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 conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or liquid immersion exposure (Liquid Immersion Lithography).

Liquid immersion exposure is an exposure method in which a resist film and a lens at the lowest position of the exposure apparatus are previously filled with a solvent (liquid immersion medium) having a refractive index greater than the refractive index of air, and exposure (immersion exposure) is performed in that state.

As the liquid immersion medium, a solvent having a refractive index greater than the refractive index of air and less 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 larger than the refractive index of air and smaller 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 mainly containing fluorine-based compounds 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 . It is possible, and the boiling point is 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 since the medium used for immersion can be removed by a simple method after the exposure is completed.

The fluorine-based inert liquid is particularly preferably a perfluoroalkyl compound in which all of the hydrogen atoms of the alkyl group are replaced with fluorine atoms. As a perfluoroalkyl compound, a perfluoroalkyl ether compound and a perfluoroalkylamine compound are mentioned specifically.

Further, specifically, examples of the perfluoroalkyl ether compound include perfluoro(2-butyl-tetrahydrofuran) (boiling point 102°C), and examples of the perfluoroalkylamine compound include perfluoro. Lotributylamine (boiling point 174°C) is mentioned.

As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental issues, and versatility.

As an alkali developing solution used for the developing treatment in the alkali developing process, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH) is exemplified.

As the organic solvent contained in the organic developer used for the developing treatment in the solvent developing process, any one capable of dissolving the component (A) (the component (A) before exposure) can be appropriately selected from known organic solvents. Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents and ether solvents, and hydrocarbon solvents may be mentioned.

The ketone 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 alcohol-based solvent is an organic solvent containing an alcoholic hydroxyl group in its structure, and the "alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. The nitrile-based solvent is an organic solvent containing a nitrile group in the structure. An amide solvent is an organic solvent containing an amide group in the structure. Ether-based solvents are organic solvents containing C-O-C in the structure.

Among the organic solvents, there is also an organic solvent including a plurality of types of functional groups that characterize each of the above-described solvents in the structure, but in that case, it is assumed to correspond to any solvent species including the functional groups that the organic solvent has. For example, diethylene glycol monomethyl ether shall correspond to any of alcohol-based solvents and ether-based solvents in the above classification.

The hydrocarbon-based solvent is a hydrocarbon solvent composed of a hydrocarbon which may be halogenated and does not have a 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.

As the organic solvent contained in the organic developer, among the above, polar solvents are preferred, and ketone solvents, ester solvents, nitrile solvents and the like are preferred.

As a specific example of each solvent, as a ketone solvent, for example, 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2 -Hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acenylacetone, ionone, diacetyl alcohol, acetylcarbinol, aceto Phenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), and the like.

As the ketone solvent, methyl amyl ketone (2-heptanone) is preferable.

As an ester solvent, for example, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol 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 acetate, 3-methyl-3 -Methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl Acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl Acetate, 3-methyl-4-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, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, 2-hydroxy methylpropionate, 2 -Ethyl hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, and the like. .

As the ester solvent, butyl acetate is preferable.

As a nitrile solvent, acetonitrile, propionitrile, valeronitrile, butyronitrile, etc. are mentioned, for example.

In the organic developer, a known additive may be blended as needed. Surfactants are mentioned as the additive, for example. Although it does not specifically limit as surfactant, For example, an ionic or nonionic fluorine-type and/or silicone-type surfactant, etc. can be used. As the surfactant, a nonionic surfactant is preferable, and a fluorine type surfactant or a silicone type surfactant is more preferable.

In the case of blending a surfactant, the blending amount is usually 0.001 to 5 mass%, preferably 0.005 to 2 mass%, and more preferably 0.01 to 0.5 mass% with respect to the total amount of the organic developer.

The developing treatment can be performed by a known developing method, for example, a method of immersing the support in a developer for a certain period of time (dip method), a method of stopping the support for a certain period of time by mounting the developer on the surface of the support by surface tension (paddle Method), a method of spraying a developer solution on the surface of the support (spray method), a method of continuously drawing a developer solution while scanning the nozzle at a constant speed on a support rotating at a constant speed (dynamic dosing method) And the like.

As the organic solvent contained in the rinse liquid used for the rinse treatment after development in the solvent development process, for example, among the organic solvents exemplified as organic solvents used in the organic developer, those that do not dissolve the resist pattern are appropriately selected. Can be used. Typically, at least one type of solvent selected from hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, alcohol-based solvents, amide-based solvents, and ether-based solvents is used. Among these, at least one type selected from hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, alcohol-based solvents and amide-based solvents is preferable, and at least one type selected from alcohol-based solvents and ester-based solvents is more preferable, Alcohol solvents are particularly preferred.

The alcohol solvent used for the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specifically, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4 -Octanol, benzyl alcohol, etc. are mentioned. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol or 2-hexanol is more preferable.

Any one of these organic solvents may be used alone, or two or more of these organic solvents may be used in combination. Moreover, you may use it, mixing with an organic solvent other than the above or water. However, in consideration of the developing characteristics, the amount of water in the rinse liquid is preferably 30 mass% or less, more preferably 10 mass% or less, even more preferably 5 mass% or less, and 3 mass% with respect to the total amount of the rinse liquid. The following are particularly preferred.

In the rinse liquid, a known additive can be blended if necessary. As the additive, a surfactant is mentioned, for example. Examples of the surfactant include those similar to those described above, and a nonionic surfactant is preferable, and a fluorine surfactant or a silicone surfactant is more preferable.

In the case of blending a surfactant, the blending amount is usually 0.001 to 5 mass%, preferably 0.005 to 2 mass%, and more preferably 0.01 to 0.5 mass% with respect to the total amount of the rinse liquid.

The rinse treatment (washing treatment) using the rinse liquid can be carried out by a known rinse method. As a method, for example, a method of continuously drawing out a rinse liquid on a support rotating at a constant speed (rotation coating method), a method of immersing the support in the rinse liquid for a certain period of time (dip method), and a rinse liquid on the surface of the support. The method of spraying (spraying method) etc. are mentioned.

Example

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

In this example, the compound represented by the general formula (1) is referred to as "compound (1)", and the compound represented by the other general formula is also described in the same manner.

<Preparation example of a polymer compound>

The polymer compound used as the base component in the present example was obtained by copolymerizing a compound represented by the following formula as a monomer in a predetermined molar ratio and copolymerized by a known radical polymerization method.

[Formula 53]

(Polymer compounds 1 to 6)

For the obtained polymer compounds 1 to 6, the monomer composition ratio of the polymer compound (ratio (molar ratio) of each structural unit in the structure) determined by ¹³ C-NMR, the mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement And molecular weight dispersion degree (Mw/Mn) are also listed in Table 1.

<Preparation of resist composition>

(Examples 1 to 7, Comparative Examples 1 to 4)

Each component shown in Table 2 was mixed and dissolved to prepare a resist composition of each example.

In Table 2, each abbreviation has the following meaning, respectively. The value in [] is the blending amount (parts by mass).

(A)-1 to (A)-6: Polymer compounds 1 to 6.

(B1)-1 to (B1)-4: An acid generator comprising a compound each represented by the following formulas (B1)-1 to (B1)-4.

(B2)-1: An acid generator comprising a compound represented by the following general formula (B2)-1.

(B2)-2: Triphenylsulfonium nonafluoro-n-butanesulfonate.

(D)-1: A photodegradable base composed of a compound represented by the following general formula (D)-1.

(F)-1: The fluorinated polymer compound represented by the following general formula (F)-1. The mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 25000, and the molecular weight dispersion degree (Mw/Mn) was 2.0.

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

[Chemical Formula 54]

A resist pattern was formed using the obtained resist composition, and each evaluation of sensitivity, line with roughness (LWR), and exposure margin (EL margin) was performed as follows.

<Formation of resist pattern>

On a 12-inch silicon wafer, an organic antireflection film composition "ARC95" (trade name, manufactured by Brewer Science) was applied using a spinner, and fired on a hot plate at 205°C for 60 seconds, followed by drying to obtain an organic system having a film thickness of 90 nm. An antireflection film was formed.

Subsequently, the resist composition of each example was applied on the organic antireflection film using a spinner, respectively, and prebaked (PAB) treatment for 60 seconds at a temperature of 110°C on a hot plate, followed by drying, to a film thickness of 90 nm. A resist film of was formed.

Next, with respect to the resist film, ArF exposure apparatus for immersion NSR-S609B [manufactured by Nikon Corporation; NA (number of openings) = 1.07, Dipole 0.97/0.78 with polano, immersion medium: water] through a binary mask. An excimer laser (193 nm) was selectively irradiated.

Then, heating (PEB) treatment was performed after exposure for 60 seconds at a temperature of 95°C.

Next, alkali development was performed for 10 seconds with a 2.38 mass% TMAH aqueous solution (trade name: NMD-3, manufactured by Tokyo Oka Industrial Co., Ltd.) at 23°C, and then water rinsed for 30 seconds using pure water, It was shaken off and dried.

As a result, in any example, a 1:1 line and space (LS) pattern having a line width of 50 nm and a pitch of 100 nm was formed, respectively.

In the formation of the resist patterns of each example, the optimum exposure amount (sensitivity) Eop (mJ/cm 2) at which the LS patterns are respectively formed was calculated. The results are shown in Table 3.

[Evaluation of Line with Roughness (LWR)]

In the LS pattern formed by the above <formation of a resist pattern>, the space width was determined in the length direction of the space by measuring SEM (scanning electron microscope, acceleration voltage 300 V, brand name: S-9380, manufactured by Hitachi High Technologies). The measurement was carried out at 400 locations, and from the result, a three-fold value (3s) of the standard deviation (s) was obtained, and a value (nm) averaged over 3s at 400 locations was calculated as a measure representing LWR. The results are shown in Table 3.

The smaller the value of 3s, the smaller the roughness of the line width, which means that an LS pattern with a more uniform width is obtained.

[Evaluation of exposure margin (EL margin)]

The exposure amount when the line of the LS pattern is formed within the range of ±5% (47.5 nm to 52.5 nm) of the target dimension (line width 50 nm) by the above <formation of the resist pattern> is obtained, and EL by the following equation The margin (unit: %) was calculated|required. The results are shown in Table 3.

EL margin (%) = (｜E1 － E2｜/ Eop) × 100

E1: Exposure amount when LS pattern with a line width of 47.5 nm is formed (mJ/cm2)

E2: Exposure amount when LS pattern with a line width of 52.5 nm is formed (mJ/cm2)

The EL margin indicates that the larger the value, the smaller the amount of change in the pattern size accompanying the change in the exposure amount.

From the results shown in Table 3, it can be confirmed that the resist compositions of Examples 1 to 7 to which the present invention is applied can form a resist pattern with reduced roughness.

Claims (4)

A base component (A) whose solubility in a developer is changed by the action of an acid, an acid generator component (B) that generates an acid by exposure, and a photodisintegrating base that loses controllability of acid diffusion by decomposition by exposure (D1) ) As a resist composition containing,
The substrate component (A) contains a polymer compound (A1) having a structural unit (a0) represented by the following general formula (a0-1),
The acid generator component (B) comprises an acid generator (B1) comprising a compound represented by the following general formula (b1).
[Formula 1]

[In the formula, 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 ⁰ is a divalent hydrocarbon group which may have a substituent. n _a0 is 0. Ra ¹ and Ra ² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or an alkylthio group, or Ra ¹ and Ra ² are bonded to each other to form an oxygen atom (-O-) or a sulfur atom It may be a C1-C6 alkylene group, an ether bond, or a thioether bond which may contain (-S-). Ra' ⁰¹ is an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms that may have a halogen atom protected by a protecting group or may have a halogen atom, and a carboxyl group forming a salt Or a substituted oxycarbonyl group. When two or more Ra' ⁰¹ are present, a plurality of Ra' ⁰¹ may be the same as or different from each other. X is a substituent selected from the group consisting of a halogen atom, a carboxyl group, an acyl group, a nitro group and a cyano group. When two or more Xs are present, a plurality of Xs may be the same or different from each other. p ₀ is an integer of 0-8. q ₀ is an integer of 1 to 9.]
[Formula 2]

[In the formula, R ¹⁰¹ is 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. q'' is an integer of 1-20. m is an integer greater than or equal to 1, and M ^m+ is an m-valent organic cation.] The method of claim 1,
A resist composition having a structural unit (a1) in which the polymer compound (A1) contains an acid-decomposable group whose polarity increases due to the action of an acid. A base component (A) whose solubility in a developer is changed by the action of an acid, an acid generator component (B) that generates an acid by exposure, and a photodisintegrating base that loses controllability of acid diffusion by decomposition by exposure (D1) ) As a resist composition containing,
The base component (A) is a structural unit (a0) represented by the following general formula (a0-1), a structural unit (a1) containing an acid-decomposable group whose polarity increases due to the action of an acid, and a lactone-containing cyclic group, -SO ₂ -containing a polymer compound (A1) having a structural unit (a2) containing a containing cyclic group or a carbonate containing cyclic group (excluding the structural unit (a0)),
The acid generator component (B) comprises an acid generator (B1) comprising a compound represented by the following general formula (b1).
[Formula 3]

[In the formula, 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 ⁰ is a divalent hydrocarbon group which may have a substituent. n _a0 is an integer from 0 to 2. Ra ¹ and Ra ² are each independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group, or an alkylthio group, or Ra ¹ and Ra ² are bonded to each other to form an oxygen atom (-O-) or a sulfur atom It may be a C1-C6 alkylene group, an ether bond, or a thioether bond which may contain (-S-). Ra' ⁰¹ is an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms that may have a halogen atom protected by a protecting group or may have a halogen atom, and a carboxyl group forming a salt Or a substituted oxycarbonyl group. When two or more Ra' ⁰¹ are present, a plurality of Ra' ⁰¹ may be the same as or different from each other. X is a substituent selected from the group consisting of a halogen atom, a carboxyl group, an acyl group, a nitro group and a cyano group. When two or more Xs are present, a plurality of Xs may be the same or different from each other. p ₀ is an integer of 0-8. q ₀ is an integer of 1 to 9.]
[Formula 4]

[In the formula, R ¹⁰¹ is 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. q'' is an integer of 1-20. m is an integer greater than or equal to 1, and M ^m+ is an m-valent organic cation.] A step of forming a resist film on a support using the resist composition according to any one of claims 1 to 3, a step of exposing the resist film, and a step of developing the resist film after exposure to form a resist pattern. How to form a resist pattern.