TWI756260B - Salt, acid generator, resist composition and method of producing resist pattern - Google Patents

Abstract

A salt represented by the formula (I).

[In the formula (I), R¹ and R² each independently represent an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent.

R³ represents an acid labile group.

X¹ represents a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be replaced by an oxygen atom or a carbonyl group.

A^- represents an organic anion.]

Description

Salt, acid generator, photoresist composition and method for producing photoresist pattern

The present invention relates to a manufacturing method of a salt, an acid generator, a photoresist composition and a photoresist pattern.

Japanese Patent Laid-Open No. 2010-44347 describes a photoresist composition containing a salt represented by the following formula as an acid generator.

Japanese Patent Application Laid-Open No. 2013-47209 describes a photoresist composition containing a salt represented by the following formula as an acid generator, respectively.

The present invention includes the following inventions.

[1] A salt represented by the following formula (I).

式(I)中，R¹及R²分別獨立地表示可具有取代基的碳數6至18之芳香族烴基。

In formula (I), R ¹ and R ² each independently represent an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms.

R ³ represents a group having an acid-labile group.

X ¹ represents a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group.

A ^- represents an organic anion.

[2] The salt according to [1], wherein X ¹ in the aforementioned formula (I) represents -X ¹² -OX ²² -* (X ¹² represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, which constitutes the 2 The methylene group of the valent aliphatic hydrocarbon group may be substituted with an oxygen atom or a carbonyl group. X ²² represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms. However, the total carbon number of X ¹² and X ²² is 11. * represents a combination with R ³ the bond bond.) is the base.

[3] The salt according to the item [1] or [2], wherein R ¹ and R ² in the aforementioned formula (I) are each independently a phenyl group which may have a substituent.

[4] The salt according to any one of the items [1] to [3], wherein R ³ of the aforementioned formula (I) is a group which leaves a leaving group to form a hydroxyl group or a carboxyl group when contacted with an acid.

[5] The salt according to any one of the items [1] to [4], wherein R ³ in the aforementioned formula (I) is a group represented by the following formula (1).

式(1)中，R^a1至R^a3分別獨立地表示可具有取代基之碳數1至8的烷基、可具有取代基之碳數3至20的脂環式烴基，R^a1及R^a2相互結合而與該等基結合的碳原子一起形成碳數3至20之非芳香族烴環。

In formula (1), R ^a1 to R ^a3 each independently represent an optionally substituted alkyl group having 1 to 8 carbon atoms, an optionally substituted alicyclic hydrocarbon group having 3 to 20 carbon atoms, R ^a1 and R ^a2 The carbon atoms bonded to each other and these groups together form a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms.

ma and na each independently represent 0 or 1, and at least one of ma and na is 1.

* Indicates a bond key.

[6] The salt according to the item [5], wherein ma is 0 and na is 1 in the aforementioned formula (1).

[7] An acid generator comprising the salt according to any one of [1] to [6].

[8] A photoresist composition comprising an acid generator and a resin containing a structural unit having an acid-labile group, wherein the acid generator contains the salt of any one of [1] to [6].

[9] The photoresist composition according to the item [8], further comprising an acid-generating salt whose acidity is lower than that of the acid generated by the acid generator.

[10] A method for manufacturing a photoresist pattern, comprising the following steps: (1) coating the photoresist composition described in item [8] or [9] on a substrate, (2) making the coating composition (3) a step of exposing the composition layer to light, (4) a step of heating the exposed composition layer, and (5) a step of developing the heated composition layer .

In this specification, "(meth)acrylic-type monomer" means at least 1 type which has a structure of "CH ₂ =CH-CO-" or "CH ₂ =C(CH ₃ )-CO-". Similarly, "(meth)acrylate" and "(meth)acrylic acid" mean "at least one kind of acrylate and methacrylate" and "at least one kind of acrylic acid and methacrylic acid", respectively.

In this specification, "solid content of a photoresist composition" means the sum total of the components after removing the solvent (E) mentioned later from the total amount of a photoresist composition.

The photoresist composition of the present invention contains a resin (A) having an acid-labile group and a salt represented by formula (I) (hereinafter, also referred to as "salt (I)" in some cases.). The photoresist composition contains a salt (I) as an acid generator.

The acid generator of the present invention contains the salt (I), and may contain an acid generator (B) other than the salt (I). The photoresist composition of the present invention may optionally contain resin (X) other than resin (A), solvent (E), quencher (C), salt (I) and acidity generated below The acid salt produced by the acid generator (B), and other components (F). Hereinafter, these components will be described.

<Salt represented by formula (I)>

The salt of the present invention is a salt (salt (I)) represented by the following formula (I).

式(I)中，R¹及R²分別獨立地表示可具有取代基之碳數6至18的芳香族烴基。

In formula (I), R ¹ and R ² each independently represent an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms.

R ³ represents an acid labile group.

X ¹ represents a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group.

A ^- represents an organic anion.

In formula (I), when -CH ₂ - contained in the aliphatic saturated hydrocarbon group is substituted with -O- or -C(=O)-, the number of carbon atoms before substitution is the number of carbon atoms in the aliphatic saturated hydrocarbon group.

<Cation constituting formula (I)>

The aromatic hydrocarbon groups with 6 to 18 carbon atoms represented by R ¹ and R ² include aryl groups such as phenyl, naphthyl, anthracenyl, biphenyl, phenanthrenyl, and perylene groups, and phenyl, naphthyl and Anthracenyl is preferred, phenyl and naphthyl are more preferred, and phenyl is even more preferred.

The substituent which the aromatic hydrocarbon group having 6 to 18 carbon atoms in R ¹ and R ² may have includes a hydroxyl group, a carboxyl group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an alkoxy group having 3 carbon atoms. Alicyclic hydrocarbon groups to 12 and groups combining these groups.

The alkyl group having 1 to 12 carbon atoms includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl Wait.

The alkoxy group having 1 to 12 carbon atoms includes a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, and 2-ethylhexyl group. oxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy and the like.

The alicyclic hydrocarbon group having 3 to 12 carbon atoms includes the groups shown below. * is a bond with a ring.

Among these substituents, hydroxyl, alkyl having 1 to 12 carbons, or alkoxy having 1 to 12 carbons are preferred, and hydroxyl or alkyl having 1 to 12 carbons are more preferred, and those having carbons Alkyl groups of 1 to 12 are further preferred, and alkyl groups of 1 to 6 carbon atoms are even more preferred.

The optionally substituted aromatic hydrocarbon group represented by R ¹ and R ² having 6 to 18 carbon atoms is preferably a phenyl group.

<acid labile group>

R ³ represents an acid labile group. The "acid-labile group" refers to a group having a leaving group which, when contacted with an acid, leaves the leaving group to form a hydrophilic group (eg, a hydroxyl group, a carboxyl group, or an amine group).

In the acid-labile group represented by R ³ , the atom bonded to X ¹ is usually an oxygen atom or a carbon atom constituting a carbonyl group.

Examples of the acid-labile group include a group represented by formula (1) (hereinafter, sometimes referred to as "acid-labile group (1)"), and a group represented by formula (2) (hereinafter, sometimes referred to as ""acid-labile group"). Acid-labile group (2)".) and so on.

In formula (1), R ^a1 to R ^a3 each independently represent an optionally substituted alkyl group having 1 to 8 carbon atoms, or an optionally substituted alicyclic hydrocarbon group having 3 to 20 carbon atoms, but R ^a1 and R ^a2 are bonded to each other to form a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms together with the carbon atoms to which these groups are bonded.

ma and na each independently represent 0 or 1, and at least one of ma and na is 1.

* Indicates a bond key.

In formula (2), R ^a1' and R ^a2' each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^a3' represents a hydrocarbon group having 1 to 20 carbon atoms, but R ^a2' and R ^a3' are combined with each other. The carbon atoms and X which are bonded to these groups together form a heterocyclic ring having 3 to 20 carbon atoms, and the non-aromatic hydrocarbon ring and the methylene group contained in the heterocyclic ring may be substituted with an oxygen atom or a sulfur atom.

X represents an oxygen atom or a sulfur atom.

na' means 0 or 1.

* Indicates a bond key.

Examples of the alkyl group represented by R ^a1 and R ^a2 include methyl, ethyl, propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl and the like.

The alicyclic hydrocarbon group represented by R ^a1 to R ^a3 may be any of a monocyclic formula and a polycyclic formula. The monocyclic alicyclic hydrocarbon group includes cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. The polycyclic alicyclic hydrocarbon group includes, for example, a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond) and the like. The carbon number of the alicyclic hydrocarbon group of R ^a1 to R ^a3 is preferably 3 to 16.

Examples of the substituent of the optionally substituted alkyl group having 1 to 8 carbon atoms include alicyclic hydrocarbon groups having 3 to 20 carbon atoms. The substituent of the alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent includes an alkyl group having 1 to 8 carbon atoms. More specifically, methylcyclohexyl, dimethylcyclohexyl, methylnorbornyl, cyclohexylmethyl, adamantylmethyl, norbornylethyl, etc. are mentioned.

Preferably, ma is 0 and na is 1.

-C(R ^a1 )(R ^a2 )(R ^a3 ) when R ^a1 and R ^a2 are bonded to each other to form a non-aromatic hydrocarbon ring include monocyclic non-aromatic hydrocarbon rings and polycyclic non-aromatic hydrocarbon rings Specific examples of the family of hydrocarbon rings include the following rings. The non-aromatic hydrocarbon ring system preferably has 3 to 12 carbon atoms. * indicates a bond with -O-.

The group represented by the formula (1) includes a group in which R ^a1 to R ^a3 in the formula (1) are alkyl groups (preferably a tertiary butoxycarbonyl group), and R ^a1 and R ^a2 in the formula (1) In order to bond with each other, an adamantane ring, R ^a3 is an alkyl group, R ^a1 and R ^a2 are an alkyl group, R ^a3 is an adamantyl group in formula (1), and the like together with these bonded carbon atoms.

The hydrocarbon group of R ^a1' to R ^a3' includes an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, a group formed by combining these groups, and the like.

The alkyl group and the alicyclic hydrocarbon group are the same as those mentioned above.

Aromatic hydrocarbon groups include phenyl, naphthyl, anthracenyl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, and cumene group, mesityl group, biphenyl group, phenanthrenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group and other aryl groups, etc.

R ^a2' and R ^a3' are bonded to each other, and the heterocyclic ring formed with the carbon atom and X to which these groups are bonded includes the following rings. * Indicates a bond key.

Preferably, at least one of R ^a1' and R ^a2' is a hydrogen atom.

Specific examples of the acid-labile group (1) include the following groups. * Indicates a bond key.

Specific examples of the acid-labile group (2) include the following groups. * Indicates a bond key.

The acid-labile group represented by R ³ is preferably a group having an acid-labile group (1), and R ^a1 and R ^a2 are combined with each other to form a carbon atom having 3 to 20 carbon atoms together with the carbon atoms to which these groups are combined. A non-aromatic hydrocarbon ring is more preferable, and an adamantane ring is formed together with the carbon atoms to which these groups are bonded by bonding of R ^a1 and R ^a2 to each other.

The divalent aliphatic saturated hydrocarbon group represented by X ¹ includes an alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, or a combination of two or more of these groups. .

Specifically, a methylene group, an ethylidene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group can be mentioned. Diyl, Heptane-1,7-diyl, Octane-1,8-diyl, Nonane-1,9-diyl, Decane-1,10-diyl, Undecane-1,11 -Diyl, dodecane-1,12-diyl and other linear alkanediyl; ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, Propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1, 4-diyl, 2-methylbutane-1,4-diyl and other branched alkanediyl; cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane Monocyclic divalent alicyclic saturated hydrocarbon groups of cycloalkanediyl such as alkane-1,4-diyl and cyclooctane-1,5-diyl; norbornane-1,4-diyl, norbornane-1,4-diyl, norbornane-1,4-diyl Polycyclic divalent alicyclic saturated hydrocarbon groups such as bornane-2,5-diyl, adamantane-1,5-diyl, adamantane-2,6-diyl and the like.

The methylene group of the aliphatic saturated hydrocarbon group constituting X ¹ can be substituted with an oxygen atom or a carbonyl group, for example, through an ether bond, an ester bond (-CO-O- or -O-CO-), and -O-CO-O, etc. Substituted aliphatic saturated hydrocarbon group.

Among the groups represented by X ¹ , a methylene group is usually bonded to R ³ .

Specifically, X ¹ is -X ¹² -OX ²² -* (X ¹² represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, and the methylene group constituting the divalent aliphatic hydrocarbon group may be substituted with an oxygen atom or Carbonyl group. X ²² represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms. However, the total carbon number of X ¹² and X ²² is 11. * represents a bond with R ^3. The group represented by the group is preferable .

The divalent aliphatic hydrocarbon group represented by X ¹² and X ²² is preferably an alkanediyl group, and more preferably an alkanediyl group having 1 to 6 carbon atoms.

Specific examples of the organic cation constituting the salt (I) include organic cations represented by the following formulae (I-c-1) to (I-c-24).

The cation (I) is preferably a cation represented by the formula (Ic-1) to the formula (Ic-20), and more preferably the cation represented by the formula (Ic-1) to the formula (Ic-14), and the cation represented by the formula ( The cations represented by Ic-1), formula (Ic-2), and formula (Ic-7) are more preferable.

<Organic anion constituting salt (I)>

The organic anion (A ⁻ ) constituting the salt (I) includes a sulfonic acid anion, a sulfonyl imide anion, a sulfonyl methide anion, and a carboxylate anion. Among these anions, sulfonic acid anions are preferred, and sulfonic acid anions represented by formula (IA) are more preferred.

式(I-A)中，Q¹及Q²分別獨立地表示氟原子或碳數1至6之全氟烷基。

In formula (IA), Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.

L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, -CH ₂ - contained in the saturated hydrocarbon group may be substituted with -O- or -CO-, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group .

Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and -CH ₂ - contained in the alicyclic hydrocarbon group may be substituted with -O-, -SO ₂ - or - CO-.

In formula (IA), when -CH ₂ - contained in a saturated hydrocarbon group or an alicyclic hydrocarbon group is substituted with -O-, -C(=O)- or -SO ₂ -, the number of carbon atoms before substitution is determined as the saturated hydrocarbon group, respectively. A hydrocarbon group, the carbon number of the alicyclic hydrocarbon group.

^The perfluoroalkyl groups of Q1 and ^Q2 include trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluoro2-butyl, perfluoro-1 Tributyl, perfluoropentyl and perfluorohexyl, etc.

Q ¹ and Q ² are preferably mutually independent fluorine atoms or trifluoromethyl groups, more preferably fluorine atoms.

The divalent saturated hydrocarbon group of L ^b1 includes straight-chain or branched alkanediyl, monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and may be two of these groups. The base formed by the above combination.

Specifically, a methylene group, an ethylidene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group can be mentioned. Diyl, Heptane-1,7-diyl, Octane-1,8-diyl, Nonane-1,9-diyl, Decane-1,10-diyl, Undecane-1,11 -diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane Linear alkanediyl such as alkane-1,16-diyl and heptadecan-1,17-diyl; ethane-1,1-diyl, propane-1,1-diyl, propane-1, 2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, Branched alkanediyl such as pentane-1,4-diyl, 2-methylbutane-1,4-diyl; cyclobutane-1,3-diyl, cyclopentane-1,3- Monocyclic divalent alicyclic saturated hydrocarbon group of cycloalkanediyl such as diyl, cyclohexane-1,4-diyl, cyclooctane-1,5-diyl; norbornane-1,4 -Diyl, norbornane-2,5-diyl, adamantane-1,5-diyl, adamantane-2,6-diyl and other polycyclic divalent alicyclic saturated hydrocarbon groups and the like.

The -CH ₂ - substituted with -O- or -CO- contained in the divalent saturated hydrocarbon group of L ^b1 includes, for example, a group represented by any of formulae (b1-1) to (b1-3). In addition, in formula (b1-1) to formula (b1-3) and the following specific examples, * represents a bond with -Y.

In formula (b1-1), L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, the hydrogen atom contained in the saturated hydrocarbon group can be substituted with a fluorine atom or a hydroxyl group, and the -CH ₂ - contained in the saturated hydrocarbon group can be substituted with -O- or -CO-.

However, the total carbon number coefficient of L ^b2 and L ^b3 is 22 or less.

In formula (b1-2), L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, the hydrogen atom contained in the saturated hydrocarbon group can be substituted with a fluorine atom or a hydroxyl group, and the -CH ₂ - contained in the saturated hydrocarbon group can be substituted with -O- or -CO-.

However, the total carbon number coefficient of L ^b4 and L ^b5 is 22 or less.

In formula (b1-3), L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

L ^b7 represents a single bond or a divalent saturated hydrocarbon group with 1 to 23 carbon atoms, the hydrogen atom contained in the saturated hydrocarbon group can be substituted with a fluorine atom or a hydroxyl group, and the -CH ₂ - contained in the saturated hydrocarbon group can be substituted with -O- or -CO-.

However, the total carbon number coefficient of L ^b6 and L ^b7 is 23 or less.

In formulas (b1-1) to (b1-3), when -CH ₂ - contained in a saturated hydrocarbon group is substituted with -O- or -CO-, the number of carbon atoms before substitution is the number of carbon atoms in the saturated hydrocarbon group.

The divalent saturated hydrocarbon group and the -CH ₂ - or hydrogen atom contained in the saturated hydrocarbon group may be the same as the above-mentioned substituted groups, and examples thereof include the same ones as those of the divalent saturated hydrocarbon group of L ^b1 .

The L ^b2 series is preferably a single bond.

L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and more preferably an alkanediyl group having 1 to 4 carbon atoms.

L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and the hydrogen contained in the divalent saturated hydrocarbon group can be replaced by a fluorine atom, more preferably an alkanediyl group having 1 to 4 carbon atoms.

L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond.

L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group with 1 to 18 carbon atoms. The hydrogen atom contained in the saturated hydrocarbon group can be replaced by a fluorine atom or a hydroxyl group. The -CH ₂ - contained in the divalent saturated hydrocarbon group can be replaced by a fluorine atom or a hydroxyl group. Replaced with -O- or -CO-.

The -CH ₂ - group substituted with -O- or -CO- contained in the divalent saturated hydrocarbon group of L ^b1 is preferably a group represented by formula (b1-1) or formula (b1-2), more preferably In formula (b1-1), L ^b2 is a single bond, L ^b3 is an alkanediyl group having 1 to 4 carbon atoms, and in formula (b1-2), L ^b4 is an alkanediyl group having 1 to 4 carbon atoms, L ^b5 is a group of a single bond.

As the formula (b1-1), a group represented by any of the formulae (b1-4) to (b1-8) can be mentioned.

In formula (b1-4), L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

In formula (b1-5), L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms.

L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

However, the total carbon number of L ^b9 and L ^b10 is 20 or less.

In formula (b1-6), L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.

L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

However, the total carbon number of L ^b11 and L ^b12 is 21 or less.

In formula (b1-7), L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.

L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.

L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

However, the total carbon number of L ^b13 to L ^b15 is 19 or less.

In formula (b1-8), L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.

L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.

L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.

However, the total carbon number of L ^b16 to L ^b18 is 19 or less.

L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.

L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.

L ^b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbons, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbons.

L ^b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.

L ^b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.

L ^b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbons, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbons.

The formula (b1-3) includes a group represented by any of the formulas (b1-9) to (b1-11).

In formula ( ^b1-9 ), L b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group.

However, the total carbon number of L ^b19 and L ^b20 is 23 or less.

In formula (b1-10), L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group.

L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group.

However, the total carbon number of L ^b21 to L ^b23 is 21 or less.

In formula (b1-11), L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b25 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group.

L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH ₂ - contained in the alkylcarbonyloxy group may be substituted with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group.

However, the total carbon number of L ^b24 to L ^b26 is 21 or less.

In formulas (b1-9) to (b1-11), when the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the number of carbon atoms in the alkylcarbonyloxy group and the CO in the ester bond are also included. and the number of O, the carbon number of the divalent saturated hydrocarbon group.

Examples of the alkylcarbonyloxy group include acetyloxy, propionyloxy, butyryloxy, cyclohexylcarbonyloxy, adamantylcarbonyloxy, and the like.

The group represented by formula (b1-4) includes the following.

The group represented by formula (b1-5) includes the following.

The group represented by formula (b1-6) includes the following.

The group represented by formula (b1-7) includes the following.

The group represented by formula (b1-8) includes the following.

The group represented by formula (b1-2) includes the following.

The group represented by formula (b1-9) includes the following.

The group represented by formula (b1-10) includes the following.

The group represented by formula (b1-11) includes the following.

The monovalent alicyclic hydrocarbon group represented by Y in formula (I-A) includes groups represented by formula (Y1) to formula (Y11) and formula (Y36) to formula (Y38).

When -CH ₂ - contained in the monovalent alicyclic hydrocarbon group represented by Y is substituted with -O-, -SO ₂ - or -CO-, the number may be one or two or more. Such groups include groups represented by formula (Y12) to formula (Y35).

Among them, the base represented by any one of formula (Y1) to formula (Y20), formula (Y30) and formula (Y31) is preferred, and more preferred is formula (Y11), formula (Y15), formula ( A group represented by Y16), formula (Y20), formula (Y30) or formula (Y31), and more preferably a group represented by formula (Y11), formula (Y15) or formula (Y30).

When Y constitutes a spiro ring of formula (Y28) to formula (Y33), etc., the alkanediyl group between two oxygens preferably has one or more fluorine atoms. Meanwhile, among the alkanediyl groups contained in the ketal structure, the methylene group adjacent to the oxygen atom is preferably an unsubstituted fluorine atom.

The substituent of the methyl group represented by Y in the formula (IA) includes a halogen atom, a hydroxyl group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a glycidyloxy group. group or -(CH ₂ ) _ja -O-CO-R ^b1 group (wherein R ^b1 represents an alkyl group having 1 to 16 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 16 carbon atoms, or a group having 6 to 18 carbon atoms The monovalent aromatic hydrocarbon group of .ja represents any integer from 0 to 4) and the like.

The substituent of the monovalent alicyclic hydrocarbon group represented by Y in the formula (IA) includes a halogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms which may be substituted by a hydroxyl group, and an alicyclic group having 3 to 16 carbon atoms. Formula hydrocarbon group, alkoxy group with 1 to 12 carbons, aromatic hydrocarbon group with 6 to 18 carbons, aralkyl group with 7 to 21 carbons, aryl group with 2 to 4 carbons, glycidyloxy or - (CH ₂ ) _ja -O-CO-R ^b1 group (wherein, R ^b1 represents an alkyl group having 1 to 16 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 16 carbon atoms, or a 1 carbon group having 6 to 18 carbon atoms. valent aromatic hydrocarbon group. ja represents any integer from 0 to 4) and the like.

As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned.

The alicyclic hydrocarbon group includes, for example, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, and an adamantyl group.

Aromatic hydrocarbon groups include, for example, phenyl, naphthyl, anthracenyl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl; tolyl, xylyl, isopropyl Aryl groups such as phenyl, mesityl, biphenyl, phenanthryl, 2,6-diethylphenyl, 2-methyl-6-ethylphenyl, etc.

Alkyl, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, heptyl, 2 -Ethylhexyl, octyl, nonyl, decyl, undecyl, dodecyl, etc.

Examples of the alkyl group substituted with a hydroxyl group include hydroxyalkyl groups such as hydroxymethyl and hydroxyethyl.

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group.

The aralkyl group includes a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, a naphthylethyl group, and the like.

Examples of the acyl group include acetyl group, propionyl group, butyryl group, and the like.

The alicyclic hydrocarbon group having 1 to 18 carbon atoms as the substituent represented by Y which may be present in the formula (I-A) includes the following groups.

Y, preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, more preferably an adamantyl group which may have a substituent, and -CH ₂ - constituting the alicyclic hydrocarbon group or the adamantyl group Can be substituted into -O-, -SO ₂ - or -CO-. More preferably, Y is an adamantyl group, a hydroxyadamantyl group, a pendant oxyadamantyl group or a group represented by the following formula.

The sulfonic acid anion represented by the formula (IA) is an anion represented by the formula (B1-A-1) to the formula (B1-A-54). "Wait. ] is preferred, and formula (B1-A-1) to formula (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula (B1-A-24) to formula (B1-A-33), formula (B1-A-36) to formula (B1-A-40), formula (B1-A-47) to formula (B1-A-54) Anions are better.

In formula (B1-A-1) to formula (B1-A-54), R ⁱ² to R ⁱ⁷ represent an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group.

R ⁱ⁸ represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, a monovalent alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these groups, more Preferred are methyl, ethyl, cyclohexyl or adamantyl.

L ^A41 , which is a single bond or an alkanediyl group having 1 to 4 carbon atoms.

Q1 and ^{Q2 have} the same meaning as described above.

Examples of the sulfonic acid anion represented by the formula (I-A) include the anions represented by the formula (B1a-1) to the formula (B1a-30).

Among them, the sulfonic acid anion is preferably an anion represented by any of the formulae (B1a-1) to (B1a-3), the formula (B1a-7) to the formula (B1a-19) and the formula (B1a-22).

As a specific example of the salt represented by Formula (I), the salt which combined the above-mentioned cation and anion arbitrarily is mentioned. Specific examples of the salt represented by the formula (I) are shown in Tables 1 to 14.

In each table, each symbol represents a symbol added to the structure representing the above-mentioned anion or cation. For example, the salt (I-1) is a salt formed by an anion represented by the formula (BIa-1) and a cation represented by the formula (I-c-1), and is a salt represented below.

When the salt (I) is used as the acid generator (I0) described later, the salt (I-1), the salt (I-2), the salt (I-3), the salt (I-16), the salt (I- 17), salt (I-18), salt (I-19), salt (I-22), salt (I-23), salt (I-24), salt (I-25), salt (I-38 ), salt (I-39), salt (I-40), salt (I-41), salt (I-44), salt (I-45), salt (I-46), salt (I-47) , salt (I-60), salt (I-61), salt (I-62), salt (I-63), salt (I-66), salt (I-133), salt (I-134), Salt (I-135), salt (I-148), salt (I-149), salt (I-150), salt (I-151) and salt (I-154) are preferred.

<Method for producing salt represented by formula (I)>

In the formula (I), the salt (I) when X ¹ and R ³ are the following bases [salt (I) (salt (II)) represented by the following formula (I1)] can be obtained by making the formula (I1- The compound represented by a) and the salt represented by the formula (I1-b) are reacted in a solvent in the presence of a base catalyst, and are produced.

X ¹ represents -X ¹² -OX ²² -* (X ¹² represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, and the methylene group constituting the divalent aliphatic saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group. X ²² Represents a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms. However, the total carbon number of X ¹² and X ²² is 11. * represents a bond with R ^3. ) group.

R ³ is a group represented by the formula (1) (*-CO-O-CR ^a1 R ^a2 R ^a3 (* represents a bonding bond.)), where ma=0 and na=1.

式中，所有的符號分別表示與上述相同之意。

In the formula, all symbols have the same meanings as described above, respectively.

Examples of the solvent include acetonitrile and the like.

Triethylamine etc. are mentioned as an alkali catalyst.

The reaction is usually carried out at a temperature in the range of 15 to 90°C for 0.5 to 24 hours.

The compound represented by formula (I1-a) includes the compound represented by the following formula, etc., which are easily commercially available.

The salt system represented by the formula (I1-b) can be produced by reacting the salt represented by the formula (I1-c) and the compound represented by the formula (I1-d) in a solvent in the presence of a catalyst.

式中，所有的符號分別表示與上述相同之意。

In the formula, all symbols have the same meanings as described above, respectively.

Examples of the catalyst include copper (II) benzoate and the like, and examples of the solvent include monochlorobenzene and the like.

The reaction is usually carried out at a temperature in the range of 20 to 120°C for 0.5 to 24 hours.

The salt represented by the formula (I1-c) includes the salt represented by the following formula, which is easily commercially available.

The compound represented by the formula (I1-d) includes the compound represented by the following formula, which is easily commercially available.

In the formula (I), R ³ is a group represented by the formula (1) (*-CO-O-CR ^a1 R ^a2 R ^a3 (* represents a bond.)) and a salt when ma=0 and ma=1 (I) [salt (I) represented by the following formula (I2) (salt (I2))] can be obtained by reacting the salt represented by the formula (I2-b) with carbonyldiimidazole in a solvent, and then reacting with It is produced by reacting the compound represented by the formula (I2-a).

式中，所有的符號分別表示與上述相同之意。

In the formula, all symbols have the same meanings as described above, respectively.

Examples of the solvent include acetonitrile, chloroform, and the like.

The reaction is usually carried out at a temperature in the range of 15 to 80°C for 0.5 to 24 hours.

The compound represented by formula (I2-a) includes the compounds represented below, and the like, which are easily commercially available.

The compound represented by the formula (I2-b) includes the compound represented by the following formula and the like, which are easily commercially available.

In the formula (I), R ³ is a group represented by the formula (1) (*-O-CR ^a1 R ^a2 R ^a3 (* represents a bond.)) and a salt (I) when ma=1 and na=0 ) [salt (I) represented by the following formula (I3) (salt (I3))], can be obtained by contacting the compound represented by the formula (I2-a) with the salt represented by the formula (I1-b) with a base It is produced by reacting in a solvent in the presence of a medium.

式中，所有的符號分別表示與上述相同之意。

In the formula, all symbols have the same meanings as described above, respectively.

Examples of the solvent include acetonitrile and the like.

As an alkali catalyst, potassium hydroxide etc. are mentioned.

The reaction is usually carried out at a temperature in the range of 5 to 80°C for 0.5 to 24 hours.

In formula (I), R ³ is a group represented by formula (1) (*-O-CO-O-CR ^a1 R ^a2 R ^a3 (* represents a bonding bond.)), and when ma=1, na=1 The salt (I) [salt (I) represented by the following formula (I4) (salt (I4))] can be obtained by combining the compound represented by the formula (I4-a) with the salt represented by the formula (I1-b) , produced by reacting in a solvent in the presence of an alkali catalyst.

式中，所有的符號分別表示與上述相同之意。

In the formula, all symbols have the same meanings as described above, respectively.

Examples of the solvent include acetonitrile and the like.

As an alkali catalyst, triethylamine, dimethylaminopyridine, etc. are mentioned.

The reaction is usually carried out at a temperature in the range of 5 to 80°C for 0.5 to 24 hours.

The compound represented by the formula (I4-a) includes the compound represented by the following formula, and the like, which are easily commercially available.

In the formula (I), R ³ is a group represented by the formula (2) (*-CO-O-CR ^a1' R ^a2' -XR ^a3' (* represents a bonding bond.)) and na'=1 The salt (I) [salt (I) represented by the following formula (I5) (salt (I5))] can be obtained by combining the compound represented by the formula (I5-a) with the salt represented by the formula (I2-b), It is produced by reacting in a solvent in the presence of an alkali catalyst.

式中，所有的符號分別表示與上述相同之意。

In the formula, all symbols have the same meanings as described above, respectively.

Examples of the solvent include acetonitrile and the like.

As an alkali catalyst, triethylamine, dimethylaminopyridine, etc. are mentioned.

The reaction is usually carried out at a temperature in the range of 5 to 80°C for 0.5 to 24 hours.

The compound represented by the formula (I5-a) includes the compound represented by the following formula, and the like, which are easily commercially available.

In formula (I), R ³ is a group represented by formula (2) (*-O-CR ^{a1 '} R ^{a2 '} -XR ^{a3 '} (* represents a bonding bond.)) and na'=0 salt ( I) [salt (I) represented by the following formula (I6) (salt (I6))] can be obtained by making the compound represented by the formula (I6-a) and the salt represented by the formula (I1-b) in a base It is produced by reacting in a solvent in the presence of a catalyst.

式中，所有的符號分別表示與上述相同之意。R^a2" ，係從R^a2' 中去除氫原子後之基。

In the formula, all symbols have the same meanings as described above, respectively. R ^{a2 "} is the radical after removing the hydrogen atom from R ^{a2 '} .

Examples of the solvent include acetonitrile and the like.

As an acid catalyst, p-toluenesulfonic acid etc. are mentioned.

The reaction is usually carried out at a temperature in the range of 5 to 80°C for 0.5 to 24 hours.

The compound represented by the formula (I6-a) includes the compounds represented below and the like, which are easily commercially available.

<Photoresist composition>

The photoresist composition of the present invention contains an acid generator and a resin having an acid-labile group (hereinafter also referred to as "resin (A)"). The photoresist composition contains the salt (I) as an acid generator. Here, the "acid-labile group" refers to a group having a leaving group, and the leaving group is removed by contact with an acid, and the structural unit is converted into a structural unit having a hydrophilic group (eg, a hydroxyl group or a carbonyl group).

The photoresist composition of the present invention contains a quenching agent (hereinafter also referred to as "quenching agent (C)") such as acid salt whose acidity is lower than the acidity generated by the acid generator, and contains a solvent (hereinafter also referred to as "quenching agent (C)"). Solvent (E)") is preferred.

<acid generator>

The acid generator of the present invention contains the salt (I). The acid generator of the present invention contains one or more, preferably two or more, of the salts (I). Hereinafter, the salt (I) which is an acid generator is also referred to as an "acid generator (I0)".

The acid generator of the present invention may contain other acid generators (hereinafter, also referred to as "acid generator (B".) other than the acid generator (I0) known in the photoresist field.

When the acid generator (I0) and the acid generator (B) are contained as the acid generator, the mass ratio of the content of the acid generator (I0) and the acid generator (B), acid generator (I0): acid generator ( B), usually 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, and even more preferably 25:75 to 75:25.

In the photoresist composition, with respect to 100 parts by weight of the resin (A), the content of the acid generator (I0) is preferably 1.5 to 40 parts by weight, and more preferably 3 to 35 parts by weight.

<Acid Generator (B)>

The acid generator (B) may be a known acid generator, and may be an ionic acid generator or a nonionic acid generator. The nonionic acid generators may contain organic halides, sulfonate compounds (such as 2-nitrobenzyl, aromatic sulfonates, oxime sulfonates, N-sulfonyloxyimine, sulfonyl sulfonates) oxyketone, naphthoquinone diazonium 4-sulfonate), sulfonated compounds (eg, disulfide, ketone, sulfonyldiazomethane), and the like. The ionic acid generator includes an ionic acid generator in which a known cation and a known anion are combined, and an onium salt containing an onium cation (for example, a diazonium salt, a phosphonium salt, a sulfonium salt) is used as the ionic acid generator. , iodonium salt) as the representative. The anions of the onium salt include a sulfonic acid anion, a sulfonyl imide anion, and a sulfonyl methide anion, and the like.

As the acid generator (B), Japanese Patent Application Laid-Open No. 63-26653, Japanese Patent Application Laid-Open No. 55-164824, Japanese Patent Application Laid-Open No. 62-69263, Japanese Patent Application Laid-Open No. 63-146038, Japanese Patent Application Laid-Open No. 63-146038 can be used -163452, Japanese Patent Laid-Open No. 62-153853, Japanese Patent Laid-Open No. 63-146029, US Patent No. 3,779,778, US Patent No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. Compounds that generate acid by radiation, acid generators described in JP 2013-68914 A, JP 2013-3155 A, and JP 2013-11905 A, and the like. Meanwhile, compounds produced by known methods can also be used.

The acid generator (B) includes organic sulfonates and the like, preferably a fluorine-containing acid generator, and more preferably an acid generator represented by the formula (B1) (hereinafter also referred to as "acid generator"). agent (B1)”).

In formula (B1), Q ¹¹ and Q ¹² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.

L ^B1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, -CH ₂ - contained in the divalent saturated hydrocarbon group can be substituted with -O- or -CO-, and the hydrogen atom contained in the divalent saturated hydrocarbon group can also be used Fluorine atom or hydroxyl substitution.

Y ^B1 represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and -CH ₂ - contained in the alicyclic hydrocarbon group may be substituted with -O-, -SO ₂ - or -CO-.

Z ⁺ represents an organic cation.

The perfluoroalkyl group represented by Q ¹¹ and Q ¹² includes the same groups as those mentioned in the perfluoroalkyl group represented by Q ¹ and Q ² .

Preferably, Q ¹¹ and Q ¹² are each independently a fluorine atom or a trifluoromethyl group, and more preferably a fluorine atom. It is more preferable that Q ¹¹ and Q ¹² together are a fluorine atom.

The divalent saturated hydrocarbon group represented by L ^B1 is the same as the divalent saturated hydrocarbon group represented by L ^b1 .

Groups substituted with -CH ₂ - by -O- or -CO- contained in the divalent saturated hydrocarbon group represented by L ^B1 include -CH ₂ - by -O- contained in the divalent saturated hydrocarbon group represented by L ^b1 . or the same group substituted by -CO-. Specifically, the group represented by the above-mentioned formula (b1-1) to formula (b1-3) can be mentioned. In addition, when L ^B1 is a group represented by formula (b1-1) to formula (b1-3), * in the group represented by formula (b1-1) to formula (b1-3) represents a bond with Y ^B1 key.

L ^B1 is preferably any one of the groups represented by formula (b1-1) to formula (b1-3), and is represented by *2-CO-O-(CH ₂ ) _t1 -, *2-(CH ₂ ) _t2 -O-CO- (t1 represents any integer from 0 to 6. t2 represents any integer from 1 to 6. *2 represents a bond with -C(Q ¹¹ )(Q ¹² )-.) better.

The monovalent alicyclic hydrocarbon group represented by Y ^B1 may be monocyclic, polycyclic, or spirocyclic. Specifically, the monovalent alicyclic hydrocarbon group represented by Y ^B1 (the group represented by the above-mentioned formula (Y1) to formula (Y38), etc.) can be mentioned. Among the groups represented by Y ^B1 , preferable groups are the same as the preferable ranges of the groups represented by Y.

The anion of the salt represented by the formula (B1) includes the formula (B1-A-1) to the formula (B1-A-55). The anions represented by the formula (B1-A-1) to the formula (B1-A-55) [hereinafter, the number corresponding to the formula may be referred to as "anion (B1-A-1)" or the like. ] is preferred, and formula (B1-A-1) to formula (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula (B1-A-24) Any of formulas to formula (B1-A-33), formula (B1-A-36) to formula (B1-A-40), formula (B1-A-47) to formula (B1-A-55) Anions are better.

Here, R ⁱ² to R ⁱ⁷ are, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group.

R ⁱ⁸ is, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these groups, more preferably is methyl, ethyl, cyclohexyl or adamantyl.

L ⁴⁴ , is a single bond or an alkanediyl group having 1 to 4 carbon atoms.

Q ¹¹ and Q ¹² are the same as above.

Examples of the anions in the salt represented by the formula (B1) include the anions represented by the formulae (Ia-1) to (Ia-34), respectively.

Among them, formula (B1a-1) to formula (B1a-3) and formula (B1a-7) to formula (B1a-16), formula (B1a-18), formula (B1a-19), formula (B1a- An anion represented by any of the formulas 22) to (B1a-34) is preferred.

The cation Z ⁺ in the acid generator (B1) is preferably an organic onium cation. The organic onium cations include organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, organic phosphonium cations, and the like, preferably organic sulfonium cations or organic iodonium cations, more preferably is the arylsulfonium cation.

Among them, a cation represented by any of the formulae (b2-1) to (b2-4) (hereinafter, the corresponding formula number may be referred to as "cation (b2-1)", etc.) is preferable.

In formula (b2-1) to formula (b2-4), R ^b4 to R ^b6 each independently represent an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an alicyclic hydrocarbon group having 6 to 36 carbon atoms. The aromatic hydrocarbon group, the hydrogen atom contained in the aliphatic hydrocarbon group can be substituted with a hydroxyl group, an alkoxy group with a carbon number of 1 to 12, an alicyclic hydrocarbon group with a carbon number of 3 to 12 or an aromatic hydrocarbon group with a carbon number of 6 to 18, The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms or a glycidyloxy group, and the hydrogen atom contained in the aromatic hydrocarbon group A hydrogen atom may be substituted with a halogen atom, a hydroxyl group or an alkoxy group having 1 to 12 carbon atoms.

R ^b4 and R ^b5 together can form a ring containing these bound sulfur atoms, and -CH ₂ - contained in the ring can be substituted into -O-, -S(=O)- or -C(=O)- .

R ^b7 and R ^b8 each independently represent a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbons, or an alkoxy group having 1 to 12 carbons.

m2 and n2 each independently represent any integer of 0 to 5.

When m2 is 2 or more, the plurality of R ^b7 may be the same or different from each other, and when n2 is 2 or more, the plurality of R ^b8 may be the same or different from each other.

R ^b9 and R ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.

R ^b9 and R ^b10 can together form a ring containing these bound sulfur atoms, and -CH ₂ - contained in the ring can be substituted into -O-, -S(=O)- or -C(=O)- .

R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.

R ^b12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aliphatic hydrocarbon group may be 6 to 18 carbon atoms. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms.

R ^b11 and R ^b12 together can form a ring containing the bound -CH-C(=O)-, and the -CH ₂ - contained in the ring can be substituted into -O-, -S(=O)- or -C(=O)-.

R ^b13 to R ^b18 each independently represent a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbons, or an alkoxy group having 1 to 12 carbons.

L ^b31 represents -S- or -O-.

o2, p2, s2, and t2 each independently represent any integer of 0 to 5.

q2 and r2 each independently represent any integer of 0 to 4.

u2 represents 0 or 1.

When o2 is 2 or more, several R ^b13 may be the same or different from each other, when p2 is 2 or more, several R ^b14 may be the same or different from each other, and when q2 is 2 or more, several R b14 ^b15 can be the same or different from each other, when r2 is 2 or more, several R ^b16 can be the same or different from each other, when s2 is 2 or more, several R ^b17 can be the same or different from each other, When t2 is 2 or more, the plurality of R ^b18 may be the same or different from each other.

The aliphatic hydrocarbon group means a chain hydrocarbon group and an alicyclic hydrocarbon group.

Examples of the chain hydrocarbon group include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl alkyl groups.

In particular, the chain hydrocarbon groups of R ^b9 to R ^b12 preferably have 1 to 12 carbon atoms.

Alicyclic hydrocarbon groups may be either monocyclic or polycyclic, and monocyclic alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl cycloalkyl, such as cyclodecyl and cyclodecyl. The polycyclic alicyclic hydrocarbon group includes a decalinyl group, an adamantyl group, a norbornyl group, and the following groups.

In particular, the alicyclic hydrocarbon groups of R ^b9 to R ^b12 are preferably 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.

Alicyclic hydrocarbon groups in which hydrogen atoms are substituted with aliphatic hydrocarbon groups include methylcyclohexyl, dimethylcyclohexyl, 2-methyladamantan-2-yl, 2-ethyladamantan-2-yl, 2-ethyladamantan-2-yl, -Isopropyladamantan-2-yl, methylnorbornyl, isobornyl, etc. In the alicyclic hydrocarbon group in which the hydrogen atom is substituted with an aliphatic hydrocarbon group, the total carbon number of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.

Aromatic hydrocarbon groups include phenyl, tolyl, xylyl, cumyl, mesityl, p-ethylphenyl, p-tert-butylphenyl, p-cyclohexylphenyl, Aryl groups such as p-adamantylphenyl, biphenyl, naphthyl, phenanthryl, 2,6-diethylphenyl, 2-methyl-6-ethylphenyl, etc.

In addition, when a chain hydrocarbon group or an alicyclic hydrocarbon group is contained in the aromatic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms are preferable.

The aromatic hydrocarbon group in which the hydrogen atom is substituted with an alkoxy group includes p-methoxyphenyl and the like.

Aralkyl groups such as benzyl, phenethyl, phenylpropyl, tolyl, naphthylmethyl, and naphthylethyl groups are mentioned as the chain hydrocarbon group in which the hydrogen atom is substituted with an aromatic hydrocarbon group.

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group.

Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group, and the like.

As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned.

The alkylcarbonyloxy group includes methylcarbonyloxy, ethylcarbonyloxy, propylcarbonyloxy, isopropylcarbonyloxy, butylcarbonyloxy, 2-butylcarbonyloxy, tertiary Butylcarbonyloxy, pentylcarbonyloxy, hexylcarbonyloxy, octylcarbonyloxy, 2-ethylhexylcarbonyloxy and the like.

The ring formed by R ^b4 and R ^b5 together with the sulfur atom to which these groups are bonded may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. As this ring, a ring having 3 to 18 carbon atoms is mentioned, and a ring having 4 to 18 carbon atoms is preferable. Meanwhile, the ring containing a sulfur atom includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and examples thereof include the following rings.

The ring formed by R ^b9 and R ^b10 together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. For this ring, a 3-membered ring to a 12-membered ring can be cited, and a 3-membered ring to a 7-membered ring is preferred. For example, thiolane-1-ium ring (tetrahydrothiophenium ring), thiane-1-onium ring, 1,4-oxathiane (1,4-oxathiane) )-4-Onium ring, etc.

The ring formed by R ^b11 and R ^b12 together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. For this ring, a 3-membered ring to a 12-membered ring can be cited, and a 3-membered ring to a 7-membered ring is preferred. A pendant oxycycloheptane ring, pendant oxycyclohexane ring, pendant oxynorbornane ring, pendant oxyadamantane ring, etc. are mentioned.

Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferred.

The cation (b2-1) includes the following cations.

The cation (b2-2) includes the following cations.

The cation (b2-3) includes the following cations.

The cation (b2-4) includes the following cations.

Among them, and with formula (b2-c-1), (b2-c-10), (b2-c-12), (b2-c-14), (b2-c-27), (b2-c- The cations represented by 30) and (b2-c-31) are preferred.

The acid generator (B) includes organic sulfonic acids, organic sulfonium salts, and the like, and examples thereof include JP 2013-68914 A, JP 2013-3155 A, and JP 2013-11905 A Acid generators described in etc. Specifically, what is represented by any one of Formula (B1-1) to Formula (B1-48) can be mentioned. Among them, those containing arylsulfonium salt cations are preferred, and formula (B1-1) to formula (B1-3), formula (B1-5) to formula (B1-7), formula (B1-11) to formula (B1-14), formula (B1-17), formula (B1-20) to formula (B1-26), formula (B1-29), formula (B1-31) to formula (B1-48) A salt represented by either formula is more preferred.

<Structural unit of resin (A)>

The resin (A) contains a structural unit having an acid-labile group (hereinafter also referred to as "structural unit (a1)"). The resin (A) preferably further contains structural units other than the structural unit (a1). Structural units other than the structural unit (a1) include structural units not having an acid-labile group (hereinafter also referred to as "structural unit (s)") and other structural units (hereinafter also referred to as "structural unit (t)"). ).

<Structural unit (a1) having an acid-labile group>

The structural unit (a1) can be derived from a monomer having an acid-labile group (hereinafter also referred to as "monomer (a1)"). Here, the "acid-labile group" refers to a group having a leaving group, and by contacting with an acid, the leaving group is released to form a hydrophilic group (for example, a hydroxyl group or a carboxyl group).

<acid labile group>

In the resin (A), the acid-labile group contained in the structural unit (a1) includes a group represented by the above formula (1), a group represented by the formula (2), and the like.

The monomer (a1) is preferably a monomer having an acid-labile group and an ethylenically unsaturated bond, and more preferably a (meth)acrylic-based monomer having an acid-labile group.

Among the (meth)acrylic-based monomers having an acid-labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferably mentioned. When the resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in a photoresist composition, the resolution of the photoresist pattern can be improved.

<Specific example of structural unit (a1)>

As a structural unit derived from the (meth)acrylic-type monomer which has a group represented by formula (1), the structural unit (henceforth also called structural unit (a1-0) represented by formula (a1-0) is preferable. ), a structural unit represented by formula (a1-1) (hereinafter also referred to as structural unit (a1-1).) or a structural unit represented by formula (a1-2) (hereinafter also referred to as structural unit (a1-2).). These structural units may be used alone or in combination of two or more.

式(a1-0)中，L^a01表示氧原子或^＊-O-(CH₂)_k01-CO-O-，k01表示1至7的任一整數，＊表示與羰基之間的鍵結鍵。

In formula (a1-0), L ^a01 represents an oxygen atom or ^* -O-(CH ₂ ) _k01 -CO-O-, k01 represents any integer of 1 to 7, and * represents a bond with a carbonyl group.

R ^a01 represents a hydrogen atom or a methyl group.

R ^a02 , R ^a03 and R ^a04 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group composed of these groups.

L ^a01 is preferably an oxygen atom or ^* -O-(CH ₂ ) _k01 -CO-O-, more preferably an oxygen atom. k01 is preferably any integer from 1 to 4, more preferably 1.

The alkyl group of R ^a02 , R ^a03 , and R ^a04 , the alicyclic hydrocarbon group, and the group composed of these groups include the same groups as those mentioned for R ^a1 to R ^a3 in the formula (1).

The alkyl group of R ^a02 , R ^a03 and R ^a04 preferably has 6 or less carbon atoms.

The alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^a04 preferably has 3 to 8 carbon atoms, more preferably 3 to 6 carbon atoms.

In the group formed by combining an alkyl group and an alicyclic hydrocarbon group, the total carbon number of the combination of the alkyl group and the alicyclic hydrocarbon group is preferably 18 or less. Examples of such groups include methylcyclohexyl, dimethylcyclohexyl, methylnorbornyl and the like.

R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group or an ethyl group.

R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.

式(a1-1)及式(a1-2)中，L^a1及L^a2分別獨立地表示-O-或^＊-O-(CH₂)_k1-CO-O-，k1表示1至7的任一整數，＊表示與-CO-之間的鍵結鍵。

In formula (a1-1) and formula (a1-2), L ^a1 and L ^a2 each independently represent -O- or ^* -O-(CH ₂ ) _k1 -CO-O-, and k1 represents any one of 1 to 7; An integer, * denotes a bond with -CO-.

R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.

R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these groups.

m1 represents any integer from 0 to 14.

n1 represents any integer from 0 to 10.

n1' represents any integer from 0 to 3.

L ^a1 and L ^a2 are preferably -O- or ^* -O-(CH ₂ ) _k1' -CO-O-, more preferably -O-. k1' is any integer from 1 to 4, preferably 1.

R ^a4 and R ^a5 are preferably methyl groups.

The alkyl groups of R ^a6 and R ^a7 include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, and n-hexyl , n-heptyl, 2-ethylhexyl, n-octyl, etc.

The alicyclic hydrocarbon group of R ^a6 and R ^a7 may be either monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group includes, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclo Cycloalkyl groups such as hexyl, methylcyclohexyl, dimethylcyclohexyl, cyclooctyl, cycloheptyl, and cyclodecyl. The polycyclic alicyclic hydrocarbon group includes, for example, decalinyl, adamantyl, 2-alkyladamantan-2-yl, 1-(adamantan-1-yl)alkyl, norbornyl, Methyl norbornyl and isobornyl, etc.

An aralkyl group is mentioned as a group formed by combining the alkyl group of R ^a6 and R ^a7 with an alicyclic hydrocarbon group, and a benzyl group, a phenethyl group, etc. are mentioned.

The carbon number of the alkyl group of R ^a6 and R ^a7 is preferably 6 or less.

The carbon number of the alicyclic hydrocarbon group of R ^a6 and R ^a7 is preferably 3 to 8, more preferably 3 to 6.

m1 is preferably any integer from 0 to 3, more preferably 0 or 1.

n1 is preferably any integer from 0 to 3, more preferably 0 or 1.

n1' is preferably 0 or 1.

The structural unit (a1-0) is preferably a structural unit represented by any one of the formulae (a1-0-1) to (a1-0-12), for example, and the structural unit (a1-0-1) to the formula The structural unit represented by any one of the formulas (a1-0-10) is more preferable.

In the above formulae (a1-0-1) to (a1-0-12), the structural unit in which the methyl group corresponding to R ^a01 is substituted with a hydrogen atom can also be mentioned as a specific example of the structural unit (a1-0). .

As a structural unit (a1-1), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Preferred are structural units represented by any of the formulae (a1-1-1) to (a1-1-8).

The structural unit (a1-2) is preferably a monomer represented by any of the formulae (a1-2-1) to (a1-2-12), and is represented by the formula (a1-2-3), the formula (a1) -2-4), the monomer represented by formula (a1-2-9) or formula (a1-2-10) is more preferable.

When the resin (A) contains the structural unit (a1-0) and/or the structural unit (a1-1) and/or the structural unit (a1-2), the total of the total structural units of the resin (A), these structural units The total content rate of the powder is usually 10 to 95 mol %, preferably 15 to 90 mol %, and more preferably 20 to 85 mol %.

As the structural unit (a1) having an acid-labile group, a structural unit represented by the formula (a1-5) (hereinafter also referred to as "structural unit (a1-5)") can be used.

式(a1-5)中，R^a8表示可具有鹵素原子的碳數1至6之烷基、氫原子或鹵素原子。

In formula (a1-5), R ^a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.

Z ^a1 represents a single bond or *-(CH ₂ ) _h3 -CO-L ⁵⁴ -, h3 represents any integer of 1 to 4, and * represents a bond with L ⁵¹ .

L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent -O- or -S-.

s1 represents any integer of 1 to 3.

s1' represents any integer from 0 to 3.

In the formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.

The L ⁵¹ series is preferably -O-.

In L ⁵² and L ⁵³ , it is preferable that one is -O- and the other is -S-.

s1 series to 1 is better.

s1' is preferably any integer from 0 to 2.

Z ^a1 is preferably a single bond or *-CH ₂ -CO-O-.

As the monomer from which the structural unit (a1-5) is derived, for example, the monomer described in JP-A-2010-61117 can be mentioned. Among them, the structural unit represented by any one of formula (a1-5-1) to formula (a1-5-4) is preferred, and formula (a1-5-1) or formula (a1-5-2) The represented structural unit is better.

When the resin (A) has structural units (a1-5), its content is preferably 1 to 50 mol % relative to the total of the total structural building units of the resin (A), and 3 to 45 mol % More preferably, and even more preferably at 5 to 40 mol %.

Moreover, as a structural unit (a1), the following structural units are mentioned.

When the resin (A) contains the above-mentioned structural units, the content of the resin (A) is preferably 10 to 95 mol %, more preferably 15 to 90 mol %, and 20 to 90 mol % relative to the total structural units of the resin (A). 85 mol% is better.

The structural unit (a1) having an acid-labile group in the resin (A) is selected from structural unit (a1-0), structural unit (a1-1), structural unit (a1-2) and structural unit (a1- 5) At least one of the formed groups is preferred, and at least two or more are more preferred, and the combination of the structural unit (a1-1) and the structural unit (a1-2), the structural unit (a1- 1) Combination of structural unit (a1-5), combination of structural unit (a1-1) and structural unit (a1-0), combination of structural unit (a1-2) and structural unit (a1-0), structure Combination of Unit (a1-5) and Structural Unit (a1-0), Structural Unit (a1-0), Combination of Structural Unit (a1-1) and Structural Unit (a1-2), Structural Unit (a1-0) , the combination of the structural unit (a1-1) and the structural unit (a1-5) is even better, and the combination of the structural unit (a1-1) and the structural unit (a1-2), the structural unit (a1-1) and A combination of structural units (a1-5) is particularly preferred.

<Structural unit (s) having no acid-labile group>

The structural unit (s) can be derived from a monomer having no acid-labile group (hereinafter also referred to as "monomer (s)"). As the monomer (s) from which the structural unit (s) is derived, a monomer having no acid-labile group known in the photoresist field can be used.

The structural unit (s) is preferably a structural unit having a hydroxyl group or a lactone ring and not having an acid-labile group. If a structural unit having a hydroxyl group and no acid-labile group (hereinafter also referred to as "structural unit (a2)") and/or a structural unit having a lactone ring and no acid-labile group (hereinafter also referred to as "structural unit (a2)") is included When the resin of the unit (a3)") is used in the photoresist composition of the present invention, the resolution of the photoresist pattern and the adhesion with the substrate can be improved.

<Structural unit (a2)>

The hydroxyl group which the structural unit (a2) has may be a phenolic hydroxyl group or an alcoholic hydroxyl group.

When manufacturing a photoresist pattern from the photoresist composition of the present invention, when high-energy rays such as KrF excimer laser (248 nm), electron beam or EUV (Extreme Ultraviolet) are used as the exposure light source, the photoresist structure contains a structure having a phenolic hydroxyl group. The unit (a2) is preferably used as the structural unit (a2). Meanwhile, when using an ArF excimer laser (193 nm) or the like, it is preferable to include a structural unit (a2) having an alcoholic hydroxyl group as the structural unit (a2), and to include a structural unit represented by the following formula (a2-1) better. The structural unit (a2) may be contained alone or two or more types may be contained.

As a structural unit (a2) which has a phenolic hydroxyl group, the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-204634 is mentioned, for example.

When the resin (A) has a structural unit (a2-0) having a phenolic hydroxyl group, its content is preferably 5 to 95 mol % relative to the total structural unit of the resin (A), and is preferably 10 to 80 mol %. Ear% is better, and 15 to 80 mole% is even better.

The structural unit (a2) having an alcoholic hydroxyl group includes a structural unit represented by the formula (a2-1) (hereinafter also referred to as "structural unit (a2-1)".

式(a2-1)中，L^a3表示-O-或＊-O-(CH₂)_k2-CO-O-，k2表示1至7的任一整數。＊表示與-CO-之間的鍵結鍵。

In formula (a2-1), L ^a3 represents -O- or *-O-(CH ₂ ) _k2 -CO-O-, and k2 represents any integer of 1 to 7. * indicates a bond with -CO-.

R ^a14 represents a hydrogen atom or a methyl group.

R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxyl group.

o1 represents any integer from 0 to 10.

In formula (a2-1), L ^a3 is preferably -O-, -O-(CH ₂ ) _f1 -CO-O- (the aforementioned f1 is any integer of 1 to 4), and -O- better.

R ^a14 is preferably methyl.

R ^a15 is preferably a hydrogen atom.

R ^a16 is preferably a hydrogen atom or a hydroxyl group.

o1 is preferably any integer from 0 to 3, more preferably 0 or 1.

Structural unit (a2-1), for example, the structural unit described in Japanese Patent Laid-Open No. 2010-204646 and represented by any one of formula (a2-1-1) to formula (a2-1-6) can be exemplified Preferably, the structural unit represented by any one of formula (a2-1-1) to formula (a2-1-4) is more preferable, and formula (a2-1-1) or formula (a2-1-3) ) represented by the structural unit is even better.

As a monomer which derives the structural unit (a2) which has an alcoholic hydroxyl group, the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example.

When the resin (A) contains the structural unit (a2) having an alcoholic hydroxyl group, the content thereof is usually 1 to 45 mol %, preferably 1 to 40 mol %, relative to all the structural units of the resin (A). , more preferably 1 to 35 mol %, and still more preferably 2 to 20 mol %.

<Structural unit (a3)>

The lactone ring possessed by the structural unit (a3) may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, a δ-valerolactone ring, or a monocyclic lactone ring and others. The condensed ring of the ring, the lactone ring, preferably includes a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring including a γ-butyrolactone ring structure.

The structural unit (a3) is preferably a structural unit represented by any one of the formulae (a3-1) to (a3-4). The resin (A) may contain a single type of these structural units, or may contain two or more types.

式(a3-1)中，L^a4表示-O-或＊-O-(CH₂)_k3-CO-O-(k3表示1至7的任一整數。)表示的基。＊表示與羰基之間的鍵結鍵。

In formula (a3-1), L ^a4 represents a group represented by -O- or *-O-(CH ₂ ) _k3 -CO-O- (k3 represents any integer of 1 to 7.). * represents a bond with a carbonyl group.

R ^a18 represents a hydrogen atom or a methyl group.

R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

p1 represents any integer from 0 to 5. When p1 is 2 or more, several R ^a21 may be the same or different from each other.

In formula (a3-2), L ^a5 represents a group represented by -O- or *-O-(CH ₂ ) _k3 -CO-O- (k3 represents any integer of 1 to 7.). * represents a bond with a carbonyl group.

R ^a19 represents a hydrogen atom or a methyl group.

R ^a22 represents a carboxyl group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

q1 represents any integer of 0 to 3. When q1 is 2 or more, several R ^a22 may be the same or different from each other.

In formula (a3-3), L ^a6 represents a group represented by -O- or *-O-(CH ₂ ) _k3 -CO-O- (k3 represents any integer of 1 to 7.). * represents a bond with a carbonyl group.

R ^a20 represents a hydrogen atom or a methyl group.

R ^a23 represents a carboxyl group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

r1 represents any integer from 0 to 3. When r1 is 2 or more, several R ^a23 may be the same or different from each other.

In formula (a3-4), R ^a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.

L ^a7 represents *-O-, *-OL ^a8 -O-, *-OL ^a8 -CO-O-, *-OL ^a8 -CO-OL ^a9 -CO-O- or *-OL ^a8 -O-CO- L ^a9 -O-.

* indicates a bond with a carbonyl group.

R ^a25 represents a carboxyl group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.

w represents any integer from 0 to 8.

L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms.

Aliphatic hydrocarbon groups of R ^a21 , R ^a22 , R ^a23 and R ^a25 include alkanes such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl and tert-butyl base.

The halogen atom of R ^a24 includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

The alkyl group of R ^a24 includes methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl and n-hexyl, and the like, and An alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.

The alkyl group having a halogen atom of R ^a24 includes trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluoro2-butyl, perfluoro3 Butyl, perfluoropentyl, perfluorohexyl, trichloromethyl, tribromomethyl, triiodomethyl, etc.

Alkanediyl of L ^a8 and L ^a9 . , methylene, ethylidene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, Hexane-1,6-diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1 ,4-diyl and 2-methylbutane-1,4-diyl, etc.

In the formula (a3-1) to the formula (a3-3), L ^a4 to L ^a6 are independent of each other and -O- or k3 is any integer of 1 to 4 *-O-(CH ₂ ) _k3 - The base represented by CO-O- is preferred, and -O- and *-O-CH ₂ -CO-O- are more preferred, and -O- is more preferred.

R ^a18 to R ^a21 are preferably methyl groups.

R ^a22 to R ^a23 , independently of each other, are preferably a carboxyl group, a cyano group or a methyl group.

p1, q1, r1 and w are each independently an integer of 0 to 2, preferably any integer, more preferably 0 or 1.

In formula (a3-4), R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.

L ^a7 is preferably *-O- or *-OL ^a8 -CO-O-, and is preferably *-O-, *-O-, *-O-CH ₂ -CO-O- or *-OC ₂ H ₄ -CO-O- is more preferred.

The formula (a3-4) is preferably the formula (a3-4').

式中，R^a24、L^a7表示與上述相同。

In the formula, R ^a24 and L ^a7 represent the same as above.

The monomers from which the structural unit (a3) is derived include the monomers described in JP 2010-204646 A, the monomers described in JP 2000-122294 A, and the monomers described in JP 2012-41274 A single recorded. Structural unit (a3) is represented by formula (a3-1-1) to formula (a3-1-4), formula (a3-2-1) to formula (a3-2-4), formula (a3-3-1) ) to formula (a3-3-4) and formula (a3-4-1) to formula (a3-4-12) The structural unit represented by any of the formulas is preferred, and is represented by formula (a3-1-1), formula Structural units represented by any of the formulas (a3-1-2), formula (a3-2-3) to formula (a3-2-4) and formula (a3-4-1) to formula (a3-4-12) More preferably, the structural unit represented by any one of formula (a3-4-1) to formula (a3-4-12) is even more preferable, and formula (a3-4-1) to formula (a3-4- The structural unit represented by any of the formulas 6) is the most preferable.

The structural unit (a3) may be contained alone or two or more types may be contained. The structural unit (a3) includes the following structural units.

Among the structural units represented by the above formulae (a3-4-1) to (a3-4-12), compounds in which the methyl group corresponding to R ^a24 is substituted with a hydrogen atom can also be mentioned as the structural unit (a3-4) specific example.

When the resin (A) contains the structural unit (a3), the total content relative to the total structural unit of the resin (A) is usually 5 to 70 mol %, preferably 10 to 65 mol %, and 10 mol %. More preferably to 60 mol%.

The respective contents of the structural units represented by the formula (a3-1), the formula (a3-2), the formula (a3-3) and the formula (a3-4) with respect to the total structural units of the resin (A) are usually 5 to 60 mol %, preferably 5 to 50 mol %, more preferably 10 to 50 mol %.

<Other structural unit (t)>

Resin (A) may further contain other structural unit (t). The structural unit (t), which is a structural unit other than the structural unit (a2) and the structural unit (a3), includes a structural unit having a halogen atom (hereinafter, also referred to as "structural unit (a4)" as appropriate.) and a structural unit having A structural unit (hereinafter also referred to as "structural unit (a5)") that does not leave a hydrocarbon group, etc.

<Structural unit (a4)>

The halogen atom in the structural unit (a4) is preferably a fluorine atom. As a structural unit (a4), the structural unit represented by formula (a4-0) is mentioned.

式(a4-0)中，R⁵表示氫原子或甲基。

In formula (a4-0), R ⁵ represents a hydrogen atom or a methyl group.

L ⁵ represents a single bond or an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.

L ³ represents a perfluoroalkanediyl group having 1 to 8 carbons or a perfluorocycloalkanediyl group having 5 to 12 carbons.

R ⁶ represents a hydrogen atom or a fluorine atom.

The aliphatic saturated hydrocarbon group of L ⁵ includes an alkanediyl group having 1 to 4 carbon atoms, for example, a methylene group, an ethylidene group, a propane-1,3-diyl group, and a butane-1,4-diyl group. Linear alkanediyl such as radicals, linear alkanediyl having a side chain of an alkyl group (among them, methyl, ethyl, etc.), ethane-1,1-diyl, propane-1,2 Branched alkanediyl such as -diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl and 2-methylpropane-1,2-diyl.

^The perfluoroalkanediyl group of L3 includes difluoromethylene, perfluoroethylidene, perfluoroethylfluoromethylene, perfluoropropane-1,3-diyl, perfluoropropane-1, 2-diyl, perfluoropropane-2,2-diyl, perfluorobutane-1,4-diyl, perfluorobutane-2,2-diyl, perfluorobutane-1,2-diyl base, perfluoropentane-1,5-diyl, perfluoropentane-2,2-diyl, perfluoropentane-3,3-diyl, perfluorohexane-1,6-diyl, perfluorohexane-2,2-diyl, perfluorohexane-3,3-diyl, perfluoroheptane-1,7-diyl, perfluoroheptane-2,2-diyl, perfluoroheptane-2,2-diyl Heptane-3,4-diyl, perfluoroheptane-4,4-diyl, perfluorooctane-1,8-diyl, perfluorooctane-2,2-diyl, perfluorooctane -3,3-diyl, perfluorooctane-4,4-diyl, etc.

The perfluorocycloalkanediyl group of L ³ includes a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantanediyl group, and the like.

L ⁵ is preferably a single bond, a methylene group or an ethylidene group, and more preferably a single bond or a methylene group.

The L ³ series is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

As a structural unit (a4-0), the following are mentioned, for example.

Among the above-mentioned structural units, a structural unit in which a methyl group corresponding to R ⁵ is substituted with a hydrogen atom can also be mentioned as a specific example of the structural unit (a4-0).

The structural unit (a4) includes the structural unit represented by the formula (a4-1).

式(a4-1)中，R^a41表示氫原子或甲基。

In formula (a4-1), R ^a41 represents a hydrogen atom or a methyl group.

R ^a42 represents an optionally substituted hydrocarbon group having 1 to 20 carbon atoms, and -CH ₂ - contained in the hydrocarbon group may be substituted with -O- or -CO-.

A ^a41 represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (a-g1). However, at least one of A ^a41 and R ^a42 has a halogen atom (preferably a fluorine atom) as a substituent.

式(a-g1)中，s表示0或1。

In formula (a-g1), s represents 0 or 1.

A ^a42 and A ^a44 each independently represent a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.

A ^a43 represents an optionally substituted divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms or a single bond.

X ^a41 and X ^a42 each independently represent -O-, -CO-, -CO-O- or -O-CO-.

However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 6 or less.

*, ** is a bond, and * is a bond with -O-CO-R ^a42 .

However, at least one of A ^a41 and R ^a42 is a group having a halogen atom as a substituent.

s is preferably 0.

The hydrocarbon group of R ^a42 includes chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed from these groups. Chain aliphatic hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, hexadecyl, and pentadecyl , hexyldecyl, heptadecyl and octadecyl alkyl groups. Cyclic aliphatic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; decahydronaphthyl, adamantyl, norbornyl, and the following groups (* denotes a bond) bond.) and other polycyclic alicyclic hydrocarbon groups.

The aromatic hydrocarbon group includes, for example, a phenyl group, a naphthyl group, an anthracenyl group, a biphenyl group, a phenanthryl group, and a perylene group.

The hydrocarbon group of R ^a42 is preferably a chain or cyclic aliphatic hydrocarbon group and a group formed by combining these groups. Although these groups may have a carbon-carbon unsaturated bond, chain and cyclic aliphatic saturated hydrocarbon groups and groups formed by combining these groups are more preferable.

The substituent of R ^a42 includes a halogen atom and a group represented by the formula (a-g3). The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a preferable one includes a fluorine atom.

*-X ^a43 -A ^a45 (a-g3) In the formula (a-g3), X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group.

A ^a45 represents an aliphatic hydrocarbon group having at least one halogen atom having 1 to 17 carbon atoms.

* represents a bond with the hydrocarbon group of R ^a42 .

The aliphatic hydrocarbon group of A ^a45 is the same as the aliphatic hydrocarbon group exemplified in R ^a42 .

R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, and more preferably an alkyl group having a halogen atom and/or an aliphatic hydrocarbon group having a group represented by formula (a-g3).

When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and a perfluoroalkyl group having 1 to 6 carbon atoms Still more preferable, and a perfluoroalkyl group having 1 to 3 carbon atoms is particularly preferable. The perfluoroalkyl group includes perfluoromethyl, perfluoroethyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, perfluorohexyl, perfluoroheptyl, and perfluorooctyl. The perfluorocycloalkyl group includes a perfluorocyclohexyl group and the like.

When R ^a42 is an aliphatic hydrocarbon group having a group represented by the formula (a-g3), it includes the number of carbon atoms contained in the group represented by the formula (a-g3), and the total carbon number of the aliphatic hydrocarbon group is preferably 15 or less, And below 12 is better. When having a group represented by formula (a-g3) as a substituent, the number is preferably one.

The aliphatic hydrocarbon group having the group represented by the formula (a-g3) is more preferably a group represented by the formula (a-g2).

*-A ^a46 -X ^a44 -A ^a47 (a-g2) In formula (a-g2), A ^a46 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.

X ^a44 represents carbonyloxy or oxycarbonyl.

A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.

However, the total number of carbon atoms of A ^a46 , A ^a47 and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.

* indicates a bond with a carbonyl group.

The carbon number of the aliphatic hydrocarbon group of A ^a46 is preferably 1 to 6, more preferably 1 to 3.

The carbon number of the aliphatic hydrocarbon group of A ^a47 is preferably 4 to 15, more preferably 5 to 12, and more preferably cycloalkyl or adamantyl.

The groups represented by the formula (a-g2) include the following groups.

As the alkanediyl group of A ^a41 , methylene group, ethylidene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane- Linear alkanediyl such as 1,6-diyl; propane-1,2-diyl, butane-1,3-diyl, 2-methylpropane-1,2-diyl, 1-methyl Branched alkanediyl such as butane-1,4-diyl and 2-methylbutane-1,4-diyl.

The substituent in the alkanediyl group of A ^a41 includes a hydroxyl group and an alkoxy group having 1 to 6 carbon atoms.

A ^a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having a carbon number of 2 to 4, and more preferably an ethylidene group.

The aliphatic hydrocarbon groups of A ^a42 , A ^a43 , and A ^a44 in the group represented by the formula (a-g1) (hereinafter, also referred to as "group (a-g1)" in some cases.) include a methylene group and an ethylidene group. base, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, 1-methylpropane-1,3-diyl, 2-methylpropane-1 , 3-diyl, 2-methylpropane-1,2-diyl, etc. As such a substituent, a hydroxyl group and an alkoxy group having 1 to 6 carbon atoms, etc. are mentioned.

X ^a42 is a group (a-g1) of an oxygen atom, and the following groups etc. are mentioned. In the following examples, * and ** represent a bond, respectively, and ** is a bond with -O-CO-R ^a42 .

The group (a-g1) in which X ^a42 is a carbonyl group includes the following groups and the like.

The group (a-g1) in which X ^a42 is a carbonyloxy group includes the following groups and the like.

A group (a-g1) in which X ^a42 is an oxycarbonyl group includes the following groups and the like.

The structural unit represented by the formula (a4-1) is preferably the structural unit represented by the formula (a4-2) and the formula (a4-3).

式(a4-2)中，R^f1表示氫原子或甲基。

In formula (a4-2), R ^f1 represents a hydrogen atom or a methyl group.

A ^f1 represents an alkanediyl group having 1 to 6 carbon atoms.

R ^f2 represents a hydrocarbon group of 1 to 10 carbon atoms having a fluorine atom.

The alkanediyl group of A ^f1 includes a methylene group, an ethylidene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1 group. ,5-diyl, hexane-1,6-diyl and other linear alkanediyl; 1-methylpropane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,3-diyl - Branched alkanediyl such as methylpropane-1,2-diyl, 1-methylbutane-1,4-diyl, 2-methylbutane-1,4-diyl.

The hydrocarbon group of R ^f2 includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and the aliphatic hydrocarbon group includes a chain type, a cyclic type, and a group formed by combining these. The aliphatic hydrocarbon group is preferably an alkyl group or an alicyclic hydrocarbon group.

The alkyl group includes methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl and 2-ethylhexyl.

Alicyclic hydrocarbon groups may be either monocyclic or polycyclic, and monocyclic alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, Cycloalkyl groups such as dimethylcyclohexyl, cyclooctyl, cycloheptyl, and cyclodecyl. The polycyclic alicyclic hydrocarbon group includes decahydronaphthyl, adamantyl, 2-alkyladamantan-2-yl, 1-(adamantan-1-yl)alkan-1-yl, and norbornyl base, methyl norbornyl and isobornyl.

Examples of the hydrocarbon group having a fluorine atom for R ^f2 include an alkyl group having a fluorine atom, an alicyclic hydrocarbon group having a fluorine atom, and the like.

Specifically, the alkyl group having a fluorine atom includes difluoromethyl, trifluoromethyl, 1,1-difluoroethyl, 2,2-difluoroethyl, and 2,2,2-trifluoroethyl base, perfluoroethyl, 1,1,2,2-tetrafluoropropyl, 1,1,2,2,3,3-hexafluoropropyl, perfluoroethylmethyl, 1-(trifluoromethyl base)-1,2,2,2-tetrafluoroethyl, perfluoropropyl, 1,1,2,2-tetrafluorobutyl, 1,1,2,2,3,3-hexafluorobutyl , 1,1,2,2,3,3,4,4-octafluorobutyl, perfluorobutyl, 1,1-bis(trifluoro)methyl-2,2,2-trifluoroethyl, 2-(Perfluoropropyl)ethyl, 1,1,2,2,3,3,4,4-octafluoropentyl, perfluoropentyl, 1,1,2,2,3,3,4 ,4,5,5-Decafluoropentyl, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl, perfluoropentyl, 2-(perfluorobutyl) base) ethyl, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl, 1,1,2,2,3,3,4,4,5,5,6 , Fluorinated alkyl groups such as 6-dodecafluorohexyl, perfluoropentylmethyl and perfluorohexyl.

The alicyclic hydrocarbon group having a fluorine atom includes fluorinated cycloalkyl groups such as perfluorocyclohexyl and perfluoroadamantyl.

In formula (a4-2), A ^f1 is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylidene group.

R ^f2 is preferably a fluorinated alkyl group having 1 to 6 carbon atoms.

式(a4-3)中，R^f11表示氫原子或甲基。

In formula (a4-3), R ^f11 represents a hydrogen atom or a methyl group.

A ^f11 represents an alkanediyl group having 1 to 6 carbon atoms.

A ^f13 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a fluorine atom.

X ^f12 represents carbonyloxy or oxycarbonyl.

A ^f14 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom.

However, at least one of A ^f13 and A ^f14 represents an aliphatic hydrocarbon group having a fluorine atom.

Examples of the alkanediyl group of A ^f11 include the same groups as those of the alkanediyl group of A ^f1 .

The aliphatic hydrocarbon group of A ^f13 includes either a chain formula or a cyclic formula, and a bivalent aliphatic hydrocarbon group formed by combining these. Although this aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, a saturated aliphatic hydrocarbon group is preferable.

The aliphatic hydrocarbon group which may have a fluorine atom of A ^f13 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group.

Divalent chain aliphatic hydrocarbon groups which may have a fluorine atom include alkanediyl groups such as methylene, ethylidene, propanediyl, butanediyl, and pentanediyl; difluoromethylene, all Perfluoroalkanediyl such as fluoroethylene, perfluoropropanediyl, perfluorobutanediyl, and perfluoropentanediyl, etc.

The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. The monocyclic aliphatic hydrocarbon group includes a cyclohexanediyl group, a perfluorocyclohexanediyl group, and the like. The polycyclic divalent aliphatic hydrocarbon group includes an adamantanediyl group, a norbornanediyl group, a perfluoroadamantanediyl group, and the like.

The aliphatic hydrocarbon group of A ^f14 includes either a chain formula or a cyclic formula, and an aliphatic hydrocarbon group formed by combining these. Although this aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, a saturated aliphatic hydrocarbon group is preferable.

The aliphatic hydrocarbon group which may have a fluorine atom of A ^f14 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom.

The chain aliphatic hydrocarbon group which may have a fluorine atom includes trifluoromethyl, difluoromethyl, methyl, perfluoroethyl, 1,1,1-trifluoroethyl, 1,1,2,2 - Tetrafluoroethyl, ethyl, perfluoropropyl, 1,1,1,2,2-pentafluoropropyl, propyl, perfluorobutyl, 1,1,2,2,3,3,4 ,4-Octafluorobutyl, butyl, 1,1,1,2,2,3,3,4,4-nonafluoropentyl, perfluoropentyl, pentyl, hexyl, perfluorohexyl, heptyl , perfluoroheptyl, octyl and perfluorooctyl, etc.

The cycloaliphatic hydrocarbon group which may have a fluorine atom may be any of a monocyclic type and a polycyclic type. Examples of the monocyclic aliphatic hydrocarbon group-containing group include cyclopropylmethyl, cyclopropyl, cyclobutylmethyl, cyclopentyl, cyclohexyl, and perfluorocyclohexyl. The polycyclic aliphatic hydrocarbon group-containing group includes an adamantyl group, an adamantylmethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, a perfluoroadamantylmethyl group, and the like.

In the formula (a4-3), A ^f11 is preferably an ethylidene group.

The aliphatic hydrocarbon group of A ^f13 is preferably 1 to 6 carbon atoms, more preferably 2 to 3 carbon atoms.

The aliphatic hydrocarbon group of A ^f14 is preferably 3 to 12 carbon atoms, more preferably 3 to 10 carbon atoms. Among them, A ^f14 is preferably an alicyclic hydrocarbon group containing 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group.

The structural unit represented by the formula (a4-2) includes, for example, the structural unit shown below and a structural unit in which a methyl group corresponding to R ^f1 in the following structural unit is substituted with a hydrogen atom.

The structural unit represented by the formula (a4-3) includes, for example, the structural unit shown below and a structural unit in which the methyl group corresponding to R ^f11 in the following structural unit is substituted with a hydrogen atom.

As the structural unit (a4), for example, the following structural units and structural units in which a methyl group bonded to the main chain is substituted with a hydrogen atom are also exemplified.

When the resin (A) has a structural unit (a4), its content is preferably 1 to 20 mol %, more preferably 2 to 15 mol % relative to the total structural unit of the resin (A), and 3 to 10 mol % is still better.

<Structural unit (a5)>

The non-leaving hydrocarbon group possessed by the structural unit (a5) includes a linear, branched or cyclic hydrocarbon group, and an alicyclic hydrocarbon group is preferred. The structural unit (a5) includes, for example, the structural unit represented by the formula (a5-1).

式(a5-1)中，R⁵¹表示氫原子或甲基。

In formula (a5-1), R ⁵¹ represents a hydrogen atom or a methyl group.

R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. However, the hydrogen atom bound to the carbon atom at the binding site of L ⁵⁵ cannot be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.

L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the methylene group contained in the saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group.

The alicyclic hydrocarbon group of R ⁵² may be either monocyclic or polycyclic. The monocyclic alicyclic hydrocarbon group includes, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. As a polycyclic alicyclic hydrocarbon group, an adamantyl group, a norbornyl group, etc. are mentioned, for example.

Aliphatic hydrocarbon groups having 1 to 8 carbon atoms include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl group and alkyl groups such as 2-ethylmethyl.

The alicyclic hydrocarbon group having a substituent includes a 3-methyladamantyl group and the like.

R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

The divalent saturated hydrocarbon group of ^L55 includes a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and a divalent aliphatic saturated hydrocarbon group is preferable.

The divalent aliphatic saturated hydrocarbon group includes, for example, an alkanediyl group such as a methylene group, an ethylidene group, a propanediyl group, a butanediyl group, and a pentanediyl group.

The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. The monocyclic alicyclic saturated hydrocarbon group includes cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl. The polycyclic divalent alicyclic saturated hydrocarbon group includes an adamantanediyl group, a norbornanediyl group, and the like.

The group in which the methylene group contained in the saturated hydrocarbon group is substituted with an oxygen atom or a carbonyl group includes, for example, groups represented by formula (L1-1) to formula (L1-4). In the following formula, * represents a bond with an oxygen atom.

式(L1-1)中，X^x1表示羰基氧基或氧基羰基。

In formula (L1-1), X ^x1 represents a carbonyloxy group or an oxycarbonyl group.

L ^x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.

L ^x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.

However, the total carbon number of L ^x1 and L ^x2 is 16 or less.

In formula (L1-2), L ^x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms.

L ^x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms.

However, the total carbon number of ^Lx3 and ^Lx4 is 17 or less.

In formula (L1-3), L ^x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms.

L ^x6 and L ^x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms.

However, the total carbon number of L ^x5 , L ^x6 and L ^x7 is 15 or less.

In formula (L1-4), L ^x8 and L ^x independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.

W ^x1 represents a divalent aliphatic saturated hydrocarbon group having 3 to 15 carbon atoms.

However, the total carbon number of L ^x8 , L ^x9 and W ^x1 is 15 or less.

L ^x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylidene group.

L ^x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond.

The L ^x3 series is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.

The L ^x4 series is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.

The L ^x5 series is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylidene group.

L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylidene group.

The L ^x7 series is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.

L ^x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.

L ^x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.

W ^x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, and more preferably a cycloalkanediyl group or adamantanediyl group.

The group represented by the formula (L1-1) includes, for example, a divalent group represented by the following formula.

The group represented by the formula (L1-2) includes, for example, a divalent group represented by the following formula.

The group represented by the formula (L1-3) includes, for example, a divalent group represented by the following formula.

The group represented by the formula (L1-4) includes, for example, a divalent group represented by the following formula.

L ⁵⁵ is preferably a single bond, a methylene group, an ethylidene group or a group represented by the formula (L1-1), and more preferably a single bond or a group represented by the formula (L1-1).

The structural unit (a5-1) includes, for example, a structural unit represented by the following formula and a structural unit in which the methyl group corresponding to R ⁵¹ in the following structural unit is substituted with a hydrogen atom.

When the resin (A) has the structural unit (a5), the content of the structural unit of the resin (A) is preferably 1 to 30 mol %, more preferably 2 to 20 mol %, and 3 to 3 mol %. 15 mol% is even better.

The resin (A) may have structural units other than the above-mentioned structural units, and such structural units include those known in the technical field.

<Resin (A)>

The resin (A) is preferably a resin composed of the structural unit (a1) and the structural unit (s), that is, a copolymer of the monomer (a1) and the monomer (s).

The structural unit (a1) is preferably at least one selected from the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group), and the structure The unit (a1-1) or at least two kinds selected from the structural unit (a1-1) and the structural unit (a1-2) (preferably a structural unit having a cyclohexyl group and a cyclopentyl group) are more preferable.

The structural unit (s) is preferably at least one of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably a structural unit represented by the formula (a2-1). The structural unit (a3) is selected from the structural unit represented by the formula (a3-1-1) to the formula (a3-1-4), the formula (a3-2-1) to the formula (a3-2-4) and the formula At least one of the structural units represented by (a3-4-1) to formula (a3-4-2) is preferred.

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and can be produced by a known polymerization method (eg, radical polymerization method) using a monomer from which these structural units are derived. The content rate of each structural unit which resin (A) has can be adjusted by the usage-amount of the monomer used for superposition|polymerization.

The weight average molecular weight of the resin (A) is preferably 2,000 or more (preferably 2,500 or more, more preferably 3,000 or more) and 50,000 or less (preferably 30,000 or less, more preferably 15,000 or less). In this specification, the weight-average molecular weight is a value obtained by using a gel permeation chromatograph under the conditions described in the examples.

<Resin (X) other than resin (A)>

The photoresist composition of this invention may contain resin (X) other than resin (A), and it does not contain the structural unit (a1) which has an acid-labile group. As such resin (X), the resin containing a structural unit (t) is mentioned, for example.

The resin (X) is preferably a resin containing the structural unit (a4) exemplified as the structural unit (t). In the resin (X), for the total structural units of the resin (X), the content of the structural unit (a4) is preferably 40 mol % or more, more preferably 45 mol % or more, and 50 mol %. The above is even better.

As a structural unit which resin (X) may have separately, the structural unit (a2) which does not have an acid-labile group, the structural unit (a3), and the structural unit derived from another known monomer are mentioned.

The weight average molecular weight of the resin (X) is preferably 8,000 or more (more preferably 10,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weight of the resin (X) is the same as that of the resin (A).

When the photoresist composition contains resin (X), for 100 parts by mass of resin (A), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, and 1 to 40 parts by mass It is still more preferable, and it is still more preferable that it is 1-20 mass parts, and it is still more preferable that it is 1.5-10 mass parts.

It is preferable that the total content rate of resin (A) and resin (X) is 80 mass % or more and 99 mass % or less with respect to the solid content of a photoresist composition. The solid content of the photoresist composition and the content ratio of the resin relative thereto can be measured by known analytical means such as a liquid chromatography or a gas chromatography.

<Solvent (E)>

In the photoresist composition, the content of the solvent (E) is usually 90 mass % or more, preferably 92 mass % or more, more preferably 94 mass % or more, 99.9 mass % or less, and 99 mass % or less. better. The content of the solvent (E) can be measured by known analytical means such as a liquid chromatograph or a gas chromatograph.

The solvent (E) includes glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate; and glycol ethers such as propylene glycol monomethyl ether; Esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone ;Wait. A solvent (E) may be contained individually by 1 type, and may contain 2 or more types.

<Quenching agent (C)>

The quenching agent (C) includes a basic nitrogen-containing organic compound or a salt of an acid whose acidity is lower than that of an acid generated by an acid generator. The content of the quenching agent (C) is preferably about 0.01 to 5 mass % based on the solid content of the photoresist composition.

<Alkaline nitrogen-containing organic compound>

The basic nitrogen-containing organic compounds include amines and ammonium salts. The amines include aliphatic amines and aromatic amines. The aliphatic amines include primary amines, secondary amines, and tertiary amines.

Amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N-methylaniline, ,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine , dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, triamylamine, trihexylamine, triheptylamine, Trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyl Dioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldibutylamine Octylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, gins[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, Ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'- Dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine , 4-methylpyridine, 1,2-bis(2-pyridyl)ethane, 1,2-bis(4-pyridyl)ethane, 1,2-bis(2-pyridyl)ethylene, 1,2-bis(2-pyridyl)ethylene 2-bis(4-pyridyl)ethylene, 1,3-bis(4-pyridyl)propane, 1,2-bis(4-pyridyloxy)ethane, bis(2-pyridyl)one, 4 ,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipyridylmethylamine, bipyridine, etc., preferably Diisopropylaniline is mentioned, and 2, 6- diisopropylaniline is mentioned more preferably.

Ammonium salts include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, and phenyltrimethylammonium hydroxide. ammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate and choline, etc.

<The acidity of the acid produced is lower than the acid salt produced by the acid generator>

The acidity of the acid produced is lower than that of the acid salt produced by the acid generator, which means that when only the salt (I) is contained as the acid generator, the acidity of the acid produced by the salt (I) is weaker than that produced by the acid generator. When the acid generator (B) containing the salt (I) and other acid generators is used as the acid generator, it means that the acidity of the acid generated is higher than that of the salt (I) and the acid generator (B). The acid is also the weak salt.

The acidity of the acid produced is lower than the acidity of the acid salt produced by the acid generator and is expressed by the acid dissociation constant (pKa). The acidity of the acid produced is lower than that of the acid salt produced by the acid generator, and the acid dissociation constant of the acid produced by the salt is usually a salt of -3<pKa, and a salt of -1<pKa<7 is preferred, And the salt with 0<pKa<5 is better.

The acidity of the generated acid is lower than that of the acid salt generated by the acid generator, and examples include salts represented by the following formulas, and Japanese Patent Laid-Open No. 2012-229206, Japanese Patent Laid-Open No. 2012-6908, and Japanese Patent Laid-Open No. 2012- Salts described in Gazette 72109, JP 2011-39502 A, and JP 2011-191745 A.

<other ingredients (F)>

The photoresist composition of the present invention may contain components other than the above-mentioned components (hereinafter also referred to as "other components (F)") as necessary. Other components (F) are not particularly limited, and additives known in the photoresist field, such as sensitizers, anti-dissolving agents, surfactants, stabilizers, dyes, and the like can be used.

<Modulation of photoresist composition>

The photoresist composition of the present invention can be prepared by mixing resin (A) and salt (I) of the present invention, and optionally resin (X), acid generator (B), solvent (E), quenching agent (C) ), and other ingredients (F) are mixed and prepared. The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing is selected from 10 to 40° C. as appropriate in accordance with the type of resin or the like, or the solubility of the solvent (E) relative to the resin or the like. As for the mixing time, an appropriate time is selected from 0.5 to 24 hours according to the mixing temperature. In addition, the mixing means is also not particularly limited, and stirring mixing or the like can be used.

After mixing each component, it is preferable to filter using a filter having a pore diameter of about 0.003 to 0.2 μm.

<Manufacturing method of photoresist pattern>

The method for manufacturing a photoresist pattern of the present invention includes the following steps: (1) a step of coating the photoresist composition of the present invention on a substrate, and (2) a step of drying the coated composition to form a composition layer , (3) the step of exposing the composition layer, (4) the step of heating the exposed composition layer, and (5) the step of developing the heated composition layer.

When applying the photoresist composition on the substrate, it can be performed by a commonly used apparatus such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers. Before applying the photoresist composition, the substrate may be cleaned, or an antireflection film or the like may be formed on the substrate.

The composition layer is formed by drying the coated composition to remove the solvent. Drying can be performed by evaporating the solvent (so-called prebaking) using a heating device such as a hot plate, or by using a decompression device. The heating temperature is preferably 50 to 200°C, and the heating time is preferably 10 to 180 seconds. Meanwhile, the pressure during drying under reduced pressure is preferably about 1 to 1.0×10 ⁵ Pa.

The obtained composition layer is usually exposed by an exposure machine. The exposure machine may be an immersion exposure machine. Exposure light source, such as KrF excimer laser (wavelength 248nm), ArF excimer laser (wavelength 193nm), F ₂ excimer laser (wavelength 157nm) emitting laser light in the ultraviolet region, will be composed of solid-state laser light source Various light sources such as those that convert wavelengths of laser light (YAG, semiconductor lasers, etc.) to emit harmonic laser light in the far ultraviolet region or vacuum ultraviolet region, electron beams, and those that irradiate extreme ultraviolet light (EUV). In addition, in this specification, irradiation of such radiation is also collectively referred to as "exposure". During exposure, exposure is usually performed through a mask corresponding to the desired pattern. When the exposure light source is an electron beam, the exposure can be performed by direct drawing without using a photomask.

The exposed composition layer is subjected to heat treatment (so-called post exposure bake) to promote the deprotection reaction in the acid labile group. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C.

The heated composition layer is usually developed using a developing device and a developing solution. As an image development method, a dipping method, a paddle method, a spray method, a dynamic distribution method, etc. are mentioned. The development temperature is preferably 5 to 60° C., for example, and the development time is preferably 5 to 300 seconds, for example. A positive type photoresist pattern or a negative type photoresist pattern can be produced by selecting the type of the developer as described below.

When producing a positive photoresist pattern from the photoresist composition of the present invention, an alkaline developer is used as the developer. The alkaline developing solution may be any of various alkaline aqueous solutions used in this field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl)trimethylammonium hydroxide (commonly referred to as choline) can be mentioned. The alkaline developing solution may contain a surfactant.

After the development, the photoresist pattern is washed with ultrapure water, and then the remaining water on the substrate and the pattern is preferably removed.

When a negative photoresist pattern is produced from the photoresist composition of the present invention, a developer containing an organic solvent is used as a developer (hereinafter also referred to as "organic developer").

Examples of the organic solvent contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; Glycol ether solvents such as methyl ether; amide solvents such as N,N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole, etc.

In the organic-based developing solution, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and substantially more preferably only the organic solvent.

Among them, the organic developer is preferably a developer containing butyl acetate and/or 2-heptanone. In the organic developing solution, the total content of butyl acetate and 2-heptanone is preferably 50 mass % or more and 100 mass % or less, more preferably 90 mass % or more and 100 mass % or less, and is substantially only It is more preferable to have butyl acetate and/or 2-heptanone.

The organic-based developing solution may contain a surfactant. At the same time, the organic-based developer may contain a small amount of water.

During development, the development can be stopped by substituting a solvent different from that of the organic-based developing solution.

It is better to wash the developed photoresist pattern with a rinse solution. The rinsing solution is not particularly limited as long as it does not dissolve the photoresist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent.

After cleaning, it is preferable to remove the rinsing liquid remaining on the substrate and the pattern.

<Use>

The photoresist composition of the present invention is suitable as a photoresist composition for KrF excimer laser exposure, a photoresist composition for ArF excimer laser exposure, a photoresist composition for electron beam (EB) exposure, or EUV The photoresist composition for exposure is more suitable as a photoresist composition for ArF excimer laser exposure, which can be used for precision processing of semiconductors.

[Example]

Examples are given to illustrate the present invention more specifically. In the example, the "%" and "part" indicating the content or usage amount are based on the quality unless otherwise specified.

The weight average molecular weight is a value determined by a gel permeation chromatograph. In addition, the analysis conditions of the gel permeation chromatography are as follows.

Separation column: TSK gel (gel) porous (Multipore) HXL-M x 3+ guide column (guardcolum) (manufactured by Tosoh Corporation)

Eluent: tetrahydrofuran

Flow: 1.0mL/min

Detector: RI detector

Separation column temperature: 40℃

Injection volume: 100 μL

Molecular weight standard: standard polystyrene (manufactured by Tosoh Corporation)

The structure of the compound was confirmed by measuring molecular ion peaks using mass spectrometry (LC: Agilent 1100 type, MASS: Agilent LC/MSD type). In the following examples, the value of the molecular ion peak is represented by "MASS".

[Example 1] Synthesis of salt represented by formula (I-2)

2.98 parts of salts represented by formula (I-2-a), 0.63 parts of compounds represented by formula (I-2-b), and 24 parts of monochlorobenzene were put into a reactor, and stirred at 23° C. for 30 minutes. Then, 0.03 part of copper benzoate represented by the formula (I-2-c) was added, and the temperature was raised to about 100°C, followed by stirring at that temperature for 1 hour. After concentrating the obtained reactant, 45 parts of chloroform and 15 parts of ion-exchanged water were added to the obtained concentrate, and the mixture was stirred at 23° C. for 30 minutes. Then, it left still, and liquid-separated, and obtained the organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer, and it stirred at 23 degreeC for 30 minutes. Then, it left still, and liquid-separated, and obtained the organic layer. Repeat this washing operation 5 times. After the recovered organic layer was filtered, the obtained filtrate was concentrated. To the obtained concentrate, 20 parts of tertiary butyl methyl ether was added and stirred. The obtained supernatant was removed, and the residue after removal of supernatant was concentrated. After dissolving the obtained concentrate in acetonitrile, 1.59 parts of salts represented by formula (I-2-d) were obtained by concentration.

0.63 parts of the salt represented by the formula (I-2-d), 0.26 parts of the compound represented by the formula (I-2-e), and 15 parts of acetonitrile were mixed, and stirred at 23° C. for 30 minutes. To the obtained mixture, 0.12 part of triethylamine was added, and it stirred at 75 degreeC for 3 hours. The obtained mixture was cooled to 23 degreeC, 30 parts of chloroform and 20 parts of ion-exchange water were added, and it stirred at 23 degreeC for 30 minutes. The obtained mixture was left to stand and liquid-separated to obtain an organic layer. Repeat this washing operation 5 times. 0.5 part of activated carbon was added to the recovered organic layer, followed by stirring and filtering. The obtained filtrate was concentrated, 10 parts of ethyl acetate was added, and the mixture was stirred to remove the supernatant. To the obtained residue was added 10 parts of tert-butyl methyl ether, followed by stirring. The obtained supernatant solution was removed, and the residue after removing the supernatant solution was concentrated. After dissolving the obtained concentrate in acetonitrile, 0.33 parts of the salt represented by formula (I-2) was obtained by concentration.

MASS (ESI(+) Spectrum): M ⁺ 507.3

MASS (ESI(-) Spectrum): M ^- 339.1

[Example 2] Synthesis of salt represented by formula (I-3)

2.91 parts of salts represented by formula (I-3-a), 0.63 parts of compounds represented by formula (I-2-b), and 24 parts of monochlorobenzene were put into a reactor, and stirred at 23° C. for 30 minutes. To the obtained mixture, 0.03 part of copper benzoate represented by formula (I-2-c) was added, and the temperature was raised to about 100°C, followed by stirring at that temperature for 1 hour. The obtained reaction was concentrated. To the obtained concentrate, 45 parts of chloroform and 15 parts of ion-exchanged water were added, and the mixture was stirred at 23° C. for 30 minutes. Then, it left still, and liquid-separated, and obtained the organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer, and it stirred at 23 degreeC for 30 minutes. Then, it left still, and liquid-separated, and obtained the organic layer. Repeat this washing operation 5 times. After the recovered organic layer was filtered, the obtained filtrate was concentrated. To the obtained concentrate, 20 parts of tertiary butyl methyl ether was added and stirred. The obtained supernatant solution was removed, and the residue after removing the supernatant solution was concentrated. After dissolving the obtained concentrate in acetonitrile, 1.72 parts of salts represented by formula (I-3-d) were obtained by concentration.

0.61 parts of the salt represented by the formula (I-3-d), 0.26 parts of the compound represented by the formula (I-2-e), and 15 parts of acetonitrile were mixed, and the mixture was stirred at 23° C. for 30 minutes. To the obtained mixture, 0.12 part of triethylamine was added, and it stirred at 75 degreeC for 3 hours. The obtained mixture was cooled to 23 degreeC, 30 parts of chloroform and 20 parts of ion-exchange water were added, and it stirred at 23 degreeC for 30 minutes. The obtained mixture was left to stand and liquid-separated to obtain an organic layer. Repeat this washing operation 5 times. 0.5 part of activated carbon was added to the recovered organic layer, followed by stirring and filtering. The obtained filtrate was concentrated, 10 parts of ethyl acetate was added, and the mixture was stirred to remove the supernatant. To the obtained residue was added 10 parts of tert-butyl methyl ether, followed by stirring. The obtained supernatant solution was removed, and the residue after removing the supernatant solution was concentrated. After dissolving the obtained concentrate in acetonitrile, 0.42 part of the salt represented by formula (I-3) was obtained by concentration.

MASS (ESI(+) spectrum): M ⁺ 507.3

MASS (ESI(-) spectrum): M ^- 323.0

[Example 3] Synthesis of salt represented by formula (I-18)

2.98 parts of salts represented by formula (I-18-a), 0.63 parts of compounds represented by formula (I-2-b), and 24 parts of monochlorobenzene were put into a reactor, and stirred at 23° C. for 30 minutes. To the obtained mixture, 0.03 part of copper benzoate represented by formula (I-2-c) was added, and the temperature was raised to about 100°C, followed by stirring at that temperature for 1 hour. The obtained reaction was concentrated. To the obtained concentrate, 45 parts of chloroform and 15 parts of ion-exchanged water were added, and the mixture was stirred at 23° C. for 30 minutes. Then, it left still, and liquid-separated, and obtained the organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer, and it stirred at 23 degreeC for 30 minutes. Then, it left still, and liquid-separated, and obtained the organic layer. Repeat this washing operation 5 times. After the recovered organic layer was filtered, the obtained filtrate was concentrated. To the obtained concentrate, 20 parts of tertiary butyl methyl ether was added and stirred. The obtained supernatant solution was removed, and the residue after removing the supernatant solution was concentrated. After dissolving the obtained concentrate in acetonitrile, 1.62 parts of salts represented by formula (I-18-d) were obtained by concentration.

0.63 parts of the salt represented by the formula (I-18-d), 0.26 parts of the compound represented by the formula (I-2-e), and 15 parts of acetonitrile were mixed, and stirred at 23° C. for 30 minutes. To the obtained mixture, 0.12 part of triethylamine was added, and it stirred at 75 degreeC for 3 hours. The obtained mixture was cooled to 23 degreeC, 30 parts of chloroform and 20 parts of ion-exchange water were added, and it stirred at 23 degreeC for 30 minutes. The obtained mixture was left to stand and liquid-separated to obtain an organic layer. Repeat this washing operation 5 times. 0.5 part of activated carbon was added to the recovered organic layer, followed by stirring and filtering. The obtained filtrate was concentrated, 10 parts of ethyl acetate was added, and the mixture was stirred to remove the supernatant. To the obtained residue was added 10 parts of tert-butyl methyl ether, followed by stirring. The obtained supernatant solution was removed, and the residue after removing the supernatant solution was concentrated. After dissolving the obtained concentrate in acetonitrile, 0.39 parts of the salt represented by formula (I-18) was obtained by concentration.

MASS (ESI(+) spectrum): M ⁺ 507.3

MASS (ESI(-) spectrum): M ^- 339.1

[Example 4] Synthesis of salt represented by formula (I-19)

2.97 parts of salts represented by formula (I-19-a), 0.63 parts of compounds represented by formula (I-2-b), and 24 parts of monochlorobenzene were put into a reactor, and stirred at 23° C. for 30 minutes. To the obtained mixture, 0.03 part of copper benzoate represented by formula (I-2-c) was added, and the temperature was raised to about 100°C, followed by stirring at that temperature for 1 hour. The obtained reaction was concentrated. To the obtained concentrate, 45 parts of chloroform and 15 parts of ion-exchanged water were added, and the mixture was stirred at 23° C. for 30 minutes. Then, it left still, and liquid-separated, and obtained the organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer, and it stirred at 23 degreeC for 30 minutes. Then, it left still, and liquid-separated, and obtained the organic layer. Repeat this washing operation 5 times. After the recovered organic layer was filtered, the obtained filtrate was concentrated. To the obtained concentrate, 20 parts of tertiary butyl methyl ether was added and stirred. The obtained supernatant solution was removed, and the residue after removing the supernatant solution was concentrated. After dissolving the obtained concentrate in acetonitrile, 1.82 parts of salts represented by formula (I-19-d) were obtained by concentration.

0.62 parts of the salt represented by the formula (I-19-d), 0.26 parts of the compound represented by the formula (I-2-e), and 15 parts of acetonitrile were mixed, and stirred at 23° C. for 30 minutes. To the obtained mixture, 0.12 part of triethylamine was added, and it stirred at 75 degreeC for 3 hours. The obtained mixture was cooled to 23 degreeC, 30 parts of chloroform and 20 parts of ion-exchange water were added, and it stirred at 23 degreeC for 30 minutes. The obtained mixture was left to stand, and the organic layer was obtained by liquid separation. Repeat this washing operation 5 times. 0.5 part of activated carbon was added to the recovered organic layer, followed by stirring and filtering. The obtained filtrate was concentrated, 10 parts of ethyl acetate was added, and the mixture was stirred to remove the supernatant. To the obtained residue was added 10 parts of t-butyl methyl ether, followed by stirring. The obtained supernatant was removed, and the residue after removal of supernatant was concentrated. After dissolving the obtained concentrate in acetonitrile, 0.44 parts of the salt represented by formula (I-19) was obtained by concentration.

MASS (ESI(+) spectrum): M ⁺ 507.3

MASS (ESI(-) spectrum): M ^- 337.1

<Synthesis of resin (A) and resin (X)>

The compounds (monomers) used for the synthesis of resin (A1) and resin (A2) of resin (A), and resin (X1) of resin (X) and resin (X2) are shown below. Hereinafter, these compounds are referred to as "monomer (a1-1-3)" or the like in combination with this formula number.

[Synthesis Example 1] Synthesis of Resin (A1)

Using monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-1) and monomer (a3-4-2) as monomers, the monomer ratio [ Monomer (a1-1-3): Monomer (a1-2-9): Monomer (a2-1-1): Monomer (a3-4-2)] to form 35:15:2.5:47.5 Mix and add 1.5 mass times of the total monomer amount of propylene glycol monomethyl ether acetate to prepare a solution. With respect to the total monomer amount, 1 mol% of azobisisobutyronitrile and 3 mol% of azobis(2,4-dimethylvaleronitrile) were added as initiators to this solution, respectively. , the compounds were heated at 75°C for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate resin, which was filtered. The obtained resin was added to a methanol/water mixed solvent, and after repulping twice, a purification operation of filtration was performed to obtain a resin (A1) having a weight average molecular weight of 8.0×10 ³ in a yield of 69%. This resin (A1) has the following structural unit.

[Synthesis Example 2] Synthesis of Resin (A2)

Using monomer (a1-1-3), monomer (a1-2-11), monomer (a2-1-1) and monomer (a3-4-2) as monomers, the monomer ratio [ Monomer (a1-1-3): Monomer (a1-2-11): Monomer (a2-1-1): Monomer (a3-4-2)] to form 35:15:2.5:47.5 Mix and add 1.5 mass times of the total monomer amount of propylene glycol monomethyl ether acetate to prepare a solution. With respect to the total monomer amount, 1 mol% of azobisisobutyronitrile and 3 mol% of azobis(2,4-dimethylvaleronitrile) were added as initiators to this solution, respectively. , the compounds were heated at 75°C for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate resin, which was filtered. The obtained resin was added to a methanol/water mixed solvent, and after repulping twice, a purification operation of filtration was performed to obtain a resin (A2) having a weight average molecular weight of 7.9×10 ³ in a yield of 65%. This resin (A2) has the following structural unit.

[Synthesis Example 3] Synthesis of Resin (X1)

Using the monomer (a4-1-7) as a monomer, methyl isobutyl ketone was added in an amount of 1.5 mass times the total monomer amount to prepare a solution. To this solution, 0.7 mol % of azobisisobutyronitrile and 2.1 mol % of azobis(2,4-dimethylvaleronitrile) were added as initiators to the total monomer amount. , the compounds were heated at 75°C for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered to obtain a resin X1 having a weight average molecular weight of 1.8×10 ⁴ in a yield of 77%. This resin X1 has the following structural units.

[Synthesis Example 4] Synthesis of Resin (X2)

The monomer (a5-1-1) and the monomer (a4-0-12) are used as monomers, and the monomer ratio is [monomer (a5-1-1):monomer (a4-0-12)] It mixed so that it might become 50:50, and 1.2 mass times of the total monomer amount was added with methyl isobutyl ketone to prepare a solution. To this solution, 3 mol% of azobis(2,4-dimethylvaleronitrile) was added as a starting agent based on the total monomer amount, and the solution was heated at 70°C for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate a resin, and the resin was filtered to obtain a resin X2 having a weight average molecular weight of 1.0×10 ⁴ in a yield of 91%. This resin X2 has the following structural unit.

<Modulation of photoresist composition>

The respective components and solvents shown in Table 15 were mixed, and the obtained mixture was filtered through a fluororesin filter having a pore diameter of 0.2 μm to prepare each photoresist composition.

<resin>

A1, A2, X1, X2: Resin (A1), Resin (A2), Resin (X1), Resin (X2)

<Acid Generator (B)>

B1-21: Salt represented by formula (B1-21) (synthesized in accordance with the Examples of Japanese Patent Laid-Open No. 2012-224611)

B1-22: Salt represented by formula (B1-22) (synthesized in accordance with the Examples of Japanese Patent Laid-Open No. 2012-224611)

<Salt used in the comparative composition>

IX-1: (synthesized according to the examples of Japanese Patent Laid-Open No. 2010-44347)

IX-2: (synthesized according to the examples of Japanese Patent Laid-Open No. 2013-47209)

IX-3: (synthesized according to the examples of Japanese Patent Laid-Open No. 2013-47209)

<Quenching agent (C)>

D1: (Tokyo Chemical Industry Co., Ltd.)

<Solvent>

[Examples 5 to 13, Comparative Examples 1 to 3] Manufacture of photoresist pattern and evaluation thereof

A composition for organic anti-reflection film (ARC-29; manufactured by Nissan Chemical Co., Ltd.) was coated on a silicon wafer, and an organic anti-reflection film with a film thickness of 78 nm was formed on the wafer by baking at 205°C for 60 seconds. membrane. Next, on this organic antireflection film, the above-mentioned photoresist composition was applied (spin-coated) so that the film thickness after drying was 85 nm. After coating, the silicon wafer was prebaked on a direct hot plate at the temperature of PB described in the column "PB/PEB" of Table 15 for 60 seconds to form a composition layer. On the silicon wafer on which the composition layer was formed, contact holes were formed using an ArF excimer stepper for immersion exposure (XT: 1900Gi; manufactured by ASML, NA=1.35, 3/4 annular (annular) XY polarized light). A photomask for a pattern (contact hole pattern) (a hole pitch of 90 nm/a diameter of 55 nm) was exposed by changing the exposure amount stepwise. In addition, ultrapure water was used as an immersion solvent.

After exposure, a post-exposure bake was performed on a hot plate at the temperature of the PEB described in the column "PB/PEB" of Table 15 for 60 seconds. Next, using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution, the composition layer on this silicon wafer was developed by a dynamic distribution method at 23° C. for 20 seconds to produce a negative photoresist pattern. .

In the photoresist pattern obtained after developing, the exposure amount with the aperture of 45 nm formed by the aforementioned photomask was used as the effective sensitivity.

<CD Uniformity (CDU) Evaluation>

In the effective sensitivity, the pore diameter of a pattern formed by a mask with an pore diameter of 55 nm was measured 24 times for each pore diameter, and the average value was used as the average pore diameter per hole. The average diameter of a pattern formed by a mask with a diameter of 55 nm in the same wafer was measured at 400 positions as a parent group, and the standard deviation was obtained.

When the standard deviation was 1.80 nm or less, the CDU was evaluated as good and A.

When the standard deviation was larger than 1.80 nm, it was evaluated as B as CDU failure.

The results are shown in Table 16. Values in parentheses indicate standard deviation (nm).

<Mask error factor (MEF) evaluation>

In the effective sensitivity, photomasks with apertures (the aperture of the light-transmitting part of the photomask) of 57 nm, 56 nm, 55 nm, 54 nm, and 53 nm (the aperture spacing is all 90 nm) are used to form a photoresist pattern. The slope of the regression line when the aperture of the photoresist pattern formed (transcribed) on the substrate by exposure as the horizontal axis and the aperture of the photoresist pattern formed (transcribed) on the substrate as the vertical axis was calculated as the MEF value.

Those with a MEF value of 4.8 or less were evaluated as good MEF and A.

Those with MEF value exceeding 4.8 were regarded as MEF poor and evaluated as B.

The results are shown in Table 16. Numerical values in parentheses indicate MEF values.

[Industrial Availability]

Since the salt of the present invention and the photoresist composition containing the salt can obtain a photoresist pattern having good CD uniformity (CDU), it is suitable for precision processing of semiconductors and is extremely useful in industry.

Claims (12)

A salt represented by the following formula (I),

In formula (I), R ¹ and R ² each independently represent an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent; R ³ represents a group represented by formula (1);

In formula (1), R ^a1 to R ^a3 each independently represent an optionally substituted alkyl group having 1 to 8 carbon atoms, an optionally substituted alicyclic hydrocarbon group having 3 to 20 carbon atoms, R ^a1 and R ^a2 Combined with each other to form a non-aromatic hydrocarbon ring with carbon number from 3 to 20; ma represents 0, na represents 1; * represents a bond; X ¹ represents -X ¹² -OX ²² -*( X ¹² represents a bivalent aliphatic hydrocarbon group with 1 to 10 carbon atoms, and the methylene group constituting the bivalent aliphatic hydrocarbon group may be substituted with an oxygen atom or a carbonyl group; X ²² represents a bivalent aliphatic group with 1 to 10 carbon atoms Hydrocarbon group; however, the total carbon number of X ¹² and X ²² is 11 or less; * represents a group represented by a bond with R ³ ); A ^- represents an organic anion. The salt described in item 1 of the claimed scope, wherein in X ¹ in the aforementioned formula (I), X ¹² is an alkanediyl group having 1 to 6 carbon atoms, and the methylene group constituting the alkanediyl group can be substituted into An oxygen atom or a carbonyl group, and X ²² is a methylene group. The salt according to claim 1 or 2, wherein R ¹ and R ² in the aforementioned formula (I) are each independently a phenyl group which may have a substituent. The salt according to claim 1 or 2, wherein the aromatic hydrocarbon group represented by R ¹ and R ² in the aforementioned formula (I) with 6 to 18 carbon atoms may have substituents that are hydroxyl, carboxyl, carbon An alkyl group having 1 to 12 carbons, an alkoxy group having 1 to 12 carbons, or an alicyclic hydrocarbon group having 3 to 12 carbons. The salt described in item 1 or 2 of the claimed scope, wherein in R ³ in the aforementioned formula (I), R ^a1 and R ^a2 are combined with each other to form a compound having 3 to 20 carbon atoms together with the bonded carbon atoms. Non-aromatic hydrocarbon ring, R ^a3 is an alkyl group with 1 to 8 carbon atoms. The salt described in claim 1 or 2 of the claimed scope, wherein A ^- is a sulfonic acid anion represented by formula (IA)

In formula (IA), Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms; L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and the saturated hydrocarbon group contains -CH ₂ - can be substituted with -O- or -CO-, the hydrogen atom contained in the saturated hydrocarbon group can be substituted with a fluorine atom or a hydroxyl group; Y represents a methyl group which may have a substituent or a carbon number 3 to 3 which may have a substituent The alicyclic hydrocarbon group of 18, the -CH ₂ - contained in the alicyclic hydrocarbon group can be substituted into -O-, -SO ₂ - or -CO-. The salt according to claim 6, wherein L ^b1 of the aforementioned formula (IA) is a group represented by any one of the formulae (b1-1) to (b1-3);

In formula (b1-1), L ^b2 represents a single bond or a divalent saturated hydrocarbon group with 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group can be replaced by a fluorine atom; L ^b3 represents a single bond or a carbon number 1 to 22. The divalent saturated hydrocarbon group of 22, the hydrogen atom contained in the saturated hydrocarbon group can be substituted into a fluorine atom or a hydroxyl group, and the -CH ₂ - contained in the saturated hydrocarbon group can be substituted into -O- or -CO-; however, L ^b2 and The total carbon number of L ^b3 is 22 or less; in formula (b1-2), L ^b4 represents a single bond or a divalent saturated hydrocarbon group with a carbon number of 1 to 22, and the hydrogen atom contained in the saturated hydrocarbon group can be substituted into a fluorine atom; L ^b5 represents a single bond or a divalent saturated hydrocarbon group with 1 to 22 carbon atoms, the hydrogen atom contained in the saturated hydrocarbon group can be substituted with a fluorine atom or a hydroxyl group, and the -CH ₂ - contained in the saturated hydrocarbon group can be substituted with -O- or -CO-; however, the total carbon number of L ^b4 and L ^b5 is 22 or less; in the formula (b1-3), L ^b6 represents a single bond or a divalent saturated hydrocarbon group with 1 to 23 carbon atoms, and in the saturated hydrocarbon group The contained hydrogen atom can be substituted into a fluorine atom or a hydroxyl group; L ^b7 represents a single bond or a divalent saturated hydrocarbon group with 1 to 23 carbon atoms, the hydrogen atom contained in the saturated hydrocarbon group can be substituted into a fluorine atom or a hydroxyl group, and in the saturated hydrocarbon group The contained -CH ₂ - may be substituted with -O- or -CO-; however, the total carbon number of L ^b6 and L ^b7 is 23 or less; * represents a bond with Y. The salt according to claim 6, wherein Y in the aforementioned formula (IA) is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and -CH ₂ - contained in the alicyclic hydrocarbon group The alicyclic hydrocarbon group that can be substituted with -O-, -SO ₂ - or -CO-, and the alicyclic hydrocarbon group represented by the aforementioned Y may have a halogen atom, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms which may be substituted by a hydroxyl group, a carbon Alicyclic hydrocarbon group of 3 to 16, alkoxy group of carbon number 1 to 12, aromatic hydrocarbon group of carbon number 6 to 18, aralkyl group of carbon number 7 to 21, aryl group of carbon number 2 to 4, ring Oxypropyloxy or -(CH ₂ ) _ja -O-CO-R ^b1 group (wherein, R ^b1 represents an alkyl group having 1 to 16 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 16 carbon atoms or A monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms; ja represents any integer of 0 to 4. An acid generator containing any one of items 1 to 8 of the claimed scope the salt mentioned in the item. A photoresist composition comprising an acid generator comprising the salt described in any one of claims 1 to 8 of the patent application scope and a resin comprising a structural unit having an acid-labile group. The photoresist composition described in claim 10 of the claimed scope further contains an acid generating salt, and the acidity of the acid generated is lower than that of the acid generated by the aforementioned acid generator. A method for manufacturing a photoresist pattern, comprising the following steps: (1) coating the photoresist composition described in claim 10 or 11 on a substrate; (2) drying the coated composition to obtain a A step of forming a composition layer, (3) a step of exposing the composition layer, (4) a step of heating the exposed composition layer, and (5) a step of developing the heated composition layer.