JP2014166983A - Salt, resist composition and method for producing resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a salt to be used for a resist composition from which a resist pattern having excellent line edge roughness (LER) can be produced, and to provide an acid generator comprising the salt, and a resist composition or the like containing the acid generator.SOLUTION: The salt is expressed by formula (I). In formula (I), Rrepresents -(X-O)-R, where Rrepresents a monovalent hydrocarbon group having 1 to 12 carbon atoms, Xrepresents a divalent hydrocarbon group having 2 to 12 carbon atoms, and n represents an integer of 0 to 6; and Arepresents an organic anion.]

Description

  The present invention relates to a salt for an acid generator used for microfabrication of a semiconductor, a resist composition, and a method for producing a resist pattern.

Patent Document 1 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator.

JP 2012-224611 A

  In the resist composition containing the above salt as an acid generator, the line edge roughness (LER) of the resulting resist pattern may not always be satisfied.

［式（Ｉ）中、Ｒ^１は、−（Ｘ^１−Ｏ）_ｎ−Ｒ^２を表す。
Ｒ^２は、炭素数１〜１２の１価の炭化水素基を表す。
Ｘ^１は、炭素数２〜１２の２価の炭化水素基を表す。
ｎは、０〜６の整数を表す。
Ａ⁻は、有機アニオンを表す。］
〔２〕 Ａ⁻が、式（Ｉ−Ａ）で表されるアニオンである〔１〕記載の塩。

［式（Ｉ−Ａ）中、Ｌ^b1は、炭素数１〜１７の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、該アルキル基及び該脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−に置き換わっていてもよい。］
〔３〕 〔１〕又は〔２〕記載の塩を含有する酸発生剤。
〔４〕 〔３〕記載の酸発生剤と酸不安定基を有する樹脂とを含有するレジスト組成物。
〔５〕 （１）〔４〕記載のレジスト組成物を基板上に塗布する工程、
（２）塗布後の組成物を乾燥させて組成物層を形成する工程、
（３）組成物層に露光する工程、
（４）露光後の組成物層を加熱する工程、及び
（５）加熱後の組成物層を現像する工程
を含むレジストパターンの製造方法。 The present invention includes the following inventions.
[1] A salt represented by the formula (I).

[In Formula (I), R ¹ represents — (X ¹ —O) _n —R ² .
R ² represents a monovalent hydrocarbon group having 1 to 12 carbon atoms.
X ¹ represents a divalent hydrocarbon group having 2 to 12 carbon atoms.
n represents an integer of 0 to 6.
A ⁻ represents an organic anion. ]
[2] The salt according to [1], wherein A ⁻ is an anion represented by the formula (IA).

[In the formula (IA), L ^b1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group represents —O— or —CO—. The hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—. ]
[3] An acid generator containing the salt according to [1] or [2].
[4] A resist composition comprising the acid generator according to [3] and a resin having an acid labile group.
[5] (1) A step of applying the resist composition according to [4] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.

  From the resist composition containing the salt of the present invention as an acid generator, a resist pattern having excellent line edge roughness (LER) can be produced.

In the present specification, unless otherwise specified, in the description of the structural formula of a compound, “aliphatic hydrocarbon group” means a linear or branched hydrocarbon group, and “alicyclic hydrocarbon group” means A group obtained by removing a number of hydrogen atoms corresponding to the valence from the ring of an alicyclic hydrocarbon. The “aromatic hydrocarbon group” also includes a group in which a hydrocarbon group is bonded to an aromatic ring. When stereoisomers exist, all stereoisomers are included.
Further, "(meth) acrylic monomer" means at least one monomer having 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 of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

［式（Ｉ）中、Ｒ^１は、−（Ｘ^１−Ｏ）_ｎ−Ｒ^２を表す。
Ｒ^２は、炭素数１〜１２の１価の炭化水素基を表す。
Ｘ^１は、炭素数２〜１２の２価の炭化水素基を表す。
ｎは、０〜６の整数を表す。
Ａ⁻は、有機アニオンを表す。］ <Salt (I)>
The salt of the present invention is a salt represented by the formula (I) (hereinafter sometimes referred to as “salt (I)”).

[In Formula (I), R ¹ represents — (X ¹ —O) _n —R ² .
R ² represents a monovalent hydrocarbon group having 1 to 12 carbon atoms.
X ¹ represents a divalent hydrocarbon group having 2 to 12 carbon atoms.
n represents an integer of 0 to 6.
A ⁻ represents an organic anion. ]

  In the following description, the side having a positive charge in the salt (I) may be referred to as “cation (I)”.

The monovalent hydrocarbon group having 1 to 12 carbon atoms representing R ² is a linear or branched monovalent aliphatic hydrocarbon group, monovalent alicyclic hydrocarbon group, monovalent aromatic group. Examples thereof include hydrocarbon groups and a combination thereof.
Examples of the linear or branched monovalent aliphatic hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, and pentyl. Group, hexyl group, octyl group and alkyl group such as 2-ethylhexyl group.
The monovalent alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic monovalent alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group. It is done. Examples of the polycyclic monovalent alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, and a norbornyl group.
Examples of the monovalent aromatic hydrocarbon group include aryl groups such as phenyl group, tolyl group, xylyl group, and naphthyl group.
Examples of the group in which a monovalent aliphatic hydrocarbon group and a monovalent alicyclic hydrocarbon group are combined include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
The monovalent hydrocarbon group having 1 to 12 carbon atoms representing R ² is preferably a monovalent aliphatic hydrocarbon group, a monovalent alicyclic hydrocarbon group, or a group having 1 to 12 carbon atoms in combination thereof. C1-6 alkyl groups are more preferred, and methyl groups or ethyl groups are more preferred.

Examples of the divalent hydrocarbon group having 2 to 12 carbon atoms representing X ¹ include an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. Hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1, Linear alkanediyl groups such as 11-diyl group, dodecane-1,12-diyl group;
Propane-1,2-diyl group, 1-methylbutane-1,3-diyl group, 2-methylpropane-1,3-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl Branched alkanediyl groups such as groups;
Cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group;
Polycyclic divalent alicyclic hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group and the like Etc.
The divalent hydrocarbon group having 2 to 12 carbon atoms representing X ¹ is preferably an alkanediyl group having 2 to 6 carbon atoms, more preferably a linear alkanediyl group having 2 to 6 carbon atoms, and 2 to 2 carbon atoms. 4 linear alkanediyl groups are more preferred.

  n is preferably an integer of 0 to 3, more preferably 0 or 1, and still more preferably 0.

Examples of the cation (I) include cations represented by formulas (Ic-1) to (Ic-16), respectively.

［式（Ｉ−Ａ）中、Ｌ^b1は、炭素数１〜１７の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、該アルキル基及び該脂環式炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−に置き換わっていてもよい。］ Examples of the organic anion (A ⁻ ) include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion. Among these, a sulfonate anion is preferable, and an anion represented by the formula (IA) is more preferable.

[In the formula (IA), L ^b1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group represents —O— or —CO—. The hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—. ]

Examples of the perfluoroalkyl group of Q ¹ and Q ² include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and perfluoro group. A hexyl group etc. are mentioned.
Q ¹ and Q ² are each independently preferably a fluorine atom or a trifluoromethyl group, and both Q ¹ and Q ² are more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and these A combination of two or more of the groups may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 , 7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group , Tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group Alkanediyl group;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, 1-methylbutane-1,3-diyl group, 2-methyl Branched alkanediyl groups such as propane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include any of formulas (b1-1) to (b1-8) The group represented by these is mentioned. In addition, Formula (b1-1)-Formula (b1-8) has described the right and left according to Formula (IA), and is C on the left side among two bonds represented by *, respectively. Bonded to (Q ¹ ) (Q ² )-and to -Y on the right side. The same applies to specific examples of the following formulas (b1-1) to (b1-8).

式（ｂ１−１）〜式（ｂ１−８）中、
Ｌ^b2は、単結合又は炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２の２価の飽和炭化水素基を表す。
Ｌ^b4は、炭素数１〜１３の２価の飽和炭化水素基を表す。但しＬ^b3及びＬ^b4の合計炭素数の上限は１３である。
Ｌ^b５は、単結合又は炭素数１〜１４の２価の飽和炭化水素基を表す。
Ｌ^b６は、炭素数１〜１５の２価の飽和炭化水素基を表す。但しＬ^b5及びＬ^b6の合計炭素数の上限は１５である。
Ｌ^b７は、単結合又は炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b８は、炭素数１〜１６の２価の飽和炭化水素基を表す。但しＬ^b７及びＬ^b８の合計炭素数の上限は１６である。
Ｌ^b9は、単結合又は炭素数１〜１３の２価の飽和炭化水素基を表す。
Ｌ^b10は、炭素数１〜１４の２価の飽和炭化水素基を表す。但しＬ^b9及びＬ^b10の合計炭素数の上限は１４である。
Ｌ^b11及びＬ^b12は、それぞれ独立に、単結合又は炭素数１〜１１の２価の飽和炭化水素基を表す。
Ｌ^b13は、炭素数１〜１２の２価の飽和炭化水素基を表す。但しＬ^b11、Ｌ^b12及びＬ^b13の合計炭素数の上限は１２である。
Ｌ^b14及びＬ^b15は、それぞれ独立に、単結合又は炭素数１〜１３の２価の飽和炭化水素基を表す。
Ｌ^b16は、炭素数１〜１４の２価の飽和炭化水素基を表す。但しＬ^b14、Ｌ^b15及びＬ^b16の合計炭素数の上限は１４である。
Ｌ^b17は、それぞれ独立に、単結合又は炭素数１〜１１の２価の飽和炭化水素基を表す。
Ｌ^b18及びＬ^b19は、炭素数１〜１２の２価の飽和炭化水素基を表す。但しＬ^b17、Ｌ^b18及びＬ^b19の合計炭素数の上限は１１である。
Ｌ^b1は、好ましくは式（ｂ１−１）〜式（ｂ１−４）及び式（ｂ１−８）のいずれかで表される基であり、さらに好ましくは式（ｂ１−１）、式（ｂ１−３）又は式（ｂ１−８）で表される基である。

In formula (b1-1) to formula (b1-8),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the total carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b6 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the total carbon number of L ^b5 and L ^b6 is 15.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b8 represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms. However, the upper limit of the total carbon number of L ^b7 and L ^b8 is 16.
L ^b9 represents a single bond or a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b10 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b9 and L ^b10 is 14.
L ^b11 and L ^b12 each independently represent a single bond or a divalent saturated hydrocarbon group having 1 to 11 carbon atoms.
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. However, the upper limit of the total carbon number of L ^b11 , L ^b12 and L ^b13 is 12.
L ^b14 and L ^b15 each independently represent a single bond or a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. However, the upper limit of the total carbon number of L ^b14 , L ^b15 and L ^b16 is 14.
L ^b17 each independently represents a single bond or a divalent saturated hydrocarbon group having 1 to 11 carbon atoms.
L ^b18 and L ^b19 represent a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. However, the upper limit of the total carbon number of L ^b17 , L ^b18 and L ^b19 is 11.
L ^b1 is preferably a group represented by any one of formula (b1-1) to formula (b1-4) and formula (b1-8), more preferably formula (b1-1) and formula (b1). -3) or a group represented by formula (b1-8).

As group represented by a formula (b1-1), the following are mentioned, for example.

Examples of the group represented by the formula (b1-2) include the following.

Examples of the group represented by formula (b1-3) include the following.

Examples of the group represented by formula (b1-4) include the following.

As group represented by a formula (b1-5), the following are mentioned, for example.

Examples of the group represented by formula (b1-6) include the following.

Examples of the group represented by formula (b1-7) include the following.

Examples of the group represented by formula (b1-8) include the following.

Examples of the group in which the hydrogen atom contained in the divalent saturated hydrocarbon group of L ^b1 is substituted with a fluorine atom or a hydroxy group include the following divalent groups.

Examples of the alkyl group for Y include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, heptyl group, 2 -Alkyl groups, such as an ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, are mentioned, Preferably, a C1-C6 alkyl group is mentioned.
Examples of the alicyclic hydrocarbon group for Y include groups represented by formulas (Y1) to (Y11).
Examples of the group in which —CH ₂ — contained in the alicyclic hydrocarbon group of Y is replaced by —O—, —SO ₂ — or —CO— are represented by formulas (Y12) to (Y26). Groups.

  Especially, it is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

Examples of the substituent for the alkyl group of Y include, for example, a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, or — (CH _{2) ja -O-CO-R} b1 group (wherein, R ^b1 represents an alkyl group having 1 to 16 carbon atoms, an aromatic alicyclic hydrocarbon group or a C6-18 3 to 16 carbon atoms carbide Represents a hydrogen group, and ja represents an integer of 0 to 4.
Examples of the substituent for the alicyclic hydrocarbon group of Y include, for example, a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and an aliphatic group having 3 to 16 carbon atoms. A cyclic hydrocarbon group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy group, or- (CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic group having 6 to 18 carbon atoms) Represents a group hydrocarbon group, and ja represents an integer of 0 to 4).

Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group; tolyl group, xylyl group, cumenyl group, mesityl group. , Aryl groups such as biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Examples of Y include the following.

When Y is an alkyl group and L ^b1 is a divalent linear or branched saturated hydrocarbon group having 1 to 17 carbon atoms, the divalent saturated hydrocarbon at the bonding position with Y The group —CH ₂ — is preferably replaced by —O— or —CO—. In this case, —CH ₂ — contained in the alkyl group of Y is not replaced with —O— or —CO—. The same applies when a hydrogen atom contained in the alkyl group of Y and / or the divalent linear or branched saturated hydrocarbon group of L ^b1 is substituted with a substituent.

  Y is 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 constitutes these groups The methylene group may be replaced by an oxygen atom, a sulfonyl group or a carbonyl group. Y is particularly preferably an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

Specific examples of the anion represented by the formula (IA) include anions described in JP 2010-204646 A, and preferably the formula (b1-1-1) to the formula (b1). -11-11), and the anions respectively represented by them. Among these, an anion represented by formula (b1-1-2), formula (b1-1-3), or formula (b1-1-11) is more preferable. In the following formulas, the definitions of the symbols have the same meaning as described above, and R ^b2 and R ^b3 each independently represent an alkyl group having 1 to 4 carbon atoms (preferably a methyl group). Other symbols represent the same meaning as described above.

Among these, more preferred anions include the anions represented by formulas (Ia-1) to (Ia-6), respectively.

  The salt (I) is a combination of the organic anion (preferably an anion represented by the formula (IA)) and the cation (I). These anions and cations can be arbitrarily combined. Specific examples of the salt (I) are shown in Tables 1 and 2.

Among these, preferred salts (I) include the following.

（式中、Ｒ^１及びＡ⁻は、前記と同義である。）
触媒としては、安息香酸銅（ＩＩ）等が挙げられる。
溶剤としては、モノクロロベンゼン等が挙げられる。 The salt (I) can be produced by reacting the salt represented by the formula (Ia) and the compound represented by the formula (Ib) in a solvent in the presence of a catalyst.

(In the formula, R ¹ and A ⁻ have the same meanings as described above.)
Examples of the catalyst include copper (II) benzoate.
Examples of the solvent include monochlorobenzene.

溶剤としては、クロロホルム等が挙げられる。
式（Ｉ−ｄ）で表される塩は、例えば特開２００８−２０９９１７号公報に記載された方法によって製造することができる。 A ^- salts when an anion of the formula (I-A) (I) may be prepared according to the above reaction formula, but, A ^- is other than an anion of the formula (I-A) The salt (I) is produced using the salt represented by the formula (Ia) which is an anion of the compound, and then the reaction is performed by exchanging A ⁻ with the anion represented by the formula (IA). May be.
The salt represented by the formula (Ie) which is the salt (I) in the case where A ⁻ is an anion represented by the formula (IA) is, for example, in the above reaction formula, in which A ⁻ is benzenesulfonic acid It can be produced by reacting a salt represented by the formula (Ic) which is a salt (I) in the case of an anion with a salt represented by the formula (Id) in a solvent.

Examples of the solvent include chloroform.
The salt represented by the formula (Id) can be produced, for example, by the method described in JP2008-209917A.

（式中、Ｘは塩素原子又は臭素原子を表す。）
溶剤としては、クロロホルム、水等が挙げられる。 The salt represented by the formula (Ia) is produced, for example, by reacting the salt represented by the formula (If) and the salt represented by the formula (Ig) in a solvent. be able to.

(In the formula, X represents a chlorine atom or a bromine atom.)
Examples of the solvent include chloroform and water.

酸触媒としては、硫酸等が挙げられる。
溶剤としては、酢酸、無水酢酸等が挙げられる。 The salt represented by the formula (If) is obtained by, for example, reacting a compound represented by the formula (Ih) with a compound represented by the formula (Ii) in a solvent under an acid catalyst. And then reacting with NaX.

Examples of the acid catalyst include sulfuric acid.
Examples of the solvent include acetic acid and acetic anhydride.

<Acid generator>
The acid generator of the present invention contains salt (I) which is a salt of the present invention. The acid generator of the present invention may further contain an acid generator other than the salt (I) (hereinafter sometimes referred to as “acid generator (B)”).
As the acid generator (B), a known acid generator can be used, and an ionic acid generator or a nonionic generator may be used, but an ionic acid generator is preferable. As the ionic acid generator, for example, an ionic acid generator composed of A ⁻ constituting the salt (I) and a cation other than the cation (I) can be mentioned.

As an acid generator (B), the salt represented by either of Formula (B1-1)-Formula (B1-24) is mentioned, for example. Among them, those containing an arylsulfonium cation are preferable. Formula (B1-1), Formula (B1-2), Formula (B1-3), Formula (B1-6), Formula (B1-7), Formula (B1-11) ), Formula (B1-12), Formula (B1-13), Formula (B1-14), Formula (B1-21), Formula (B1-22), Formula (B1-23), and Formula (B1-24) Or a salt represented by any of the above.

  In the acid generator of the present invention, the content of the salt (I) is preferably 10% by mass or more, more preferably 30% by mass or more, and further preferably 50% by mass with respect to the total amount of the acid generator of the present invention. That's it.

<Resist composition>
The resist composition of the present invention contains the acid generator of the present invention and a resin having an acid labile group (hereinafter sometimes referred to as “resin (A)”).
The resist composition of the present invention preferably further contains a solvent (D).
The resist composition of the present invention preferably further contains a basic compound (C).

<Acid generator>
The content of the acid generator of the present invention is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 30 parts by mass or less (more preferably 25 parts by mass) with respect to 100 parts by mass of the resin (A). Part or less).

<Resin (A)>
The resin (A) has a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a1)”). The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as “monomer (a1)”).
The resin (A) may further have a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”).

［式（１）中、Ｒ^a1〜Ｒ^a3は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組合わせた基を表すか、Ｒ^a1及びＲ^a2は互いに結合して炭素数２〜２０の２価の炭化水素基を形成する。＊は結合手を表す。］

［式（２）中、Ｒ^a1’及びＲ^a2’は、それぞれ独立に、水素原子又は炭素数１〜１２の１価の炭化水素基を表し、Ｒ^a3’は、炭素数１〜２０の炭化水素基を表すか、Ｒ^a2’及びＲ^a3’は互いに結合して炭素数２〜２０の２価の炭化水素基を形成し、該炭化水素基及び該２価の炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−Ｓ−で置き換わってもよい。＊は結合手を表す。］ <Acid labile group>
The “acid labile group” means a group having a leaving group and forming a hydrophilic group (for example, a hydroxy group or a carboxy group) by leaving the leaving group by contact with an acid. Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2).

[In Formula (1), R ^<a1 > -R < ^a3 > respectively independently represents a C1-C8 alkyl group, a C3-C20 alicyclic hydrocarbon group, or the group which combined these, R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms. * Represents a bond. ]

[In Formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a carbon atom having 1 to 20 carbon atoms. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and are contained in the hydrocarbon group and the divalent hydrocarbon group— CH ₂ — may be replaced by —O— or —S—. * Represents a bond. ]

アルキル基と脂環式炭化水素基とを組合わせた基としては、例えば、メチルシクロヘキシル基、ジメチルシクロへキシル基、メチルノルボルニル基等が挙げられ、好ましくは炭素数２０以下である。 Examples of the alkyl group represented by R ^{a1 to} R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group for R ^{a1 to} R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond). The alicyclic hydrocarbon group is preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms.

Examples of the group in which an alkyl group and an alicyclic hydrocarbon group are combined include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group, and preferably have 20 or less carbon atoms.

Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group include the following groups. The divalent hydrocarbon group preferably has 3 to 12 carbon atoms. * Represents a bond with -O-.

Examples of the group represented by the formula (1) include a 1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^{a1 to} R ^a3 are alkyl groups, preferably a tert-butoxycarbonyl group), 2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and a carbon atom form an adamantyl group, and R ^a3 is an alkyl group) and 1- (adamantane-1- Yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

Examples of the hydrocarbon group of R ^{a1 ′ to} R ^{a3 ′} include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and the like.
Examples of the aliphatic hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
Examples of the alicyclic hydrocarbon group are the same as those described above.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.
When R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group, * —C (R ^{a1 ′} ) (R ^{a2 ′} ) (OR ^{a3 ′} ) is the following group (in the formula: , * Represents a bond.). The divalent hydrocarbon group preferably has 3 to 12 carbon atoms.

In Formula (2), it is preferable that at least one of R ^{a1 ′} and R ^{a2 ′} is a hydrogen atom.
Specific examples of the group represented by the formula (2) include the following groups. * Represents a bond.

<Structural unit (a1)>
The monomer (a1) leading to the structural unit (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth) acrylic monomer having an acid labile group.

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

［式（ａ１−０）中、
Ｌ^a01は、酸素原子又は＊−Ｏ−（ＣＨ₂）_k01−ＣＯ−Ｏ−を表し、ｋ０１は１〜７の整数を表し、＊はカルボニル基との結合手を表す。
Ｒ^a01は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a02、Ｒ^a03及びＲ^a04は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合わせた基を表す。］ Examples of the structural unit (a1) having a group represented by the formula (1) include those represented by the formula (a1-0), the formula (a1-1), the formula (a1-2), and the formula (a1-3). Structural units (hereinafter referred to as “structural unit (a1-0)”, “structural unit (a1-1)”, “structural unit (a1-2)”, “structural unit (a1-3)”, respectively). There is).

[In the formula (a1-0),
L ^a01 represents an oxygen atom or * —O— (CH ₂ ) _k01 —CO—O—, k01 represents an integer of 1 to 7, and * represents a bond to a carbonyl group.
R ^a01 independently 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 obtained by combining these. ]

L ^a01 is preferably an oxygen atom. k01 is preferably an integer of 1 to 4, more preferably 1.
Examples of the alkyl group of R ^a02 , R ^a03, and R ^a04 , the alicyclic hydrocarbon group, and the group obtained by combining these include the same groups as those described for R ^{a1 to} R ^a3 in formula (1).
The alkyl group of R ^a02 , R ^a03 and R ^a04 is preferably an alkyl group having 6 or less carbon atoms.
The alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^a04 is preferably an alicyclic hydrocarbon group having 10 or less carbon atoms, and more preferably an alicyclic hydrocarbon group having 6 or less carbon atoms.
The group combining the alkyl group and the alicyclic hydrocarbon group preferably has a total carbon number of 18 or less, combining the alkyl group and the alicyclic hydrocarbon group. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
R ^a02 , R ^a03 and R ^a04 each independently ^represent an alkyl group having 1 to 8 carbon atoms, or two of R ^a02 , R ^a03 and R ^a04 each independently ^represent a carbon number It is preferable that it is a 1-8 alkyl group, and the remaining one is a C3-C18 alicyclic hydrocarbon group.
R ^a02 , R ^a03 and R ^a04 are each independently an alkyl group having 1 to 6 carbon atoms, or two of R ^a02 , R ^a03 and R ^a04 are each independently It is more preferable that it is a 1-6 alkyl group, and the remaining one is a C5-C12 alicyclic hydrocarbon group.
R ^a02 , R ^a03 and R ^a04 are each independently a methyl group, an ethyl group or a propyl group, or two of R ^a02 , R ^a03 and R ^a04 are each independently a methyl group More preferably, they are an ethyl group or a propyl group, and the remaining one is a cyclohexyl group or an adamantyl group.

The monomer for deriving the structural unit (a1-0) (hereinafter sometimes referred to as “monomer (a1-0)”) is represented by the formula (a1-0-1) to the formula (a1-0-12). And a monomer in which the methacryloyl group in the formula (a1-0-1) to the formula (a1-0-12) is replaced by an acryloyl group, the formula (a1-0-1) to the formula (a1-0- The monomer represented by 10) is preferred.

  When the resin (A) contains the structural unit (a1-0), the content is preferably 1 to 70 mol%, more preferably 3 to 65 mol, based on all the structural units of the resin (A). %.

［式（ａ１−１）中、
Ｌ^a1は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_h1−ＣＯ−Ｏ−を表し、ｈ１は１〜７の整数を表し、＊はカルボニル基との結合手を表す。
Ｒ^a4は、水素原子又はメチル基を表す。
Ｒ^a6は、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合わせた基を表す。
ｍ１は、０〜１４の整数を表す。］

[In the formula (a1-1),
L ^a1 represents an oxygen atom or ^* —O— (CH ₂ ) _h1 —CO—O—, h1 represents an integer of 1 to 7, and * represents a bond to a carbonyl group.
R ^a4 represents a hydrogen atom or a methyl group.
R ^a6 represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group obtained by combining these.
m1 represents the integer of 0-14. ]

アルキル基と脂環式炭化水素基とを組合わせた基としては、例えば、メチルシクロヘキシル基、ジメチルシクロへキシル基及びメチルノルボルニル基等が挙げられる。
Ｒ^a6は、炭素数１〜８のアルキル基であることが好ましく、炭素数１〜６のアルキル基であることがより好ましい。 h1 is preferably an integer of 1 to 4, more preferably 1.
L ^a1 is preferably an oxygen atom.
R ^a4 is preferably a methyl group.
^Examples of the alkyl group for R ^a6 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. The alkyl group preferably has 6 or less carbon atoms.
The alicyclic hydrocarbon group for R ^a6 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond). The alicyclic hydrocarbon group is preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms, more preferably an alicyclic hydrocarbon group having 3 to 8 carbon atoms, and further preferably 3 to 3 carbon atoms. 6 alicyclic hydrocarbon groups.

Examples of the group in which an alkyl group and an alicyclic hydrocarbon group are combined include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.
R ^a6 is preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms.

  m1 is preferably an integer of 0 to 3, more preferably 0 or 1.

Examples of the monomer that leads to the structural unit (a1-1) (hereinafter sometimes referred to as “monomer (a1-1)”) include monomers described in JP 2010-204646 A. Among these, a monomer represented by any one of formula (a1-1-1) to formula (a1-1-8) is preferable, and any one of formula (a1-1-1) to formula (a1-1-4) is preferable. The monomer represented by is more preferable.

  When the resin (A) includes the structural unit (a1-1), the content is preferably 20 to 70 mol%, more preferably 25 to 65, based on all the structural units of the resin (A). Mol%.

［式（ａ１−２）中、
Ｌ^a2は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_h2−ＣＯ−Ｏ−を表し、ｈ２は１〜７の整数を表し、＊はカルボニル基との結合手を表す。
Ｒ^a5は、水素原子又はメチル基を表す。
Ｒ^a7は、炭素数１〜８のアルキル基、炭素数３〜１８の脂環式炭化水素基又はこれらを組合わせた基を表す。
ｎ１は、０〜１０の整数を表す。
ｎ１’は、０〜３の整数を表す。］

[In the formula (a1-2),
L ^a2 represents an oxygen atom or ^* —O— (CH ₂ ) _h2 —CO—O—, h2 represents an integer of 1 to 7, and * represents a bond with a carbonyl group.
R ^a5 represents a hydrogen atom or a methyl group.
R ^a7 represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group obtained by combining these.
n1 represents the integer of 0-10.
n1 ′ represents an integer of 0 to 3. ]

h2 is preferably an integer of 1 to 4, more preferably 1.
L ^a2 is preferably an oxygen atom.
R ^a5 is preferably a methyl group.
Examples of the alkyl group for R ^a7 , the alicyclic hydrocarbon group, and a group obtained by combining these include the same groups as those ^exemplified for R ^a6 .
The alkyl group for R ^a7 is preferably an alkyl group having 6 or less carbon atoms.
The alicyclic hydrocarbon group for R ^a7 is preferably an alicyclic hydrocarbon group having 8 or less carbon atoms, and more preferably an alicyclic hydrocarbon group having 6 or less carbon atoms.
R ^a7 is preferably an alkyl group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 6 carbon atoms. n1 is preferably an integer of 0 to 3, more preferably 0 or 1. n1 ′ is preferably 0 or 1.

Examples of the monomer that leads to the structural unit (a1-2) (hereinafter sometimes referred to as “monomer (a1-2)”) include 1-ethylcyclopentan-1-yl (meth) acrylate and 1-ethylcyclohexane. -1-yl (meth) acrylate, 1-ethylcycloheptan-1-yl (meth) acrylate, 1-methylcyclopentan-1-yl (meth) acrylate, 1-methylcyclohexane-1-yl (meth) acrylate, Examples include 1-isopropylcyclopentan-1-yl (meth) acrylate, 1-isopropylcyclohexane-1-yl (meth) acrylate, 1-isopropylcycloheptan-1-yl (meth) acrylate, and the like. Among these, a monomer represented by any one of formula (a1-2-1) to formula (a1-2-12) is preferable, and formula (a1-2-3) to formula (a1-2-4) and formula The monomer represented by any one of (a1-2-9) to formula (a1-2-10) is more preferable, and the monomer represented by formula (a1-2-3) and formula (a1-2-9) Is more preferable.

  When the resin (A) includes the structural unit (a1-2), the content is preferably 3 to 35 mol%, more preferably 5 to 30% with respect to all the structural units of the resin (A). Mol%.

式（ａ１−３）中、
Ｒ^a13は、ヒドロキシ基を有していてもよい炭素数１〜３の脂肪族炭化水素基、カルボキシ基、シアノ基、水素原子又は−ＣＯＯＲ^aeを表す。
Ｒ^aeは、炭素数１〜８の脂肪族炭化水素基、炭素数３〜２０の脂環式炭化水素基、又はこれらを組み合わせた基を表し、該脂肪族炭化水素基及び該脂環式炭化水素基に含まれる水素原子は、ヒドロキシ基で置換されていてもよく、該脂肪族炭化水素基及び該脂環式炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基で置き換わっていてもよい。
Ｒ^a10、Ｒ^a11及びＲ^a12は、それぞれ独立に、炭素数１〜８のアルキル基、炭素数３〜２０の脂環式炭化水素基又はこれらを組合わせた基を表すか、Ｒ^a10及びＲ^a11は互いに結合して炭素数２〜２０の２価の炭化水素基を形成する。

In formula (a1-3),
R ^a13 represents an aliphatic hydrocarbon group having 1 to 3 carbon atoms which may have a hydroxy group, a carboxy group, a cyano group, a hydrogen atom, or —COOR ^ae .
R ^ae represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof, and the aliphatic hydrocarbon group and the alicyclic carbon group. The hydrogen atom contained in the hydrogen group may be substituted with a hydroxy group, and the methylene group contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group may be replaced with an oxygen atom or a carbonyl group. Good.
R ^a10, R ^a11 and R ^a12 are each independently an alkyl group having 1 to 8 carbon atoms, or an alicyclic hydrocarbon group or a group obtained by combining these C3-20, R ^a10 and R ^a11 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms.

Here, examples of —COOR ^ae for R ^a13 include a group in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group.

^Examples of the aliphatic hydrocarbon group which may have a hydroxyl group for R ^a13 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group.
Examples of the group consisting of R ^ae aliphatic hydrocarbon group, alicyclic hydrocarbon group, and aliphatic hydrocarbon group having 1 to 8 carbon atoms and alicyclic hydrocarbon group having 3 to 20 carbon atoms include, for example, methyl Group, ethyl group, propyl group, cyclopentyl group, cyclopropyl group, adamantyl group, adamantylmethyl group, 1-adamantyl-1-methylethyl group, 2-oxo-oxolan-3-yl group and 2-oxo-oxolane-4 -An yl group etc. are mentioned.
^{Examples of} R ^{a10 to} R ^a12 include the same groups as R ^{a1 to} R ^a3 in formula (1).
As —C (R ^a10 ) (R ^a11 ) (R ^a12 ) when R ^a10 and R ^a11 are bonded to each other to form a divalent hydrocarbon group, the following groups are preferred.

  Specific examples of the monomer that leads to the structural unit (a1-3) (hereinafter sometimes referred to as “monomer (a1-3)”) include 5-norbornene-2-carboxylic acid-tert-butyl, 5- 1-cyclohexyl-1-methylethyl norbornene-2-carboxylate, 1-methylcyclohexyl 5-norbornene-2-carboxylate, 2-methyl-2-adamantyl 5-norbornene-2-carboxylate, 5-norbornene-2- 2-ethyl-2-adamantyl carboxylate, 1- (4-methylcyclohexyl) -1-methylethyl 5-norbornene-2-carboxylate, 1- (4-hydroxycyclohexyl) -1 5-norbornene-2-carboxylic acid -Methylethyl, 1-methyl-1- (4-oxocyclohexyl) ethyl 5-norbornene-2-carboxylate Beauty 5-norbornene-2-carboxylic acid 1- (1-adamantyl) -1-methylethyl, and the like.

  Since the resin (A) containing the structural unit (a1-3) includes a sterically bulky structural unit, the resist composition of the present invention containing such a resin (A) is more expensive. A resist pattern can be obtained with resolution. Further, since a rigid norbornane ring is introduced into the main chain, the resulting resist pattern tends to be excellent in dry etching resistance.

  When the resin (A) contains the structural unit (a1-3), the content thereof is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, based on all the structural units of the resin (A). 20-85 mol% is more preferable.

［式（ａ１−４）中、
Ｒ^a32は、水素原子、ハロゲン原子、又は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｒ^a33は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
ｌａは０〜４の整数を表す。ｌａが２以上である場合、複数のＲ^a33は互いに同一であっても異なってもよい。
Ｒ^a34及びＲ^a35は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^a36は、炭素数１〜２０の炭化水素基を表すか、Ｒ^a35及びＲ^a36は互いに結合して炭素数２〜２０の２価の炭化水素基を形成し、該炭化水素基及び該２価の炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−Ｓ−に置き換わってもよい。］ Examples of the structural unit (a1) having the group (2) include a structural unit represented by the formula (a1-4) (hereinafter sometimes referred to as “structural unit (a1-4)”) and a formula (a1- 5) (hereinafter sometimes referred to as “structural unit (a1-5)” and the like).

[In the formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
la represents an integer of 0 to 4. When la is 2 or more, the plurality of R ^a33 may be the same as or different from each other.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a36 may represent a hydrocarbon group having 1 to 20 carbon atoms, R ^a35 and R ^a36 are each To form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group is replaced by —O— or —S—. Also good. ]

^Examples of the alkyl group for R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.
Examples of the halogen atom for R ^a32 and R ^a33 include a fluorine atom, a chlorine atom and a bromine atom.
R ^a34, as the hydrocarbon group of R ^a35 and R ^a36, for example, aliphatic hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group., R ^{a1 'to} R ^a3 of formula (2) ^'include the same groups as.
Of these, the hydrocarbon group of R ^a34, R ^a35 and R ^a36, isopropyl group, n- butyl group, sec- butyl group, tert- butyl group, a pentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, A cyclohexyl group, an adamantyl group, a 2-alkyladamantan-2-yl group, a 1- (adamantan-1-yl) alkane-1-yl group, an isobornyl group, and the like are preferable.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
R ^a33 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group.
la is preferably 0 or 1, more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrocarbon group having 1 to 12 carbon atoms, more preferably a methyl group or an ethyl group.
The hydrocarbon group for R ^a36 is preferably an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or these. A combined group, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms.

As a monomer which introduce | transduces structural unit (a1-4), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Among these, monomers represented by formula (a1-4-1) to formula (a1-4-7) are preferable, and monomers represented by formula (a1-4-1) to formula (a1-4-5) are preferable. Is more preferable.

  When the resin (A) includes the structural unit (a1-4), the content is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, based on all the structural units of the resin (A). 20 to 85 mol% is more preferable.

［式（ａ１−５）中、
Ｒ^a8は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｚ^ａ１は、単結合又は＊−（ＣＨ₂）_h3−ＣＯ−Ｌ^ａ６−を表し、ｈ３は１〜４の整数を表し、＊は、Ｌ^ａ１との結合手を表す。
Ｌ^ａ３、Ｌ^ａ４、Ｌ^ａ５及びＬ^ａ６は、それぞれ独立に、酸素原子又は硫黄原子を表す。
ｓ１は、１〜３の整数を表す。
ｓ１’は、０〜３の整数を表す。］

[In the formula (a1-5),
R ^a8 represents a C 1-6 alkyl group optionally having a halogen atom, a hydrogen atom, or a halogen atom.
Z ^a1 represents a single bond or * — (CH ₂ ) _h3 —CO—L ^a6 —, h3 represents an integer of 1 to 4, and * represents a bond to L ^a1 .
L ^a3 , L ^a4 , L ^a5 and L ^a6 each independently represent an oxygen atom or a sulfur atom.
s1 represents an integer of 1 to 3.
s1 ′ represents an integer of 0 to 3. ]

Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is preferable. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group and a trifluoromethyl group. Groups.
In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ^a5 is preferably an oxygen atom.
One of L ^a3 and L ^a4 is preferably an oxygen atom and the other is a sulfur atom.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

Examples of the monomer that leads to the structural unit (a1-5) (hereinafter sometimes referred to as “monomer (a1-5)”) include monomers described in JP-A-2010-61117. Among these, monomers represented by formulas (a1-5-1) to (a1-5-4) are preferable, and monomers represented by formula (a1-5-1) or formula (a1-5-2) are preferable. Is more preferable.

  When the resin (A) contains the structural unit (a1-5), the content is preferably from 1 to 50 mol%, more preferably from 3 to 45 mol%, based on all the structural units of the resin (A). 5 to 40 mol% is more preferable.

The structural unit (a1) is preferably at least one selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1), the structural unit (a1-2), and the structural unit (a1-5). More preferably, it is at least one selected from the group consisting of the structural unit (a1-1), the structural unit (a1-2) and the structural unit (a1-5), and more preferably the structural unit (a1). -1), structural unit (a1-2), and structural unit (a1-5), at least two selected from the group consisting of structural unit (a1-5), particularly preferably structural unit (a1-1) and structural unit (a1- 2) and / or structural unit (a1-5).
The structural unit (a1) is preferably a structural unit including the structural unit (a1-1).

<Structural unit (s)>
The structural unit (s) is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “monomer (s)”). The monomer for deriving the structural unit (s) (hereinafter sometimes referred to as “monomer (s)”) is not particularly limited as long as it does not have an acid labile group, and monomers known in the resist field can be used.
As the structural unit (s), a structural unit having a hydroxy group or a lactone ring and having no acid labile group is preferable. A structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring and having no acid labile group If a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”) is used for the resist composition, the resolution of the resist pattern and the adhesion to the substrate can be improved.
The structural unit (s) is preferably a structural unit (s) having a halogen atom (hereinafter sometimes referred to as “structural unit (a4)”).

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When the resist composition is used for high energy beam exposure such as KrF excimer laser exposure (248 nm), electron beam or EUV (extreme ultraviolet light), the structural unit (a2) is preferably a structural unit having a phenolic hydroxy group. When ArF excimer laser exposure (193 nm) or the like is used, the structural unit (a2) is preferably a structural unit having an alcoholic hydroxy group.

［式（ａ２−０）中、
Ｒ^a30は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｒ^a31は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイルオキシ基又はメタクリロイルオキシ基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^a31は同一又は相異なる。］ Examples of the structural unit (a2) having a phenolic hydroxy group include a structural unit represented by the formula (a2-0) (hereinafter sometimes referred to as “structural unit (a2-0)”).

[In the formula (a2-0),
R ^a30 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a31 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or Represents a methacryloyloxy group.
ma represents an integer of 0 to 4. When ma is an integer of 2 or more, the plurality of R ^a31 are the same or different. ]

The R ^a30, include the same groups as R ^a32 of formula (a1-4). Among them, R ^a30 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.
The alkoxy group of R ^a31 is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group.
ma is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.

Examples of the monomer that derives the structural unit (a2-0) include monomers described in JP 2010-204634 A.
Among them, the structural unit (a2-0) is represented by formula (a2-0-1), formula (a2-0-2), formula (a2-0-3), and formula (a2-0-4), respectively. What is represented is preferable, and what is represented by a formula (a2-0-1) or a formula (a2-0-2) is more preferable.

  Resin (A) containing the structural unit (a2-0) is polymerized using a monomer in which the phenolic hydroxy group of the monomer that derives the structural unit (a2-0) is protected with a protective group such as an acetyl group. And then deprotecting. However, when the deprotection treatment is performed, the acid labile group of the structural unit (a1) needs to be not significantly impaired.

  When the resin (A) has the structural unit (a2-0), the content is preferably from 5 to 95 mol%, more preferably from 10 to 80 mol%, based on all the structural units of the resin (A). 15-80 mol% is more preferable.

式（ａ２−１）中、
Ｌ^a3は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−を表し、
ｋ２は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、互いに独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。 Examples of the structural unit (a2) having an alcoholic hydroxy group include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as “structural unit (a2-1)”).

In formula (a2-1),
L ^a3 represents —O— or ^* —O— (CH ₂ ) _k2 —CO—O—,
k2 represents an integer of 1 to 7. * Represents 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 hydroxy group.
o1 represents an integer of 0 to 10.

In the formula (a2-1), L ^a3 is preferably, -O -, - O- (CH 2) f1 -CO-O- and is (wherein f1 is an integer from 1 to 4), more preferably Is —O—.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

As a monomer which introduce | transduces structural unit (a2-1), the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. A monomer represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferable, and represented by any one of formula (a2-1-1) to formula (a2-1-4). The monomer represented by Formula (a2-1-1) or Formula (a2-1-3) is more preferable.

  When the resin (A) contains the structural unit (a2), the content is usually 1 to 45 mol%, preferably 1 to 40 mol%, based on all structural units of the resin (A). More preferably, it is 1-35 mol%, More preferably, it is 2-20 mol%.

<Structural unit (a3)>
The lactone ring included in the structural unit (a3) may be a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, and may be a monocyclic lactone ring and another ring. A condensed ring may be used. Among these lactone rings, a bridged ring containing a γ-butyrolactone ring or a γ-butyrolactone ring structure is preferable.

  The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3) or the formula (a3-4).

［式（ａ３−１）中、
Ｌ^a4は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^a18は、水素原子又はメチル基を表す。
Ｒ^a21は炭素数１〜４の脂肪族炭化水素基を表す。
ｐ１は０〜５の整数を表す。ｐ１が２以上のとき、複数のＲ^a21は互いに同一又は相異なる。
式（ａ３−２）中、
Ｌ^a5は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^a19は、水素原子又はメチル基を表す。
Ｒ^a22は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表す。
ｑ１は、０〜３の整数を表す。ｑ１が２以上のとき、複数のＲ^a22は互いに同一又は相異なる。
式（ａ３−３）中、
Ｌ^a6は、酸素原子又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−（ｋ３は１〜７の整数を表す。）で表される基を表す。＊はカルボニル基との結合手を表す。
Ｒ^a20は、水素原子又はメチル基を表す。
Ｒ^a23は、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表す。
ｒ１は、０〜３の整数を表す。ｒ１が２以上のとき、複数のＲ^a23は互いに同一又は相異なる。
式（ａ３−４）中、
Ｒ^a24は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ｌ^a7は、単結合、^＊−Ｌ^a8−Ｏ−、^＊−Ｌ^a8−ＣＯ−Ｏ−、^＊−Ｌ^a8−ＣＯ−Ｏ−Ｌ^a9−ＣＯ−Ｏ−又は^＊−Ｌ^a8−Ｏ−ＣＯ−Ｌ^a9−Ｏ−を表す。
＊は−Ｏ−との結合手を表す。
Ｌ^a8及びＬ^a9は、互いに独立に、炭素数１〜６のアルカンジイル基を表す。］

[In the formula (a3-1),
L ^a4 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an 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 an integer of 0 to 5. When p1 is 2 or more, the plurality of R ^a21 are the same or different from each other.
In formula (a3-2),
L ^a5 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an 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 carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 represents an integer of 0 to 3. When q1 is 2 or more, the plurality of R ^a22 are the same or different from each other.
In formula (a3-3),
L ^a6 represents an oxygen atom or a group represented by ^* —O— (CH ₂ ) _k3 —CO—O— (k3 represents an 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 carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
r1 represents an integer of 0 to 3. When r1 is 2 or more, the plurality of R ^a23 are 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 is a single bond, ^* —L ^a8 —O—, ^* —L ^a8 —CO—O—, ^* —L ^a8 —CO—O—L ^a9 —CO—O— or ^* —L ^a8 —O—CO —L ^a9 —O— is represented.
* Represents a bond with -O-.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms. ]

Examples of the halogen atom for R ^a24 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
^Examples of the alkyl group for R ^a24 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and n-hexyl group. , Preferably it is a C1-C4 alkyl group, More preferably, it is a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom of R ^a24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluoro group. A hexyl group, a trichloromethyl group, a tribromomethyl group, a triiodomethyl group, etc. are mentioned.

^Examples of the alkanediyl group represented by L ^a8 and L ^a9 include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5. -Diyl group and hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, 4-diyl group, 2-methylbutane-1,4-diyl group, etc. are mentioned.

In the formula (a3-1) to the formula (a3-3), L ^{a4 to} L ^a6 are independently of each other preferably an oxygen atom or k- is an integer of 1 to 4 * —O— (CH ₂ ). A group represented by _{k 3} —CO—O—, more preferably an oxygen atom and * —O—CH ₂ —CO—O—, still more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are independently of each other preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0-2.

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 still more preferably a hydrogen atom or a methyl group.
L ^a7 is preferably a single bond or ^* -L ^a8 —CO—O—, and more preferably a single bond, —CH ₂ —CO—O— or —C ₂ H ₄ —CO—O—. .

  As the monomer for deriving the structural unit (a3), a monomer described in JP2010-204646A, a monomer described in JP2000-122294A, a monomer described in JP2012-41274A, For example, Formula (a3-1-1) to Formula (a3-1-6), Formula (a3-2-1) to Formula (a3-2-4), Formula (a3-3-1) to Formula (a3) -3-4) and a monomer represented by any one of formulas (a3-4-1) to (a3-4-6). Among them, the formula (a3-1-1), the formula (a3-1-2), the formula (a3-2-3), the formula (a3-2-4), the formula (a3-4-1), or the formula ( The structural unit derived from the monomer represented by a3-4-2) is more preferable, and represented by the formula (a3-1-1), the formula (a3-2-3), or the formula (a3-4-2). More preferred are structural units derived from monomers.

In the above structural unit, a compound in which a methyl group corresponding to R ^a24 is replaced with a hydrogen atom can also be given as a specific example of a monomer that leads to the structural unit (a3-4).

  Among structural units (a3), formula (a3-1-1), formula (a3-1-2), formula (a3-2-3), formula (a3-2-4), formula (a3-4-) 1) or a structural unit derived from a monomer represented by the formula (a3-4-2) is more preferable, and the formula (a3-1-1), the formula (a3-2-3) or the formula (a3-4-2) The structural unit derived from a monomer represented by

When the resin (A) includes the structural unit (a3), the total content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A). More preferably, it is 10-60 mol%.
Moreover, content of a structural unit (a3-1), a structural unit (a3-2), a structural unit (a3-3), and a structural unit (a3-4) is respectively with respect to all the structural units of resin (A). 5 to 60 mol% is preferable, 5 to 50 mol% is more preferable, and 10 to 50 mol% is more preferable.

<Structural unit (a4)>
Examples of the halogen atom that the structural unit (a4) has include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Especially, it is preferable that the structural unit (a4) has a fluorine atom.

［式（ａ４−０）中、
Ｒ^５は、水素原子又はメチル基を表す。
Ｌ^２は、炭素数１〜４の脂肪族飽和炭化水素基を表す。
Ｌ^３は、炭素数１〜８のペルフルオロアルカンジイル基を表す。
Ｒ^６は、水素原子又はフッ素原子を表す。］ As the structural unit (a4), a structural unit represented by formula (a4-0) can be given.

[In the formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ² represents an aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms.
L ³ represents a C 1-8 perfluoroalkanediyl group.
R ⁶ represents a hydrogen atom or a fluorine atom. ]

Examples of the L ³ perfluoroalkanediyl group include a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, and a perfluorobutane-1,4. -Diyl group, perfluoropentane-1,5-diyl group, perfluorohexane-1,6-diyl group, perfluoroheptane-1,7-diyl group, perfluorooctane-1,8-diyl group and the like.

L ² is preferably a methylene group or an ethylene group, and more preferably a methylene group.
L ³ is preferably a C 1-6 perfluoroalkanediyl group, and more preferably a C ^1-3 C perfluoroalkanediyl group.

Examples of the structural unit (a4-0) include the following.

In the above structural unit, a structural unit in which a methyl group corresponding to R ³ is replaced by a hydrogen atom can also be given as a specific example of the structural unit (a4-0).

［式（ａ４−１）中、
Ｒ^a41は、ハロゲン原子を有してもよい炭素数１〜６のアルキル基、水素原子又はハロゲン原子を表す。
Ａ^a41は、置換基を有していてもよい炭素数１〜６のアルカンジイル基又は式（ａ−ｇ１）

〔式（ａ−ｇ１）中、
ｓは０又は１を表す。
Ａ^a42及びＡ^a44は、互いに独立に、置換基を有していてもよい炭素数１〜５の２価の脂肪族炭化水素基を表す。
Ａ^a43は、単結合又は置換基を有していてもよい炭素数１〜５の２価の脂肪族炭化水素基を表す。
Ｘ^a41及びＸ^a42は、互いに独立に、−Ｏ−、−ＣＯ−、−ＣＯ−Ｏ−又は−Ｏ−ＣＯ−を表す。
ただし、Ａ^a42、Ａ^a43及びＡ^a44の炭素数の合計は７以下である。〕
で表される基を表す。
Ｒ^a42は、置換基を有していてもよい炭素数１〜２０の炭化水素基を表し、該炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。
ただし、Ａ^a41及びＲ^a42のうち少なくとも一方は、ハロゲン原子を有する基である。］ As the structural unit (a4), a structural unit represented by formula (a4-1) can be given.

[In the formula (a4-1),
R ^a41 represents a C 1-6 alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom.
A ^a41 is an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a formula (a-g1).

[In the formula (a-g1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent a ^C 1-5 divalent aliphatic hydrocarbon group which may have a substituent.
A ^a43 represents a ^C1-C5 divalent aliphatic hydrocarbon group which may have a single bond or a substituent.
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 and A ^a44 is 7 or less. ]
Represents a group represented by
R ^a42 represents an ^optionally substituted hydrocarbon group having 1 to 20 carbon atoms, and the methylene group contained in the hydrocarbon group may be replaced with an oxygen atom or a carbonyl group.
However, at least one of A ^a41 and R ^a42 is a group having a halogen atom. ]

脂肪族炭化水素基と脂環式炭化水素基とを組み合わせた基としては、例えば、シクロプロピルメチル基、シクロブチルメチル基、アダマンチルメチル基、ノルボルニルメチル基等が挙げられる。
芳香族炭化水素基としては、例えば、フェニル基、トリル基、キシリル基、ナフチル基、アントリル基、ビフェニリル基、フェナントリル基、フルオレニル基等が挙げられる。 R ^a41 includes the same group as R ^a24 in formula (a3-4). Of these, R ^a41 is preferably a hydrogen atom or a methyl group.
^Examples of the hydrocarbon group for R ^a42 include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group obtained by combining these. The aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, but is preferably an aliphatic saturated hydrocarbon group. Similarly, the alicyclic hydrocarbon group is preferably an alicyclic saturated hydrocarbon group. .
Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, hexadecyl group, pentadecyl group, hexyl. Examples include alkyl groups such as decyl group, heptadecyl group, and octadecyl group.
Examples of the alicyclic aliphatic hydrocarbon group include a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* Represents a bond.) And a polycyclic alicyclic hydrocarbon group.

Examples of the group obtained by combining an aliphatic hydrocarbon group and an alicyclic hydrocarbon group include a cyclopropylmethyl group, a cyclobutylmethyl group, an adamantylmethyl group, and a norbornylmethyl group.
Examples of the aromatic hydrocarbon group include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, an anthryl group, a biphenylyl group, a phenanthryl group, and a fluorenyl group.

^As the hydrocarbon group for R ^a42 , an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or a group obtained by combining these is preferable, and an aliphatic saturated hydrocarbon group, an alicyclic saturated hydrocarbon group, or a combination thereof. Groups are more preferred.

As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned, Preferably it is a fluorine atom.
The hydrocarbon group having a halogen atom is preferably a hydrocarbon group having a fluorine atom, more preferably an aliphatic hydrocarbon group having a fluorine atom, an alicyclic hydrocarbon group having a fluorine atom, or a combination thereof. It is a group.

Examples of the aliphatic hydrocarbon group having a fluorine atom include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, Perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2 , 2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2, 2,3,3,4,4-octafluorobutyl, perfluorobutyl, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl, 2- (perfluoro Olopropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5- Decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2- (perfluorobutyl) ethyl group, 1,1,2, 2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentyl Fluorinated alkyl groups such as a methyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group are exemplified, and among them, a perfluoroalkyl group is preferable.
Examples of the alicyclic hydrocarbon group having a fluorine atom include a perfluorocycloalkyl group such as a perfluorocyclohexyl group; a perfluoroadamantyl group.
The hydrocarbon group having a halogen atom preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.
Examples of the group having a fluorine atom in which an aliphatic hydrocarbon group and an alicyclic hydrocarbon group are combined include a perfluoroadamantylmethyl group.

^Examples of the substituent that the hydrocarbon group of R ^a42 may have include a halogen atom, —O—R ^h1 , —CO—R ^h2 , —O—CO—R ^h3 and —CO—O—R ^h4. Can be mentioned.
R ^{h1 to} R ^h4 each independently represent a hydrocarbon group optionally having a halogen atom having 1 to 18 carbon atoms. However, the ^sum of the carbon number of the hydrocarbon group of R ^a42 , the carbon number of the substituent, and the number of —O— and —CO— contained in the substituent is 20 or less, preferably 15 or less. More preferably, it is 12 or less.

When R ^a42 is a group having a halogen atom, the hydrocarbon group of R ^a42 is, as a substituent, a halogen atom, —O—R ^h1 , —CO—R ^h2 , —O—CO—R ^h3 and —CO—. It is preferable to have at least one selected from the group consisting of O—R ^h4 .
^When the hydrocarbon group of R ^a42 has —O—R ^h1 , —CO—R ^h2 , —O—CO—R ^h3 or —CO—O—R ^h4 , the number is preferably one.
R ^{h1 to} R ^h4 each independently represent a hydrocarbon group having a halogen atom having 1 to 18 carbon atoms. However, the ^sum of the carbon number of the hydrocarbon group of R ^a42 , the carbon number of the substituent, and the number of —O— and —CO— contained in the substituent is 20 or less, preferably 15 or less. More preferably, it is 12 or less.
The hydrocarbon group of R ^{h1 to} R ^h4 is preferably an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or a group obtained by combining these. The hydrocarbon group having a halogen atom is preferably a hydrocarbon group having a fluorine atom, more preferably an aliphatic hydrocarbon group having a fluorine atom, an alicyclic hydrocarbon group having a fluorine atom, or a combination thereof. Specific examples thereof include the above-described groups.

［式（ａ−ｇ２）中、
Ａ^a46は、ハロゲン原子を有していてもよい炭素数１〜１７の２価の炭化水素基を表す。
Ｘ^a44は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数１〜１７の１価の炭化水素基を表す。
ただし、Ａ^a46及びＡ^a47の炭素数の合計は１８以下であり、Ａ^a46及びＡ^a47のうち、少なくとも一方は、少なくとも１つのハロゲン原子を有する。］ When R ^a42 is a group having a halogen atom, R ^a42 is preferably a group represented by the formula (a-g2).

[In the formula (a-g2),
A ^a46 represents a C ^1-17 divalent hydrocarbon group which may have a halogen atom.
X ^a44 represents a carbonyloxy group or an oxycarbonyl group.
A ^a47 represents a monovalent hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 and A ^a47 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom. ]

Of A ^a46 and A ^a47 , both may be a group having a halogen atom, but A ^a46 is preferably a group having a halogen atom.
A ^a46 is preferably a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom, or a divalent alicyclic group having 3 to 17 carbon atoms which may have a halogen atom. Or a divalent group having 4 to 17 carbon atoms, or a combination thereof, more preferably a divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms which may have a halogen atom. More preferably, it is a C 1-3 divalent aliphatic hydrocarbon group which may have a halogen atom. In particular,
A ^a47 is preferably a monovalent aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom, or a monovalent alicyclic group having 3 to 17 carbon atoms which may have a halogen atom. A monovalent group having 4 to 17 carbon atoms or a combination thereof, more preferably a monovalent aliphatic hydrocarbon group having 1 to 15 carbon atoms which may have a halogen atom, halogen A monovalent alicyclic hydrocarbon group having 3 to 15 carbon atoms which may have atoms, or a monovalent group having 4 to 15 carbon atoms in combination thereof, more preferably a halogen atom. And a monovalent alicyclic hydrocarbon group having 5 to 12 carbon atoms.
A ^a47 is particularly preferably a cyclohexyl group or an adamantyl group.

Examples of the group represented by the formula (a-g2) include the following structures.

^As the alkanediyl group of ^Aa41 , a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group , A straight-chain alkanediyl group such as hexane-1,6-diyl group; 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 -Branched alkanediyl groups such as a diyl group, 1-methylbutane-1,4-diyl group, 2-methylbutane-1,4-diyl group.
^Examples of the substituent in the alkanediyl group of A ^a41 include a halogen atom, a hydroxy 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 2 to 4 carbon atoms, and still more preferably an ethylene group.

In the group represented by the formula (a-g1) of A ^a41 (hereinafter sometimes referred to as “group (a-g1)”), A ^a44 is ^bonded to —O—CO—R ^a42 .
As the aliphatic hydrocarbon group for A ^a42 , A ^a43 and A ^{a44 in} the group (a-g1), a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane- Examples include alkanediyl groups such as 1,4-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, and 2-methylpropane-1,2-diyl group. . Examples of these substituents include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
s is preferably 0.

^Examples of the group (a-g1) in which X ^a42 is an oxygen atom include the following groups. In the following examples, * is a bond with —O—CO—R ^a42 .

Examples of the group (a-g1) in which X ^a42 is a carbonyl group include the following groups.

Examples of the group (a-g1) in which X ^a42 is a carbonyloxy group include the following groups.

Examples of the group (a-g1) in which X ^a42 is an oxycarbonyl group include the following groups.

［式（ａ４−２）中、
Ｒ^ｆ1は、水素原子又はメチル基を表す。
Ａ^ｆ1は、炭素数１〜６のアルカンジイル基を表す。
Ｒ^ｆ2は、フッ素原子を有する炭素数１〜１０の炭化水素基を表す。］ As the structural unit represented by the formula (a4-1), a structural unit represented by the formula (a4-2) or the formula (a4-3) is preferable.

[In the 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 C 1-10 hydrocarbon group having a fluorine atom. ]

As the alkanediyl group of A ^f1 , a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group Linear alkanediyl group such as propane-1,2-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2 -Branched alkanediyl groups such as a diyl group, 1-methylbutane-1,4-diyl group, 2-methylbutane-1,4-diyl group.

The hydrocarbon group for R ^f2 includes an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group obtained by combining these. The aliphatic hydrocarbon group is preferably an aliphatic saturated hydrocarbon group, and the alicyclic hydrocarbon group is preferably an alicyclic saturated hydrocarbon group. As the hydrocarbon group for R ^f2, the same groups as the hydrocarbon groups for R ^a42 in formula (a4-1) can be mentioned.

Examples of the hydrocarbon group having a fluorine atom of R ^f2 include the same groups as the aliphatic hydrocarbon group having a fluorine atom and the alicyclic hydrocarbon group having a fluorine atom, which are mentioned as the group representing R ^a42 .

In formula (a4-2), as A ^f1 , an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.
R ^f2 is preferably a C 1-10 aliphatic hydrocarbon group having a fluorine atom or a C 3-10 alicyclic hydrocarbon group having a fluorine atom, and a C 1-6 fluorinated alkyl group. Is more preferable.

［式（ａ４−３）中、
Ｒ^ｆ11は、水素原子又はメチル基を表す。
Ａ^ｆ11は、炭素数１〜６のアルカンジイル基を表す。
Ａ^ｆ13は、フッ素原子を有していてもよい炭素数１〜１７の２価の脂肪族炭化水素基、フッ素原子を有していてもよい炭素数３〜１７の２価の脂環式炭化水素基又はこれらを組み合わせた２価の基を表す。
Ｘ^ｆ12は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ａ^ｆ14は、フッ素原子を有していてもよい炭素数１〜１７の脂肪族炭化水素基、フッ素原子を有していてもよい炭素数３〜１７の脂環式炭化水素基又はこれらを組み合わせた基を表す。
ただし、Ａ^ｆ13及びＡ^ｆ14のうち少なくとも一方は、フッ素原子を有する基を表す。］

[In the 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 is a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom, or a divalent alicyclic carbon group having 3 to 17 carbon atoms which may have a fluorine atom. A hydrogen group or a divalent group in which these are combined is represented.
X ^f12 represents a carbonyloxy group or an oxycarbonyl group.
A ^f14 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom, an alicyclic hydrocarbon group having 3 to 17 carbon atoms which may have a fluorine atom, or a combination thereof. Represents a group.
However, at least one of A ^f13 and A ^f14 represents a group having a fluorine atom. ]

^Examples of the alkanediyl group for A ^f11 include the same groups as the alkanediyl group for A ^f1 , and an ethylene group is preferable.

As the divalent aliphatic hydrocarbon group which may have a fluorine atom of A ^{f13 and} the divalent alicyclic hydrocarbon group which may have a fluorine atom, the same groups as those in R ^a42 may be used. And a group in which one hydrogen atom or fluorine atom has been removed.
A ^f13 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group.
Examples of the divalent aliphatic hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; difluoromethylene group, perfluoroethylene group, perfluoro Examples thereof include perfluoroalkanediyl groups such as propanediyl group, perfluorobutanediyl group and perfluoropentanediyl group.
The divalent alicyclic hydrocarbon group which may have a fluorine atom may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic divalent aliphatic hydrocarbon group include an adamantanediyl group, a norbornanediyl group, a perfluoroadamantanediyl group, and the like.
The divalent group formed by combining the divalent aliphatic hydrocarbon group which may have a fluorine atom and the divalent alicyclic hydrocarbon group which may have a fluorine atom has a total carbon number of 17 It is as follows.
A ^f13 is preferably a C 1-6 divalent aliphatic hydrocarbon group which may have a fluorine atom, or a C 3-6 divalent fat which may have a fluorine atom. A cyclic hydrocarbon group or a divalent group having 4 to 6 carbon atoms, or a combination thereof, more preferably a divalent aliphatic hydrocarbon group having 1 to 6 carbon atoms which may have a fluorine atom. More preferably, it is a C2-C3 bivalent aliphatic hydrocarbon group which may have a fluorine atom.

As the aliphatic hydrocarbon group which may have a fluorine atom of A ^{f14 and} the alicyclic hydrocarbon group which may have a fluorine atom, the same groups as those in R ^a42 may be mentioned. The aliphatic hydrocarbon group which may have a fluorine atom is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom, and the alicyclic hydrocarbon group which may have a fluorine atom is An alicyclic saturated hydrocarbon group which may have a fluorine atom is preferred. The group combining the aliphatic hydrocarbon group which may have a fluorine atom and the alicyclic hydrocarbon group which may have a fluorine atom has a total carbon number of 17 or less.
A ^f14 is preferably an aliphatic hydrocarbon group having 1 to 12 carbon atoms which may have a fluorine atom, an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a fluorine atom, or C4-12 group which combined these, More preferably, C1-C10 aliphatic hydrocarbon group, C3-C10 alicyclic hydrocarbon group, or carbon number 4 which combined these -12 groups, more preferably an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or a group having 4 to 10 carbon atoms in which an aliphatic hydrocarbon group and an alicyclic hydrocarbon group are combined. . A ^f14 is particularly preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group or an adamantyl group.

At least one of A ^f13 and A ^f14 is a group having a fluorine atom, and preferably A ^f13 is a group having a fluorine atom.

Examples of the structural unit represented by formula (a4-2) include structural units represented by formula (a4-1-1) to formula (a4-1-22), respectively.

Examples of the structural unit represented by formula (a4-3) include structural units represented by formula (a4-1′-1) to formula (a4-1′-22), respectively.

［式（ａ４−４）中、
Ｒ^f21は、水素原子又はメチル基を表す。
Ａ^f21は、−（ＣＨ_２）_ｊ１−、−（ＣＨ_２）_ｊ２−Ｏ−（ＣＨ_２）_ｊ３−又は−（ＣＨ_２）_ｊ４−ＣＯ−Ｏ−（ＣＨ_２）_ｊ５−を表す。
ｊ１〜ｊ５は、互いに独立に、１〜６の整数を表す。
Ｒ^f22は、フッ素原子を有する炭素数１〜１０の炭化水素基を表す。］ Examples of the structural unit (a4) include a structural unit represented by the formula (a4-4).

[In the formula (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 represents — (CH ₂ ) _j1 —, — (CH ₂ ) _j2 —O— (CH ₂ ) _j3 — or — (CH ₂ ) _j4 —CO—O— (CH ₂ ) _j5 —.
j1 to j5 each independently represent an integer of 1 to 6.
R ^f22 represents a C 1-10 hydrocarbon group having a fluorine atom. ]

^Examples of the hydrocarbon group having a fluorine atom of R ^f22 include the same hydrocarbon groups as R ^f2 in formula (a4-2).

In Formula (a4-4), as A ^f21 , — (CH ₂ ) _j1 — is preferable, an ethylene group or a methylene group is more preferable, and a methylene group is further preferable.
R ^f22 is preferably a ^C 1-10 aliphatic hydrocarbon group having a fluorine atom or a C 1-10 alicyclic hydrocarbon group having a fluorine atom, and a C 1-10 aliphatic having a fluorine atom. An aromatic saturated hydrocarbon group is more preferable, and an aliphatic saturated hydrocarbon group having 1 to 6 carbon atoms having a fluorine atom is more preferable.

As a structural unit represented by Formula (a4-4), the structural unit represented by the following is mentioned, for example.

  When the resin (A) has a structural unit (a4), the content is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, based on all structural units of the resin (A). More preferably, it is 10 mol%.

<Other structural units (t)>
Examples of the structural unit (t) include the structural unit (a2), the structural unit (a3), and the structural unit (s) having a non-leaving hydrocarbon group in addition to the structural unit (a4) (hereinafter referred to as “structural unit (a5)”). In some cases).

［式（ａ５−１）中、
Ｒ⁵¹は、水素原子又はメチル基を表す。
Ｒ⁵²は、炭素数３〜１８の脂環式炭化水素基を表し、該脂環式炭化水素基に含まれる水素原子は炭素数１〜８の脂肪族炭化水素基又はヒドロキシ基で置換されていてもよい。但し、Ｌ⁵¹との結合位置にある炭素原子に結合する水素原子は、炭素数１〜８の脂肪族炭化水素基で置換されない。
Ｌ⁵¹は、単結合又は炭素数１〜１８の２価の飽和炭化水素基を表し、該飽和炭化水素基に含まれるメチレン基は、酸素原子又はカルボニル基に置き換わっていてもよい。］ <Structural unit (a5)>
Examples of the non-leaving hydrocarbon group that the structural unit (a5) has include a linear, branched, or cyclic hydrocarbon group. Especially, it is preferable that a structural unit (a5) is an alicyclic hydrocarbon group.
As a structural unit (a5), the structural unit represented by a formula (a5-1) is mentioned, for example.

[In the 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 a hydrogen atom contained in the alicyclic hydrocarbon group is substituted with an aliphatic hydrocarbon group or hydroxy group having 1 to 8 carbon atoms. May be. However, the hydrogen atom bonded to the carbon atom at the bonding position with L ⁵¹ is not substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms.
L ⁵¹ 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 replaced with an oxygen atom or a carbonyl group. ]

The alicyclic hydrocarbon group for R ⁵² may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group.
Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Examples thereof include alkyl groups such as octyl group and 2-ethylhexyl group.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-hydroxyadamantyl group and a 3-methyladamantyl group.
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.

Examples of the divalent saturated hydrocarbon group for L ⁵¹ include a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent aliphatic saturated hydrocarbon group. .
Examples of the divalent aliphatic saturated hydrocarbon group include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group.
The divalent alicyclic saturated hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

式（Ｌ１−１）中、
Ｘ^x1は、カルボニルオキシ基又はオキシカルボニル基を表す。
Ｌ^x1は、炭素数１〜１６の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x2は、単結合又は炭素数１〜１５の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x1及びＬ^x2の合計炭素数は、１６以下である。
式（Ｌ１−２）中、
Ｌ^x3は、炭素数１〜１７の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x4は、単結合又は炭素数１〜１６の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x1及びＬ^x2の合計炭素数は、１７以下である。
式（Ｌ１−３）中、
Ｌ^x5は、炭素数１〜１５の２価の脂肪族飽和炭化水素基を表す。
Ｌ^x6及びＬ^x７は、それぞれ独立に、単結合又は炭素数１〜１４の２価の脂肪族飽和炭化水素基を表す。
ただし、Ｌ^x5、Ｌ^x6及びＬ^x7の合計炭素数は、１５以下である。
式（Ｌ１−４）中、
Ｌ^x8及びＬ^x9は、単結合又は炭素数１〜１２の２価の脂肪族飽和炭化水素基を表す。
Ｗ^x1は、炭素数３〜１５の２価の脂環式飽和炭化水素基を表す。
ただし、Ｌ^x8、Ｌ^x9及びＷ^x1の合計炭素数は、１５以下である。 Examples of the group in which the methylene group contained in the saturated hydrocarbon group is replaced with an oxygen atom or a carbonyl group include groups represented by formulas (L1-1) to (L1-4). In the following formula, * represents a bond with an oxygen atom.

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 L ^x1 and L ^x2 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 ^x9 represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms.
W ^x1 represents a divalent alicyclic 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 C 1-8 divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene 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.
L ^x3 is preferably a C 1-8 divalent aliphatic saturated hydrocarbon group.
L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x7 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, more preferably a cyclohexanediyl group or an adamantanediyl group.

As group represented by a formula (L1-1), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-2), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-3), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-4), the bivalent group shown below is mentioned, for example.

L ⁵¹ is preferably a single bond or a group represented by the formula (L1-1).

Examples of the structural unit (a5-1) include the following.

In the above structural unit, a structural unit in which a methyl group corresponding to R ⁵¹ is replaced with a hydrogen atom can also be given as a specific example of the structural unit (a5-1).

  The resin (A) may further have a structural unit other than the above-described structural unit, and examples of such a structural unit include structural units well known in the art.

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 of the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), more preferably the structural unit (a1- 1).
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 the structural unit (a2-1). The structural unit (a3) is preferably at least one of the structural unit (a3-1), the structural unit (a3-2), and the structural unit (a3-4).

  The resin (A) preferably contains 15 mol% or more of a structural unit derived from a monomer having an adamantyl group. When the content of the structural unit having an adamantyl group is increased, the dry etching resistance of the resist pattern is improved.

Each structural unit constituting the resin (A) may be contained alone or in combination of two or more, and a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. Can be manufactured by.
The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 4,000 or more), 50,000 or less (more preferably 30,000 or less, and further preferably 15,000 or less).

<Resin other than resin (A)>
The resist composition of the present invention may contain a resin other than the resin (A). An example of such a resin is a resin composed of only the structural unit (s).
Especially, as resin other than resin (A), resin (henceforth "resin (X)") which has structural unit (a4) is preferable. In the resin (X), the content ratio of the structural unit (a4) is preferably 80 mol% or more, more preferably 85 mol% or more, and still more preferably 90 mol% or more with respect to all the structural units of the resin (X). .
Examples of the structural unit that the resin (X) may further include include a structural unit derived from the structural unit (a3) and other known monomers in the structural unit (a2).
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 for the resin (A).

  When the resist composition of this invention contains resin (X), the content becomes like this. Preferably it is 1-60 mass parts with respect to 100 mass parts of resin (A), More preferably, it is 3-50 mass parts More preferably, it is 5-40 mass parts, Most preferably, it is 7-30 mass parts.

  The resin content in the resist composition of the present invention is preferably 80% by mass or more and 99% by mass or less with respect to the solid content of the resist composition. In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent (D) described later from the total amount of the resist composition. The solid content of the resist composition and the resin content relative to the solid content can be measured, for example, by known analytical means such as liquid chromatography or gas chromatography.

<Solvent (E)>
The content of the solvent (E) is, for example, 90% by mass or more in the resist composition, preferably 92% by mass or more, more preferably 94% by mass or more, for example 99.9% by mass or less, preferably 99% by mass or less. It is. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and pyruvic acid Examples thereof include esters such as ethyl; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (E) may contain 1 type independently, and may contain 2 or more types.

［式（Ｄ）中、
Ｒ^Ｄ１及びＲ^Ｄ２は、それぞれ独立に、炭素数１〜１２の炭化水素基、炭素数１〜６のアルコキシ基、炭素数２〜７のアシル基、炭素数２〜７のアシルオキシ基、炭素数２〜７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ’及びｎ’は、それぞれ独立に、０〜４の整数を表し、ｍ’が２以上の場合、複数のＲ^Ｄ１は同一又は相異なり、ｎ’が２以上の場合、複数のＲ^Ｄ２は同一又は相異なる。］ <Compound (D)>
The compound (D) is a compound represented by the formula (D).

[In the formula (D),
R ^D1 and R ^D2 are each independently a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, or a carbon number Represents 2 to 7 alkoxycarbonyl groups, nitro groups or halogen atoms.
m ′ and n ′ each independently represents an integer of 0 to 4, and when m ′ is 2 or more, the plurality of R ^D1 are the same or different, and when n ′ is 2 or more, the plurality of R ^D2 are Same or different. ]

In the compound represented by the formula (D), examples of the hydrocarbon group of R ^D1 and R ^D2 include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and combinations thereof. .
Examples of the aliphatic hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, and nonyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and may be either saturated or unsaturated. Examples thereof include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group, and cyclododecyl group, norbornyl group, adamantyl group, and the like.
As aromatic hydrocarbon group, phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-propylphenyl group 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group , Aryl groups such as mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, and the like.
These combinations include alkyl-cycloalkyl groups, cycloalkyl-alkyl groups, aralkyl groups (eg, phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl-1-propyl group, 1- Phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl Group) and the like.

Examples of the alkoxy group include a methoxy group and an ethoxy group.
Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, and a cyclohexanecarbonyl group.
Examples of the acyloxy group include a group in which an oxy group (—O—) is bonded to the acyl group.
Examples of the alkoxycarbonyl group include a group in which a carbonyl group (—CO—) is bonded to the above alkoxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

In the formula (D), R ^D1 and R ^D2 are each independently an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or 2 to 2 carbon atoms. Preferred are an acyl group having 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group, or a halogen atom.
m ′ and n ′ are each independently preferably an integer of 0 to 2, and more preferably 0. When m ′ is 2 or more, the plurality of R ^D1 are the same or different, and when n ′ is 2 or more, the plurality of R ^D2 are the same or different.

Examples of the compound (D) include the following compounds.

  Compound (D) can be produced by the method described in “Tetrahedron Vol. 45, No. 19, p6281-6296”. Moreover, the compound (D) can use the compound marketed.

  0.01-12 mass parts is preferable with respect to 100 mass parts of resin (A), and, as for the content rate of a compound (D), 0.03-10 mass parts is more preferable, and 0.06-6 mass parts is further. preferable. The content of the compound (D) is preferably 0.01 to 10% by mass, more preferably 0.03 to 8% by mass, and still more preferably 0, based on the solid content of the resist composition. 0.05 to 5% by mass.

<Basic compound (C)>
The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. The basic compound (C) is used as a quencher in the resist composition of the present invention. A quencher is a compound having an action of capturing an acid generated from an acid generator upon exposure. Amines include aliphatic and aromatic amines; primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by any one of formulas (C1) to (C8), more preferably a compound represented by formula (C1), and more preferably It is a compound represented by a formula (C1-1).

［式（Ｃ１）中、Ｒ^c1、Ｒ^c2及びＲ^c3は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基、炭素数５〜１０の脂環式炭化水素基又は炭素数６〜２０の芳香族炭化水素基を表し、該アルキル基及び該脂環式炭化水素基に含まれる水素原子は、ヒドロキシ基、アミノ基又は炭素数１〜６のアルコキシ基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、炭素数１〜６のアルコキシ基で置換されていてもよい。］

[In formula (C1), R ^c1 , R ^c2 and R ^c3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or 6 to 6 carbon atoms. 20 represents an aromatic hydrocarbon group, the hydrogen atom contained in the alkyl group and the alicyclic hydrocarbon group may be substituted with a hydroxy group, an amino group or an alkoxy group having 1 to 6 carbon atoms, The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 6 carbon atoms. ]

［式（Ｃ１−１）中、Ｒ^c2及びＲ^c3は、上記と同じ意味を表す。
Ｒ^c4は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基を表す。
ｍ３は０〜３の整数を表し、ｍ３が２以上のとき、複数のＲ^c4は同一又は相異なる。］ The compound represented by the formula (C1) is preferably a compound represented by the formula (C1-1).

[In Formula (C1-1), R ^c2 and R ^c3 represent the same meaning as described above.
R ^c4 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
m3 represents an integer of 0 to 3, and when m3 is 2 or more, the plurality of R ^c4 are the same or different. ]

［式（Ｃ２）、式（Ｃ３）及び式（Ｃ４）中、Ｒ^c5、Ｒ^c6、Ｒ^c7及びＲ^c8は、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c9は、炭素数１〜６のアルキル基、炭素数３〜６の脂環式炭化水素基又は炭素数２〜７のアシル基を表す。
ｎ３は０〜８の整数を表し、ｎ３が２以上のとき、複数のＲ^c9は同一又は相異なる。］

[In Formula (C2), Formula (C3) and Formula (C4), R ^c5 , R ^c6 , R ^c7 and R ^c8 each independently represent the same meaning as R ^c1 .
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an acyl group having 2 to 7 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 are the same or different. ]

［式（Ｃ５）及び式（Ｃ６）中、Ｒ^c10、Ｒ^c11、Ｒ^c12、Ｒ^c13及びＲ^c16は、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c14、Ｒ^c15及びＲ^c17は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
ｏ３及びｐ３は、それぞれ独立に、０〜３の整数を表し、ｏ３が２以上のとき、複数のＲ^c1４は同一又は相異なり、ｐ３が２以上のとき、複数のＲ^c15は同一又は相異なる。
Ｌ^c1は、炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

[In Formula (C5) and Formula (C6), R ^c10 , R ^c11 , R ^c12 , R ^c13 and R ^c16 each independently represent the same meaning as R ^c1 .
R ^c14 , R ^c15 and R ^c17 each independently represent the same meaning as R ^c4 .
o3 and p3 each independently represent an integer of 0 to 3, when o3 is 2 or more, the plurality of R ^c14 are the same or different, and when p3 is 2 or more, the plurality of R ^c15 are the same or different. .
L ^c1 represents an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

［式（Ｃ７）及び式（Ｃ８）中、Ｒ^c18、Ｒ^c19及びＲ^c20は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
ｑ３、ｒ３及びｓ３は、それぞれ独立に０〜３の整数を表し、ｑ３が２以上のとき、複数のＲ^c18は同一又は相異なり、ｒ３が２以上のとき、複数のＲ^c1９は同一又は相異なり、ｓ３が２以上のとき、複数のＲ^c20は同一又は相異なる。
Ｌ^c2は、単結合又は炭素数１〜６のアルカンジイル基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

Wherein (C7) and formula ^{(C8), R c18, R} c19 and R ^c20 in each occurrence independently represent the same meaning as R ^c4.
q3, r3 and s3 each independently represents an integer of 0 to 3, and when q3 is 2 or more, a plurality of R ^c18 are the same or different, and when r3 is 2 or more, a plurality of R ^c19 are the same or different. In contrast, when s3 is 2 or more, the plurality of R ^c20 are the same or different.
L ^c2 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

In formula (C1) to formula (C8) and formula (C1-1), the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, alkoxy group, alkanediyl group are the same as those described above. Is mentioned.
Examples of the acyl group include acetyl group, 2-methylacetyl group, 2,2-dimethylacetyl group, propionyl group, butyryl group, isobutyryl group, pentanoyl group, and 2,2-dimethylpropionyl group.

  Examples of the compound represented by the formula (C1) include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N- Dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tri Pentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonyl Amine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2- Examples include diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and preferably diisopropyl. Piruanirin. Particularly preferred include 2,6-diisopropylaniline.

Examples of the compound represented by the formula (C2) include piperazine.
Examples of the compound represented by the formula (C3) include morpholine.
Examples of the compound represented by the formula (C4) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound represented by the formula (C5) include 2,2′-methylenebisaniline.
Examples of the compound represented by the formula (C6) include imidazole and 4-methylimidazole.
Examples of the compound represented by the formula (C7) include pyridine and 4-methylpyridine.
Examples of the compound represented by the formula (C8) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1, 2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipiconylamine, bipyridine and the like.

  As ammonium salts, tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethyl Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like can be mentioned.

  The content of the basic compound (C) in the solid content of the resist composition is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass, and particularly preferably 0.8. It is about 01 to 1% by mass.

<Other ingredients>
The resist composition of the present invention may contain other components (hereinafter sometimes referred to as “other components (F)”) other than the above-described components, if necessary. The other component (F) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, and the like can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises a resin (A), an acid generator (B), a resin other than the resin (A) used as necessary, a solvent (E), a basic compound (C), a compound (D ) And other components (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select the suitable temperature range from the range of 10-40 degreeC according to the solubility with respect to the solvent (E), such as a kind, etc. of resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) The process of apply | coating the resist composition of this invention on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) The process of heating the composition layer after exposure, (5) The process of developing the composition layer after a heating is included.

  Application of the resist composition onto the substrate can be performed by a commonly used apparatus such as a spin coater. By adjusting the conditions of the coating apparatus, the film thickness of the composition after coating can be adjusted. Examples of the substrate include a silicon wafer. Before applying the resist composition, the substrate may be washed or an antireflection film may be formed using a commercially available organic antireflection film composition.

By drying the composition after coating, the solvent is removed and a composition layer is formed. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or using a decompression device. The heating temperature is preferably 50 to 200 ° C., for example, and the heating time is preferably 10 to 180 seconds, for example. The pressure during drying under reduced pressure is preferably about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser) Etc.) Using various types of laser light such as those that convert wavelength of laser light from the laser and emit harmonic laser light in the far ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams or extreme ultraviolet light (EUV), etc. Can do. In this specification, irradiating these radiations may be collectively referred to as “exposure”. The exposure is usually performed through a mask corresponding to a desired resist pattern. When the exposure light source is an electron beam, a desired pattern may be directly drawn without using a photomask.

  The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) in order to promote the deprotection reaction of the resin (A). 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 developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., for example, and the development time is preferably 5 to 300 seconds, for example.

By selecting the type of developer, a positive resist pattern or a negative resist pattern can be produced.
When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline). The alkali developer may contain a surfactant.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove the water remaining on the substrate and the pattern.

In the case of producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
Organic solvents 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; glycols such as propylene glycol monomethyl ether Examples include ether solvents; amide solvents such as N, N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
In the organic developer, 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 still 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 developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and substantially butyl acetate and / or 2 -More preferred is heptanone alone.
The organic developer may contain a surfactant. The organic developer may contain a trace amount of water.
At the time of development, the development may be stopped by substituting a solvent of a different type from the organic developer.

It is preferable to wash the developed resist pattern with a rinse solution. The rinsing liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, and an alcohol solvent or an ester solvent is preferable.
After the cleaning, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

<Application>
The resist composition of the present invention is a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, particularly a liquid. It is suitable as a resist composition for immersion exposure and useful for fine processing of semiconductors.

The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or amount used are based on mass unless otherwise specified.
The structure of the compound was confirmed by MASS (LC: Agilent 1100 type, MASS: Agilent LC / MSD type or LC / MSD TOF type).
The weight average molecular weight is a value determined by gel permeation chromatography under the following conditions.
Apparatus: HLC-8120GPC type (manufactured by Tosoh Corporation)
Column: TSKgel Multipore HXL-M x 3 + guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min
Detector: RI detector Column temperature: 40 ° C
Injection volume: 100 μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)

式（Ｉ−２−ａ）で表される化合物５．００部及びアセトニトリル２５部を仕込み、２３℃で３０分間攪拌した後、酸化銀２．４９部を仕込み、２３℃で１時間攪拌した後、ろ過した。回収されたろ液に、式（Ｉ−２−ｃ）で表される化合物９．０８部を仕込み、２３℃で１２時間攪拌した。得られた反応マスをろ過した後、回収されたろ液を濃縮した。回収された残渣に、クロロホルム１００部及びイオン交換水３５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水３５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて攪拌した後、ろ過することにより、式（Ｉ−２−ｄ）で表される塩１１．６９部を得た。 Example 1: Synthesis of a salt represented by the formula (I-2)

After adding 5.00 parts of the compound represented by the formula (I-2-a) and 25 parts of acetonitrile and stirring at 23 ° C. for 30 minutes, 2.49 parts of silver oxide was added and stirred at 23 ° C. for 1 hour. And filtered. To the collected filtrate, 9.08 parts of the compound represented by the formula (I-2-c) was charged and stirred at 23 ° C. for 12 hours. The obtained reaction mass was filtered, and then the collected filtrate was concentrated. To the collected residue, 100 parts of chloroform and 35 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. 35 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After concentration of the obtained organic layer, 50 parts of tert-butyl methyl ether was added to the resulting residue, stirred, and then filtered to obtain the salt represented by the formula (I-2-d) 11. 69 parts were obtained.

式（Ｉ−２−ｄ）で表される塩３．００部及びクロロホルム３０部を仕込んだ後、式（Ｉ−２−ｅ）で表される塩４．６３部及びイオン交換水１５部を仕込み、２３℃で１２時間攪拌した。得られた反応液を分液して有機層を取り出した。回収された有機層にイオン交換水１５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を２回繰り返した。得られた残渣を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル１７．６５部を加えて攪拌した後、上澄み液を除去した。得られた残渣を濃縮した後、ｎ−ヘプタン１３．７５部を加えて攪拌した後、ろ過することにより、式（Ｉ−２−ｆ）で表される塩２．５８部を得た。

After charging 3.00 parts of the salt represented by the formula (I-2-d) and 30 parts of chloroform, 4.63 parts of the salt represented by the formula (I-2-e) and 15 parts of ion-exchanged water were added. The mixture was charged and stirred at 23 ° C. for 12 hours. The obtained reaction solution was separated and the organic layer was taken out. 15 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated twice. After the obtained residue was concentrated, 17.65 parts of tert-butyl methyl ether was added to the obtained residue and stirred, and then the supernatant was removed. After concentrating the obtained residue, 13.75 parts of n-heptane was added and stirred, followed by filtration to obtain 2.58 parts of the salt represented by the formula (I-2-f).

式（Ｉ−２−ｆ）で表される塩２．０２部、式（Ｉ−２−ｇ）で表される化合物０．４６部及びモノクロロベンゼン２０部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．０２部を添加した後、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮した後、得られた残渣に、クロロホルム３５部、イオン交換水１２部及び２８％アンモニア水０．１５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１２部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル１５部を加えて攪拌した後、ろ過することにより、式（Ｉ−２）で表される塩０．７２部を得た。

2.02 parts of a salt represented by the formula (I-2-f), 0.46 parts of a compound represented by the formula (I-2-g) and 20 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. . After adding 0.02 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 35 parts of chloroform, 12 parts of ion-exchanged water and 0.15 part of 28% aqueous ammonia were added to the obtained residue, and the mixture was stirred at 23 ° C. for 30 minutes, followed by liquid separation. The organic layer was removed. To the recovered organic layer, 12 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated three times. After concentrating the obtained organic layer, 15 parts of tert-butyl methyl ether was added to the resulting residue and stirred, followed by filtration to obtain 0.72 part of the salt represented by the formula (I-2). Got.

MASS (ESI (+) Spectrum): M ⁺ 211.1
MASS (ESI (−) Spectrum): M ^- 339.1

式（Ｉ−８−ａ）で表される化合物５．００部及びアセトニトリル２５部を仕込み、２３℃で３０分間攪拌した後、酸化銀２．４９部を仕込み、２３℃で１時間攪拌した後、ろ過した。回収されたろ液に、式（Ｉ−８−ｃ）で表される化合物９．６８部を仕込み、２３℃で１２時間攪拌した。得られた反応マスをろ過した後、回収されたろ液を濃縮した。回収された残渣に、クロロホルム１００部及びイオン交換水３５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水３５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて攪拌した後、ろ過することにより、式（Ｉ−８−ｄ）で表される塩１２．１１部を得た。 Example 2: Synthesis of a salt represented by the formula (I-8)

After adding 5.00 parts of the compound represented by the formula (I-8-a) and 25 parts of acetonitrile and stirring at 23 ° C. for 30 minutes, 2.49 parts of silver oxide was added and stirred at 23 ° C. for 1 hour. And filtered. The recovered filtrate was charged with 9.68 parts of a compound represented by the formula (I-8-c) and stirred at 23 ° C. for 12 hours. The obtained reaction mass was filtered, and then the collected filtrate was concentrated. To the collected residue, 100 parts of chloroform and 35 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. 35 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After concentrating the obtained organic layer, 50 parts of tert-butyl methyl ether was added to the resulting residue and stirred, followed by filtration to obtain the salt represented by the formula (I-8-d) 12. 11 parts were obtained.

式（Ｉ−８−ｄ）で表される塩２．８８部、式（Ｉ−８−ｅ）で表される化合物０．５０部及びモノクロロベンゼン３０部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二酢酸銅（ＩＩ）０．０４部を添加した後、更に、１００℃で１時間加熱攪拌した。得られた反応溶液を濃縮した後、回収された残渣に、クロロホルム５０部及びイオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水２０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて２３℃で３０分間攪拌した後、ろ過することにより、式（Ｉ−８−ｆ）で表される塩１．１２部を得た。

2.88 parts of a salt represented by the formula (I-8-d), 0.50 part of a compound represented by the formula (I-8-e) and 30 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. . After adding 0.04 part of copper (II) diacetate to the obtained mixture, the mixture was further heated and stirred at 100 ° C. for 1 hour. After concentrating the obtained reaction solution, 50 parts of chloroform and 20 parts of ion-exchanged water were added to the collected residue and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. 20 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After concentrating the obtained organic layer, 30 parts of tert-butyl methyl ether was added to the resulting residue, and the mixture was stirred at 23 ° C. for 30 minutes, and then filtered to obtain a compound represented by formula (I-8-f). 1.12 parts of the salt obtained are obtained.

式（Ｉ−８−ｆ）で表される塩２．３９部及びクロロホルム２５部を仕込んだ後、式（Ｉ−８−ｇ）で表される塩４．６３部及びイオン交換水１５部を仕込み、２３℃で１２時間攪拌した。得られた反応液を分液して有機層を取り出した。回収された有機層にイオン交換水１５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を２回繰り返した。得られた残渣を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル１８．２２部を加えて攪拌した後、上澄み液を除去した。得られた残渣を濃縮した後、ｎ−ヘプタン１５．５５部を加えて攪拌した後、ろ過することにより、式（Ｉ−８）で表される塩２．２２部を得た。

After charging 2.39 parts of the salt represented by the formula (I-8-f) and 25 parts of chloroform, 4.63 parts of the salt represented by the formula (I-8-g) and 15 parts of ion-exchanged water were added. The mixture was charged and stirred at 23 ° C. for 12 hours. The obtained reaction solution was separated and the organic layer was taken out. 15 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated twice. After the obtained residue was concentrated, 18.22 parts of tert-butyl methyl ether was added to the obtained residue and stirred, and then the supernatant was removed. After concentrating the obtained residue, 15.55 parts of n-heptane was added and stirred, followed by filtration to obtain 2.22 parts of the salt represented by the formula (I-8).

MASS (ESI (+) Spectrum): M ⁺ 225.1
MASS (ESI (−) Spectrum): M ^- 339.1

式（Ｉ−２−ｄ）で表される塩３．００部及びクロロホルム３０部を仕込んだ後、式（Ｉ−３−ｅ）で表される塩４．４６部及びイオン交換水１５部を仕込み、２３℃で１２時間攪拌した。得られた反応液を分液して有機層を取り出した。回収された有機層にイオン交換水１５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を２回繰り返した。得られた残渣を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル１５部を加えて攪拌した後、上澄み液を除去した。得られた残渣を濃縮した後、ｎ−ヘプタン１５部を加えて攪拌した後、ろ過することにより、式（Ｉ−３−ｆ）で表される塩２．３１部を得た。 Example 3: Synthesis of a salt represented by the formula (I-3)

After charging 3.00 parts of the salt represented by the formula (I-2-d) and 30 parts of chloroform, 4.46 parts of the salt represented by the formula (I-3-e) and 15 parts of ion-exchanged water were added. The mixture was charged and stirred at 23 ° C. for 12 hours. The obtained reaction solution was separated and the organic layer was taken out. 15 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated twice. After concentrating the obtained residue, 15 parts of tert-butyl methyl ether was added to the obtained residue and stirred, and then the supernatant was removed. After concentrating the obtained residue, 15 parts of n-heptane was added and stirred, followed by filtration to obtain 2.31 parts of the salt represented by the formula (I-3-f).

式（Ｉ−３−ｆ）で表される塩１．９７部、式（Ｉ−３−ｇ）で表される化合物０．４６部及びモノクロロベンゼン２０部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．０２部を添加した後、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮した後、得られた残渣に、クロロホルム３５部、イオン交換水１２部及び２８％アンモニア水０．１５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１２部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル１５部を加えて攪拌した後、ろ過することにより、式（Ｉ−３）で表される塩０．６５部を得た。

1.97 parts of a salt represented by the formula (I-3-f), 0.46 parts of a compound represented by the formula (I-3-g) and 20 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. . After adding 0.02 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 35 parts of chloroform, 12 parts of ion-exchanged water and 0.15 part of 28% aqueous ammonia were added to the obtained residue, and the mixture was stirred at 23 ° C. for 30 minutes, followed by liquid separation. The organic layer was removed. To the recovered organic layer, 12 parts of ion exchange water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated three times. After concentrating the obtained organic layer, 15 parts of tert-butyl methyl ether was added to the resulting residue and stirred, followed by filtration to give 0.65 part of the salt represented by the formula (I-3). Got.

MASS (ESI (+) Spectrum): M ⁺ 211.1
MASS (ESI (-) Spectrum): M ^- 323.0

式（Ｉ−８−ｆ）で表される塩２．３９部及びクロロホルム２５部を仕込んだ後、式（Ｉ−３−ｅ）で表される塩４．４６部及びイオン交換水１５部を仕込み、２３℃で１２時間攪拌した。得られた反応液を分液して有機層を取り出した。回収された有機層にイオン交換水１５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を２回繰り返した。得られた残渣を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル１５部を加えて攪拌した後、上澄み液を除去した。得られた残渣を濃縮した後、ｎ−ヘプタン１５部を加えて攪拌した後、ろ過することにより、式（Ｉ−９）で表される塩１．８５部を得た。 Example 4: Synthesis of salt represented by formula (I-9)

After charging 2.39 parts of the salt represented by the formula (I-8-f) and 25 parts of chloroform, 4.46 parts of the salt represented by the formula (I-3-e) and 15 parts of ion-exchanged water were added. The mixture was charged and stirred at 23 ° C. for 12 hours. The obtained reaction solution was separated and the organic layer was taken out. 15 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated twice. After concentrating the obtained residue, 15 parts of tert-butyl methyl ether was added to the obtained residue and stirred, and then the supernatant was removed. After concentrating the obtained residue, 15 parts of n-heptane was added and stirred, followed by filtration to obtain 1.85 parts of the salt represented by the formula (I-9).

MASS (ESI (+) Spectrum): M ⁺ 225.1
MASS (ESI (-) Spectrum): M ^- 323.0

式（Ｉ−４４−ａ）で表される化合物１５．４６部、式（Ｉ−４４−ｂ）で表される化合物５．６２部、酢酸１６．８６部及び無水酢酸８．４３部を仕込み、２３℃で３０分間攪拌した後、５℃まで冷却した。得られた混合物に、５℃で、硫酸５．６２部を３０分かけて滴下し、５℃で３時間攪拌した後、さらに、２３℃で１２時間攪拌した。得られた反応混合物に、ｔｅｒｔ−ブチルメチルエーテル１６．８６部及びイオン交換水１６．８６部を加えて２３℃で３０分間攪拌した後、ろ過した。回収されたろ液に、臭化ナトリウム２．８１部及びイオン交換水１４．０５部を加えて攪拌した後、ろ過することにより、式（Ｉ−４４−ｃ）で表される塩６．０２部を得た。 Example 5: Synthesis of salt represented by formula (I-44)

Charge 15.46 parts of the compound represented by the formula (I-44-a), 5.62 parts of the compound represented by the formula (I-44-b), 16.86 parts of acetic acid and 8.43 parts of acetic anhydride. The mixture was stirred at 23 ° C. for 30 minutes and then cooled to 5 ° C. To the obtained mixture, 5.62 parts of sulfuric acid was added dropwise at 5 ° C. over 30 minutes, and the mixture was stirred at 5 ° C. for 3 hours, and further stirred at 23 ° C. for 12 hours. To the obtained reaction mixture, 16.86 parts of tert-butyl methyl ether and 16.86 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes, followed by filtration. To the collected filtrate, 2.81 parts of sodium bromide and 14.05 parts of ion-exchanged water are added and stirred, followed by filtration to give 6.02 parts of the salt represented by the formula (I-44-c). Got.

式（Ｉ−４４−ｃ）で表される塩５．７５部、式（Ｉ−４４−ｄ）で表される塩５．１０部、クロロホルム４１．０４部及びイオン交換水２０．５２部を仕込み、２３℃で１２時間攪拌した。得られた反応液を分液して有機層を取り出した。回収された有機層にイオン交換水１５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた残渣を濃縮した後、得られた残渣に、アセトニトリル６．８０部及びｔｅｒｔ−ブチルメチルエーテル１６．０５部を加えて攪拌した後、ろ過することにより、式（Ｉ−４４−ｅ）で表される塩４．１４部を得た。

5.75 parts of a salt represented by the formula (I-44-c), 5.10 parts of a salt represented by the formula (I-44-d), 41.04 parts of chloroform and 20.52 parts of ion-exchanged water. The mixture was charged and stirred at 23 ° C. for 12 hours. The obtained reaction solution was separated and the organic layer was taken out. 15 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After the obtained residue was concentrated, 6.80 parts of acetonitrile and 16.05 parts of tert-butyl methyl ether were added to the obtained residue and stirred, followed by filtration to give a compound of formula (I-44-e). 4.14 parts of the salt represented by

MASS (ESI (+) Spectrum): M ⁺ 517.1
MASS (ESI (−) Spectrum): M ^- 339.1

式（Ｉ−４４−ｅ）で表される塩２．５４部、式（Ｉ−４４−ｆ）で表される化合物０．４６部及びモノクロロベンゼン２０部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．０２部を添加した後、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮した後、得られた残渣に、クロロホルム３５部、イオン交換水１２部及び２８％アンモニア水０．１５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１５部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を３回繰り返した。得られた有機層を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル２０部を加えて攪拌した後、ろ過することにより、式（Ｉ−４４）で表される塩０．８９部を得た。

2.54 parts of a salt represented by the formula (I-44-e), 0.46 parts of a compound represented by the formula (I-44-f) and 20 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. . After adding 0.02 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 35 parts of chloroform, 12 parts of ion-exchanged water and 0.15 part of 28% aqueous ammonia were added to the obtained residue, and the mixture was stirred at 23 ° C. for 30 minutes, followed by liquid separation. The organic layer was removed. 15 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated three times. After concentrating the obtained organic layer, 20 parts of tert-butyl methyl ether was added to the resulting residue and stirred, followed by filtration to obtain 0.89 parts of the salt represented by the formula (I-44). Got.

MASS (ESI (+) Spectrum): M ⁺ 299.1
MASS (ESI (−) Spectrum): M ^- 339.1

Synthesis of Resin (A) The compound (monomer) used for the synthesis of resin (A) is shown below. Hereinafter, these monomers are referred to as “monomer (a1-1-3)” or the like according to the formula number.

Synthesis Example 1 [Synthesis of Resin A1]
The monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-3), monomer (a3-2-3) and monomer (a3-4-2) are mixed in a molar ratio [ Monomer (a1-1-3): Monomer (a1-2-9): Monomer (a2-1-3): Monomer (a3-2-3): Monomer (a3-4-2)] is 45:14: It mixed so that it might become 2.5: 22.5: 16, and 1.5 mass times dioxane of the total monomer amount was added, and it was set as the solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was dissolved again in dioxane, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by two reprecipitation operations of filtering the resin, and a weight average molecular weight of 8.8. × 10 ³ of the resin A1 (copolymer) was obtained in 71% yield. This resin A1 has the following structural units.

Synthesis Example 2 [Synthesis of Resin A2]
As the monomer, monomer (a1-1-3), monomer (a1-2-9), monomer (a2-1-3) and monomer (a3-4-2) were used, and the molar ratio [monomer (a1-1 -3): Monomer (a1-2-9): Monomer (a2-1-3): Monomer (a3-4-2)] are mixed at 45: 14: 2.5: 38.5, A solution was prepared by adding propylene glycol monomethyl ether acetate of 1.5 mass times the total monomer amount. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A2 (copolymer) having a molecular weight of 7.6 × 10 ³ was obtained in a yield of 68%. This resin A2 has the following structural units.

Synthesis Example 3 [Synthesis of Resin X1]
Monomer (a4-1-7) was used as a monomer, and 1.5 mass times dioxane of the total monomer amount was added to prepare a solution. Azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the solution in an amount of 0.7 mol% and 2.1 mol%, respectively, with respect to the total monomer amount, and these were added at 75 ° C. Heated for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered.
The resin thus obtained was again dissolved in dioxane, and the solution obtained by pouring the solution into a methanol / water mixed solvent was precipitated twice, and the resin was filtered twice. 8 × 10 ⁴ resin X1 was obtained with a yield of 77%. This resin X1 has the following structural units.

式（Ｂ１−５−ａ）で表される塩５０．４９部及びクロロホルム２５２．４４部を反応器に仕込み、２３℃で３０分間攪拌した後、式（Ｂ１−５−ｂ）で表される化合物１６．２７部を滴下し、２３℃で１時間攪拌することにより、式（Ｂ１−５−ｃ）で表される塩を含む溶液を得た。得られた式（Ｂ１−５−ｃ）で表される塩を含む溶液に、式（Ｂ１−５−ｄ）で表される塩４８．８０部及びイオン交換水８４．１５部を添加し、２３℃で１２時間攪拌した。得られた反応液が２層に分離していたので、クロロホルム層を分液して取り出し、更に、該クロロホルム層にイオン交換水８４．１５部を添加し、水洗した。この操作を５回繰り返した。得られたクロロホルム層に、活性炭３．８８部を添加攪拌した後、ろ過した。回収されたろ液を濃縮し、得られた残渣に、アセトニトリル１２５．８７部を添加攪拌後、濃縮した。得られた残渣に、アセトニトリル２０．６２部及びｔｅｒｔ−ブチルメチルエーテル３０９．３０部を加えて２３℃で３０分間攪拌した後、上澄み液を除去した後、濃縮した。得られた残渣に、ｎ−ヘプタン２００部を添加、２３℃で３０分間攪拌した後、ろ過することにより、式（Ｂ１−５）で表される塩６１．５４部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ３７５．２
ＭＡＳＳ（ＥＳＩ（−）Ｓｐｅｃｔｒｕｍ）：Ｍ⁻ ３３９．１ Synthesis Example 4 [Synthesis of salt represented by formula (B1-5)]

50.49 parts of the salt represented by the formula (B1-5-a) and 252.44 parts of chloroform are charged into a reactor, stirred at 23 ° C. for 30 minutes, and then represented by the formula (B1-5-b). 16.27 parts of the compound was added dropwise and stirred at 23 ° C. for 1 hour to obtain a solution containing a salt represented by the formula (B1-5-c). To the obtained solution containing the salt represented by the formula (B1-5-c), 48.80 parts of the salt represented by the formula (B1-5-d) and 84.15 parts of ion-exchanged water are added, The mixture was stirred at 23 ° C. for 12 hours. Since the resulting reaction solution was separated into two layers, the chloroform layer was separated and removed, and 84.15 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. To the obtained chloroform layer, 3.88 parts of activated carbon was added and stirred, followed by filtration. The collected filtrate was concentrated, 125.87 parts of acetonitrile was added to the resulting residue, and the mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butyl methyl ether were added and stirred at 23 ° C. for 30 minutes, and then the supernatant was removed and concentrated. To the obtained residue, 200 parts of n-heptane was added, stirred at 23 ° C. for 30 minutes, and then filtered to obtain 61.54 parts of a salt represented by the formula (B1-5).
MASS (ESI (+) Spectrum): M ⁺ 375.2
MASS (ESI (−) Spectrum): M ^- 339.1

Synthesis Example 5 [Synthesis of salt represented by formula (B1-21)]

  30.00 parts of a compound represented by the formula (B1-21-b) obtained by the method described in JP-A-2008-209917, and a salt 35.50 represented by the formula (B1-21-a). Part, 100 parts of chloroform, and 50 parts of ion-exchanged water were stirred at 23 ° C. for 15 hours. Since the obtained reaction solution was separated into two layers, the chloroform layer was separated and taken out, and 30 parts of ion-exchanged water was further added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 100 parts of tert-butyl methyl ether was added to the resulting residue, and the mixture was stirred at 23 ° C. for 30 minutes, and then filtered to obtain the salt 48 represented by the formula (B1-21-c). .57 parts were obtained.

式（Ｂ１−２１−ｃ）で表される塩２０．００部、式（Ｂ１−２１−ｄ）で表される化合物２．８４部及びモノクロロベンゼン２５０部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．２１部を添加した後、更に、１００℃で１時間攪拌した。得られた反応溶液を濃縮した後、得られた残渣に、クロロホルム２００部及びイオン交換水５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を５回繰り返した。得られた有機層を濃縮した後、得られた残渣に、アセトニトリル５３．５１部に溶解し、濃縮した後、ｔｅｒｔ−ブチルメチルエーテル１１３．０５部を加えて攪拌した後、ろ過することにより、式（Ｂ１−２１）で表される塩１０．４７部を得た。

20.00 parts of a salt represented by the formula (B1-21-c), 2.84 parts of a compound represented by the formula (B1-21-d) and 250 parts of monochlorobenzene were charged and stirred at 23 ° C. for 30 minutes. . After adding 0.21 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for further 1 hour. After concentrating the obtained reaction solution, 200 parts of chloroform and 50 parts of ion-exchanged water were added to the obtained residue and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 times. After concentrating the obtained organic layer, the residue obtained was dissolved in 53.51 parts of acetonitrile, concentrated, 113.05 parts of tert-butyl methyl ether was added and stirred, and then filtered. 10.47 parts of the salt represented by the formula (B1-21) were obtained.

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (−) Spectrum): M ^- 339.1

式（Ｂ１−２２−ａ）で表される塩１１．２６部、式（Ｂ１−２２−ｂ）で表される化合物１０．００部、クロロホルム５０部及びイオン交換水２５部を仕込み、２３℃で１５時間攪拌した。得られた反応液が２層に分離していたので、クロロホルム層を分液して取り出し、更に、該クロロホルム層にイオン交換水１５部を添加し、水洗した。この操作を５回繰り返した。クロロホルム層を濃縮し、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて２３℃で３０分間攪拌した後、ろ過することにより、式（Ｂ１−２２−ｃ）で表される塩１１．７５部を得た。 Synthesis Example 6 [Synthesis of salt represented by formula (B1-22)]

11.26 parts of a salt represented by the formula (B1-22-a), 10.00 parts of a compound represented by the formula (B1-22-b), 50 parts of chloroform and 25 parts of ion-exchanged water were charged at 23 ° C. For 15 hours. Since the obtained reaction liquid was separated into two layers, the chloroform layer was separated and taken out, and further 15 parts of ion-exchanged water was added to the chloroform layer and washed with water. This operation was repeated 5 times. The chloroform layer was concentrated, 50 parts of tert-butyl methyl ether was added to the resulting residue, the mixture was stirred at 23 ° C. for 30 minutes, and then filtered to obtain the salt 11 represented by the formula (B1-22-c). .75 parts were obtained.

式（Ｂ１−２２−ｃ）で表される塩１１．７１部、式（Ｂ１−２２−ｄ）で表される化合物１．７０部及びモノクロロベンゼン４６．８４部を仕込み、２３℃で３０分間攪拌した。得られた混合液に、二安息香酸銅（ＩＩ）０．１２部を添加した後、更に、１００℃で３０分間攪拌した。得られた反応溶液を濃縮した後、得られた残渣に、クロロホルム５０部及びイオン交換水１２．５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。回収された有機層にイオン交換水１２．５０部を加えて２３℃で３０分間攪拌した後、分液して有機層を取り出した。この水洗操作を８回繰り返した。得られた有機層を濃縮した後、得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて攪拌した後、ろ過することにより、式（Ｂ１−２２）で表される塩６．８４部を得た。

11.71 parts of a salt represented by the formula (B1-22-c), 1.70 parts of a compound represented by the formula (B1-22-d) and 46.84 parts of monochlorobenzene were charged, and the mixture was charged at 23 ° C. for 30 minutes. Stir. After adding 0.12 part of copper (II) dibenzoate to the obtained liquid mixture, it stirred at 100 degreeC for 30 minutes further. After concentrating the obtained reaction solution, 50 parts of chloroform and 12.50 parts of ion-exchanged water were added to the obtained residue and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. 12.50 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 8 times. After concentration of the obtained organic layer, 50 parts of tert-butyl methyl ether was added to the obtained residue, stirred, and then filtered to obtain 6.84 parts of the salt represented by the formula (B1-22). Got.

MASS (ESI (+) Spectrum): M ⁺ 237.1
MASS (ESI (-) Spectrum): M ^- 323.0

Examples 6-13, Comparative Examples 1 and 2
<Preparation of resist composition>
Each of the components shown below was dissolved in a solvent at parts by mass shown in Table 3, and further filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

<Resin>
A1, A2, X1: Resin A1, Resin A2, Resin X1
<Acid generator>
I-2: Salt represented by formula (I-2) I-3: Salt represented by formula (I-3) I-8: Salt represented by formula (I-8) I-9: Formula Salt represented by (I-9) I-44: Salt represented by formula (I-44) B1-5: Salt represented by formula (B1-5) B1-21: Formula (B1-21) B1-22: a salt represented by the formula (B1-22) B1-X: a salt represented by the following formula, synthesized according to the examples of JP 2012-224611 A

<Compound (D)>
D1: (Tokyo Chemical Industry Co., Ltd.)

<Solvent>
Propylene glycol monomethyl ether acetate 265 parts Propylene glycol monomethyl ether 20 parts 2-heptanone 20 parts γ-butyrolactone 3.5 parts

Examples 6 to 13 and Comparative Examples 1 and 2
<Manufacture of negative resist pattern>
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer, and baked under the conditions of 205 ° C. and 60 seconds, whereby an organic layer having a thickness of 78 nm was obtained. An antireflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness of the composition layer after drying (pre-baking) was 100 nm. After coating, this silicon wafer was pre-baked on a direct hot plate at the temperature described in the “PB” column of Table 3 for 60 seconds to form a composition layer on the silicon wafer.
ArF excimer laser stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, Annular σ _out = 0.85 σ _in = 0.65 XY− pol. Illumination], using a mask for forming a trench pattern (pitch 120 nm / trench width 40 nm), the exposure amount was changed stepwise to perform exposure. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 3. Next, the composition layer on the silicon wafer is developed by using a butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution by a dynamic dispensing method at 23 ° C. for 20 seconds, thereby forming a negative resist pattern. Manufactured.

  In the obtained resist pattern, the exposure amount at which the width of the trench pattern was 40 nm was defined as effective sensitivity.

<Line edge roughness evaluation (LER)>
About the obtained resist pattern, the fluctuation width of the unevenness | corrugation of a wall surface was observed and measured with the scanning electron microscope. This swing width is shown in Table 4 as LER (nm).

  From the above results, it can be seen that according to the resist composition of the present invention, a negative resist pattern can be produced with excellent line edge roughness (LER).

  According to the resist composition of the present invention, an excellent line edge roughness (LER) negative resist pattern can be produced, which is suitable for semiconductor microfabrication and industrially useful.

Claims (5)

A salt represented by the formula (I).

[In Formula (I), R ¹ represents — (X ¹ —O) _n —R ² .
R ² represents a monovalent hydrocarbon group having 1 to 12 carbon atoms.
X ¹ represents a divalent hydrocarbon group having 2 to 12 carbon atoms.
n represents an integer of 0 to 6.
A ⁻ represents an organic anion. ] A ^- is a salt of claim 1, wherein an anion of the formula (I-A).

[In the formula (IA), L ^b1 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group represents —O— or —CO—. The hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. —CH ₂ — contained in the alicyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—. ]   The acid generator containing the salt of Claim 1 or 2.   A resist composition comprising the acid generator according to claim 3 and a resin having an acid labile group. (1) The process of apply | coating the resist composition of Claim 4 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) A method for producing a resist pattern, comprising a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.