JP7449064B2 - Salt, acid generator, resist composition, and method for producing resist pattern - Google Patents

Description

The present invention relates to a salt for an acid generator used in semiconductor microfabrication, an acid generator containing the salt, 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.

Patent Document 2 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator.

Patent Document 3 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator.

Patent Document 4 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator.

Patent Document 5 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator.

Japanese Patent Application Publication No. 2009-191054 Japanese Patent Application Publication No. 2011-046694 Japanese Patent Application Publication No. 2011-126869 JP2017-019997A JP2012-226325A

The present invention provides a salt that forms a resist pattern with better CD uniformity (CDU) than the resist pattern formed with the above resist composition.

［式（Ｉ）中、
Ｑ^１及びＱ^２は、それぞれ独立に、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
Ｒ^１及びＲ^２は、それぞれ独立に、水素原子、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
ｚは、０～６のいずれかの整数を表し、ｚが２以上のとき、複数のＲ^１及びＲ^２は互いに同一であっても異なってもよい。
Ｘ¹及びＸ^２は、それぞれ独立に、＊－ＣＯ－Ｏ－、＊－Ｏ－ＣＯ－、＊－Ｏ－ＣＯ－Ｏ－又は＊－Ｏ－を表し、＊は、Ｃ（Ｒ^１）（Ｒ^２）もしくはＣ（Ｑ^１）（Ｑ^２）又はＡ^１もしくはＬ^２との結合部位を表す。
Ｌ¹は、単結合又は置換基を有してもよい炭素数１～２８の炭化水素基を表し、該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ａ^１は、置換基を有してもよい炭素数３～３６のラクトン環を表す。
Ｌ^２は、単結合又は炭素数１～６のアルカンジイル基を表す。
Ｒ^３は、炭素数１～１８のフッ素化炭化水素基を表す。
Ｚ^＋は、有機カチオンを表す。］
［２］Ａ^１が、ノルボルナンラクトン環である［１］記載の塩。
［３］Ｌ²が、単結合である［１］又は［２］記載の塩。
［４］Ｌ¹が、単結合、炭素数１～４のアルカンジイル基、炭素数１～４のアルカンジイル基とアダマンタンジイル基とを組み合わせてなる基（該アルカンジイル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。）又は炭素数１～４のアルカンジイル基とフッ素原子を有してもよいフェニレン基とを組み合わせてなる基（該アルカンジイル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。）である［１］～［３］のいずれかに記載の塩。
［５］Ｒ^３が、炭素数１～８のフッ素化アルキル基又は式（Ｒ３－１）で表される基である［１］～［４］のいずれかに記載の塩。

［式（Ｒ３－１）中、
Ｌ^３は、単結合又は炭素数１～６のアルカンジイル基を表す。
ｍ３は、１～５のいずれかの整数を表す。
Ｒ^４は、ハロゲン原子又は炭素数１～６のアルキル基を表し、該アルキル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
ｍ４は、０～４のいずれかの整数を表し、ｍ４が２以上のとき、複数のＲ^４は互いに同一であっても異なってもよい。
＊は、Ｘ^２との結合部位を表す。］
［６］［１］～［５］のいずれかに記載の塩を含有する酸発生剤。
［７］［６］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。
［８］酸不安定基を有する樹脂が、式（ａ１－１）で表される構造単位及び式（ａ１－２）で表される構造単位からなる群より選ばれる少なくとも１種を含む［７］記載のレジスト組成物。

［式（ａ１－１）及び式（ａ１－２）中、
Ｌ^ａ１及びＬ^ａ２は、それぞれ独立に、－Ｏ－又は＊－Ｏ－（ＣＨ_２）_ｋ１－ＣＯ－Ｏ－を表し、ｋ１は１～７のいずれかの整数を表し、＊は－ＣＯ－との結合部位を表す。
Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^ａ６及びＲ^ａ７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せた基を表す。
ｍ１は、０～１４のいずれかの整数を表す。
ｎ１は、０～１０のいずれかの整数を表す。
ｎ１’は、０～３のいずれかの整数を表す。］
［９］酸発生剤から発生する酸よりも酸性度の弱い酸を発生する塩をさらに含有する［７］又は［８］記載のレジスト組成物。
［１０］（１）［７］～［９］のいずれかに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] Salt represented by formula (I).

[In formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents any integer from 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² may be the same or different.
X ¹ and X ² each independently represent *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, and * represents C(R ¹ )( R ² ) or C(Q ¹ )(Q ² ), or represents a binding site with A ¹ or L ² .
L ¹ represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH ₂ - contained in the hydrocarbon group is -O-, -S-, -SO ₂ - or -CO- may be substituted.
A ¹ represents a lactone ring having 3 to 36 carbon atoms which may have a substituent.
L ² represents a single bond or an alkanediyl group having 1 to 6 carbon atoms.
R ³ represents a fluorinated hydrocarbon group having 1 to 18 carbon atoms.
Z ⁺ represents an organic cation. ]
[2] The salt according to [ ¹ ], wherein A 1 is a norbornane lactone ring.
[3] The salt according to [1] or [2], wherein L ² is a single bond.
[4] L ¹ is a single bond, an alkanediyl group having 1 to 4 carbon atoms, a group formed by combining an alkanediyl group having 1 to 4 carbon atoms and an adamantanediyl group (-CH ₂ contained in the alkanediyl group) - may be replaced with -O- or -CO-) or a group formed by combining an alkanediyl group having 1 to 4 carbon atoms and a phenylene group which may have a fluorine atom (the alkanediyl group -CH ₂ - contained in may be replaced with -O- or -CO-.) The salt according to any one of [1] to [3].
[5] The salt according to any one of [1] to [4], wherein R ³ is a fluorinated alkyl group having 1 to 8 carbon atoms or a group represented by formula (R3-1).

[In formula (R3-1),
L ³ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms.
m3 represents an integer of 1 to 5.
R ⁴ represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and -CH ₂ - contained in the alkyl group may be replaced with -O- or -CO-.
m4 represents any integer from 0 to 4, and when m4 is 2 or more, a plurality of R ^4s may be the same or different.
* represents the binding site with ^X2 . ]
[6] An acid generator containing the salt according to any one of [1] to [5].
[7] A resist composition containing the acid generator according to [6] and a resin having an acid-labile group.
[8] The resin having an acid-labile group contains at least one type selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2) [7 ] The resist composition described.

[In formula (a1-1) and formula (a1-2),
L ^a1 and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, k1 represents any integer from 1 to 7, and * represents -CO- represents the binding site with
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents any integer from 0 to 14.
n1 represents any integer from 0 to 10.
n1' represents any integer from 0 to 3. ]
[9] The resist composition according to [7] or [8], further containing a salt that generates an acid that is weaker in acidity than the acid generated from the acid generator.
[10] (1) Applying the resist composition according to any one of [7] to [9] on a substrate,
(2) a step of drying the applied composition to form a composition layer;
(3) exposing the composition layer to light;
(4) a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.

By using a resist composition containing the salt of the present invention, a resist pattern can be manufactured with good CD uniformity (CDU).

In this specification, "(meth)acrylic monomer" refers to monomers having a structure of "CH ₂ = CH-CO-" and monomers having a structure of "CH ₂ = C(CH ₃ )-CO-". It means at least one kind selected from the group consisting of: Similarly, "(meth)acrylate" and "(meth)acrylic acid" refer to "at least one type selected from the group consisting of acrylate and methacrylate" and "at least one type selected from the group consisting of acrylic acid and methacrylic acid," respectively. ” means. When a structural unit having "CH ₂ = C(CH ₃ )-CO-" or "CH ₂ = CH-CO-" is exemplified, a structural unit having both groups is similarly exemplified. shall be taken as a thing. Moreover, in the groups described in this specification, those that can have both a linear structure and a branched structure may have either of them. A "combined group" means a group in which two or more of the exemplified groups are bonded together, and the valency of these groups may be changed as appropriate depending on the bonding form. If stereoisomers exist, all stereoisomers are included.
As used herein, "solid content of the resist composition" refers to the total amount of components excluding the solvent (E) described below from the total amount of the resist composition.

<Salt represented by formula (I)>
The present invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)").
Of the salt (I), the side having a negative charge may be referred to as an "anion (I)", and the side having a positive charge may be referred to as a "cation (I)".

The perfluoroalkyl groups for Q ¹ , Q ² , R ¹ and R ² include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluoro sec-butyl group, perfluoro tert-butyl group. , perfluoropentyl group, perfluorohexyl group, etc.
Q ¹ and Q ² are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.
R ¹ and R ² are each independently preferably a hydrogen atom or a fluorine atom.
It is preferable that z is 0 or 1.

X ¹ is *-CO-O- or *-O-CO- (* represents the bonding site with C(R ¹ )(R ² ) or C(Q ¹ )(Q ² ).) is preferred, and *-CO-O- is more preferred.

Examples of the divalent hydrocarbon group represented by L ¹ include alkanediyl groups, monocyclic or polycyclic divalent alicyclic hydrocarbon groups, and divalent aromatic hydrocarbon groups. The group may be a combination of two or more of these groups (for example, a divalent hydrocarbon group formed from an alicyclic hydrocarbon group and an alkanediyl group).
Examples of alkanediyl groups include methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, and heptane-1,6-diyl group. 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 linear groups such as 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; and ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group , 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, branched alkanediyl group such as 2-methylbutane-1,4-diyl group There are many basics.
Monocyclic or polycyclic divalent alicyclic hydrocarbon groups include cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane Monocyclic divalent alicyclic hydrocarbon group which is a cycloalkanediyl group such as -1,5-diyl group; and norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane- Examples include polycyclic divalent alicyclic hydrocarbon groups such as 1,5-diyl group and adamantane-2,6-diyl group.
Examples of the divalent aromatic hydrocarbon group include aromatic hydrocarbon groups such as arylene groups such as phenylene group, naphthylene group, anthrylene group, biphenylene group, and phenanthrylene group.
A group combining two or more types refers to a group combining an alicyclic hydrocarbon group and an alkanediyl group, or a group combining an aromatic hydrocarbon group and an alkanediyl group. alicyclic hydrocarbon group - alkanediyl group -, - alkanediyl group - divalent alicyclic hydrocarbon group - alkanediyl group -, - alkanediyl group - divalent alicyclic hydrocarbon group -, - Divalent aromatic hydrocarbon group - alkanediyl group -, - alkanediyl group - divalent aromatic hydrocarbon group - alkanediyl group -, - alkanediyl group - divalent aromatic hydrocarbon group -, etc. It will be done.
-CH ₂ - contained in the divalent hydrocarbon group having 1 to 28 carbon atoms in L ¹ may be replaced with -O-, -S-, -SO ₂ - or -CO-.
When -CH ₂ - contained in the hydrocarbon group having 1 to 28 carbon atoms represented by L ¹ is replaced with -O-, -S-, -SO ₂ - or -CO-, the number of carbon atoms before substitution Let be the number of carbon atoms in the hydrocarbon group.

Examples of substituents that L ¹ may have include a hydroxy group, a carboxy group, a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an alkoxy group having 2 to 13 carbon atoms. Examples include a carbonyl group, an alkylcarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyloxy group having 2 to 13 carbon atoms, or a combination thereof.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of alkyl groups having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group, nonyl group, decyl group, undecyl group. group, dodecyl group, etc.
Examples of the alkoxy group having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group group, dodecyloxy group, etc.
The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group having 2 to 13 carbon atoms are groups in which a carbonyl group or carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. represents. Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group, and examples of the alkylcarbonyl group having 2 to 13 carbon atoms include acetyl group, propionyl group, butyryl group, etc. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, a butyryloxy group, and the like.

The substituent is preferably an alkyl group having 1 to 6 carbon atoms, a hydroxy group, or a halogen atom, more preferably an alkyl group having 1 to 4 carbon atoms or a halogen atom, and a methyl group or a fluorine atom. is even more preferable.

L ¹ is a single bond, an alkanediyl group having 1 to 4 carbon atoms (however, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-), a carbon number A group consisting of a combination of an alkanediyl group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (however, -CH ₂ - contained in the alkanediyl group is replaced by -O- or -CO-). -CH ₂ - contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -SO ₂ - or -CO-) or a group having 1 carbon number. A group formed by combining a ~4 alkanediyl group and an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent (however, -CH ₂ - contained in the alkanediyl group is -O - or -CO-), preferably a single bond, an alkanediyl group having 1 to 4 carbon atoms, an alkanediyl group having 1 to 4 carbon atoms and an alicyclic ring having 3 to 12 carbon atoms. (However, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-) or an alkanediyl group having 1 to 4 carbon atoms. A group formed by combining a group and a phenylene group which may have a substituent (however, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-). More preferably, there is a single bond, an alkanediyl group having 1 to 4 carbon atoms, a group formed by combining an alkanediyl group having 1 to 4 carbon atoms and an adamantanediyl group (provided that -CH contained in the alkanediyl group) ₂ - may be replaced with -O- or -CO-) or a group formed by combining an alkanediyl group having 1 to 4 carbon atoms and a phenylene group which may have a fluorine atom (however, -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-.
It is even more preferable that L ¹ is a single bond.

Ａ^１としては、以下で表される環がより好ましい。

Ａ^１としては、以下で表されるノルボルナンラクトン環がさらに好ましい。

The lactone ring having 3 to 36 carbon atoms in A ¹ represents a ring in which -CH ₂ -CH ₂ - contained in an alicyclic hydrocarbon ring having 3 to 38 carbon atoms is replaced with -CO-O-, for example, , and the rings represented below.

As A ¹ , a ring represented by the following is more preferable.

As ^A1 , a norbornane lactone ring represented below is more preferable.

Examples of substituents that A ¹ may have include a hydroxy group, a carboxy group, a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an alkoxy group having 2 to 13 carbon atoms. Examples include a carbonyl group, an alkylcarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyloxy group having 2 to 13 carbon atoms, or a combination thereof.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of alkyl groups having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group, nonyl group, decyl group, undecyl group. group, dodecyl group, etc.
Examples of the alkoxy group having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group group, dodecyloxy group, etc.
The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group having 2 to 13 carbon atoms are groups in which a carbonyl group or carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. represents. Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group, and examples of the alkylcarbonyl group having 2 to 13 carbon atoms include acetyl group, propionyl group, butyryl group, etc. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, a butyryloxy group, and the like.

The substituent that A ¹ may have is preferably an alkyl group having 1 to 6 carbon atoms, a hydroxy group, a hydroxyalkyl group, a carboxy group, a cyano group, or a halogen atom, and an alkyl group having 1 to 4 carbon atoms. , a hydroxy group, a carboxy group, a cyano group, or a halogen atom, and even more preferably a hydroxy group, a cyano group, or a halogen atom.

Examples of the alkanediyl group having 1 to 6 carbon atoms in L ² include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,5-diyl group. Straight chain alkanediyl group such as 1,6-diyl group;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group;
Examples include cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group.
L ² is preferably a single bond or an alkanediyl group having 1 to 3 carbon atoms, and more preferably a single bond.

X ² is preferably *-CO-O- or *-O-CO- (* represents a binding site with A ¹ or L ² ), and more preferably *-CO-O-. preferable.

The fluorinated hydrocarbon group having 1 to 18 carbon atoms represented by R ³ includes aliphatic hydrocarbon groups (chain hydrocarbon groups and alicyclic hydrocarbon groups such as alkyl groups, alkenyl groups, and alkynyl groups); Examples include aromatic hydrocarbon groups and groups in which at least one of the hydrogen atoms contained in a combination thereof is replaced with a fluorine atom.
Examples of the alkyl group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group, and nonyl group. The alkyl group preferably has 1 to 9 carbon atoms, more preferably 1 to 4 carbon atoms.
Examples of the alkenyl group include an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octynyl group, an isooctynyl group, and a nonenyl group.
Examples of the alkynyl group include ethynyl group, propynyl group, isopropynyl group, butynyl group, isobutynyl group, tert-butynyl group, pentynyl group, hexynyl group, octynyl group, nonynyl group, and the like.
The alicyclic hydrocarbon group may be monocyclic, polycyclic, or spirocyclic, and may be saturated or unsaturated. Examples of alicyclic hydrocarbon groups include monocyclic cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, and cyclododecyl group, norbornyl group, and adamantyl group. and polycyclic cycloalkyl groups such as groups.
Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, phenanthryl group, and fluorenyl group, with phenyl group, naphthyl group, and anthryl group being preferred, and phenyl group and naphthyl group being preferred. More preferred is a phenyl group.

The combined group is
A group combining an alicyclic hydrocarbon group and a chain hydrocarbon group such as an alkyl group, an alkenyl group, and/or an alkynyl group, a chain combination of an aromatic hydrocarbon group and an alkyl group, an alkenyl group, and/or an alkynyl group, etc. It represents a group that combines a hydrocarbon group and a group that combines an alicyclic hydrocarbon group and an aromatic hydrocarbon group. In addition, in the combined groups, two or more types of alicyclic hydrocarbon groups, chain hydrocarbon groups (alkyl groups, alkenyl groups, alkynyl groups), and aromatic hydrocarbon groups may be combined.
As a combined group,
Alicyclic hydrocarbon groups such as adamantylmethyl group and cyclohexylmethyl group - chain hydrocarbon group -*,
Chain hydrocarbon group such as methyladamantyl group - alicyclic hydrocarbon group - *,
Chain hydrocarbon groups such as tolyl group, xylyl group, cyclohexylphenyl group - aromatic hydrocarbon group - *, alicyclic hydrocarbon group - aromatic hydrocarbon group - *,
Chain hydrocarbon group such as methylcyclohexylmethyl group - alicyclic hydrocarbon group - chain hydrocarbon group - *,
Aromatic hydrocarbon groups such as benzyl groups - chain hydrocarbon groups -*,
Chain hydrocarbon group such as tolylmethyl group - aromatic hydrocarbon group - chain hydrocarbon group - *
etc. Here, * represents the bonding position with ^X2 .

［式（Ｒ３－１）中、
Ｌ^３は、単結合又は炭素数１～６のアルカンジイル基を表す。
ｍ３は、１～５のいずれかの整数を表す。
Ｒ^４は、ハロゲン原子又は炭素数１～６のアルキル基を表し、該アルキル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
ｍ４は、０～４のいずれかの整数を表し、ｍ４が２以上のとき、複数のＲ^４は互いに同一であっても異なってもよい。］ The fluorinated hydrocarbon group having 1 to 18 carbon atoms represented by R ³ is preferably a fluorinated alkyl group having 1 to 8 carbon atoms or a group represented by formula (R3-1).

[In formula (R3-1),
L ³ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms.
m3 represents an integer of 1 to 5.
R ⁴ represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and -CH ₂ - contained in the alkyl group may be replaced with -O- or -CO-.
m4 represents any integer from 0 to 4, and when m4 is 2 or more, a plurality of R ⁴ may be the same or different. ]

Examples of the fluorinated alkyl group having 1 to 8 carbon atoms include trifluoromethyl group, difluoromethyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, and 1,1,2,2-tetrafluoroethyl group. group, perfluoropropyl group, 3,3,3-trifluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, perfluorobutyl group, 4,4,4-trifluorobutyl group, 3,3 , 4,4,4-pentafluorobutyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group group, perfluoropentyl group, 4,4,5,5,5-pentafluoropentyl group, 3,3,4,4,5,5,5-heptafluoropentyl group, 2,2,3,3,4, 4,5,5,5-nonafluoropentyl group, perfluorohexyl group, 5,5,6,6,6-pentafluorohexyl group, 4,4,5,5,6,6,6-heptafluorohexyl group , 3,3,4,4,5,5,6,6,6-nonafluorohexyl group, 2,2,3,3,4,4,5,5,6,6,6-dodecafluorohexyl group , perfluoroheptyl group, perfluorooctyl group, and the like.
Among them, *-(CH ₂ ) _m5 -Rf1 (m5 represents any integer from 0 to 2. Rf1 represents a perfluoroalkyl group having 1 to 4 carbon atoms. * represents a bond with X ² A group represented by (representing a moiety) is preferable.

Examples of the alkanediyl group having 1 to 6 carbon atoms in L ³ include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,5-diyl group. Straight chain alkanediyl groups such as 1,6-diyl groups;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group;
Examples include cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group.
^L3 is preferably a single bond or a methylene group, and more preferably a methylene group.

Examples of the alkyl group having 1 to 6 carbon atoms for R ⁴ include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, and hexyl group. The number of carbon atoms in the alkyl group is preferably 1 to 4.
Examples of the halogen atom for R ⁴ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
m4 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2.
It is preferable that m3 is an integer of 2 or more.

Examples of the anion in the salt (I) include anions represented by the following formulas (Ia-1) to (Ia-20). Among them, anions represented by formulas (Ia-1) to (Ia-6) are preferred, and anions represented by formulas (Ia-1) to (Ia-4) and formula (Ia-6) are more preferred. preferable.

Examples of the organic cation of Z ⁺ include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, a cation represented by any of formulas (b2-1) to (b2-4) (hereinafter sometimes referred to as "cation (b2-1)" etc. depending on the formula number) is Can be mentioned.

式（ｂ２－１）～式（ｂ２－４）において、
Ｒ^b4～Ｒ^b6は、それぞれ独立に、炭素数１～３０の鎖式炭化水素基、炭素数３～３６の脂環式炭化水素基又は炭素数６～３６の芳香族炭化水素基を表し、該鎖式炭化水素基に含まれる水素原子は、ヒドロキシ基、炭素数１～１２のアルコキシ基、炭素数３～１２の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基で置換されていてもよく、該脂環式炭化水素基に含まれる水素原子は、ハロゲン原子、炭素数１～１８の脂肪族炭化水素基、炭素数２～４のアルキルカルボニル基又はグリシジルオ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、ハロゲン原子、ヒドロキシ基又は炭素数１～１２のアルコキシ基で置換されていてもよい。
Ｒ^b4とＲ^b5とは、互いに結合してそれらが結合する硫黄原子と一緒になって環を形成してもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b7及びＲ^b8は、それぞれ独立に、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
ｍ２及びｎ２は、それぞれ独立に０～５のいずれかの整数を表す。
ｍ２が２以上のとき、複数のＲ^b7は同一でも異なってもよく、ｎ２が２以上のとき、複数のＲ^b8は同一でも異なってもよい。
Ｒ^b9及びＲ^b10は、それぞれ独立に、炭素数１～３６の鎖式炭化水素基又は炭素数３～３６の脂環式炭化水素基を表す。
Ｒ^b9とＲ^b10とは、互いに結合してそれらが結合する硫黄原子と一緒になって環を形成してもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b11は、水素原子、炭素数１～３６の鎖式炭化水素基、炭素数３～３６の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基を表す。
Ｒ^b12は、炭素数１～１２の鎖式炭化水素基、炭素数３～１８の脂環式炭化水素基又は炭素数６～１８の芳香族炭化水素基を表し、該鎖式炭化水素に含まれる水素原子は、炭素数６～１８の芳香族炭化水素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１～１２のアルコキシ基又は炭素数１～１２のアルキルカルボニルオキシ基で置換されていてもよい。
Ｒ^b11とＲ^b12とは、互いに結合してそれらが結合する－ＣＨ－ＣＯ－を含めて環を形成していてもよく、該環に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－又は－ＣＯ－に置き換わってもよい。
Ｒ^b13～Ｒ^b18は、それぞれ独立に、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基又は炭素数１～１２のアルコキシ基を表す。
Ｌ^b31は、硫黄原子又は酸素原子を表す。
ｏ２、ｐ２、ｓ２、及びｔ２は、それぞれ独立に、０～５のいずれかの整数を表す。
ｑ２及びｒ２は、それぞれ独立に、０～４のいずれかの整数を表す。
ｕ２は０又は１を表す。
ｏ２が２以上のとき、複数のＲ^b13は同一又は相異なり、ｐ２が２以上のとき、複数のＲ^b14は同一又は相異なり、ｑ２が２以上のとき、複数のＲ^b15は同一又は相異なり、ｒ２が２以上のとき、複数のＲ^b16は同一又は相異なり、ｓ２が２以上のとき、複数のＲ^b17は同一又は相異なり、ｔ２が２以上のとき、複数のＲ^b18は同一又は相異なる。

In formulas (b2-1) to (b2-4),
R ^b4 to R ^b6 each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, The hydrogen atom contained in the chain hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may bond to each other and form a ring together with the sulfur atom to which they are bonded, and -CH ₂ - contained in the ring may be -O-, -S- or -CO- may be substituted.
R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent any integer from 0 to 5.
When m2 is 2 or more, multiple R ^b7s may be the same or different; when n2 is 2 or more, multiple R ^b8s may be the same or different.
R ^b9 and R ^b10 each independently represent a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may bond to each other and form a ring together with the sulfur atom to which they are bonded, and -CH ₂ - contained in the ring may be -O-, -S- or -CO- may be substituted.
R ^b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms; The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. It may be substituted with 12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may be bonded to each other to form a ring including -CH-CO- to which they are bonded, and -CH ₂ - contained in the ring is -O-, -S - or -CO- may be substituted.
R ^b13 to R ^b18 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^b31 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represent an integer of 0 to 5.
q2 and r2 each independently represent an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, multiple R ^b13s are the same or different; when p2 is 2 or more, multiple R ^b14s are the same or different; when q2 is 2 or more, multiple R ^b15s are the same or different. , when r2 is 2 or more, multiple R ^b16s are the same or different; when s2 is 2 or more, multiple R ^b17s are the same or different; when t2 is 2 or more, multiple R ^b18s are the same or different; different.

特に、Ｒ^b9～Ｒ^b12の脂環式炭化水素基は、好ましくは炭素数３～１８、より好ましくは炭素数４～１２である。 The aliphatic hydrocarbon group refers to a chain hydrocarbon group and an alicyclic hydrocarbon group.
Examples of chain hydrocarbon groups include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, and 2-ethylhexyl group. Can be mentioned.
In particular, the chain hydrocarbon groups R ^b9 to R ^b12 preferably have 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclo Examples include cycloalkyl groups such as heptyl group, cyclooctyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups.

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

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

Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, biphenyl group, naphthyl group, and phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group having a chain hydrocarbon group having 1 to 18 carbon atoms (tolyl group, xylyl group, group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and alicyclic groups having 3 to 18 carbon atoms. Examples include aromatic hydrocarbon groups having the formula hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.). In addition, when the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms. is preferred.
Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include p-methoxyphenyl group.
Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, and naphthylethyl 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 alkylcarbonyl 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 the alkylcarbonyloxy group include methylcarbonyloxy group, ethylcarbonyloxy group, propylcarbonyloxy group, isopropylcarbonyloxy group, butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, and pentylcarbonyloxy group. , hexylcarbonyloxy group, octylcarbonyloxy group, and 2-ethylhexylcarbonyloxy group.

The ring formed by R ^b4 and R ^b5 combined with each other and the sulfur atom to which they are bonded may be monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. It may be a ring. Examples of this ring include a ring having 3 to 18 carbon atoms, preferably a ring having 4 to 18 carbon atoms. Further, examples of the ring containing a sulfur atom include a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, such as the following rings. * represents a binding site.

The ring formed by R ^b9 and R ^b10 together may be monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. Examples of this ring include a 3- to 12-membered ring, preferably a 3- to 7-membered ring. Examples include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring.
The ring formed by R ^b11 and R ^b12 together may be monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. Examples of this ring include a 3- to 12-membered ring, preferably a 3- to 7-membered ring. Examples include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

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

Examples of the cation (b2-1) include the following cations.

Examples of the cation (b2-2) include the following cations.

Examples of the cation (b2-3) include the following cations.

Examples of the cation (b2-4) include the following cations.

Salt (I) is a combination of the above-mentioned anions and the above-mentioned organic cations, which can be arbitrarily combined. The salt (I) is preferably a combination of an anion represented by any one of formulas (Ia-1) to (Ia-6) and a cation (b2-1) or a cation (b2-3). It will be done.

Examples of the salt (I) include the salts listed in Table 1. In the table below, each code represents the code attached to the structure representing the above-mentioned anion or cation. For example, salt (I-1) means a salt consisting of an anion represented by formula (Ia-1) and a cation represented by formula (b2-c-1), and represents the salt shown below.

Among them, salt (I) includes salt (I-1) to salt (I-6), salt (I-15) to salt (I-20), salt (I-29) to salt (I-34), Salt (I-43) ~ Salt (I-48), Salt (I-57) ~ Salt (I-62), Salt (I-71) ~ Salt (I-76), Salt (I-85) ~ Salt (I-90) is preferred.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における溶剤としては、クロロホルム、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 <Method for producing salt (I)>
In salt (I), X ¹ is *-CO-O- (* represents the bonding site with C(R ¹ )(R ² ) or C(Q ¹ )(Q ² ).) (Salt represented by formula (I1)) can be obtained by, for example, reacting the salt represented by formula (I1-a) with carbonyldiimidazole in a solvent, and then further reacting the salt represented by formula (I1-b) with carbonyldiimidazole. It can be produced by reacting with a compound.

(In the formula, all symbols represent the same meanings as above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 to 24 hours.

式（Ｉ１－ｂ）で表される化合物において、Ｘ^２が、＊－Ｘ^２ｂ－Ｏ－（Ｘ^２ｂは、単結合、カルボニル基又は－Ｏ－ＣＯ－＊＊を表す。＊は、Ｌ^２との結合部位を表す。＊＊は、酸素原子との結合部位を表す。）である化合物（式（Ｉ１－ｂ１）で表される化合物）は、例えば、式（Ｉ１－ｃ１）で表される化合物とカルボニルジイミダゾールとを溶剤中で反応させた後、さらに、式（Ｉ１－ｄ１）で表される化合物と反応させることにより製造することができる。

（式中、全ての符号は、それぞれ前記と同じ意味を表す。Ｘ^２ｂは、単結合、カルボニル基又は、－Ｏ－ＣＯ－＊を表す。＊は酸素原子との結合部位を表す。）
この反応における溶剤としては、クロロホルム、アセトニトリル等が挙げられる。
式（Ｉ１－ｃ１）で表される化合物としては、下記式で表される化合物等が挙げられ、市場より容易に入手することができる。

Examples of the salt represented by formula (I1-a) include salts represented by the following, and can be produced by the method described in JP-A No. 2008-127367 and JP-A No. 2011-046694. Can be done.

In the compound represented by formula (I1-b), X ² is *-X ^2b -O- (X ^2b represents a single bond, a carbonyl group, or -O-CO-**. * is L ² ** represents a bonding site with an oxygen atom) (a compound represented by formula (I1-b1)) is, for example, a compound represented by formula (I1-c1). It can be produced by reacting a compound represented by the formula (I1-d1) with carbonyldiimidazole in a solvent, and then reacting the compound with a compound represented by the formula (I1-d1).

(In the formula, all symbols have the same meanings as above. X ^2b represents a single bond, a carbonyl group, or -O-CO-*. * represents a bonding site with an oxygen atom.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
Examples of the compound represented by formula (I1-c1) include compounds represented by the following formula, which are easily available on the market.

式（Ｉ１－ｂ１）で表される化合物は、例えば、式（Ｉ１－ｃ１）で表される化合物と式（Ｉ１－ｄ２）で表される化合物とを塩基存在下、溶剤中で反応させることにより製造することもできる。

（式中、全ての符号は、それぞれ前記と同じ意味を表す。Ｘは、ハロゲン原子を表す。）
この反応における溶剤としては、ジメチルホルムアミド、テトラヒドロフラン、クロロホルム、アセトニトリル等が挙げられる。
この反応における塩基としては、炭酸カリウム、ヨウ化カリウム、トリエチルアミン、ピリジン等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 Examples of the compound represented by formula (I1-d1) include compounds represented by the following formula, etc., which can be easily obtained from the market.

The compound represented by formula (I1-b1) can be obtained by, for example, reacting a compound represented by formula (I1-c1) with a compound represented by formula (I1-d2) in a solvent in the presence of a base. It can also be manufactured by

(In the formula, all symbols have the same meanings as above. X represents a halogen atom.)
Examples of the solvent in this reaction include dimethylformamide, tetrahydrofuran, chloroform, and acetonitrile.
Examples of the base in this reaction include potassium carbonate, potassium iodide, triethylamine, and pyridine.
The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 to 24 hours.

Examples of the compound represented by the formula (I1-d2) include compounds represented by the following formula, etc., which can be easily obtained from the market.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における溶剤としては、ジメチルホルムアミド、テトラヒドロフラン、クロロホルム、アセトニトリル等が挙げられる。
この反応における塩基としては、トリエチルアミン、ピリジン、ジメチルアミノピリジン等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 In the compound represented by formula (I1-b), a compound (represented by formula (I1-b3)) in which X ² is *-O-CO- (* represents the bonding site with L ² ) For example, the compound represented by formula (I1-c1) and the compound represented by formula (I1-d3) can be reacted in a solvent in the presence of a base.

(In the formula, all symbols represent the same meanings as above.)
Examples of the solvent in this reaction include dimethylformamide, tetrahydrofuran, chloroform, and acetonitrile.
Examples of the base in this reaction include triethylamine, pyridine, dimethylaminopyridine, and the like.
The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 to 24 hours.

Examples of the compound represented by the formula (I1-d3) include compounds represented by the following formula, which can be easily obtained from the market.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における溶剤としては、クロロホルム、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 In salt (I), X ¹ is *-O-CO- (* represents the bonding site with C(R ¹ )(R ² ) or C(Q ¹ )(Q ² ).) (Salt represented by formula (I2)) can be prepared by, for example, reacting a compound represented by formula (I2-b) with carbonyldiimidazole in a solvent, and then further reacting the compound represented by formula (I2-a) with carbonyldiimidazole. It can be produced by reacting with a salt.

(In the formula, all symbols represent the same meanings as above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 to 24 hours.

式（Ｉ２－ｂ）で表される化合物としては、下記式で表される化合物等が挙げられ、市場より容易に入手することができる。

Examples of the salt represented by formula (I2-a) include salts represented by the following, and can be produced by the method described in JP-A-2012-193170.

Examples of the compound represented by formula (I2-b) include compounds represented by the following formula, etc., which can be easily obtained from the market.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における溶剤としては、クロロホルム、アセトニトリル等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 In salt (I), X ¹ is *-O-CO-O- (* represents the bonding site with C(R ¹ )(R ² ) or C(Q ¹ )(Q ² ).) A certain salt (salt represented by formula (I3)) can be obtained by, for example, reacting a salt represented by formula (I2-a) with carbonyldiimidazole in a solvent, and then further reacting the salt represented by formula (I1-b) with carbonyldiimidazole. It can be produced by reacting with a compound represented by:

(In the formula, all symbols represent the same meanings as above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 to 24 hours.

（式中、全ての符号は、それぞれ前記と同じ意味を表す。）
この反応における塩基としては、水酸化カリウム等が挙げられる。
この反応における溶剤としては、クロロホルム、アセトニトリル、テトラヒドロフラン、ジメチルホルムアミド等が挙げられる。
反応温度は通常５℃～８０℃であり、反応時間は通常０．５時間～２４時間である。 ^In the salt ( ^{I )} , ^{a salt} (formula (I4)) can be obtained by, for example, reacting the salt represented by formula (I2-a) with the compound represented by formula (I1-b) in a solvent in the presence of a base. can be manufactured.

(In the formula, all symbols represent the same meanings as above.)
Examples of the base in this reaction include potassium hydroxide.
Examples of the solvent in this reaction include chloroform, acetonitrile, tetrahydrofuran, dimethylformamide, and the like.
The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 to 24 hours.

<Acid generator>
The acid generator of the present invention is an acid generator containing salt (I). It may contain one type of salt (I), or it may contain two or more types of salt (I).
The acid generator of the present invention may contain, in addition to the salt (I), an acid generator known in the field of resists (hereinafter sometimes referred to as "acid generator (B)"). The acid generator (B) may be used alone or in combination of two or more.

The acid generator (B) may be either nonionic or ionic. Examples of nonionic acid generators include sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane), etc. Typical ionic acid generators include onium salts containing onium cations (eg, diazonium salts, phosphonium salts, sulfonium salts, and iodonium salts). Examples of the anion of the onium salt include a sulfonic acid anion, a sulfonylimide anion, a sulfonylmethide anion, and the like.

As the acid generator (B), JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Patent No. 3,779,778, U.S. Patent No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. It is possible to use compounds that generate acids upon radiation as described in . Moreover, you may use the compound manufactured by the well-known method. The acid generator (B) may be used in combination of two or more types.

［式（Ｂ１）中、
Ｑ^ｂ１及びＱ^ｂ２は、それぞれ独立に、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。
Ｌ^ｂ１は、炭素数１～２４の２価の飽和炭化水素基を表し、該２価の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２価の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メチ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、該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ（Ｏ）_２－又は－ＣＯ－に置き換わっていてもよい。
Ｚ^＋は、有機カチオンを表す。］ The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)").

[In formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH ₂ - contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. , the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group that may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms that may have a substituent, and is included in the alicyclic hydrocarbon group. CH ₂ - may be replaced by -O-, -S(O) ₂ - or -CO-.
Z ⁺ represents an organic cation. ]

The perfluoroalkyl groups represented by Q ^b1 and Q ^b2 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, and Examples include perfluorohexyl group.
Q ^b1 and Q ^b2 are each independently preferably a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

Examples of the divalent saturated hydrocarbon group in L ^b1 include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. It may also be a group formed by combining two or more of the groups.
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, pentane-2,4-diyl group, 2-methylpropane- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group;
A monocyclic cycloalkanediyl group such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, or a cyclooctane-1,5-diyl group. alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbons such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group Examples include groups.

Examples of groups in which -CH ₂ - contained in the divalent saturated hydrocarbon group represented by L ^b1 are replaced with -O- or -CO- include formulas (b1-1) to (b1-3) Examples include groups represented by any of the following. In addition, in the groups represented by formulas (b1-1) to (b1-3) and the groups represented by formulas (b1-4) to (b1-11), which are specific examples thereof, * and * * represents a binding site, and * represents a bond with -Y.

［式（ｂ１－１）中、
Ｌ^ｂ２は、単結合又は炭素数１～２２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水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ３は、単結合又は炭素数１～２２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水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、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い。
ただし、Ｌ^ｂ２とＬ^ｂ３との炭素数合計は、２２以下である。
式（ｂ１－２）中、
Ｌ^ｂ４は、単結合又は炭素数１～２２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水素原子は、フッ素原子に置換されていてもよい。
Ｌ^ｂ５は、単結合又は炭素数１～２２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水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、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い。
ただし、Ｌ^ｂ４とＬ^ｂ５との炭素数合計は、２２以下である。
式（ｂ１－３）中、
Ｌ^ｂ６は、単結合又は炭素数１～２３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水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
Ｌ^ｂ７は、単結合又は炭素数１～２３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水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよく、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い。
ただし、Ｌ^ｂ６とＬ^ｂ７との炭素数合計は、２３以下である。
＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。］

[In formula (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated -CH ₂ - contained in the hydrocarbon group may be replaced with -O- or -CO-.
However, the total carbon number of L ^b2 and L ^b3 is 22 or less.
In formula (b1-2),
L ^b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated -CH ₂ - contained in the hydrocarbon group may be replaced with -O- or -CO-.
However, the total carbon number of L ^b4 and L ^b5 is 22 or less.
In formula (b1-3),
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and the saturated -CH ₂ - contained in the hydrocarbon group may be replaced with -O- or -CO-.
However, the total carbon number of L ^b6 and L ^b7 is 23 or less.
* and ** represent a binding site, and * represents a binding site with Y. ]

In the groups represented by formulas (b1-1) to (b1-3), when -CH ₂ - contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the carbon before being replaced The number is the number of carbon atoms in the saturated hydrocarbon group.
Examples of the divalent saturated hydrocarbon group include those similar to the divalent saturated hydrocarbon group of L ^b1 .

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group; -CH ₂ - contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-.

The group in which -CH ₂ - contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced with -O- or -CO- is represented by formula (b1-1) or formula (b1-3). Preferred groups are

［式（ｂ１－４）中、
Ｌ^ｂ８は、単結合又は炭素数１～２２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水素原子は、フッ素原子又はヒドロキシ基に置換されていてもよい。
式（ｂ１－５）中、
Ｌ^ｂ９は、炭素数１～２０の２価の飽和炭化水素基を表し、該２価の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い。
Ｌ^ｂ１０は、単結合又は炭素数１～１９の２価の飽和炭化水素基を表し、該２価の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に置換されていてもよい。
ただし、Ｌ^ｂ９及びＬ^ｂ１０の合計炭素数は２０以下である。
式（ｂ１－６）中、
Ｌ^ｂ１１は、炭素数１～２１の２価の飽和炭化水素基を表す。
Ｌ^ｂ１２は、単結合又は炭素数１～２０の２価の飽和炭化水素基を表し、該２価の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に置換されていてもよい。
ただし、Ｌ^ｂ１１及びＬ^ｂ１２の合計炭素数は２１以下である。
式（ｂ１－７）中、
Ｌ^ｂ１３は、炭素数１～１９の２価の飽和炭化水素基を表す。
Ｌ^ｂ１４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２価の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い。
Ｌ^ｂ１５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２価の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に置換されていてもよい。
ただし、Ｌ^ｂ１３～Ｌ^ｂ１５の合計炭素数は１９以下である。
式（ｂ１－８）中、
Ｌ^ｂ１６は、炭素数１～１８の２価の飽和炭化水素基を表し、該２価の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い。
Ｌ^ｂ１７は、炭素数１～１８の２価の飽和炭化水素基を表す。
Ｌ^ｂ１８は、単結合又は炭素数１～１７の２価の飽和炭化水素基を表し、該２価の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に置換されていてもよい。
ただし、Ｌ^ｂ１６～Ｌ^ｂ１８の合計炭素数は１９以下である。
＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。］ Examples of the group represented by formula (b1-1) include groups represented by formulas (b1-4) to (b1-8), respectively.

[In formula (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
In formula (b1-5),
L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and -CH ₂ - contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-.
L ^b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b9 and L ^b10 is 20 or less.
In formula (b1-6),
L ^b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b11 and L ^b12 is 21 or less.
In formula (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH ₂ - contained in the divalent saturated hydrocarbon group is replaced with -O- or -CO-. Good too.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b13 to L ^b15 is 19 or less.
In formula (b1-8),
L ^b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH ₂ - contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-.
L ^b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b16 to L ^b18 is 19 or less.
* and ** represent a binding site, and * represents a binding site with Y. ]

L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms.
L ^b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

［式（ｂ１－９）中、
Ｌ^b19は、単結合又は炭素数１～２３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水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b20は、単結合又は炭素数１～２３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水素原子は、フッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b19及びＬ^b20の合計炭素数は２３以下である。
式（ｂ１－１０）中、
Ｌ^b21は、単結合又は炭素数１～２１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水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b22は、単結合又は炭素数１～２１の２価の飽和炭化水素基を表す。
Ｌ^b23は、単結合又は炭素数１～２１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水素原子は、フッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b21、Ｌ^b22及びＬ^b23の合計炭素数は２１以下である。
式（ｂ１－１１）中、
Ｌ^b24は、単結合又は炭素数１～２０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水素原子は、フッ素原子に置換されていてもよい。
Ｌ^b25は、炭素数１～２１の２価の飽和炭化水素基を表す。
Ｌ^b26は、単結合又は炭素数１～２０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水素原子は、フッ素原子、ヒドロキシ基又はアルキルカルボニルオキシ基に置換されていてもよい。該アルキルカルボニルオキシ基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該アルキルカルボニルオキシ基に含まれる水素原子は、ヒドロキシ基に置換されていてもよい。
ただし、Ｌ^b24、Ｌ^b25及びＬ^b26の合計炭素数は２１以下である。
＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。］ Examples of the group represented by formula (b1-3) include groups represented by formulas (b1-9) to (b1-11), respectively.

[In formula (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group, or an alkylcarbonyloxy group. Good too. -CH ₂ - contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b19 and L ^b20 is 23 or less.
In formula (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group, or an alkylcarbonyloxy group. Good too. -CH ₂ - contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b21 , L ^b22 and L ^b23 is 21 or less.
In formula (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.
L ^b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms.
L ^b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group, or an alkylcarbonyloxy group. Good too. -CH ₂ - contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b24 , L ^b25 and L ^b26 is 21 or less.
* and ** represent a binding site, and * represents a binding site with Y. ]

In addition, in the group represented by formula (b1-9) to the group represented by formula (b1-11), when the hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the substituted Let the previous carbon number be the carbon number of the saturated hydrocarbon group.

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

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-4) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-5) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-6) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-7) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-8) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-2) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-9) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-10) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

（＊及び＊＊は結合部位を表し、＊はＹとの結合部位を表す。） Examples of the group represented by formula (b1-11) include the following.

(* and ** represent the binding site, * represents the binding site with Y.)

Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y11) and formulas (Y36) to (Y38).
When -CH ₂ - contained in the alicyclic hydrocarbon group represented by Y is replaced with -O-, -S(O) ₂ - or -CO-, the number may be one or two or more. good. Examples of such groups include groups represented by formulas (Y12) to (Y35) and formulas (Y39) to (Y41).

Ｙで表される脂環式炭化水素基としては、好ましくは式（Ｙ１）～式（Ｙ２０）、式（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）～式（Ｙ４１）のいずれかで表される基であり、より好ましくは式（Ｙ１１）、式（Ｙ１５）、式（Ｙ１６）、式（Ｙ２０）、式（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）又は式（Ｙ４０）で表される基であり、さらに好ましくは式（Ｙ１１）、式（Ｙ１５）、式（Ｙ２０）、式（Ｙ２６）、式（Ｙ２７）、式（Ｙ３０）、式（Ｙ３１）、式（Ｙ３９）又は式（Ｙ４０）で表される基である。
Ｙで表される脂環式炭化水素基が式（Ｙ２８）～式（Ｙ３５）、式（Ｙ３９）又は式（Ｙ４０）等の酸素原子を有するスピロ環である場合には、２つの酸素原子間のアルカンジイル基は、１以上のフッ素原子を有することが好ましい。また、ケタール構造に含まれるアルカンジイル基のうち、酸素原子に隣接するメチレン基には、フッ素原子が置換されていないのが好ましい。

The alicyclic hydrocarbon group represented by Y preferably includes formulas (Y1) to (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), and formula (Y39). ~ A group represented by any one of formula (Y41), more preferably formula (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y26), formula (Y27), or formula (Y30), formula (Y31), formula (Y39), or formula (Y40), more preferably formula (Y11), formula (Y15), formula (Y20), formula (Y26), or formula (Y27), formula (Y30), formula (Y31), formula (Y39) or formula (Y40).
When the alicyclic hydrocarbon group represented by Y is a spiro ring having an oxygen atom such as formula (Y28) to formula (Y35), formula (Y39) or formula (Y40), between two oxygen atoms The alkanediyl group preferably has one or more fluorine atoms. Moreover, among the alkanediyl groups included in the ketal structure, it is preferable that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

Substituents for the methyl group represented by Y include 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, -( CH ₂ ) _ja -CO-O-R ^b1 group or -(CH ₂ ) _ja -O-CO-R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, Represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, and -CH ₂ - contained in the alkyl group and the alicyclic hydrocarbon group is -O- , -SO ₂ - or -CO-, and the hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group is replaced with a hydroxy group or a fluorine atom. ja represents any integer from 0 to 4).
Substituents for the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms which may be substituted with a hydroxy group, and an alicyclic group having 3 to 16 carbon atoms. Hydrocarbon group, alkoxy group having 1 to 12 carbon atoms, aromatic hydrocarbon group having 6 to 18 carbon atoms, aralkyl group having 7 to 21 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, glycidyloxy group, -( CH ₂ ) _ja -CO-O-R ^b1 group or -(CH ₂ ) _ja -O-CO-R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, Represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, and -CH ₂ - contained in the alkyl group and the alicyclic hydrocarbon group is -O- , -SO ₂ - or -CO-, and the hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group is replaced with a hydroxy group or a fluorine atom. ja represents any integer from 0 to 4).

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, and an adamantyl group.
Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples of the aromatic hydrocarbon group having a chain hydrocarbon group include tolyl group, xylyl group, and cumenyl group. , mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc., and aromatic groups having an alicyclic hydrocarbon group. Examples of the hydrocarbon group include p-cyclohexylphenyl group and p-adamantylphenyl group.
Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, and nonyl group. group, decyl group, undecyl group, dodecyl group, etc.
Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as 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 aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.

Examples of Y include the following.

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; -CH ₂ - constituting the hydrogen group or adamantyl group may be replaced with -CO-, -S(O) ₂ - or -CO-. Y is more preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, or a group represented below.

Anions in the salt represented by formula (B1) include anions represented by formulas (B1-A-1) to (B1-A-55) [hereinafter referred to as "anion (B1-A-55)" according to the formula number. -1)” etc. ] is preferred, and formulas (B1-A-1) to (B1-A-4), formula (B1-A-9), formula (B1-A-10), and formulas (B1-A-24) to (B1-A-24) are preferred. (B1-A-33), Formula (B1-A-36) to Formula (B1-A-40), Formula (B1-A-47) to Formula (B1-A-55) Anions are more preferred.

ここでＲ^ｉ２～Ｒ^ｉ７は、互いに独立に、例えば、炭素数１～４のアルキル基、好ましくはメチル基又はエチル基である。Ｒ^ｉ８は、例えば、炭素数１～１２の脂肪族炭化水素基、好ましくは炭素数１～４のアルキル基、炭素数５～１２の脂環式炭化水素基又はこれらを組合せることにより形成される基、より好ましくはメチル基、エチル基、シクロヘキシル基又はアダマンチル基である。Ｌ^Ａ４は、単結合又は炭素数１～４のアルカンジイル基である。
Ｑ^ｂ１及びＱ^ｂ２は、上記と同じ意味を表す。
式（Ｂ１）で表される塩におけるアニオンとしては、具体的には、特開２０１０－２０４６４６号公報に記載されたアニオンが挙げられる。

Here, R ⁱ² to R ⁱ⁷ each independently represent, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R ⁱ⁸ is formed, for example, by an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. and more preferably a methyl group, ethyl group, cyclohexyl group or adamantyl group. L ^A4 is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Q ^b1 and Q ^b2 represent the same meanings as above.
Specific examples of the anion in the salt represented by formula (B1) include the anions described in JP-A No. 2010-204646.

Preferred anions in the salt represented by formula (B1) include anions represented by formulas (B1a-1) to (B1a-34), respectively.

Among them, formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-16), formula (B1a-18), formula (B1a-19), formula (B1a-22 ) to (B1a-30) are preferred.

Examples of the organic cation of Z1 ⁺ include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations, and the same as the cation Z ⁺ in salt (I) Can be mentioned.

The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the acid generator (B), preferably formulas (B1a-1) to (B1a-3), formulas (B1a-7) to (B1a-16), formula (B1a-18), and formula (B1a- 19), a combination of an anion represented by any one of formulas (B1a-22) to (B1a-34) and a cation (b2-1) or a cation (b2-3).

Preferable examples of the acid generator (B) include those represented by formulas (B1-1) to (B1-48). Among these, those containing an arylsulfonium cation are preferred, and include formulas (B1-1) to (B1-3), formulas (B1-5) to (B1-7), and formulas (B1-11) to (B1-14). ), formulas (B1-20) to (B1-26), formula (B1-29), and formulas (B1-31) to (B1-48) are particularly preferred.

When containing salt (I) and acid generator (B) as acid generators, the content ratio of salt (I) and acid generator (B) (mass ratio; salt (I): acid generator ( B)) is usually 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, and even more preferably 10:90 to 90. :10, particularly preferably 15:85 to 85:15.
In the resist composition of the present invention, the total content of the acid generator is preferably 1 part by mass or more and 40 parts by mass or less, more preferably 3 parts by mass or more, based on 100 parts by mass of the resin (A) described below. It is 35 parts by mass or less.

<Resist composition>
The resist composition of the present invention contains an acid generator containing salt (I) and a resin having an acid-labile group (hereinafter sometimes referred to as "resin (A)"). Here, the term "acid-labile group" refers to a structure that has a leaving group, the leaving group is removed by contact with an acid, and the structural unit has a hydrophilic group (for example, a hydroxy group or a carboxy group). means a group that is converted into a unit.
The resist composition of the present invention preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") such as a salt that generates an acid that is weaker in acidity than the acid generated from the acid generator. , a solvent (hereinafter sometimes referred to as "solvent (E)") is preferably contained.

<Resin (A)>
The resin (A) has a structural unit (hereinafter sometimes referred to as "structural unit (a1)") having an acid-labile group. It is preferable that the resin (A) further contains a structural unit other than the structural unit (a1). Structural units other than structural unit (a1) include structural units that do not have acid-labile groups (hereinafter sometimes referred to as "structural units (s)"), structural units other than structural units (a1) and structural units (s) Structural units (for example, structural units having a halogen atom (hereinafter referred to as "structural unit (a4)") described later, structural units having a non-eliminating hydrocarbon group (hereinafter referred to as "structural unit (a5)"), ) and other structural units derived from monomers known in the art.

［式（１）中、Ｒ^a1、Ｒ^a２及び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み合わせた基を表すか、Ｒ^a1及びＲ^a2は互いに結合してそれらが結合する炭素原子とともに炭素数３～２０の脂環式炭化水素基を形成する。
ｍａ及びｎａは、それぞれ独立して、０又は１を表し、ｍａ及びｎａの少なくとも一方は１を表す。
＊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’は互いに結合してそれらが結合する炭素原子及びＸとともに炭素数３～２０の複素環基を形成し、該炭化水素基及び該複素環基に含まれる－ＣＨ_２－は、－Ｏ－又は－Ｓ－で置き換わってもよい。
Ｘは、酸素原子又は硫黄原子を表す。
ｎａ’は、０又は１を表す。
＊は結合手を表す。］ <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 acid labile group contained in the resin (A) is a group represented by formula (1) (hereinafter also referred to as group (1)) and/or a group represented by formula (2) (hereinafter referred to as group (2)). ) is preferred.

[In formula (1), R ^a1 , R ^a2 and R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a combination thereof. Watermelon, R ^a1 and R ^a2 combine with each other to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
ma and na each independently represent 0 or 1, and at least one of ma and na represents 1.
* represents a bond. ]

[In formula (2), R ^a1' and R ^a2' each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^a3' represents a hydrocarbon group having 1 to 20 carbon atoms. Alternatively, R ^a2' and R ^a3' combine with each other to form a heterocyclic group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and are included in the hydrocarbon group and the heterocyclic group - CH ₂ - may be replaced with -O- or -S-.
X represents an oxygen atom or a sulfur atom.
na' represents 0 or 1.
* represents a bond. ]

アルキル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、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、シクロヘキシルメチル基、アダマンチルメチル基、アダマンチルジメチル基、ノルボルニルエチル基等が挙げられる。
好ましくは、ｍａは０であり、ｎａは１である。
Ｒ^a1及びＲ^a2が互いに結合して脂環式炭化水素基を形成する場合の－Ｃ（Ｒ^a1）（Ｒ^a2）（Ｒ^a3）としては、下記の基が挙げられる。脂環式炭化水素基は、好ましくは炭素数３～１２である。＊は－Ｏ－との結合手を表す。

Examples of the alkyl group for R ^a1 , R ^a2 and R ^a3 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, and the like.
The alicyclic hydrocarbon group in R ^a1 , R ^a2 and R ^a3 may be either 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 groups of R ^a1 , R ^a2 and R ^a3 preferably have 3 to 16 carbon atoms.

Examples of groups combining an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, and a norbornyl group. Examples include ethyl group.
Preferably ma is 0 and na is 1.
Examples of --C(R ^a1 )(R ^a2 )(R ^a3 ) when R ^a1 and R ^a2 combine with each other to form an alicyclic hydrocarbon group include the following groups. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * represents a bond with -O-.

Ｒ^ａ１’及びＲ^ａ２’のうち、少なくとも１つは水素原子であることが好ましい。
ｎａ’は、好ましくは０である。 Examples of the hydrocarbon group for R ^a1' , R ^a2' and R ^a3' include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group and alicyclic hydrocarbon group include the same groups as those listed for R ^a1 , R ^a2 and R ^a3 .
Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group.
Examples of combined groups include groups combining the above-mentioned alkyl groups and alicyclic hydrocarbon groups (for example, cycloalkylalkyl groups), aralkyl groups such as benzyl groups, aromatic hydrocarbon groups having alkyl groups (p-methyl phenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group), alicyclic hydrocarbon group Examples include aromatic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) and aryl-cycloalkyl groups such as phenylcyclohexyl group.
Examples of the heterocyclic group formed by R ^a2' and R ^a3' together with the carbon atom to which they are bonded and X include the following groups. * represents a bond.

It is preferable that at least one of R ^a1' and R ^a2' is a hydrogen atom.
na' is preferably 0.

Examples of the group (1) include the following groups.
A group in which R ^a1 , R ^a2 and R ^a3 are alkyl groups, ma=0, and na=1 in formula (1). The group is preferably a tert-butoxycarbonyl group.
In formula (1), R ^a1 and R ^a2 form an adamantyl group together with the carbon atom to which they are bonded, R ^a3 is an alkyl group, ma = 0, and na = 1. .
In formula (1), R ^a1 and R ^a2 are each independently an alkyl group, R ^a3 is an adamantyl group, ma=0, and na=1.
Specific examples of the group (1) include the following groups. * represents a bond.

Specific examples of group (2) include the following groups. * represents a bond.

The monomer (a1) is preferably a monomer having an acid-labile group and an ethylenically unsaturated bond, 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 preferred. 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）、式（ａ１－１）及び式（ａ１－２）中、
Ｌ^a01、Ｌ^ａ１及びＬ^ａ２は、それぞれ独立に、－Ｏ－又は^＊－Ｏ－（ＣＨ_２）_ｋ１－ＣＯ－Ｏ－を表し、ｋ１は１～７のいずれかの整数を表し、＊は－ＣＯ－との結合手を表す。
Ｒ^a01、Ｒ^ａ４及びＲ^ａ５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み合わせた基を表す。
Ｒ^ａ６及びＲ^ａ７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せることにより形成される基を表す。
ｍ１は０～１４のいずれかの整数を表す。
ｎ１は０～１０のいずれかの整数を表す。
ｎ１’は０～３のいずれかの整数を表す。］ As a structural unit derived from a (meth)acrylic monomer having group (1), a structural unit represented by formula (a1-0) (hereinafter sometimes referred to as structural unit (a1-0)), a formula ( a1-1) (hereinafter sometimes referred to as structural unit (a1-1)) or the structural unit represented by formula (a1-2) (hereinafter referred to as structural unit (a1-2)) ) may be mentioned. Preferably, it is at least one structural unit selected from the group consisting of structural unit (a1-1) and structural unit (a1-2). These may be used alone or in combination of two or more.

[In formula (a1-0), formula (a1-1) and formula (a1-2),
L ^a01 , L ^a1 and L ^a2 each independently represent -O- or ^* -O-(CH ₂ ) _k1 -CO-O-, k1 represents any integer from 1 to 7, and * Represents a bond with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent 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 combination thereof.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents any integer from 0 to 14.
n1 represents any integer from 0 to 10.
n1' represents any integer from 0 to 3. ]

R ^a01 , R ^a4 and R ^a5 are preferably methyl groups.
L ^a01 , L ^a1 and L ^a2 are preferably an oxygen atom or *-O-(CH ₂ ) _k01 -CO-O- (however, k01 is preferably an integer of 1 to 4, more preferably is 1), more preferably an oxygen atom.
Examples of the alkyl group, alicyclic hydrocarbon group, and a combination thereof in R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 include the groups listed for R ^a1 , R ^a2 and R ^a3 in formula (1). Examples include groups similar to .
The alkyl group in R ^a02 , R ^a03 , and R ^a04 preferably has 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.
The alkyl group in R ^a6 and R ^a7 preferably has 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, or an isopropyl group, and even more preferably an ethyl group or an isopropyl group.
The number of carbon atoms in the alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^a04 is preferably 5 to 12, more preferably 5 to 10.
In the group that is a combination of an alkyl group and an alicyclic hydrocarbon group, it is preferable that the total carbon number of the alkyl group and alicyclic hydrocarbon group is 18 or less.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, more preferably a methyl group, ethyl group, cyclohexyl group or adamantyl group.
R ^a6 and R ^a7 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, or an isopropyl group, and even more preferably an ethyl group or an isopropyl group.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1' is preferably 0 or 1.

As the structural unit (a1-0), for example, a structural unit represented by any one of formulas (a1-0-1) to (a1-0-12) and R ^a01 in the structural unit (a1-0) Examples include structural units in which the corresponding methyl group is replaced with a hydrogen atom, and structural units represented by any of formulas (a1-0-1) to (a1-0-10) are preferred.

Examples of the structural unit (a1-1) include structural units derived from monomers described in JP-A No. 2010-204646. Among them, the structural unit represented by any one of formulas (a1-1-1) to formula (a1-1-4) and the methyl group corresponding to R ^a4 in the structural unit (a1-1) are replaced with a hydrogen atom. Structural units are preferred, and structural units represented by any of formulas (a1-1-1) to (a1-1-4) are more preferred.

The structural unit (a1-2) corresponds to a structural unit represented by any one of formulas (a1-2-1) to formula (a1-2-6) and R ^a5 in the structural unit (a1-2). Examples include structural units in which a methyl group is replaced with a hydrogen atom, and structural units represented by formula (a1-2-2), formula (a1-2-5), and formula (a1-2-6) are preferred.

When the resin (A) contains a structural unit (a1-0) and/or a structural unit (a1-1) and/or a structural unit (a1-2), the total content of these is the total structure of the resin (A). For the unit,
Usually 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, even more preferably 25 to 70 mol%, even more preferably 30 to 70 mol%. be.

［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のアルキルカルボニル基、炭素数２～４のアルキルカルボニルオキシ基、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のいずれかの整数を表す。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は互いに結合してそれらが結合する－Ｃ－Ｏ－とともに炭素数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－ＣＨ₂－は、－Ｏ－又は－Ｓ－で置き換わってもよい。］ Examples of the structural unit having a group (2) in the structural unit (a1) include a structural unit represented by formula (a1-4) (hereinafter sometimes referred to as "structural unit (a1-4)"). .

[In formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms that may have a halogen atom.
R ^a33 is a halogen atom, hydroxy group, alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl Represents an oxy group or a methacryloyloxy group.
la represents any integer from 0 to 4. When la is 2 or more, a plurality of R ^a33 's may be the same or different.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^a35 and R ^a36 are bonded to each other. to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -C-O- to which they are bonded, and the -CH ₂ - contained in the hydrocarbon group and the divalent hydrocarbon group is - May be replaced with O- or -S-. ]

芳香族炭化水素基としては、フェニル基、ナフチル基、アントリル基、ビフェニル基、フェナントリル基等のアリール基等が挙げられる。
組み合わせた基としては、上述したアルキル基と脂環式炭化水素基とを組み合わせた基（例えばシクロアルキルアルキル基）、ベンジル基等のアラルキル基、アルキル基を有する芳香族炭化水素基（ｐ－メチルフェニル基、ｐ－ｔｅｒｔ－ブチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、２，６－ジエチルフェニル基、２－メチル－６－エチルフェニル基等）、脂環式炭化水素基を有する芳香族炭化水素基（ｐ－シクロヘキシルフェニル基、ｐ－アダマンチルフェニル基等）、フェニルシクロヘキシル基等のアリール－シクロアルキル基等が挙げられる。特に、Ｒ^a36としては、炭素数１～１８のアルキル基、炭素数３～１８の脂環式炭化水素基、炭素数６～１８の芳香族炭化水素基又はこれらを組み合わせることにより形成される基が挙げられる。 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 even more 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.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1, 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3, 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, etc. Can be mentioned.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group and hexyloxy group. Among these, an alkoxy group having 1 to 4 carbon atoms is preferred, a methoxy group or an ethoxy group is more preferred, and a methoxy group is even more preferred.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, and the like.
Examples of the hydrocarbon group for R ^a34 , R ^a35 and R ^a36 include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a combination thereof.
Examples of the alkyl group include a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, and octyl group.
The alicyclic hydrocarbon group 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 bonding site).

Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group.
Examples of combined groups include groups combining the above-mentioned alkyl groups and alicyclic hydrocarbon groups (for example, cycloalkylalkyl groups), aralkyl groups such as benzyl groups, aromatic hydrocarbon groups having alkyl groups (p-methyl phenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group), alicyclic hydrocarbon group Examples thereof include aromatic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) and aryl-cycloalkyl groups such as phenylcyclohexyl group. In particular, R ^a36 is an alkyl 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 a group formed by a combination thereof. can be mentioned.

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 even more preferably a methoxy group.
la is preferably 0 or 1, and more preferably 0.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably an alkyl group or an alicyclic hydrocarbon group having 1 to 12 carbon atoms, more preferably a methyl group or an ethyl group.
The hydrocarbon group of R ^a36 is preferably an alkyl 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 a combination thereof. More preferably, it is an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and alicyclic hydrocarbon group in R ^a36 are preferably unsubstituted. The aromatic hydrocarbon group for R ^a36 is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

--OC(R ^a34 )(R ^a35 )-O-R ^a36 in structural unit (a1-4) comes into contact with an acid (for example, p-toluenesulfonic acid) and is eliminated to form a hydroxy group.

Examples of the structural unit (a1-4) include structural units derived from monomers described in JP-A No. 2010-204646. Preferably, a structure in which the hydrogen atom corresponding to R ^a32 in the structural units represented by formulas (a1-4-1) to (a1-4-12) and the structural unit (a1-4) is replaced with a methyl group Examples include structural units, and more preferably structural units represented by formulas (a1-4-1) to (a1-4-5) and formula (a1-4-10), respectively.

When the resin (A) has a structural unit (a1-4), its content is preferably 5 to 60 mol%, and 5 to 50 mol%, based on the total of all structural units of the resin (A). It is more preferably mol%, and even more preferably 10 to 40 mol%.

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－Ｌ⁵⁴－を表し、ｈ３は１～４のいずれかの整数を表し、＊は、Ｌ⁵¹との結合手を表す。
Ｌ⁵¹、Ｌ⁵²、Ｌ⁵³及びＬ⁵⁴は、それぞれ独立に、－Ｏ－又は－Ｓ－を表す。
ｓ１は、１～３のいずれかの整数を表す。
ｓ１’は、０～３のいずれかの整数を表す。 Examples of the structural unit derived from the (meth)acrylic monomer having group (2) include the structural unit represented by formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)"). It will be done.

In formula (a1-5),
R ^a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or *-(CH ₂ ) _h3 --CO-L ⁵⁴ --, h3 represents an integer of 1 to 4, and * represents a bond with L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent -O- or -S-.
s1 represents an integer of 1 to 3.
s1' represents any integer from 0 to 3.

Examples of the halogen atom include a fluorine atom and a chlorine atom, with a fluorine atom being preferred.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, fluoromethyl group, and trifluoromethyl group. Examples include groups.
In formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.
L ⁵¹ is preferably an oxygen atom.
It is preferable that one of L ⁵² and L ⁵³ is -O- and the other is -S-.
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 structural unit (a1-5) include structural units derived from monomers described in JP-A No. 2010-61117. Among these, structural units represented by formulas (a1-5-1) to (a1-5-4), respectively, are preferred, and structural units represented by formula (a1-5-1) or formula (a1-5-2) are preferred. Structural units are more preferred.

When the resin (A) has a structural unit (a1-5), its content is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, based on the total structural units of the resin (A). , 5 to 40 mol% is more preferable, and 5 to 30 mol% is even more preferable.

［式（ａ１－０Ｘ）中、
Ｒ^ｘ１は、水素原子又はメチル基を表す。
Ｒ^ｘ２及びＲ^ｘ３は、互いに独立に、炭素数１～６の飽和炭化水素基を表す。
Ａｒ^ｘ１は、炭素数６～３６の芳香族炭化水素基を表す。］ Examples of the structural unit (a1) include a structural unit represented by formula (a1-0X) (hereinafter sometimes referred to as structural unit (a1-0X)).

[In formula (a1-0X),
R ^x1 represents a hydrogen atom or a methyl group.
R ^x2 and R ^x3 each independently represent a saturated hydrocarbon group having 1 to 6 carbon atoms.
Ar ^x1 represents an aromatic hydrocarbon group having 6 to 36 carbon atoms. ]

Examples of the saturated hydrocarbon group for R ^x2 and R ^x3 include an alkyl group, an alicyclic hydrocarbon group, and a group formed by a combination thereof.
Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

Examples of the aromatic hydrocarbon group for Ar ^x1 include aryl groups having 6 to 36 carbon atoms such as phenyl group, naphthyl group, and anthryl group.
The aromatic hydrocarbon group preferably has 6 to 24 carbon atoms, more preferably 6 to 18 carbon atoms, and even more preferably a phenyl group.

Ar ^x1 is preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms, more preferably a phenyl group or a naphthyl group, and even more preferably a phenyl group.
R ^x1 , R ^x2 and R ^x3 are each independently preferably a methyl group or an ethyl group, more preferably a methyl group.

Examples of the structural unit (a1-0X) include the structural units described below and compounds in which the methyl group corresponding to R ^x1 in the structural unit (a1-0X) is replaced with a hydrogen atom. The structural unit (a1-0X) is preferably one of the structural units (a1-0X-1) to (a1-0X-3).

When the resin (A) has a structural unit (a1-0X), its content is preferably 5 to 60 mol%, and 5 to 50 mol%, based on the total monomers in the resin (A). It is more preferable that the amount is 10 to 40 mol%.
The resin (A) may contain two or more types of structural units (a1-0X).

Moreover, as the structural unit (a1), the following structural units may also be mentioned.

When the resin (A) contains the above structural unit, its content is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, and 10 to 40 mol%, based on the total structural units of the resin (A). % is more preferred.

<Structural unit (s)>
As the monomer leading to the structural unit (s), monomers having no acid-labile groups known in the field of resists can be used.
The structural unit (s) preferably has a hydroxy group or a lactone ring. A structural unit having a hydroxy group and not having an acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and/or a structure having a lactone ring and not having an acid-labile group By using a resin having the unit (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group that the structural unit (a2) has may be an alcoholic hydroxy group or a phenolic hydroxy group.
When producing a resist pattern from the resist composition of the present invention, when a high-energy beam such as a KrF excimer laser (248 nm), an electron beam, or EUV (ultra-ultraviolet light) is used as an exposure light source, the structural unit (a2) is It is preferable to use a structural unit (a2) having a phenolic hydroxy group. Furthermore, when using an ArF excimer laser (193 nm) etc., the structural unit (a2) is preferably a structural unit (a2) having an alcoholic hydroxy group, and it is more preferable to use the structural unit (a2-1) described below. preferable. The structural unit (a2) may contain one type alone or two or more types.

［式（ａ２－Ａ）中、
Ｒ^a50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^a51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のアルキルカルボニル基、炭素数２～４のアルキルカルボニルオキシ基、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。
Ａ^a50は、単結合又は＊－Ｘ^a51－（Ａ^a52－Ｘ^a52）_nｂ－を表し、＊は－Ｒ^a50が結合する炭素原子との結合手を表す。
Ａ^a52は、炭素数１～６のアルカンジイル基を表す。
Ｘ^a51及びＸ^a52は、それぞれ独立に、－Ｏ－、－ＣＯ－Ｏ－又は－Ｏ－ＣＯ－を表す。
ｎｂは、０又は１を表す。
ｍｂは０～４のいずれかの整数を表す。ｍｂが２以上のいずれかの整数である場合、複数のＲ^a51は互いに同一であっても異なってもよい。］ Examples of the structural unit having a phenolic hydroxy group in the structural unit (a2) include a structural unit represented by formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)").

[In formula (a2-A),
R ^a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a51 is a halogen atom, hydroxy group, alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl Represents an oxy group or a methacryloyloxy group.
A ^a50 represents a single bond or *-X ^a51 --(A ^a52 --X ^a52 ) _nb --, and * represents a bond with the carbon atom to which --R ^a50 is bonded.
A ^a52 represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 each independently represent -O-, -CO-O- or -O-CO-.
nb represents 0 or 1.
mb represents any integer from 0 to 4. When mb is any integer of 2 or more, a plurality of R ^a51 's may be the same or different. ]

Examples of the halogen atom for R ^a50 include a fluorine atom, a chlorine atom, a bromine atom, and the like.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R ^a50 include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1 , 1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3 , 3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group and perfluorohexyl group Examples include groups.
R ^a50 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.
Examples of the alkyl group for R ^a51 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group.
Examples of the alkoxy group for R ^a51 include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, and tert-butoxy group. An alkoxy group having 1 to 4 carbon atoms is preferred, a methoxy group or an ethoxy group is more preferred, and a methoxy group is even more preferred.
Examples of the alkylcarbonyl group for R ^a51 include an acetyl group, a propionyl group, a butyryl group, and the like.
Examples of the alkylcarbonyloxy group for R ^a51 include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
R ^a51 is preferably a methyl group.

*-X ^a51 -(A ^a52 -X ^a52 ) _nb - includes *-O-, *-CO-O-, *-O-CO-, *-CO-O-A ^a52 -CO-O-, *-O-CO-A ^a52 -O-, *-O-A ^a52 -CO-O-, *-CO-O-A ^a52 -O-CO-, *-O-CO-A ^a52 -O-CO -. Among these, *-CO-O-, *-CO-O-A ^a52 -CO-O-, or *-O-A ^a52 -CO-O- is preferred.

Examples of alkanediyl groups include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, and hexane-1,5-diyl group. 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 and -methylbutane-1,4-diyl group and the like.
A ^a52 is preferably a methylene group or an ethylene group.

A ^a50 is preferably a single bond, *-CO-O- or *-CO-O-A ^a52 -CO-O-, and is preferably a single bond, *-CO-O- or *-CO-O-CH ₂ -CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

mb is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0.
The hydroxy group is preferably bonded to the ortho or para position of the benzene ring, and more preferably to the para position.

Structural units (a2-A) include structural units represented by formulas (a2-2-1) to (a2-2-6) and formulas (a2-2-1) to (a2-2- Examples of the structural unit represented by 6) include a structural unit in which the methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom. The structural unit (a2-A) is a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), or a structural unit represented by formula (a2-2-6). In the structural unit represented by formula (a2-2-1), the structural unit represented by formula (a2-2-3) or the structural unit represented by formula (a2-2-6), It is preferable that the structural unit (a2-A) is a structural unit in which the methyl group corresponding to R ^a50 is replaced with a hydrogen atom.

When the structural unit (a2-A) is contained in the resin (A), the content of the structural unit (a2-A) is preferably 5 to 80 mol%, more preferably 5 to 80 mol% based on the total structural units. The content is 10 to 70 mol%, more preferably 15 to 65 mol%, even more preferably 20 to 65 mol%.
The structural unit (a2-A) can be incorporated into the resin (A) by, for example, polymerizing the structural unit (a1-4) and then treating it with an acid such as p-toluenesulfonic acid. Further, the structural unit (a2-A) can be included in the resin (A) by polymerizing with acetoxystyrene or the like and then treating with an alkali such as tetramethylammonium hydroxide.

式（ａ２－１）中、
Ｌ^a3は、－Ｏ－又は^＊－Ｏ－（ＣＨ₂）_k2－ＣＯ－Ｏ－を表し、
ｋ２は１～７のいずれかの整数を表す。＊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、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０～１０のいずれかの整数を表す。 Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include a structural unit represented by 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 any integer from 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 any integer from 0 to 10.

In formula (a2-1), L ^a3 is preferably -O-, -O-(CH ₂ ) _f1 -CO-O- (the f1 represents any integer from 1 to 4) , more preferably -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.

Examples of the structural unit (a2-1) include structural units derived from monomers described in JP-A No. 2010-204646. A structural unit represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferable, and a structural unit represented by any one of formula (a2-1-1) to formula (a2-1-4) is preferable. The structural unit represented by the formula (a2-1-1) or the formula (a2-1-3) is more preferred.

When the resin (A) contains the structural unit (a2-1), its content is usually 1 to 45 mol%, preferably 1 to 40 mol%, based on the total structural units of the resin (A). The content is more preferably 1 to 35 mol%, still more preferably 2 to 20 mol%, and even more preferably 2 to 10 mol%.

<Structural unit (a3)>
The lactone ring possessed by the structural unit (a3) may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or may be a fused ring of a monocyclic lactone ring and another ring. But that's fine. Preferred examples include a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)).

［式（ａ３－１）、式（ａ３－２）、式（ａ３－３）及び式（ａ３－４）中、
Ｌ^ａ４、Ｌ^ａ５及びＬ^ａ６は、それぞれ独立に、－Ｏ－又は＊－Ｏ－（ＣＨ_２）_ｋ３－ＣＯ－Ｏ－（ｋ３は１～７のいずれかの整数を表す。）で表される基を表す。
Ｌ^ａ７は、－Ｏ－、＊－Ｏ－Ｌ^ａ８－Ｏ－、＊－Ｏ－Ｌ^ａ８－ＣＯ－Ｏ－、＊－Ｏ－Ｌ^ａ８－ＣＯ－Ｏ－Ｌ^ａ９－ＣＯ－Ｏ－又は＊－Ｏ－Ｌ^ａ８－Ｏ－ＣＯ－Ｌ^ａ９－Ｏ－を表す。
Ｌ^ａ８及びＬ^ａ９は、それぞれ独立に、炭素数１～６のアルカンジイル基を表す。
＊はカルボニル基との結合部位を表す。
Ｒ^ａ１８、Ｒ^ａ１９及びＲ^ａ２０は、それぞれ独立に、水素原子又はメチル基を表す。
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。
Ｘ^ａ３は、－ＣＨ_２－又は酸素原子を表す。
Ｒ^ａ２１は炭素数１～４の脂肪族炭化水素基を表す。
Ｒ^ａ２２、Ｒ^ａ２３及びＲ^ａ２５は、それぞれ独立に、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。
ｐ１は０～５のいずれかの整数を表す。
ｑ１は、０～３のいずれかの整数を表す。
ｒ１は、０～３のいずれかの整数を表す。
ｗ１は、０～８のいずれかの整数を表す。
ｐ１、ｑ１、ｒ１及び／又はｗ１が２以上のとき、複数のＲ^ａ２１、Ｒ^ａ２２、Ｒ^ａ２３及び／又はＲ^ａ２５は互いに同一であってもよく、異なっていてもよい。］ Structural unit (a3) is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3) or formula (a3-4). One type of these may be contained alone, or two or more types may be contained.

[In formula (a3-1), formula (a3-2), formula (a3-3) and formula (a3-4),
L ^a4 , L ^a5 and L ^a6 are each independently represented by -O- or *-O-(CH ₂ ) _k3 -CO-O- (k3 represents any integer from 1 to 7); represents a group.
L ^a7 is -O-, *-OL ^a8 -O-, *-OL ^a8 -CO-O-, *-OL ^a8 -CO-OL ^a9 -CO-O-, or * -O-L ^a8 -O-CO-L ^a9 -O-.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms.
* represents a bonding site with a carbonyl group.
R ^a18 , R ^a19 and R ^a20 each independently represent a hydrogen atom or a methyl group.
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.
X ^a3 represents -CH ₂ - or an oxygen atom.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
R ^a22 , R ^a23 and R ^a25 each independently represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents any integer from 0 to 5.
q1 represents any integer from 0 to 3.
r1 represents any integer from 0 to 3.
w1 represents any integer from 0 to 8.
When p1, q1, r1 and/or w1 is 2 or more, the plurality of R ^a21 , R ^a22 , R ^a23 and/or R ^a25 may be the same or different. ]

Examples of the aliphatic hydrocarbon groups for R ^a21 , R ^a22 , R ^a23 and R ^a25 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group and tert-butyl group. It will be done.
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 in R ^a24 include a methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group, preferably having 1 to 4 carbon atoms. Examples include alkyl groups, more preferably methyl groups or ethyl groups.
Examples of the alkyl group having a halogen atom in R ^a24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluoro Examples include hexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group, and the like.
Examples of alkanediyl groups in L ^a8 and L ^a9 include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5 -diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, Examples include 4-diyl group and 2-methylbutane-1,4-diyl group.

In formulas (a3-1) to (a3-3), L ^a4 to L ^a6 are each independently preferably -O- or *-O-(CH ₂ ) _k3 -CO-O-, k3 is an integer of 1 to 4, more preferably -O- and *-O-CH ₂ -CO-O-, even more preferably an oxygen atom.
R ^a18 to R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group, or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

（式中、Ｒ^ａ２４、Ｌ^ａ７は、上記と同じ意味を表す。） In formula (a3-4), R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom or a methyl group. It is.
R ^a25 is preferably a carboxy group, a cyano group or a methyl group.
L ^a7 is preferably -O- or *-O-L ^a8 -CO-O-, more preferably -O-, -O-CH ₂ -CO-O- or -O-C ₂ H ₄ - CO-O-.
w1 is preferably an integer of 0 to 2, more preferably 0 or 1.
In particular, formula (a3-4) is preferably formula (a3-4)'.

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

As the structural unit (a3), structures derived from monomers described in JP-A No. 2010-204646, monomers described in JP-A No. 2000-122294, and monomers described in JP-A No. 2012-41274 can be used. Units are listed. As the structural unit (a3), formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3- 1), a structural unit represented by formula (a3-3-2) and any one of formulas (a3-4-1) to formula (a3-4-12), and in the structural unit, formula (a3-1 ) ~ Structural units in which the methyl groups corresponding to R ^a18 , R ^a19 , R ^a20 and R ^a24 in formula (a3-4) are replaced with hydrogen atoms are preferred.

When the resin (A) contains the structural unit (a3), the total content thereof is usually 1 to 70 mol%, preferably 1 to 65 mol%, based on the total structural units of the resin (A). , more preferably 1 to 60 mol%.
In addition, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3), or the structural unit (a3-4) is relative to the total structural units of the resin (A), respectively. The amount is preferably 1 to 60 mol%, more preferably 1 to 50 mol%, even more preferably 1 to 50 mol%.

［式（ａ４）中、
Ｒ⁴¹は、水素原子又はメチル基を表す。
Ｒ⁴²は、炭素数１～２４のフッ素原子を有する飽和炭化水素基を表し、該飽和炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯに置き換わっていてもよい。］
Ｒ⁴²で表される飽和炭化水素基は、鎖式炭化水素基及び単環又は多環の脂環式炭化水素基、並びに、これらを組み合わせることにより形成される基等が挙げられる。 <Structural unit (a4)>
Examples of the structural unit (a4) include the following structural units.

[In formula (a4),
R ⁴¹ represents a hydrogen atom or a methyl group.
R ⁴² represents a saturated hydrocarbon group having 1 to 24 carbon atoms and having a fluorine atom, and -CH ₂ - contained in the saturated hydrocarbon group may be replaced with -O- or -CO. ]
Examples of the saturated hydrocarbon group represented by R ⁴² include a chain hydrocarbon group, a monocyclic or polycyclic alicyclic hydrocarbon group, and a group formed by combining these.

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の脂環式炭化水素基とを組み合わせることにより形成される基が挙げられ、－アルカンジイル基－脂環式炭化水素基、－脂環式炭化水素基－アルキル基、－アルカンジイル基－脂環式炭化水素基－アルキル基等が挙げられる。 Examples of chain hydrocarbon groups include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and octadecyl group. Can be mentioned.
Examples of monocyclic or polycyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups. Examples include polycyclic alicyclic hydrocarbon groups such as (* represents a bond).

Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, such as -alkanediyl group- Examples thereof include alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

［式（ａ４－０）中、
Ｒ^5ａは、水素原子又はメチル基を表す。
Ｌ^4ａは、単結合又は炭素数１～４のアルカンジイル基を表す。
Ｌ^3ａは、炭素数１～８のペルフルオロアルカンジイル基又は炭素数３～１２のペルフルオロシクロアルカンジイル基を表す。
Ｒ^6ａは、水素原子又はフッ素原子を表す。］ The structural unit (a4) is at least one selected from the group consisting of formula (a4-0), formula (a4-1), formula (a4-2), formula (a4-3) and formula (a4-4). Examples include structural units represented by one.

[In formula (a4-0),
R ^5a represents a hydrogen atom or a methyl group.
L ^4a represents a single bond or an alkanediyl group having 1 to 4 carbon atoms.
L ^3a represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ^6a represents a hydrogen atom or a fluorine atom. ]

Examples of the alkanediyl group in L ^4a include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, ethane-1,1-diyl group, Branched alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group are mentioned. It will be done.

The perfluoroalkanediyl group in L ^3a includes a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, and a perfluoropropane group. -2,2-diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane -2,2-diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane -1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane -2,2-diyl group, perfluorooctane-3,3-diyl group, perfluorooctane-4,4-diyl group and the like.
Examples of the perfluorocycloalkanediyl group for L ^3a include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantanediyl group, and the like.

L ^4a is preferably a single bond, a methylene group or an ethylene group, more preferably a single bond or a methylene group.
L ^3a is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

Examples of the structural unit (a4-0) include the structural units shown below and structural units in which the methyl group corresponding to R ^5a in the structural unit (a4-0) in the following structural units is replaced with a hydrogen atom.

［式（ａ４－１）中、
Ｒ^a41は、水素原子又はメチル基を表す。
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い。
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）で表される基を表す。ただし、Ａ^ａ４１及びＲ^ａ４２のうち少なくとも１つは、置換基としてハロゲン原子（好ましくはフッ素原子）を有する。

〔式（ａ－ｇ１）中、
ｓは０又は１を表す。
Ａ^a42及びＡ^a44は、それぞれ独立に、置換基を有していてもよい炭素数１～５の２価の飽和炭化水素基を表す。
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、それぞれ独立に、－Ｏ－、－ＣＯ－、－ＣＯ－Ｏ－又は－Ｏ－ＣＯ－を表す。
ただし、Ａ^a42、Ａ^a43、Ａ^a44、Ｘ^a41及びＸ^a42の炭素数の合計は７以下である。〕
＊は結合手であり、右側の＊が－Ｏ－ＣＯ－Ｒ^a42との結合手である。］

[In formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH ₂ - contained in the saturated hydrocarbon group is replaced with -O- or -CO-. It's okay.
A ^a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by formula (a-g1). However, at least one of A ^a41 and R ^a42 has a halogen atom (preferably a fluorine atom) as a substituent.

[In formula (a-g1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
A ^a43 represents a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms 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 , A ^a44 , X ^a41 and X ^a42 is 7 or less. ]
* is a bond, and the * on the right is a bond with -O-CO-R ^a42 . ]

Examples of the saturated hydrocarbon group for R ^a42 include a chain saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and a group formed by combining these.

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の飽和脂環式炭化水素基とを組み合わせることにより形成される基が挙げられ、－アルカンジイル基－飽和脂環式炭化水素基、－飽和脂環式炭化水素基－アルキル基、－アルカンジイル基－飽和脂環式炭化水素基－アルキル基等が挙げられる。 Examples of chain saturated hydrocarbon groups include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and octadecyl group. can be mentioned.
Examples of monocyclic or polycyclic alicyclic saturated hydrocarbon groups include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group; decahydronaphthyl group, adamantyl group, norbornyl group, and the following. Examples include polycyclic alicyclic saturated hydrocarbon groups such as groups (* represents a bond).

Examples of groups formed by a combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more saturated alicyclic hydrocarbon groups, and -alkanediyl groups -saturated alicyclic hydrocarbon group, -saturated alicyclic hydrocarbon group-alkyl group, -alkanediyl group-saturated alicyclic hydrocarbon group, and the like.

［式（ａ－ｇ３）中、
Ｘ^a43は、酸素原子、カルボニル基、＊＊－Ｏ－ＣＯ－又は＊＊－ＣＯ－Ｏ－を表す（＊＊はＲ^a42との結合手を表す。）。
Ａ^a45は、ハロゲン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を表す。
＊は結合手を表す。］
ただし、Ｒ^a42－Ｘ^a43－Ａ^a45において、Ｒ^a42がハロゲン原子を有しない場合は、Ａ^a45は、少なくとも１つのハロゲン原子を有する炭素数１～１７の脂肪族炭化水素基を表す。 Examples of the substituent that R ^a42 may have include at least one selected from the group consisting of a halogen atom and a group represented by formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred.

[In formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, **-O-CO- or **-CO-O- (** represents a bond with R ^a42 ).
A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
* represents a bond. ]
However, in R ^a42 -X ^a43 -A ^a45 , when R ^a42 does not have a halogen atom, A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms and having at least one halogen atom.

組み合わせにより形成される基としては、１以上のアルキル基又は１以上のアルカンジイル基と、１以上の脂環式炭化水素基とを組み合わせることにより形成される基が挙げられ、－アルカンジイル基－脂環式炭化水素基、－脂環式炭化水素基－アルキル基、－アルカンジイル基－脂環式炭化水素基－アルキル基等が挙げられる。 The aliphatic hydrocarbon group in A ^a45 includes methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and Alkyl groups such as octadecyl groups;
Monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; and decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bond) ) and other polycyclic alicyclic hydrocarbon groups.

Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, such as -alkanediyl group- Examples include alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, -alkanediyl group-alicyclic hydrocarbon group-alkyl group, and the like.

R ^a42 is preferably a saturated hydrocarbon group which may have a halogen atom, more preferably a saturated hydrocarbon group having an alkyl group having a halogen atom and/or a group represented by formula (a-g3).
When R ^a42 is a saturated hydrocarbon group having a halogen atom, it is preferably a saturated hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and even more preferably a group having 1 to 1 carbon atoms. 6 perfluoroalkyl group, particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group.
When R ^a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), the total carbon number of R ^a42 including the number of carbon atoms contained in the group represented by formula (a-g3) The number is preferably 15 or less, more preferably 12 or less. When having a group represented by formula (a-g3) as a substituent, the number thereof is preferably one.

［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価の飽和炭化水素基を表す。
Ｘ^a44は、＊＊－Ｏ－ＣＯ－又は＊＊－ＣＯ－Ｏ－を表す（＊＊はＡ^a46との結合手を表す。）。
Ａ^a47は、ハロゲン原子を有していてもよい炭素数１～１７の脂肪族炭化水素基を表す。
ただし、Ａ^a46、Ａ^a47及びＸ^a44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。
＊はカルボニル基との結合手を表す。］ When R ^a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), R ^a42 is more preferably a group represented by formula (a-g2).

[In formula (a-g2),
A ^a46 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents **-O-CO- or **-CO-O- (** represents a bond with A ^a46 ).
A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
However, the total number of carbon atoms of A ^a46 , A ^a47 and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* represents a bond with a carbonyl group. ]

The saturated hydrocarbon group of A ^a46 preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.
The aliphatic hydrocarbon group of A ^a47 preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, and A ^a47 is more preferably a cyclohexyl group or an adamantyl group.

A preferable structure of the group represented by formula (a-g2) is the following structure (* is a bond with a carbonyl group).

As the alkanediyl group in A ^a41 , methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group Linear alkanediyl groups such as; propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, Examples include branched alkanediyl groups such as 2-methylbutane-1,4-diyl group.
Examples of the substituent on the alkanediyl group represented by A ^a41 include 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 even more preferably an ethylene group.

The divalent saturated hydrocarbon groups represented by A ^a42 , A ^a43 and A ^a44 in the group represented by formula (a-g1) include linear or branched alkanediyl groups and monocyclic or polycyclic divalent hydrocarbon groups. Examples thereof include an alicyclic hydrocarbon group and a group formed by combining an alkanediyl group and a divalent alicyclic hydrocarbon group. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, 1-methylpropane-1,3-diyl group, Examples include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
Examples of the substituent for the divalent saturated hydrocarbon group represented by A ^a42 , A ^a43 and A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
Preferably, s is 0.

Examples of the group represented by formula (a-g1) in which X ^a42 is -O-, -CO-, -CO-O- or -O-CO- include the following groups. In the following examples, * and ** each represent a bond, and ** is a bond with -O-CO-R ^a42 .

As the structural unit represented by formula (a4-1), the methyl group corresponding to R ^a41 in the structural unit shown below and the structural unit represented by formula (a4-1) in the following structural unit is a hydrogen atom. Examples include substituted structural units.

［式（ａ４－２）中、
Ｒ^f5は、水素原子又はメチル基を表す。
Ｌ⁴⁴は、炭素数１～６のアルカンジイル基を表し、該アルカンジイル基に含まれる－ＣＨ₂－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
Ｒ^f6は、炭素数１～２０のフッ素原子を有する飽和炭化水素基を表す。
ただし、Ｌ⁴⁴及びＲ^f6の合計炭素数の上限は２１である。］ The structural unit represented by formula (a4-1) is preferably a structural unit represented by formula (a4-2).

[In formula (a4-2),
R ^f5 represents a hydrogen atom or a methyl group.
L ⁴⁴ represents an alkanediyl group having 1 to 6 carbon atoms, and -CH ₂ - contained in the alkanediyl group may be replaced with -O- or -CO-.
R ^f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and having a fluorine atom.
However, the upper limit of the total number of carbon atoms in L ⁴⁴ and R ^f6 is 21. ]

Examples of the alkanediyl group for L ⁴⁴ include the same groups as exemplified for A ^a41 .
Examples of the saturated hydrocarbon group for R ^f6 include the same groups as exemplified for R ^a42 .
The alkanediyl group in L ⁴⁴ is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.

Examples of the structural unit represented by formula (a4-2) include structural units represented by formulas (a4-1-1) to (a4-1-11), respectively. A structural unit in which the methyl group corresponding to R ^f5 in structural unit (a4-2) is replaced with a hydrogen atom is also included as a structural unit represented by formula (a4-2).

［式（ａ４－３）中、
Ｒ^f7は、水素原子又はメチル基を表す。
Ｌ⁵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１～１８の２価の飽和炭化水素基を表す。
Ｘ^f12は、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＡ^f13との結合手を表す。）。
Ａ^f14は、フッ素原子を有していてもよい炭素数１～１７の飽和炭化水素基を表す。
但し、Ａ^f13及びＡ^f14の少なくとも１つは、フッ素原子を有し、Ｌ⁵、Ａ^f13及びＡ^f14の合計炭素数の上限は２０である。］

[In formula (a4-3),
R ^f7 represents a hydrogen atom or a methyl group.
L ⁵ represents an alkanediyl group having 1 to 6 carbon atoms.
A ^f13 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms which may have a fluorine atom.
X ^f12 represents *-O-CO- or *-CO-O- (* represents a bond with A ^f13 ).
A ^f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom.
However, at least one of A ^f13 and A ^f14 has a fluorine atom, and the upper limit of the total number of carbon atoms in L ⁵ , A ^f13 and A ^f14 is 20. ]

Examples of the alkanediyl group for L ⁵ include the same groups as exemplified for the alkanediyl group for A ^a41 .

The divalent saturated hydrocarbon group which may have a fluorine atom in A ^f13 is preferably a divalent chain saturated hydrocarbon group which may have a fluorine atom and a divalent saturated hydrocarbon group which may have a fluorine atom. A divalent alicyclic saturated hydrocarbon group is preferable, and a perfluoroalkanediyl group is more preferable.
Examples of the divalent chain 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, perfluoroethylene group, etc. Examples include perfluoroalkanediyl groups such as a propanediyl group, a perfluorobutanediyl group, and a perfluoropentanediyl group.
The divalent alicyclic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic group include an adamantanediyl group, a norbornanediyl group, and a perfluoroadamantanediyl group.

Examples of the saturated hydrocarbon group of A ^f14 and the saturated hydrocarbon group which may have a fluorine atom include the same groups as those exemplified for R ^a42 . Among them, trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, Fluorination of 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group, perfluorooctyl group, etc. Alkyl group, cyclopropylmethyl group, cyclopropyl group, cyclobutylmethyl group, cyclopentyl group, cyclohexyl group, perfluorocyclohexyl group, adamantyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl group, norbornylmethyl group, perfluoroadamantyl group , perfluoroadamantylmethyl group, etc. are preferred.

In formula (a4-3), L ⁵ is preferably an ethylene group.
The divalent saturated hydrocarbon group of A ^f13 is preferably a group containing a divalent chain hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms; More preferred are two to three divalent chain hydrocarbon groups.
The saturated hydrocarbon group of A ^f14 is preferably a group containing a chain hydrocarbon group having 3 to 12 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and a chain hydrocarbon group having 3 to 10 carbon atoms. and a group containing an alicyclic hydrocarbon group having 3 to 10 carbon atoms is more preferred. Among these, A ^f14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group.

Examples of the structural unit represented by formula (a4-3) include structural units represented by formulas (a4-1'-1) to (a4-1'-11), respectively. A structural unit in which the methyl group corresponding to R ^f7 in structural unit (a4-3) is replaced with a hydrogen atom is also included as the structural unit represented by formula (a4-3).

［式（ａ４－４）中、
Ｒ^f21は、水素原子又はメチル基を表す。
Ａ^f21は、－（ＣＨ₂）_j1－、－（ＣＨ₂）_j2－Ｏ－（ＣＨ₂）_j3－又は－（ＣＨ₂）_j4－ＣＯ－Ｏ－（ＣＨ₂）_j5－を表す。
ｊ１～ｊ５は、それぞれ独立に、１～６のいずれかの整数を表す。
Ｒ^f22は、フッ素原子を有する炭素数１～１０の飽和炭化水素基を表す。］ The structural unit (a4) also includes a structural unit represented by formula (a4-4).

[In 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 saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom. ]

Examples of the saturated hydrocarbon group for R ^f22 include the same saturated hydrocarbon group as the saturated hydrocarbon group represented by R ^a42 . R ^f22 is preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom. Preferably, an alkyl group having 1 to 6 carbon atoms and having a fluorine atom is more preferable.

In formula (a4-4), A ^f21 is preferably -(CH ₂ ) _j1 -, more preferably an ethylene group or a methylene group, and even more preferably a methylene group.

As the structural unit represented by formula (a4-4), for example, in the following structural units and the structural unit represented by the following formula, the methyl group corresponding to R ^f21 in structural unit (a4-4) is hydrogen. Examples include structural units that replace atoms.

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

［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で置換されていてもよい。
Ｌ⁵⁵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－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。］ <Structural unit (a5)>
Examples of the non-eliminating hydrocarbon group possessed by the structural unit (a5) include groups having a linear, branched or cyclic hydrocarbon group. Among these, the structural unit (a5) is preferably a group having an alicyclic hydrocarbon group.
Examples of the structural unit (a5) include a structural unit represented by formula (a5-1).

[In formula (a5-1),
R ⁵¹ represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. .
L ⁵⁵ represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH ₂ - contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. . ]

The alicyclic hydrocarbon group for R ⁵² may be either 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 aliphatic hydrocarbon groups having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, and - Alkyl groups such as ethylhexyl group.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group.
R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, norbornyl group or cyclohexyl group.

Examples of the divalent saturated hydrocarbon group in L ⁵⁵ include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and preferably a divalent chain saturated hydrocarbon group. .
Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group, and pentanediyl group.
The divalent alicyclic saturated hydrocarbon group may be either 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、＊－Ｏ－ＣＯ－又は＊－ＣＯ－Ｏ－を表す（＊はＬ^x1との結合手を表す。）。
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^x3及びＬ^x4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 groups in which -CH ₂ - contained in the divalent saturated hydrocarbon group represented by L ⁵⁵ are replaced with -O- or -CO- include formulas (L1-1) to (L1-4). The groups represented are exemplified. In the following formula, * and ** each represent a bond, and * represents a bond with an oxygen atom.

In formula (L1-1),
X ^x1 represents *-O-CO- or *-CO-O- (* represents a bond with L ^x1 ).
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 ^x3 and L ^x4 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 divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, 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 divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
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.

Examples of the group represented by formula (L1-1) include the divalent groups shown below.

Examples of the group represented by formula (L1-2) include the divalent groups shown below.

Examples of the group represented by formula (L1-3) include the divalent groups shown below.

Examples of the group represented by formula (L1-4) include the divalent groups shown below.

L ⁵⁵ is preferably a single bond or a group represented by formula (L1-1).

樹脂（Ａ）が、構造単位（ａ５）を有する場合、その含有率は、樹脂（Ａ）の全構造単位に対して、１～３０モル％が好ましく、２～２０モル％がより好ましく、３～１５モル％がさらに好ましい。 Examples of the structural unit (a5-1) include the structural units shown below and structural units in which the methyl group corresponding to R ⁵¹ in the structural unit (a5-1) in the following structural units is replaced with a hydrogen atom.

When the resin (A) has a structural unit (a5), its content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and 3 to 30 mol%, based on the total structural units of the resin (A). More preferably 15 mol%.

<Structural unit (II)>
The resin (A) may further contain a structural unit (hereinafter sometimes referred to as "structural unit (II)") that decomposes upon exposure to generate an acid. Specific examples of the structural unit (II) include the structural unit described in JP-A-2016-79235, which includes a structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain, or a structural unit having a sulfonate group or a carboxylate group in the side chain. A structural unit having a group and an organic anion is preferable.

［式（ＩＩ－２－Ａ’）中、
Ｘ^ＩＩＩ３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－ＣＨ_２－は、－Ｏ－、－Ｓ－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、ハロゲン原子、ハロゲン原子を有していてもよい炭素数１～６のアルキル基又はヒドロキシ基で置き換わっていてもよい。
Ａ^ｘ１は、炭素数１～８のアルカンジイル基を表し、該アルカンジイル基に含まれる水素原子は、フッ素原子又は炭素数１～６のペルフルオロアルキル基で置換されていてもよい。
ＲＡ^－は、スルホナート基又はカルボキシレート基を表す。
Ｒ^ＩＩＩ３は、水素原子、ハロゲン原子又はハロゲン原子を有していてもよい炭素数１～６のアルキル基を表す。
ＺＡ^＋は、有機カチオンを表す。］ The structural unit having a sulfonate group or carboxylate group in its side chain is preferably a structural unit represented by formula (II-2-A').

[In formula (II-2-A'),
X ^III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH ₂ - contained in the saturated hydrocarbon group may be replaced with -O-, -S- or -CO-. Often, the hydrogen atom contained in the saturated hydrocarbon group may be replaced with a halogen atom, an alkyl group having 1 to 6 carbon atoms which may contain a halogen atom, or a hydroxy group.
A ^x1 represents an alkanediyl group having 1 to 8 carbon atoms, and the hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
RA ⁻ represents a sulfonate group or a carboxylate group.
R ^III3 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
ZA ⁺ represents an organic cation. ]

Examples of the halogen atom represented by R ^III3 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The alkyl group having 1 to 6 carbon atoms and optionally having a halogen atom represented by R ^III3 includes the alkyl group having 1 to 6 carbon atoms optionally having a halogen atom represented by R ^a8 ; The same things can be mentioned.
The alkanediyl group having 1 to 8 carbon atoms represented by A ^x1 includes a methylene group, 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, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2, 4-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. Can be mentioned.
Examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted by ^A -butyl group, perfluoropentyl group, perfluorohexyl group, etc.
Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by ^XIII3 include a linear or branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. or a combination of these may be used.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-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 , linear alkanediyl groups such as dodecane-1,12-diyl group; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group , pentane-1,4-diyl group, branched alkanediyl group such as 2-methylbutane-1,4-diyl group; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1 ,4-diyl group, cycloalkanediyl group such as cyclooctane-1,5-diyl group; norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane Examples include divalent polycyclic alicyclic saturated hydrocarbon groups such as -2,6-diyl group.
Examples of saturated hydrocarbon groups in which -CH ₂ - is replaced with -O-, -S- or -CO- include divalent groups represented by formulas (X1) to (X53). Can be mentioned. However, the number of carbon atoms in each of the saturated hydrocarbon groups before --CH ₂ -- is replaced with --O-, --S-, or --CO- is 17 or less. In the formula below, * and ** represent a binding site, and * represents a bond with A ^x1 .

X ³ represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms.
X ⁴ represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
X ⁵ represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
X ⁶ represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
X ⁷ represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms.
X ⁸ represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

Examples of ZA ⁺ in formula (II-2-A') include the same cation Z ⁺ in salt (I).

［式（ＩＩ－２－Ａ）中、Ｒ^ＩＩＩ３、Ｘ^ＩＩＩ３及びＺＡ^＋は、上記と同じ意味を表す。
ｚ２Ａは、０～６のいずれかの整数を表す。
Ｒ^ＩＩＩ２及びＲ^ＩＩＩ４は、それぞれ独立して、水素原子、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表し、ｚが２以上のとき、複数のＲ^ＩＩＩ２及びＲ^ＩＩＩ４は互いに同一であってもよいし、異なっていてもよい。
Ｑ^ａ及びＱ^ｂは、それぞれ独立して、フッ素原子又は炭素数１～６のペルフルオロアルキル基を表す。］
Ｒ^ＩＩＩ２、Ｒ^ＩＩＩ４、Ｑ^ａ及びＱ^ｂで表される炭素数１～６のペルフルオロアルキル基としては、前述のＱ^ｂ１で表される炭素数１～６のペルフルオロアルキル基と同じものが挙げられる。 The structural unit represented by formula (II-2-A') is preferably a structural unit represented by formula (II-2-A).

[In formula (II-2-A), R ^III3 , X ^III3 and ZA ⁺ have the same meanings as above.
z2A represents any integer from 0 to 6.
R ^III2 and R ^III4 each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms, and when z is 2 or more, a plurality of R ^III2 and R ^III4 are the same as each other; It may be different or it may be different.
Q ^a and Q ^b each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. ]
Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by R ^III2 , R ^III4 , Q ^a and Q ^b include the same perfluoroalkyl group having 1 to 6 carbon atoms represented by Q ^b1 described above. .

［式（ＩＩ－２－Ａ－１）中、
Ｒ^ＩＩＩ２、Ｒ^ＩＩＩ３、Ｒ^ＩＩＩ４、Ｑ^a、Ｑ^b及びＺＡ^＋は、上記と同じ意味を表す。
Ｒ^ＩＩＩ５は、炭素数１～１２の飽和炭化水素基を表す。
ｚ２Ａ１は、０～６のいずれかの整数を表す。
Ｘ^Ｉ2は、炭素数１～１１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－、－Ｓ－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、ハロゲン原子又はヒドロキシ基で置換されていてもよい。］
Ｒ^ＩＩＩ５で表される炭素数１～１２の飽和炭化水素基としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、ｓｅｃ－ブチル基、ｔｅｒｔ－ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ウンデシル基及びドデシル基等の直鎖又は分岐のアルキル基が挙げられる。
Ｘ^Ｉ２で表される２価の飽和炭化水素基としては、Ｘ^ＩＩＩ３で表される２価の飽和炭化水素基と同様のものが挙げられる。 The structural unit represented by formula (II-2-A) is preferably a structural unit represented by formula (II-2-A-1).

[In formula (II-2-A-1),
R ^III2 , R ^III3 , R ^III4 , Q ^a , Q ^b and ZA ⁺ represent the same meanings as above.
R ^III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
z2A1 represents any integer from 0 to 6.
X ^I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, and -CH ₂ - contained in the saturated hydrocarbon group may be replaced with -O-, -S- or -CO-. Often, the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with a halogen atom or a hydroxy group. ]
The saturated hydrocarbon group having 1 to 12 carbon atoms represented by R ^III5 includes methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Straight chain or branched alkyl groups such as heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group are mentioned.
Examples of the divalent saturated hydrocarbon group represented by X ^I2 include those similar to the divalent saturated hydrocarbon group represented by X ^III3 .

［式（ＩＩ－２－Ａ－２）中、Ｒ^ＩＩＩ３、Ｒ^ＩＩＩ５及びＺＡ^＋は、上記と同じ意味を表す。
ｍ及びｎは、それぞれ独立に、１又は２を表す。］ As the structural unit represented by formula (II-2-A-1), a structural unit represented by formula (II-2-A-2) is more preferable.

[In formula (II-2-A-2), R ^III3 , R ^III5 and ZA ⁺ have the same meanings as above.
m and n each independently represent 1 or 2. ]

Examples of the structural unit represented by formula (II-2-A') include the following structural unit, in which the group corresponding to the methyl group of R ^III3 contains a hydrogen atom, a halogen atom (for example, a fluorine atom), or a halogen atom. Examples include structural units substituted with optional alkyl groups having 1 to 6 carbon atoms (eg, trifluoromethyl group, etc.) and structural units described in International Publication No. 2012/050015. ZA ⁺ represents an organic cation.

［式（ＩＩ－１－１）中、
Ａ^ＩＩ１は、単結合又は２価の連結基を表す。
Ｒ^ＩＩ１は、炭素数６～１８の２価の芳香族炭化水素基を表す。
Ｒ^ＩＩ２及びＲ^ＩＩ３は、それぞれ独立して、炭素数１～１８の炭化水素基を表し、Ｒ^ＩＩ２及びＲ^ＩＩ３は互いに結合してそれらが結合する硫黄原子とともに環を形成していてもよい。
Ｒ^II4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。
Ａ^－は、有機アニオンを表す。］
Ｒ^ＩＩ１で表される炭素数６～１８の２価の芳香族炭化水素基としては、フェニレン基及びナフチレン基等が挙げられる。
Ｒ^ＩＩ２及びＲ^ＩＩ３で表される炭化水素基としては、アルキル基、脂環式炭化水素基、芳香族炭化水素基及びこれらを組み合わせることにより形成される基等が挙げられる。
Ｒ^ＩＩ４で表されるハロゲン原子としては、フッ素原子、塩素原子、臭素原子及びヨウ素原子等が挙げられる。
Ｒ^ＩＩ４で表されるハロゲン原子を有していてもよい炭素数１～６のアルキル基としては、Ｒ^ａ８で表されるハロゲン原子を有していてもよい炭素数１～６のアルキル基と同じものが挙げられる。
Ａ^ＩＩ１で表される２価の連結基としては、例えば、炭素数１～１８の２価の飽和炭化水素基が挙げられ、該２価の飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－又は－ＣＯ－で置き換わっていてもよい。具体的には、Ｘ^ＩＩＩ３で表される炭素数１～１８の２価の飽和炭化水素基と同じものが挙げられる。 The structural unit having a sulfonio group and an organic anion in its side chain is preferably a structural unit represented by formula (II-1-1).

[In formula (II-1-1),
A ^II1 represents a single bond or a divalent linking group.
R ^II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^II2 and R ^II3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and R ^II2 and R ^II3 may be bonded to each other to form a ring with the sulfur atom to which they are bonded.
R ^II4 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
A ⁻ represents an organic anion. ]
Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R ^II1 include a phenylene group and a naphthylene group.
Examples of the hydrocarbon group represented by R ^II2 and R ^II3 include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the halogen atom represented by R ^II4 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The alkyl group having 1 to 6 carbon atoms and optionally having a halogen atom represented by R ^II4 includes the alkyl group having 1 to 6 carbon atoms optionally having a halogen atom represented by R ^a8 ; The same things can be mentioned.
Examples of the divalent linking group represented by A ^II1 include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH ₂ - contained in the divalent saturated hydrocarbon group is It may be replaced with -O-, -S- or -CO-. Specifically, the same divalent saturated hydrocarbon group having 1 to 18 carbon atoms as represented by ^XIII3 can be mentioned.

As the structural unit containing a cation in formula (II-1-1), the structural unit represented below and the group corresponding to the methyl group of R ^II4 are replaced with a hydrogen atom, a fluorine atom, trifluoromethyl, etc. Examples include structural units.

Examples of the organic anion represented by A ^- include sulfonic acid anions, sulfonylimide anions, sulfonylmethide anions, and carboxylic acid anions. The organic anion represented by A ^- is preferably a sulfonate anion, and the sulfonate anion is more preferably an anion contained in the salt represented by the above-mentioned formula (B1).

Examples of the sulfonylimide anion represented by A ^- include the following.

Examples of sulfonyl methide anions include the following.

Examples of carboxylic acid anions include the following.

Examples of the structural unit represented by formula (II-1-1) include the structural units shown below.

When the structural unit (II) is contained in the resin (A), the content of the structural unit (II) is preferably 1 to 20 mol%, and more preferably 1 to 20 mol% based on the total structural units of the resin (A). It is preferably 2 to 15 mol%, more preferably 3 to 10 mol%.

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

The resin (A) is preferably a resin consisting of a structural unit (a1) and a structural unit (s).
Structural unit (a1) is preferably a group consisting of structural unit (a1-0), structural unit (a1-1) and structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group). At least one type selected from, more preferably at least two types.
The structural unit (s) is preferably at least one selected from the group consisting of the structural unit (a2) and the structural unit (a3). Structural unit (a2) is preferably a structural unit represented by formula (a2-A) or a structural unit represented by formula (a2-1). Structural unit (a3) is preferably a group consisting of a structural unit represented by formula (a3-1), a structural unit represented by formula (a3-2), and a structural unit represented by formula (a3-4). At least one type selected from

Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (e.g. radical polymerization method) using a monomer that leads to these structural units. be able to. The content of each structural unit in the resin (A) can be adjusted by adjusting the amount of monomer used for polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, even more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, even more preferably 15,000 or less). In this specification, the weight average molecular weight is a value determined by gel permeation chromatography under the conditions described in Examples.

<Resin other than resin (A)>
The resist composition of the present invention may contain resins other than resin (A) in combination.
Examples of resins other than resin (A) include resins containing structural unit (a4) or structural unit (a5) (hereinafter sometimes referred to as resin (X)).

Among the resins (X), preferred are resins containing the structural unit (a4), that is, a structural unit having a fluorine atom.
In the resin (X), the content of the structural unit (a4) is preferably 30 mol% or more, more preferably 40 mol% or more, based on the total of all structural units of the resin (X). , more preferably 45 mol% or more.
Examples of structural units that the resin (X) may further include include structural units (a2), structural units (a3), and structural units derived from other known monomers. Among these, the resin (X) is preferably a resin consisting only of the structural unit (a4) and/or the structural unit (a5), and more preferably a resin consisting only of the structural unit (a4).

Each structural unit constituting the resin (X) may be used alone or in combination of two or more, and may be produced by a known polymerization method (for example, radical polymerization method) using a monomer that induces these structural units. can do. The content of each structural unit in the resin (X) can be adjusted by adjusting the amount of monomer used for polymerization.
The weight average molecular weight of the resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weight of resin (X) is the same as in the case of resin (A).
Further, when the resist composition contains resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, based on 100 parts by mass of resin (A). , more preferably 1 to 40 parts by weight, particularly preferably 1 to 30 parts by weight, particularly preferably 1 to 8 parts by weight.

The content of the resin (A) in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. In addition, when a resin other than the resin (A) is included, the total content of the resin (A) and the resin other than the resin (A) is 80% by mass or more and 99% by mass based on the solid content of the resist composition. It is preferably at most 90% by mass and at most 99% by mass. As used herein, "solid content of the resist composition" refers to the total amount of components excluding the solvent (E) described below 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 by known analytical means such as liquid chromatography or gas chromatography.

<Solvent (E)>
The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, and more preferably 94% by mass or more and 99% by mass. % or less. The content of the solvent (E) can be measured by known analytical means such as liquid chromatography or gas chromatography.

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, ethyl pyruvate, etc. Ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; Cyclic esters such as γ-butyrolactone; and the like. One type of solvent (E) may be used alone, or two or more types may be used.

<Quencher (C)>
Examples of the quencher (C) include basic nitrogen-containing organic compounds and salts that generate an acid that is weaker in acidity than the acid generated from the acid generator (B). The content of the quencher (C) is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass, based on the solid content of the resist composition.
Basic nitrogen-containing organic compounds include amines and ammonium salts. Amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.

Examples of amines 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, tripentylamine, trihexylamine, tri- Heptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, Ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, Isopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3 , 3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-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'-dipicolylamine, bipyridine, etc. Preferably, aromatic amines such as diisopropylaniline are used, and 2,6-diisopropylaniline is more preferable.

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

The acidity of a salt that generates an acid with weaker acidity than the acid generated from the acid generator (B) is indicated by the acid dissociation constant (pKa). The salt that generates an acid with weaker acidity than the acid generated from the acid generator (B) is a salt in which the acid dissociation constant of the acid generated from the salt is usually -3<pKa, preferably -1<pKa. A salt with a pKa<7, more preferably a salt with a pKa<5.
Examples of the salt that generates an acid with weaker acidity than the acid generated from the acid generator (B) include a salt represented by the following formula, a salt represented by the formula (D) described in JP-A-2015-147926; (hereinafter sometimes referred to as "weak acid inner salt (D)"), as well as JP 2012-229206, JP 2012-6908, JP 2012-72109, and JP 2011-39502. Examples include salts described in publications and JP-A No. 2011-191745. A weak acid inner salt (D) is preferable as a salt that generates an acid with weaker acidity than the acid generated from the acid generator (B).

Examples of the weak acid inner salt (D) include the following salts.

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

<Preparation of resist composition>
The resist composition of the present invention comprises a salt (I), a resin (A), and, if necessary, an acid generator (B), a resin other than the resin (A), a solvent (E), and a quencher (C). and other components (F). The mixing order is arbitrary and is not particularly limited. An appropriate temperature for mixing can be selected from 10 to 40° C. depending on the type of resin and the solubility of the resin in the solvent (E). An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. Note that the mixing means is not particularly limited, and stirring and mixing can be used.
After mixing each component, it is preferable to filter it using a filter with a pore size of about 0.003 to 0.2 μm.

<Resist pattern manufacturing method>
The method for manufacturing a resist pattern of the present invention includes:
(1) Applying the resist composition of the present invention onto a substrate,
(2) drying the applied composition to form a composition layer;
(3) exposing the composition layer to light;
(4) a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.

The resist composition can be applied onto the substrate using a commonly used device such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers. Before applying the resist composition, the substrate may be cleaned, or an antireflection film or the like may be formed on the substrate.

By drying the applied composition, 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 by using a pressure reduction device. The heating temperature is preferably 50 to 200°C, and the heating time is preferably 10 to 180 seconds. Further, the pressure during reduced pressure drying 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. Examples of 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), _F2 excimer laser (wavelength 157 nm), and solid-state laser light sources (YAG or semiconductor lasers). etc.) that converts the wavelength of laser light and emits harmonic laser light in the far ultraviolet or vacuum ultraviolet range, and uses various methods such as those that emit electron beams and ultra-ultraviolet light (EUV). Can be done. Note that in this specification, irradiation with these radiations may be collectively referred to as "exposure." During exposure, the exposure is usually performed through a mask corresponding to the desired pattern. When the exposure light source is an electron beam, exposure may be performed by direct writing without using a mask.

The exposed composition layer is subjected to a heat treatment (so-called post-exposure bake) in order to promote the deprotection reaction in acid-labile groups. 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 dip method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably, for example, 5 to 60°C, and the development time is, for example, preferably 5 to 300 seconds. By selecting the type of developer as described below, a positive resist pattern or a negative resist pattern can be manufactured.

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 any of the various alkaline aqueous solutions used in this field. Examples include aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline). The alkaline developer may contain a surfactant.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove water remaining on the substrate and pattern.

When producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as "organic developer") is used as the developer.
Examples of organic solvents contained in organic developers 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; and aromatic hydrocarbon solvents such as anisole.
The content of the organic solvent in the organic developer 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 even more preferably substantially only the organic solvent.
Among these, as the organic developer, a developer containing butyl acetate and/or 2-heptanone is preferred. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and substantially contains butyl acetate and/or 2-heptanone. - More preferably only heptanone.
The organic developer may contain a surfactant. Further, the organic developer may contain a trace amount of water.
During development, development may be stopped by replacing the organic developer with a different type of solvent.

It is preferable to wash the resist pattern after development with a rinsing liquid. The rinsing liquid is not particularly limited as long as it does not dissolve the resist pattern, and solutions containing common organic solvents can be used, preferably alcohol solvents or ester solvents.
After cleaning, it is preferable to remove the rinsing liquid remaining on the substrate and 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 for electron beam (EB) exposure. It is suitable as a resist composition for line (EB) exposure or a resist composition for EUV exposure, and is useful for microfabrication of semiconductors.

The present invention will be explained in more detail with reference to Examples. In the examples, "%" and "part" representing the content or amount used are based on mass unless otherwise specified.
The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows.
Column: TSKgel Multipore HXL-M x 3+guardcolumn (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0mL/min
Detector: RI detector Column temperature: 40℃
Injection volume: 100μl
Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation)
The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Model 1100 manufactured by Agilent; MASS: Model LC/MSD manufactured by Agilent). In the following examples, the value of this molecular ion peak is indicated by "MASS".

式（Ｉ－１－ａ）で表される化合物３部、ジメチルホルムアミド１０部、炭酸カリウム１．０５部及びヨウ化カリウム１．２６部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－１－ｂ）で表される化合物８．４９部を添加し、その後、２３℃で１８時間撹拌した。得られた反応混合物に、ｔｅｒｔ－ブチルメチルエーテル５０部及びイオン交換水３０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。得られた有機層に、イオン交換水３０部を添加し、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、濃縮混合物をカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝３／１）を用いて分取することにより、式（Ｉ－１－ｃ）で表される化合物５．１９部を得た。

式（Ｉ－１－ｅ）で表される塩２．５部及びアセトニトリル３０部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－１－ｆ）で表される化合物１．１７部を添加し、５０℃に昇温後、５０℃で２時間撹拌した。得られた反応混合物に、式（Ｉ－１－ｃ）で表される化合物３．０４部を添加し、５０℃で１０時間撹拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水２５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。得られた有機層に、イオン交換水２５部を添加し、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。得られた有機層に、５％シュウ酸水２５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層に、イオン交換水７５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層を濃縮し、濃縮残渣に、アセトニトリル２部及び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、上澄み液を除去し、濃縮することにより、式（Ｉ－１）で表される塩４．１８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ６０１．０ Example 1: Synthesis of salt represented by formula (I-1)

3 parts of the compound represented by formula (I-1-a), 10 parts of dimethylformamide, 1.05 parts of potassium carbonate and 1.26 parts of potassium iodide were mixed and stirred at 23°C for 30 minutes. 8.49 parts of the compound represented by I-1-b) was added, followed by stirring at 23°C for 18 hours. To the obtained reaction mixture, 50 parts of tert-butyl methyl ether and 30 parts of ion-exchanged water were added, and the mixture was stirred at 23°C for 30 minutes, and then the organic layer was separated. After adding 30 parts of ion-exchanged water to the obtained organic layer and stirring at 23°C for 30 minutes, the organic layer was separated. This water washing operation was repeated three times. The obtained organic layer was concentrated, and the concentrated mixture was purified using a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Kagaku Co., Ltd., developing solvent: n-heptane/ethyl acetate = 3/1). By fractionating, 5.19 parts of a compound represented by formula (I-1-c) was obtained.

After mixing 2.5 parts of the salt represented by formula (I-1-e) and 30 parts of acetonitrile and stirring at 23°C for 30 minutes, compound 1.17 represented by formula (I-1-f) was mixed. After the temperature was raised to 50°C, the mixture was stirred at 50°C for 2 hours. 3.04 parts of the compound represented by formula (I-1-c) was added to the obtained reaction mixture, and the mixture was stirred at 50° C. for 10 hours. After cooling the obtained reaction mixture to 23°C, 50 parts of chloroform and 25 parts of ion-exchanged water were added, and after stirring at 23°C for 30 minutes, the mixture was separated and the organic layer was taken out. After adding 25 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated five times. To the obtained organic layer, 25 parts of 5% oxalic acid water was added, and after stirring at 23° C. for 30 minutes, the organic layer was separated. After adding 75 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. The obtained organic layer was concentrated, 2 parts of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 4.18 parts of the salt represented by I-1) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 601.0

式（Ｉ－１－ａ）で表される化合物４部、ジメチルホルムアミド１０部、炭酸カリウム１．３９部及びヨウ化カリウム１．６８部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－２－ｂ）で表される化合物５．２７部を添加し、その後、２３℃で１８時間撹拌した。得られた反応混合物に、ｔｅｒｔ－ブチルメチルエーテル５０部及びイオン交換水３０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。得られた有機層に、イオン交換水３０部を添加し、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、濃縮混合物をカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝３／１）を用いて分取することにより、式（Ｉ－２－ｃ）で表される化合物４．６６部を得た。

式（Ｉ－１－ｅ）で表される塩２．５部及びアセトニトリル３０部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－１－ｆ）で表される化合物１．１７部を添加し、５０℃に昇温後、５０℃で２時間撹拌した。得られた反応混合物に、式（Ｉ－２－ｃ）で表される化合物２．５９部を添加し、５０℃で１０時間撹拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水２５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。得られた有機層に、イオン交換水２５部を添加し、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。得られた有機層に、５％シュウ酸水２５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層に、イオン交換水７５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層を濃縮し、濃縮残渣に、アセトニトリル２部及び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、上澄み液を除去し、濃縮することにより、式（Ｉ－２）で表される塩２．９９部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５３５．０ Example 2: Synthesis of salt represented by formula (I-2)

4 parts of the compound represented by formula (I-1-a), 10 parts of dimethylformamide, 1.39 parts of potassium carbonate and 1.68 parts of potassium iodide were mixed and stirred at 23°C for 30 minutes. 5.27 parts of the compound represented by I-2-b) was added, followed by stirring at 23°C for 18 hours. To the resulting reaction mixture were added 50 parts of tert-butyl methyl ether and 30 parts of ion-exchanged water, and the mixture was stirred at 23° C. for 30 minutes, then separated and the organic layer was taken out. After adding 30 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated three times. The obtained organic layer was concentrated, and the concentrated mixture was purified using a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Kagaku Co., Ltd., developing solvent: n-heptane/ethyl acetate = 3/1). By fractionating, 4.66 parts of a compound represented by formula (I-2-c) was obtained.

After mixing 2.5 parts of the salt represented by formula (I-1-e) and 30 parts of acetonitrile and stirring at 23°C for 30 minutes, compound 1.17 represented by formula (I-1-f) was mixed. The mixture was heated to 50°C, and then stirred at 50°C for 2 hours. 2.59 parts of the compound represented by formula (I-2-c) was added to the obtained reaction mixture, and the mixture was stirred at 50° C. for 10 hours. After cooling the obtained reaction mixture to 23°C, 50 parts of chloroform and 25 parts of ion-exchanged water were added, and after stirring at 23°C for 30 minutes, the mixture was separated and the organic layer was taken out. After adding 25 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated five times. To the obtained organic layer, 25 parts of 5% oxalic acid water was added, and after stirring at 23° C. for 30 minutes, the organic layer was separated. After adding 75 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. The obtained organic layer was concentrated, 2 parts of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 2.99 parts of the salt represented by I-2) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 535.0

式（Ｉ－１－ａ）で表される化合物３部、ジメチルホルムアミド１０部、炭酸カリウム１．０５部及びヨウ化カリウム１．２６部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－３－ｂ）で表される化合物５．９７部を添加し、その後、２３℃で１８時間撹拌した。得られた反応混合物に、ｔｅｒｔ－ブチルメチルエーテル５０部及びイオン交換水３０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。得られた有機層に、イオン交換水３０部を添加し、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、濃縮混合物をカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝３／１）を用いて分取することにより、式（Ｉ－３－ｃ）で表される化合物３．９６部を得た。

式（Ｉ－１－ｅ）で表される塩２．５部及びアセトニトリル３０部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－１－ｆ）で表される化合物１．１７部を添加し、５０℃に昇温後、５０℃で２時間撹拌した。得られた反応混合物に、式（Ｉ－３－ｃ）で表される化合物２．６０部を添加し、５０℃で１０時間撹拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水２５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。得られた有機層に、イオン交換水２５部を添加し、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。得られた有機層に、５％シュウ酸水２５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層に、イオン交換水７５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層を濃縮し、濃縮残渣に、アセトニトリル２部及び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、上澄み液を除去し、濃縮することにより、式（Ｉ－３）で表される塩３．０１部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５３７．０ Example 3: Synthesis of salt represented by formula (I-3)

3 parts of the compound represented by formula (I-1-a), 10 parts of dimethylformamide, 1.05 parts of potassium carbonate and 1.26 parts of potassium iodide were mixed and stirred at 23°C for 30 minutes. 5.97 parts of the compound represented by I-3-b) was added, followed by stirring at 23°C for 18 hours. To the resulting reaction mixture were added 50 parts of tert-butyl methyl ether and 30 parts of ion-exchanged water, and the mixture was stirred at 23° C. for 30 minutes, then separated and the organic layer was taken out. After adding 30 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated three times. The obtained organic layer was concentrated, and the concentrated mixture was purified using a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Kagaku Co., Ltd., developing solvent: n-heptane/ethyl acetate = 3/1). By fractionating, 3.96 parts of a compound represented by formula (I-3-c) was obtained.

After mixing 2.5 parts of the salt represented by formula (I-1-e) and 30 parts of acetonitrile and stirring at 23°C for 30 minutes, compound 1.17 represented by formula (I-1-f) was mixed. The mixture was heated to 50°C, and then stirred at 50°C for 2 hours. 2.60 parts of the compound represented by formula (I-3-c) was added to the obtained reaction mixture, and the mixture was stirred at 50° C. for 10 hours. After cooling the obtained reaction mixture to 23°C, 50 parts of chloroform and 25 parts of ion-exchanged water were added, and after stirring at 23°C for 30 minutes, the mixture was separated and the organic layer was taken out. After adding 25 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated five times. To the obtained organic layer, 25 parts of 5% oxalic acid water was added, and after stirring at 23° C. for 30 minutes, the organic layer was separated. After adding 75 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. The obtained organic layer was concentrated, 2 parts of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 3.01 parts of the salt represented by I-3) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 537.0

式（Ｉ－１－ａ）で表される化合物４部、ジメチルホルムアミド１０部、炭酸カリウム１．３９部及びヨウ化カリウム１．６８部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－４－ｂ）で表される化合物４．５４部を添加し、その後、２３℃で１８時間撹拌した。得られた反応混合物に、ｔｅｒｔ－ブチルメチルエーテル５０部及びイオン交換水３０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。得られた有機層に、イオン交換水３０部を添加し、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、濃縮混合物をカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝３／１）を用いて分取することにより、式（Ｉ－２－ｃ）で表される化合物４．２４部を得た。

式（Ｉ－１－ｅ）で表される塩２．５部及びアセトニトリル３０部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－１－ｆ）で表される化合物１．１７部を添加し、５０℃に昇温後、５０℃で２時間撹拌した。得られた反応混合物に、式（Ｉ－４－ｃ）で表される化合物２．３４部を添加し、５０℃で１０時間撹拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水２５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。得られた有機層に、イオン交換水２５部を添加し、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。得られた有機層に、５％シュウ酸水２５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層に、イオン交換水７５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層を濃縮し、濃縮残渣に、アセトニトリル２部及び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、上澄み液を除去し、濃縮することにより、式（Ｉ－４）で表される塩３．１２部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ４９９．０ Example 4: Synthesis of salt represented by formula (I-4)

4 parts of the compound represented by formula (I-1-a), 10 parts of dimethylformamide, 1.39 parts of potassium carbonate and 1.68 parts of potassium iodide were mixed and stirred at 23°C for 30 minutes. 4.54 parts of the compound represented by I-4-b) was added, followed by stirring at 23°C for 18 hours. To the resulting reaction mixture were added 50 parts of tert-butyl methyl ether and 30 parts of ion-exchanged water, and the mixture was stirred at 23° C. for 30 minutes, then separated and the organic layer was taken out. After adding 30 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated three times. The obtained organic layer was concentrated, and the concentrated mixture was purified using a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Kagaku Co., Ltd., developing solvent: n-heptane/ethyl acetate = 3/1). By fractionating, 4.24 parts of a compound represented by formula (I-2-c) was obtained.

After mixing 2.5 parts of the salt represented by formula (I-1-e) and 30 parts of acetonitrile and stirring at 23°C for 30 minutes, compound 1.17 represented by formula (I-1-f) was mixed. After the temperature was raised to 50°C, the mixture was stirred at 50°C for 2 hours. 2.34 parts of the compound represented by formula (I-4-c) was added to the obtained reaction mixture, and the mixture was stirred at 50° C. for 10 hours. After cooling the obtained reaction mixture to 23°C, 50 parts of chloroform and 25 parts of ion-exchanged water were added, and after stirring at 23°C for 30 minutes, the mixture was separated and the organic layer was taken out. After adding 25 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated five times. To the obtained organic layer, 25 parts of 5% oxalic acid water was added, and after stirring at 23° C. for 30 minutes, the organic layer was separated. After adding 75 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. The obtained organic layer was concentrated, 2 parts of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 3.12 parts of a salt represented by I-4) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 499.0

式（Ｉ－１－ａ）で表される化合物４部、ジメチルホルムアミド１０部、炭酸カリウム１．３９部及びヨウ化カリウム１．６８部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－６－ｂ）で表される化合物４．１８部を添加し、その後、２３℃で１８時間撹拌した。得られた反応混合物に、ｔｅｒｔ－ブチルメチルエーテル５０部及びイオン交換水３０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。得られた有機層に、イオン交換水３０部を添加し、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、濃縮混合物をカラム（シリカゲル６０Ｎ（球状、中性）１００－２１０μｍ；関東化学（株）製、展開溶媒：ｎ－ヘプタン／酢酸エチル＝３／１）を用いて分取することにより、式（Ｉ－６－ｃ）で表される化合物４．３２部を得た。

式（Ｉ－１－ｅ）で表される塩２．５部及びアセトニトリル３０部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－１－ｆ）で表される化合物１．１７部を添加し、５０℃に昇温後、５０℃で２時間撹拌した。得られた反応混合物に、式（Ｉ－６－ｃ）で表される化合物２．２２部を添加し、５０℃で１０時間撹拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水２５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。得られた有機層に、イオン交換水２５部を添加し、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。得られた有機層に、５％シュウ酸水２５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層に、イオン交換水７５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層を濃縮し、濃縮残渣に、アセトニトリル２部及び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、上澄み液を除去し、濃縮することにより、式（Ｉ－６）で表される塩３．７２部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ４８１．０ Example 5: Synthesis of salt represented by formula (I-6)

4 parts of the compound represented by formula (I-1-a), 10 parts of dimethylformamide, 1.39 parts of potassium carbonate and 1.68 parts of potassium iodide were mixed and stirred at 23°C for 30 minutes. 4.18 parts of the compound represented by I-6-b) was added, followed by stirring at 23°C for 18 hours. To the resulting reaction mixture were added 50 parts of tert-butyl methyl ether and 30 parts of ion-exchanged water, and the mixture was stirred at 23° C. for 30 minutes, then separated and the organic layer was taken out. After adding 30 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated three times. The obtained organic layer was concentrated, and the concentrated mixture was purified using a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Kagaku Co., Ltd., developing solvent: n-heptane/ethyl acetate = 3/1). By fractionating, 4.32 parts of a compound represented by formula (I-6-c) was obtained.

After mixing 2.5 parts of the salt represented by formula (I-1-e) and 30 parts of acetonitrile and stirring at 23°C for 30 minutes, compound 1.17 represented by formula (I-1-f) was mixed. The mixture was heated to 50°C, and then stirred at 50°C for 2 hours. 2.22 parts of the compound represented by formula (I-6-c) was added to the obtained reaction mixture, and the mixture was stirred at 50° C. for 10 hours. After cooling the obtained reaction mixture to 23°C, 50 parts of chloroform and 25 parts of ion-exchanged water were added, and after stirring at 23°C for 30 minutes, the mixture was separated and the organic layer was taken out. After adding 25 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated five times. To the obtained organic layer, 25 parts of 5% oxalic acid water was added, and after stirring at 23° C. for 30 minutes, the organic layer was separated. After adding 75 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. The obtained organic layer was concentrated, 2 parts of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 3.72 parts of the salt represented by I-6) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (-) Spectrum): M ^- 481.0

式（Ｉ－３４－ｅ）で表される塩２．６部及びアセトニトリル３０部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－１－ｆ）で表される化合物１．１７部を添加し、５０℃に昇温後、５０℃で２時間撹拌した。得られた反応混合物に、式（Ｉ－６－ｃ）で表される化合物２．２２部を添加し、５０℃で１０時間撹拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水２５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。得られた有機層に、イオン交換水２５部を添加し、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。得られた有機層に、５％シュウ酸水２５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層に、イオン交換水７５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層を濃縮し、濃縮残渣に、アセトニトリル２部及び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、上澄み液を除去し、濃縮することにより、式（Ｉ－３４）で表される塩３．６９部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２８１．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ４８１．０ Example 6: Synthesis of salt represented by formula (I-34)

After mixing 2.6 parts of the salt represented by formula (I-34-e) and 30 parts of acetonitrile and stirring at 23°C for 30 minutes, compound 1.17 represented by formula (I-1-f) was mixed. The mixture was heated to 50°C, and then stirred at 50°C for 2 hours. 2.22 parts of the compound represented by formula (I-6-c) was added to the obtained reaction mixture, and the mixture was stirred at 50° C. for 10 hours. After cooling the obtained reaction mixture to 23°C, 50 parts of chloroform and 25 parts of ion-exchanged water were added, and after stirring at 23°C for 30 minutes, the mixture was separated and the organic layer was taken out. After adding 25 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated five times. To the obtained organic layer, 25 parts of 5% oxalic acid water was added, and after stirring at 23° C. for 30 minutes, the organic layer was separated. After adding 75 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. The obtained organic layer was concentrated, 2 parts of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 3.69 parts of a salt represented by I-34) was obtained.
MASS (ESI (+) Spectrum): M ⁺ 281.1
MASS (ESI (-) Spectrum): M ^- 481.0

式（Ｉ－４８－ｅ）で表される塩２．８部及びアセトニトリル３０部を混合し、２３℃で３０分間攪拌した後、式（Ｉ－１－ｆ）で表される化合物１．１７部を添加し、５０℃に昇温後、５０℃で２時間撹拌した。得られた反応混合物に、式（Ｉ－６－ｃ）で表される化合物２．２２部を添加し、５０℃で１０時間撹拌した。得られた反応混合物を２３℃まで冷却した後、クロロホルム５０部及びイオン交換水２５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。得られた有機層に、イオン交換水２５部を添加し、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。得られた有機層に、５％シュウ酸水２５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層に、イオン交換水７５部を添加し、２３℃で３０分間攪拌した後、分液して有機層を取り出した。得られた有機層を濃縮し、濃縮残渣に、アセトニトリル２部及び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、上澄み液を除去し、濃縮することにより、式（Ｉ－４８）で表される塩３．２２部を得た。 Example 7: Synthesis of salt represented by formula (I-48)

After mixing 2.8 parts of the salt represented by formula (I-48-e) and 30 parts of acetonitrile and stirring at 23°C for 30 minutes, compound 1.17 represented by formula (I-1-f) was mixed. After the temperature was raised to 50°C, the mixture was stirred at 50°C for 2 hours. 2.22 parts of the compound represented by formula (I-6-c) was added to the obtained reaction mixture, and the mixture was stirred at 50° C. for 10 hours. After cooling the obtained reaction mixture to 23°C, 50 parts of chloroform and 25 parts of ion-exchanged water were added, and after stirring at 23°C for 30 minutes, the mixture was separated and the organic layer was taken out. After adding 25 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. This water washing operation was repeated five times. To the obtained organic layer, 25 parts of 5% oxalic acid water was added, and after stirring at 23° C. for 30 minutes, the organic layer was separated. After adding 75 parts of ion-exchanged water to the obtained organic layer and stirring at 23° C. for 30 minutes, the organic layer was separated. The obtained organic layer was concentrated, 2 parts of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue, and after stirring at 23°C for 30 minutes, the supernatant liquid was removed and concentrated to obtain the formula ( 3.22 parts of a salt represented by I-48) was obtained.

MASS (ESI (+) Spectrum): M ⁺ 317.1
MASS (ESI (-) Spectrum): M ^- 481.0

Synthesis of Resin The compounds (monomers) used in the synthesis of resin (A) are shown below. Hereinafter, these compounds will be referred to as "monomers (a1-1-3)" etc. according to their formula numbers.

Synthesis example 1 [Synthesis of resin A1]
As monomers, monomer (a1-4-2), monomer (a1-1-3) and monomer (a1-2-6) were used, and their molar ratio [monomer (a1-4-2): monomer (a1-1 -3):monomer (a1-2-6)] were mixed in a ratio of 38:24:38, and then added to this monomer mixture by 1.5 times the total mass of all monomers. of methyl isobutyl ketone were mixed. To the obtained mixture, azobisisobutyronitrile was added as an initiator in an amount of 7 mol% based on the total number of moles of all monomers, and the mixture was heated at 85° C. for about 5 hours to perform polymerization. Ta. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, and by filtering and collecting it, a resin A1 (copolymer) having a weight average molecular weight of about 5.3×10 ³ was obtained in a yield of 78%. Obtained in %. This resin A1 has the following structural units.

<Preparation of resist composition>
As shown in Table 2, a resist composition was prepared by mixing the following components and filtering the resulting mixture through a fluororesin filter with a pore size of 0.2 μm.

ＩＸ－２：式（ＩＸ－２）で表される塩（特開２０１１－０４６６９４号公報記載の方法で合成）

ＩＸ－３：式（ＩＸ－３）で表される塩（特開２０１１－１２６８６９号公報記載の方法で合成）

ＩＸ－４：式（ＩＸ－４）で表される塩（特開２０１７－０１９９９７号公報記載の方法で合成）

ＩＸ－５：式（ＩＸ－５）で表される塩（特開２０１２－２２６３２５号公報記載の方法で合成）

＜クエンチャー（Ｃ）＞
Ｃ１：特開２０１１－３９５０２号公報記載の方法で合成

＜溶剤＞
プロピレングリコールモノメチルエーテルアセテート ４００部
プロピレングリコールモノメチルエーテル １００部
γ－ブチロラクトン ５部 <Resin>
A1: Resin A1
<Salt (I)>
I-1: Salt represented by formula (I-1) I-2: Salt represented by formula (I-2) I-3: Salt represented by formula (I-3) I-4: Formula Salt represented by (I-4) I-6: Salt represented by formula (I-6) I-34: Salt represented by formula (I-34) I-48: Formula (I-48) Salt represented by <acid generator>
IX-1: Salt represented by formula (IX-1) (synthesized by the method described in JP-A-2009-191054)

IX-2: Salt represented by formula (IX-2) (synthesized by the method described in JP-A-2011-046694)

IX-3: Salt represented by formula (IX-3) (synthesized by the method described in JP-A-2011-126869)

IX-4: Salt represented by formula (IX-4) (synthesized by the method described in JP 2017-019997 A)

IX-5: Salt represented by formula (IX-5) (synthesized by the method described in JP-A-2012-226325)

<Quencher (C)>
C1: Synthesized by the method described in JP-A-2011-39502

<Solvent>
Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 100 parts γ-butyrolactone 5 parts

(Electron beam exposure evaluation of resist composition)
A 6-inch silicon wafer was treated with hexamethyldisilazane at 90° C. for 60 seconds on a direct hot plate. A resist composition was spin-coated onto this silicon wafer so that the thickness of the composition layer was 0.04 μm. Thereafter, it was prebaked for 60 seconds on a direct hot plate at the temperature shown in the "PB" column of Table 2 to form a composition layer. A contact hole pattern (hole pitch 40 nm/hole) was formed on the composition layer formed on the wafer by using an electron beam drawing machine [ELS-F125 125 keV manufactured by Elionix Co., Ltd.] and changing the exposure amount stepwise. 17 nm in diameter) was directly drawn.
After exposure, post-exposure baking was performed for 60 seconds on a hot plate at the temperature shown in the "PEB" column of Table 2, and further paddle development was performed for 60 seconds with a 2.38% by mass tetramethylammonium hydroxide aqueous solution. , a resist pattern was obtained.

In the resist pattern obtained after development, the exposure amount at which the hole diameter formed was 17 nm was defined as the effective sensitivity.

<CD uniformity (CDU) evaluation>
In terms of effective sensitivity, the hole diameter of a pattern formed with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was taken as the average hole diameter of one hole. The average hole diameter of a pattern formed with a hole diameter of 17 nm within the same wafer was measured at 400 locations, and the standard deviation was determined using the population as a population.
The results are shown in Table 3. Numerical values in the table indicate standard deviation (nm).

Compared to Comparative Compositions 1 to 5, Compositions 1 to 7 had smaller standard deviations and better CD uniformity (CDU) evaluation.

The resist composition of the present invention provides a resist pattern with good CD uniformity (CDU), and is therefore suitable for microfabrication of semiconductors and is extremely useful industrially.

Claims (11)

A salt represented by formula (I).

[In formula (I),
Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents any integer from 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² may be the same or different.
X ¹ and X ² each independently represent *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, and * represents C(R ¹ )( R ² ) or C(Q ¹ )(Q ² ), or represents a binding site with A ¹ or L ² .
L ¹ represents a single bond or an alkanediyl group having 1 to 4 carbon atoms.
A ¹ represents a lactone ring having 3 to 36 carbon atoms, and the lactone ring may have an alkyl group having 1 to 4 carbon atoms, a hydroxy group, a carboxy group, or a cyano group; Excludes cyclic.
L ² represents a single bond or an alkanediyl group having 1 to 6 carbon atoms.
R ³ represents a fluorinated alkyl group having 1 to 8 carbon atoms.
Z ⁺ represents an organic cation. ] A salt represented by formula (I').

[In formula (I'),
Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents any integer from 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² may be the same or different.
X ¹ and X ² each independently represent *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, and * represents C(R ¹ )( R ² ) or C(Q ¹ )(Q ² ), or represents a binding site with A ¹ or L ² .
L ¹ represents a single bond or an alkanediyl group having 1 to 4 carbon atoms.
A ¹ represents a lactone ring having 3 to 36 carbon atoms, and the lactone ring may have an alkyl group having 1 to 4 carbon atoms, a hydroxy group, a carboxy group, or a cyano group; Excludes cyclic.
L ² represents a single bond or an alkanediyl group having 1 to 6 carbon atoms.
R ^3' represents a group represented by formula (R3-1).
Z ^'+ represents an organic cation represented by formula (b2-1). ]

[In formula (R3-1),
L ³ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms.
m3 represents 2 .
R ⁴ represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and -CH ₂ - contained in the alkyl group may be replaced with -O- or -CO-.
m4 represents any integer from 0 to 4, and when m4 is 2 or more, a plurality of R ⁴ may be the same or different.
* represents the binding site with ^X2 . ]

[In formula (b2-1),
R ^b4 is a phenylene group having one fluorine atom,
R ^b5 and R ^b6 are each independently a phenylene group which may have one fluorine atom. ] The salt according to claim 1 or 2, wherein A ¹ is a norbornane lactone ring. The salt according to any one of claims 1 to 3, wherein L ² is a single bond. The salt according to any one of claims 1 to 4, wherein L ¹ is a single bond. An acid generator containing the salt according to any one of claims 1 to 5. A resist composition comprising the acid generator according to claim 6 and a resin having an acid-labile group. 8. The resin having an acid-labile group contains at least one member selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2). resist composition.

[In formula (a1-1) and formula (a1-2),
L ^a1 and L ^a2 each independently represent -O- or *-O-(CH ₂ ) k1-CO-O-, k1 represents any integer from 1 to 7, and * represents -CO- represents the binding site with
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
m1 represents any integer from 0 to 14.
n1 represents any integer from 0 to 10.
n1' represents any integer from 0 to 3. ] 9. The resist composition according to claim 7, further comprising a salt that generates an acid less acidic than the acid generated from the acid generator. An acid generator containing a salt represented by formula (I'');
A resist composition for electron beam or EUV exposure containing a structural unit having an acid-labile group and a resin containing a structural unit represented by formula (a2-A).

[In formula (I''),
Q ¹ and Q ² each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms.
z represents any integer from 0 to 6, and when z is 2 or more, a plurality of R ¹ and R ² may be the same or different.
X ¹ and X ² each independently represent *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, and * represents C(R ¹ )( R ² ) or C(Q ¹ )(Q ² ), or represents a binding site with A ¹ or L ² .
L ¹ represents a single bond or an alkanediyl group having 1 to 4 carbon atoms.
A ¹ represents a lactone ring having 3 to 36 carbon atoms, and the lactone ring may have an alkyl group having 1 to 4 carbon atoms, a hydroxy group, a carboxy group, or a cyano group; Excludes cyclic.
L ² represents a single bond or an alkanediyl group having 1 to 6 carbon atoms.
R ^3'' represents a fluorinated hydrocarbon group having 1 to 18 carbon atoms.
Z ⁺ represents an organic cation. ]

[In formula (a2-A),
R ^a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a51 is a halogen atom, hydroxy group, alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl Represents an oxy group or a methacryloyloxy group.
A ^a50 represents a single bond or *-X ^a51 --(A ^a52 --X ^a52 ) _nb --, and * represents a bond with the carbon atom to which --R ^a50 is bonded.
A ^a52 represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 each independently represent -O-, -CO-O- or -O-CO-.
nb represents 0 or 1.
mb represents any integer from 0 to 4. When mb is any integer of 2 or more, a plurality of R ^a51 's may be the same or different. ] (1) applying the resist composition according to any one of claims 7 to 10 onto a substrate;
(2) drying the applied composition to form a composition layer;
(3) exposing the composition layer to light;
(4) A method for producing a resist pattern, including the steps of: heating the exposed composition layer; and (5) developing the heated composition layer.