JP2024037170A - Resist composition and method for producing resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition, enabling the production of a resist pattern with superior CD uniformity.

SOLUTION: The present invention provides a resist composition that comprises an acid generator comprising a salt represented by formula (I) and a resin comprising a structural unit represented by formula (a2-A).

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a resist composition and a method for producing a resist pattern.

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

JP 2018-120218 Publication

The present invention provides a resist composition containing a salt that can produce a resist pattern with better CD uniformity (CDU) than resist patterns formed from the resist compositions described above.

［式（Ｉ）中、
Ｑ^１及びＱ^２は、それぞれ独立に、水素原子、フッ素原子、炭素数１～６のアルキル基又は炭素数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、炭素数１～６のアルキル基又は炭素数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。
Ｘ^１は、＊－ＣＯ－Ｏ－、＊－Ｏ－ＣＯ－、＊－Ｏ－ＣＯ－Ｏ－又は＊－Ｏ－を表し、＊は、Ｃ（Ｒ^１）（Ｒ^２）又はＣ（Ｑ^１）（Ｑ^２）との結合部位を表す。
Ｌ^１及びＬ^２は、それぞれ独立に、単結合又はフッ素原子を有していてもよい炭素数１～１２の脂肪族炭化水素基を表し、該脂肪族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。
Ａ^１は、単結合又は置換基を有してもよい炭素数３～３６の環状炭化水素基を表し、該環状炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－ＣＯ－、－Ｓ－又は－ＳＯ_２－で置き換わっていてもよい。
ｍ１は、１～３のいずれかの整数を表す。
Ａｒ^１は、炭素数６～１０の芳香族炭化水素基又は炭素数４～９の複素環式芳香族炭化水素基を表す。
Ｒｆ^１は、フッ素原子又は炭素数１～６のフッ素化アルキル基を表す。
Ｒ^４は、ハロゲン原子、炭素数１～１２のハロアルキル基又は炭素数１～１８の炭化水素基を表し、該炭化水素基は、置換基を有してもよく、該ハロアルキル基及び該炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－ＣＯ－、－Ｓ－又は－ＳＯ_２－で置き換わっていてもよい。
ｍ４は、０～８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。
Ｚ^＋は、有機カチオンを表す。］

［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いてもよい炭素数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２～１２のアルコキシアルキル基、炭素数２～１２のアルコキシアルコキシ基、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部位を表す。
Ａ^a52は、炭素数１～８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いてもよい。］
［２］Ａｒ^１が、ベンゼン環、ナフタレン環、フラン環又はチオフェン環に由来する基である［１］に記載のレジスト組成物。
［３］Ｘ^１が、＊－ＣＯ－Ｏ－又は＊－Ｏ－ＣＯ－である［１］又は［２］に記載のレジスト組成物。
［４］Ａ^１が、置換基を有してもよい炭素数３～３６の環状炭化水素基（該環状炭化水素基に含まれる－ＣＨ₂－は、－Ｏ－、－ＣＯ－、－Ｓ－又は－ＳＯ_２－で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レジスト組成物。
［５］樹脂が、式（ａ１－０）で表される構造単位、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［１］～［４］のいずれかに記載のレジスト組成物。

［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－との結合部位を表す。
Ｒ^a01、Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、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。
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、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２～８のアルケニル基、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。］
［６］樹脂が、式（ａ３－４）’で表される構造単位を含む［１］～［５］のいずれかに記載のレジスト組成物。

［式（ａ３－４）’中、
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^ａ２４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。］
［７］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［１］～［６］のいずれかに記載のレジスト組成物。
［８］（１）［１］～［７］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] A resist composition containing an acid generator containing a salt represented by formula (I) and a resin containing a structural unit represented by formula (a2-A).

[In formula (I),
Q ¹ and Q ² each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, or a perfluoroalkyl group having 1 to 6 carbon atoms.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, 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 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, and * represents C(R ¹ )(R ² ) or C(Q ¹ ) represents the binding site with (Q ² ).
L ¹ and L ² each independently represent a single bond or an aliphatic hydrocarbon group having 1 to 12 carbon atoms which may have a fluorine atom, and -CH ₂ - contained in the aliphatic hydrocarbon group may be replaced with -O- or -CO-.
A ¹ represents a single bond or a cyclic hydrocarbon group having 3 to 36 carbon atoms which may have a substituent, and -CH ₂ - contained in the cyclic hydrocarbon group is -O-, -CO-, -S- or -SO ₂ - may be substituted.
m1 represents an integer of 1 to 3.
Ar ¹ represents an aromatic hydrocarbon group having 6 to 10 carbon atoms or a heterocyclic aromatic hydrocarbon group having 4 to 9 carbon atoms.
Rf ¹ represents a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
R ⁴ represents a halogen atom, a haloalkyl group having 1 to 12 carbon atoms, or a hydrocarbon group having 1 to 18 carbon atoms, and the hydrocarbon group may have a substituent, and the haloalkyl group and the hydrocarbon group -CH ₂ - contained in the group may be replaced with -O-, -CO-, -S- or -SO ₂ -.
m4 represents any integer from 0 to 8, and when m4 is 2 or more, a plurality of R ⁴ may be the same or different.
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, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, a carbon number Represents an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group.
A ^a50 represents a single bond or *-X ^a51 --(A ^a52 --X ^a52 ) _nb --, and * represents a bonding site with the carbon atom to which --R ^a50 is bonded.
A ^a52 represents an alkanediyl group having 1 to 8 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. ]
[2] The resist composition according to [ ¹ ], wherein Ar 1 is a group derived from a benzene ring, a naphthalene ring, a furan ring, or a thiophene ring.
[3] The resist composition according to [ ¹ ] or [2], wherein X 1 is *-CO-O- or *-O-CO-.
[4] A ¹ is a cyclic hydrocarbon group having 3 to 36 carbon atoms which may have a substituent (-CH ₂ - contained in the cyclic hydrocarbon group is -O-, -CO-, -S - or -SO ₂ -.) The resist composition according to any one of [1] to [3].
[5] The resin is selected from the group consisting of a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), and a structural unit represented by formula (a1-2). The resist composition according to any one of [1] to [4], containing at least one resist composition.

[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 binding site with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
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, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or any of these. Represents a combined group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic group having 6 to 18 carbon atoms. Represents a hydrocarbon group 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. ]
[6] The resist composition according to any one of [1] to [5], wherein the resin contains a structural unit represented by formula (a3-4)'.

[In formula (a3-4)',
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 ^a24 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms that may have a halogen atom. ]
[7] The resist composition according to any one of [1] to [6], further containing a salt that generates an acid that is weaker in acidity than the acid generated from the acid generator.
[8] (1) Applying the resist composition according to any one of [1] to [7] 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.
A method for manufacturing a resist pattern including:

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

As used herein, "(meth)acrylic monomer" means "at least one of an acrylic monomer and a methacrylic monomer." Notations such as "(meth)acrylate" and "(meth)acrylic acid" also represent the same meaning. Groups described in this specification that can have both a linear structure and a branched structure may have either one. When -CH ₂ - contained in a hydrocarbon group etc. is replaced with -O-, -S-, -CO- or -SO ₂ -, the same examples apply to each group. 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. "Derived from" or "derivated" means that a polymerizable C=C bond contained in the molecule becomes a -C-C- group (single bond) through polymerization, or a hydrogen atom becomes a bonding site. refers to If stereoisomers exist, all stereoisomers are included. In each group, depending on the number of substituents, hydrogen atoms contained in the group may be substituted at arbitrary positions and numbers at the bonding site. The number of carbon atoms in a substituent is not included in the number of carbon atoms in a substituent.
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.

[Resist composition]
The resist composition of the present invention comprises an acid generator containing a salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)") and a structural unit represented by formula (a2-A). (hereinafter sometimes referred to as "resin (A)"). Preferably, the resin further includes a structural unit having an acid-labile group. The "acid labile group" here has a leaving group, and upon contact with an acid, the leaving group is eliminated and converted into a structural unit having a hydrophilic group (e.g., hydroxy group or carboxy group). means base.
The resist composition of the present invention may further contain a resin other than resin (A).
The resist composition of the present invention may further contain 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. Preferably, it is more preferable to contain a solvent (hereinafter sometimes referred to as "solvent (E)").

<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)".

[Anion (I)]
In formula (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, perfluorosec-butyl group. , perfluoro tert-butyl group, perfluoropentyl group, perfluorohexyl group, and the like. The number of carbon atoms in the perfluoroalkyl group is preferably 1 to 4, more preferably 1 to 3.
Examples of the alkyl group for Q ¹ , Q ² , R ¹ and R ² include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, etc. It will be done. The number of carbon atoms in the alkyl group is preferably 1 to 4, more preferably 1 to 3.
It is preferable that at least one of Q ¹ and Q ² contains a fluorine atom or a perfluoroalkyl group, it is more preferable that at least one of them contains a fluorine atom or a perfluoroalkyl group, and each independently contains a trifluoromethyl group or a fluorine atom. It is more preferably an atom, and even more preferably both are fluorine atoms.
R ¹ and R ² are each independently preferably a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, more preferably a hydrogen atom or a fluorine atom, and still more preferably a hydrogen atom.
z is preferably an integer of 0 to 4, more preferably an integer of 0 to 3, even more preferably an integer of 0 to 2, 0 or 1. Even more preferably.
X ¹ is preferably *-CO-O-, *-O-CO- or *-O-CO-O-, more preferably *-CO-O- or *-O-CO- Preferred (* represents a binding site with C(R ¹ )(R ² ) or C(Q ¹ )(Q ² ).)

Examples of the aliphatic hydrocarbon group having 1 to 12 carbon atoms for L ¹ and L ² include linear or branched chain hydrocarbon groups, monocyclic or polycyclic alicyclic hydrocarbon groups, etc. It may also be a combination of two or more of these groups.
Examples of chain hydrocarbon groups include alkanediyl groups, and examples of alkanediyl groups include methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, and pentane-1,4-diyl group. 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 linear alkanediyl groups such as undecane-1,11-diyl group, dodecane-1,12-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 are mentioned.
The chain hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms.
Examples of alicyclic hydrocarbon groups include monocyclic groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group. Formula cycloalkanediyl group;
Examples include polycyclic cycloalkanediyl groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.
Specific examples of the alicyclic hydrocarbon group include the following groups. The binding site can be at any position.
The alicyclic hydrocarbon group preferably has 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, and still more preferably 3 to 6 carbon atoms.
Examples of the aliphatic hydrocarbon group having 1 to 12 carbon atoms having a fluorine atom in L ¹ and L ² include perfluoromethylene group, perfluoroethylene group, perfluoropropane-1,3-diyl group, and perfluoropropane-2,2-diyl group. fluorinated alkanediyl groups such as perfluorobutane-1,4-diyl group, perfluorobutane-2,3-diyl group, perfluoropentane-1,5-diyl group, perfluorohexane-1,6-diyl group, etc. Examples thereof include an alkanediyl group having a certain fluorine atom, and a cycloalkanediyl group having a fluorine atom such as a perfluorocyclohexanediyl group.

-CH ₂ - contained in the aliphatic hydrocarbon groups of L ¹ and L ² may be replaced with -O- or -CO-. When -CH ₂ - contained in the aliphatic hydrocarbon groups of L ¹ and L ² is replaced with -O- and -CO-, the number of carbon atoms before being replaced is the aliphatic hydrocarbon group of L ¹ and L ² . The total number of carbon atoms is Moreover, the number may be one or two or more.
Groups in which -CH ₂ - contained in an aliphatic hydrocarbon group are replaced with -O- or -CO- include an oxy group (a group in which -CH ₂ - contained in a methylene group is replaced with -O-); ), carbonyl group (a group in which -CH ₂ - contained in a methylene group is replaced with -CO-), a hydroxy group (a group in which -CH ₂ - contained in a methyl group is replaced by -O-), Carboxy group (a group in which -CH ₂ -CH ₂ - contained in an ethyl group is replaced with -O-CO-), alkoxy group (a group in which -CH 2 - contained in an alkyl group is replaced with -O-CO-), an alkoxy group (a group in which -CH ₂ - contained in an alkyl group is replaced with -O-CO-), -), alkoxycarbonyl group (group in which -CH ₂ -CH ₂ - at any position contained in the alkyl group is replaced with -O-CO-), alkylcarbonyl group (group in which -O-CO- is substituted for -CH 2 -CH 2 - contained in the alkyl group), (a group in which -CH ₂ - at any position in the alkyl group is replaced with -CO-), an alkylcarbonyloxy group (a group in which -CH ₂ -CH ₂ - at any position contained in the alkyl group is replaced by -CO-O-), a substituted group), an alkanediyloxy group (a group in which -CH ₂ - at any position contained in an alkanediyl group is replaced with -O-), an alkanediyloxycarbonyl group (an arbitrary group contained in an alkanediyl group) -CH ₂ -CH ₂ - at the position is replaced with -O-CO-), alkanediylcarbonyl group (-CH ₂ - at any position contained in the alkanediyl group is replaced with -CO-) a group), an alkanediylcarbonyloxy group (a group in which -CH ₂ -CH ₂ - contained at any position in the alkanediyl group is replaced with -CO-O-), a cycloalkoxy group, a cycloalkylalkoxy group, Examples include an alkoxycarbonyloxy group and a combination of two or more of these groups.
Examples of the alkoxy group include alkoxy groups having 1 to 11 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, and nonyloxy group. group, decyloxy group, undecyloxy group, etc. The alkoxy group preferably has 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 11 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group, and the like. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 12 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 11 carbon atoms, such as an acetyloxy group, a propionyloxy group, a butyryloxy group, and the like. The alkoxycarbonyl group preferably has 2 to 9 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms. The alkylcarbonyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 9, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3.
Examples of the alkanediyloxy group include alkanediyloxy groups having 1 to 11 carbon atoms, such as methyleneoxy group, ethyleneoxy group, propanediyloxy group, butanediyloxy group, pentanediyloxy group, and hexanediyloxy group. , octanediyloxy group, 2-ethylhexanediyloxy group, nonanediyloxy group, decanediyloxy group, undecanediyloxy group and the like. The alkanediyloxy group preferably has 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the alkanediyloxycarbonyl group include alkanediyloxycarbonyl groups having 2 to 11 carbon atoms, such as methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propanediyloxycarbonyl group, butanediyloxycarbonyl group, and pentanediyloxycarbonyl group. Examples include carbonyl group, hexanediyloxycarbonyl group, octanediyloxycarbonyl group, 2-ethylhexanediyloxycarbonyl group, nonanediyloxycarbonyl group, decanediyloxycarbonyl group, undecanediyloxycarbonyl group, and the like. The alkanediyloxycarbonyl group preferably has 2 to 9 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms.
Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 12 carbon atoms, such as methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, pentanediylcarbonyl group, and hexanediylcarbonyl group. , octanediylcarbonyl group, 2-ethylhexanediylcarbonyl group, nonanediylcarbonyl group, decanediylcarbonyl group, undecanediylcarbonyl group, and the like. The alkanediylcarbonyl group preferably has 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms.
Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 11 carbon atoms, such as methylenecarbonyloxy group, ethylenecarbonyloxy group, propanediylcarbonyloxy group, butanediylcarbonyloxy group, and pentanediylcarbonyloxy group. Examples include oxy group, hexanediylcarbonyloxy group, octanediylcarbonyloxy group, 2-ethylhexanediylcarbonyloxy group, nonanediylcarbonyloxy group, decanediylcarbonyloxy group, undecanediylcarbonyloxy group, and the like. The alkanediylcarbonyloxy group preferably has 2 to 9 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms.
Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 11 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include a cycloalkylalkoxy group having 4 to 11 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 10 carbon atoms, such as a butoxycarbonyloxy group.
Examples of groups in which -CH ₂ - contained in the cycloalkanediyl group are replaced with -O- or -CO- include the following. The binding site can be at any position.

L ¹ is a chain hydrocarbon group having 1 to 10 carbon atoms which may have a single bond or a fluorine atom (-CH ₂ - contained in the chain hydrocarbon group is -O- or -CO- ) is preferable, and is preferably a single bond or a linear or branched alkanediyl group having 1 to 8 carbon atoms (-CH ₂ - contained in the alkanediyl group is -O- or -CO-), more preferably a single bond or a linear alkanediyl group having 1 to 6 carbon atoms, and more preferably a single bond or a linear alkanediyl group having 1 to 6 carbon atoms. Even more preferred is a linear alkanediyl group.
L ² is a chain hydrocarbon group having 1 to 10 carbon atoms which may have a single bond or a fluorine atom (-CH ₂ - contained in the chain hydrocarbon group is -O- or -CO- ) is preferable, and is preferably a single bond or a linear or branched alkanediyl group having 1 to 8 carbon atoms (-CH ₂ - contained in the alkanediyl group is -O- or -CO-) is more preferable, and a single bond or a linear alkanediyl group having 1 to 6 carbon atoms (one -CH ₂ - contained in the alkanediyl group is , -CO-, and the other -CH ₂ - may be replaced with -O- or -CO-), and is more preferably a single bond or a straight chain having 1 to 4 carbon atoms. alkanediyl group (one -CH ₂ - contained in the alkanediyl group is replaced with -CO-, and the other -CH ₂ - may be replaced with -O- or -CO-) ) is even more preferable. Furthermore, when containing an alkanediyl group having 2 or more carbon atoms, one -CH ₂ -CH ₂ - contained in the alkanediyl group may be replaced with -O-CO- or -CO-O-. preferable.

具体的に、単環式の脂環式炭化水素基としては、シクロプロパンジイル基、シクロブタンジイル基、シクロペンタンジイル基、シクロヘキサンジイル基、シクロヘプタンジイル基、シクロオクタンジイル基、シクロデカンジイル基等の単環式シクロアルカンジイル基等が挙げられる。多環式の脂環式炭化水素基としては、デカヒドロナフタンジイル基、アダマンタンジイル基、ノルボルナンジイル基、ノルボルネンジイル基、ビシクロ[３．３．０]オクタンジイル基等の多環式シクロアルカンジイル基、スピロシクロヘキサン－１，２’－シクロペンタン基、スピロアダマンタン－２，３’－シクロペンタン基等のシクロアルキル基、ノルボニル基もしくはアダマンチル基とそれぞれにスピロで結合したシクロアルキル基を有するスピロ環等が挙げられる。
また、上述した基の水素原子の１つ以上を結合部位に置き換えた基等も挙げられる。
また、脂環式炭化水素基に含まれる隣接する２つの炭素原子間で二重結合を形成している環状炭化水素基は、以下の環状炭化水素基が挙げられる。

The cyclic hydrocarbon group having 3 to 36 carbon atoms in ^A1 may be either saturated or unsaturated, and may be monocyclic or polycyclic, and the polycyclic cyclic hydrocarbon group is It may be a bridging ring or may form a spiro. The cyclic hydrocarbon group includes an alicyclic hydrocarbon group (-CH ₂ - contained in the alicyclic hydrocarbon group is replaced with -O-, -S-, -CO- or -SO ₂ -); ) or an aromatic hydrocarbon group. Note that the carbon atoms contained in the alicyclic hydrocarbon group may form a double bond between two adjacent carbon atoms. The number of carbon atoms in the cyclic hydrocarbon group is preferably 3 to 30, more preferably 3 to 24, and still more preferably 3 to 20.
Examples of the alicyclic hydrocarbon group include the following alicyclic hydrocarbon groups. The binding site can be at any position.

Specifically, monocyclic alicyclic hydrocarbon groups include cyclopropanediyl group, cyclobutanediyl group, cyclopentanediyl group, cyclohexanediyl group, cycloheptanediyl group, cyclooctanediyl group, cyclodecanediyl group, etc. Examples include monocyclic cycloalkanediyl groups. Examples of the polycyclic alicyclic hydrocarbon group include polycyclic cycloalkanediyl such as decahydronaphthanediyl, adamantanediyl, norbornanediyl, norbornenediyl, and bicyclo[3.3.0]octanediyl. a spiro ring having a cycloalkyl group bonded to a spiro group, a cycloalkyl group such as a spirocyclohexane-1,2'-cyclopentane group, a spiroadamantane-2,3'-cyclopentane group, a norbornyl group or an adamantyl group, respectively. etc.
Also included are groups in which one or more hydrogen atoms of the above-mentioned groups are replaced with bonding sites.
Further, examples of the cyclic hydrocarbon group forming a double bond between two adjacent carbon atoms included in the alicyclic hydrocarbon group include the following cyclic hydrocarbon groups.

脂環式炭化水素基の炭素数は、好ましくは３～２４であり、より好ましくは３～１８であり、さらに好ましくは３～１６であり、より一層好ましくは３～１４であり、さらに一層好ましくは３～１２である。
芳香族炭化水素基としては、フェニレン基、ナフチレン基、アントリレン基、ビフェニレン基、フェナントリレン基等のアリーレン基等の芳香族炭化水素基が挙げられる。
また、上述した基の水素原子の１つ以上を結合部位に置き換えた基等も挙げられる。
芳香族炭化水素基の炭素数は、好ましくは６～２４であり、より好ましくは６～１８であり、さらに好ましくは６～１４であり、さらにより好ましくは６～１０である。
環状炭化水素基は、炭素数３～１８の環状炭化水素基（該環状炭化水素基は、置換基を有していてもよく、該環状炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－ＳＯ_２－に置き換わっていてもよい。）であることが好ましく、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（該脂環式炭化水素基及び該芳香族炭化水素基は、置換基を有していてもよく、該脂環式炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－ＳＯ_２－で置き換わっていてもよい。）であることがより好ましく、式（ｗ１－１）～式（ｗ１－３２）のいずれかで表される基であることがさらに好ましい。

［式（ｗ１－１）～式（ｗ１－３２）中、
該基は、置換基を有していてもよく、該基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－ＳＯ_２－に置き換わっていてもよい。結合部位は任意の位置である。］ Furthermore, examples of the group in which -CH ₂ - contained in the alicyclic hydrocarbon group is replaced with -O-, -S-, -CO- or -SO ₂ - include the following groups. Also included are groups in which -O- in the following groups is replaced with -S-, and -CO- is replaced with -SO ₂ -, respectively. The binding site can be at any position.

The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 24, more preferably 3 to 18, still more preferably 3 to 16, even more preferably 3 to 14, and even more preferably is 3 to 12.
Examples of the aromatic hydrocarbon group include aromatic hydrocarbon groups such as arylene groups such as phenylene group, naphthylene group, anthrylene group, biphenylene group, and phenanthrylene group.
Also included are groups in which one or more hydrogen atoms of the above-mentioned groups are replaced with bonding sites.
The aromatic hydrocarbon group preferably has 6 to 24 carbon atoms, more preferably 6 to 18 carbon atoms, still more preferably 6 to 14 carbon atoms, and even more preferably 6 to 10 carbon atoms.
The cyclic hydrocarbon group is a cyclic hydrocarbon group having 3 to 18 carbon atoms (the cyclic hydrocarbon group may have a substituent, and -CH ₂ - contained in the cyclic hydrocarbon group is -O -, -S-, -CO- or -SO ₂ -) is preferable, and is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic carbonized group having 6 to 18 carbon atoms. Hydrogen group (the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have a substituent, and -CH ₂ - contained in the alicyclic hydrocarbon group is -O-, - (optionally substituted with S-, -CO- or -SO ₂ -) is more preferable, and is a group represented by any one of formulas (w1-1) to (w1-32). is even more preferable.

[In formulas (w1-1) to (w1-32),
The group may have a substituent, and -CH ₂ - contained in the group may be replaced with -O-, -S-, -CO- or -SO ₂ -. The binding site can be at any position. ]

［式中、＊は、Ｌ^１との結合部位、水素原子又はＡ^１が有してもよい置換基との結合部位を表し、１以上の＊のうち１つは、Ｌ^１との結合部位を表す。
＊＊は、水素原子、Ａ^１が有してもよい置換基との結合部位又はＬ^２との結合部位を表し、１以上の＊＊のうち１つから３つは、Ｌ^２との結合部位を表す。
該環に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－ＳＯ_２－で置き換わってもよい。］
ｍ１は、１又は２であることが好ましく、１であることがより好ましい。
ｍ１が２又は３の場合、Ａ^１は、シクロヘキサンジイル基、アダマンタンジイル基と該アダマンタンジイル基がスピロで結合した炭素数５～８のシクロアルカンジイル基もしくはビシクロアルカンジイル基（該シクロアルカンジイル基及びビシクロアルカンジイル基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。該シクロアルカンジイル基は、アセタール環を形成していることが好ましい。）からなるスピロ環又はフェニレン基であることが好ましい。 A ¹ is a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (-CH ₂ - contained in the cyclic hydrocarbon group is -O-, -S-, -CO- or -SO ₂ -) is preferable, and is preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms which may have a substituent (contained in the alicyclic hydrocarbon group). -CH ₂ - may be substituted with -O- or -CO-) or an aromatic hydrocarbon group having 6 to 14 carbon atoms which may have a substituent, and cyclohexane diyl group, norbornanediyl group, norbornenediyl group, adamantanediyl group, a cycloalkanediyl group or bicycloalkanediyl group having 5 to 8 carbon atoms in which an adamantanediyl group and the adamantanediyl group are spiro-bonded (each group is a substituted -CH ₂ - contained in the cycloalkanediyl group and bicycloalkanediyl group may be replaced with -O- or -CO-.) or a phenylene group. It is more preferable that Here, the carbon atoms contained in the alicyclic hydrocarbon group may form a double bond between two adjacent carbon atoms. Moreover, it is preferable that the cycloalkanediyl group contained in the spiro ring forms an acetal ring.
Examples of the substituent for A ¹ include a halogen atom, a haloalkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 12 carbon atoms (-CH ₂ - contained in the alkyl group is replaced with -O- or -CO-). ) may be mentioned.
Examples of the above-mentioned halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The above-mentioned haloalkyl group having 1 to 6 carbon atoms refers to a fluorinated alkyl group having 1 to 6 carbon atoms, a chlorinated alkyl group having 1 to 6 carbon atoms, an alkyl bromide group having 1 to 6 carbon atoms, and a brominated alkyl group having 1 to 6 carbon atoms. Examples include an iodized alkyl group. Examples of haloalkyl groups include perfluoroalkyl groups having 1 to 6 carbon atoms (trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, etc.), 2,2,2-trifluoroethyl group, 3, 3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, chloromethyl group, bromomethyl group, iodomethyl group, fluoromethyl group, difluoro Examples include methyl group, trifluoromethyl group, perfluorobutyl group, and the like. The haloalkyl group preferably has 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms.
Examples of the alkyl group 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, etc. Examples include groups. The alkyl group preferably has 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms.
When the -CH ₂ - contained in the above-mentioned alkyl group is replaced with -O- or -CO-, the number of carbon atoms before being replaced is the total number of carbon atoms in the alkyl group.
Substituted groups include a hydroxy group (a group in which -CH ₂ - contained in a methyl group is replaced with -O-), a carboxy group (a group in which -CH 2 -CH ₂ - contained in an ethyl group is replaced with -O-), and a carboxy group (a group in which -CH ₂ - contained in an ethyl group is replaced with -O-) (a group in which -CO- is replaced with -CO-), an alkoxy group (a group in which -CH 2 - at any position contained in an alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -O- is substituted for -CH ₂ - at any position contained in an alkyl group) (a group in which -CH ₂ -CH ₂ - is replaced with -O-CO-), an alkylcarbonyl group (a group in which -CH ₂ - at any position contained in the alkyl group is replaced with -CO-), Examples thereof include an alkylcarbonyloxy group (a group in which -CH ₂ -CH ₂ - contained in an alkyl group is replaced with -CO-O-) and the like.
Examples of the alkoxy group include alkoxy groups having 1 to 11 carbon atoms. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 11 carbon atoms. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 12 carbon atoms. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 11 carbon atoms. These include the same ones as mentioned above.
The substituent that A ¹ may have is a fluorine atom, an iodine atom, a haloalkyl group having 1 to 3 carbon atoms, or an alkyl group having 1 to 6 carbon atoms (-CH ₂ -- contained in the alkyl group is -O - or -CO-), preferably a fluorine atom, an iodine atom, a fluorinated alkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 3 carbon atoms, a hydroxy group, a methoxy group. , an ethoxy group or a carboxy group.
The number of substituents that A ¹ may have is not particularly limited, but is preferably 0, 1, or 2.
The bonding position of L ¹ to A ¹ and the bonding position of L ² to A ¹ are not particularly limited, and L ¹ and one or more L ² are each independently any one contained in the cyclic hydrocarbon group of A ¹ . It is preferable that the carbon atoms are bonded to different carbon atoms. A ¹ is a cyclohexanediyl group, a norbornediyl group, a norbornenediyl group, an adamantanediyl group, a cycloalkanediyl group having 5 to 8 carbon atoms in which an adamantanediyl group and the adamantanediyl group are bonded via a spiro bond (to the cycloalkanediyl group) In the case of a spiro ring or a phenylene group, the -CH ₂ - contained therein may be replaced with -O- or -CO-.The cycloalkanediyl group preferably forms an acetal ring. , the preferred binding position of L ¹ to A ¹ and the preferred binding position of L ² to A ¹ are represented below.

[In the formula, * represents a bonding site with ^L1 , a bonding site with a hydrogen atom or a substituent that ^A1 may have, and one of the one or more * is a bonding site with ^L1 represents.
** represents a hydrogen atom, a bonding site with a substituent that ^A1 may have, or a bonding site with ^L2 , and one to three of the one or more ** are bonding sites with ^L2 . Represents a part.
-CH ₂ - contained in the ring may be replaced with -O-, -S-, -CO- or -SO ₂ -. ]
m1 is preferably 1 or 2, more preferably 1.
When m1 is 2 or 3, ^A1 is a cyclohexanediyl group, a cycloalkanediyl group having 5 to 8 carbon atoms in which an adamantanediyl group and the adamantanediyl group are bonded via spiro, or a bicycloalkanediyl group (the cycloalkanediyl group). and -CH ₂ - contained in the bicycloalkanediyl group may be replaced with -O- or -CO-. The cycloalkanediyl group preferably forms an acetal ring. A ring or a phenylene group is preferred.

Examples of the aromatic hydrocarbon group having 6 to 10 carbon atoms for Ar ¹ include groups derived from a benzene ring or a naphthalene ring, such as a phenylene group or a naphthylene group. Further, examples of the heterocyclic aromatic hydrocarbon group having 4 to 9 carbon atoms for Ar ¹ include groups derived from a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, and the like.
Ar ¹ is preferably a group derived from a benzene ring, a naphthalene ring, a furan ring or a thiophene ring, and more preferably a group derived from a benzene ring.

Examples of the fluorinated alkyl group having 1 to 6 carbon atoms in Rf ¹ include trifluoromethyl group, perfluoroethyl group, perfluoro n-propyl group, perfluoroisopropyl group, hexafluoroisopropyl group, perfluoro n-butyl group, perfluoro sec-butyl group. and fluorinated alkyl groups such as perfluoro tert-butyl group, perfluoropentyl group, and perfluorohexyl group. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 4, more preferably 1 to 3.
Among these, Rf ¹ is preferably a fluorine atom or a fluorinated alkyl group having 1 to 4 carbon atoms, more preferably a fluorine atom or a fluorinated alkyl group having 1 to 3 carbon atoms, and a fluorine atom or a fluorinated alkyl group having 1 to 3 carbon atoms. More preferably, it is a trifluoromethyl group.

具体的には、単環式の脂環式炭化水素基としては、シクロプロピル基、シクロブチル基、シクロペンチル基、シクロヘキシル基、シクロヘプチル基、シクロオクチル基、シクロノニル基、シクロデシル基、シクロドデシル基等の単環式シクロアルキル基が挙げられる。多環式の脂環式炭化水素基としては、デカヒドロナフチル基、アダマンチル基、ノルボルニル基等の多環式シクロアルキル基が挙げられる。脂環式炭化水素基の炭素数は、好ましくは３～１８であり、より好ましくは３～１６であり、さらに好ましくは３～１２である。
芳香族炭化水素基としては、フェニル基、ナフチル基、ビフェニル基、アントリル基、フェナントリル基、ビナフチル基等が挙げられる。芳香族炭化水素基の炭素数は、好ましくは６～１８であり、より好ましくは６～１４であり、さらに好ましくは６～１０である。 Examples of the halogen atom for R ⁴ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The haloalkyl group having 1 to 12 carbon atoms of R ⁴ represents an alkyl group having 1 to 12 carbon atoms having a halogen atom, such as a fluorinated alkyl group having 1 to 12 carbon atoms, a chlorinated alkyl group having 1 to 12 carbon atoms, Examples include an alkyl bromide group having 1 to 12 carbon atoms and an alkyl iodide group having 1 to 12 carbon atoms. Examples of haloalkyl groups include perfluoroalkyl groups having 1 to 12 carbon atoms (trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, etc.), 2,2,2-trifluoroethyl group, 3, Examples include 3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, chloromethyl group, bromomethyl group, and iodomethyl group. The haloalkyl group preferably has 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
The hydrocarbon group having 1 to 18 carbon atoms for R ⁴ is an alkyl group, a chain hydrocarbon group such as an alkanediyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a combination thereof. Examples include groups.
The alkyl group is a straight-chain or branched alkyl group, such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group. group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, and dodecyl group.
The alkanediyl group is a linear or branched alkanediyl group, such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, Linear alkanediyl groups such as hexane-1,6-diyl groups; and ethane-1,1-diyl groups, propane-1,1-diyl groups, propane-1,2-diyl groups, 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- Branched alkanediyl groups such as 1,4-diyl groups are mentioned.
The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 12, more preferably 1 to 9, still more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples include the groups shown below. The binding site can be at any position.

Specifically, monocyclic alicyclic hydrocarbon groups include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cyclododecyl group, etc. Examples include monocyclic cycloalkyl groups. Examples of the polycyclic alicyclic hydrocarbon group include polycyclic cycloalkyl groups such as a decahydronaphthyl group, an adamantyl group, and a norbornyl group. The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 3 to 16 carbon atoms, and even more preferably 3 to 12 carbon atoms.
Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, a biphenyl group, an anthryl group, a phenanthryl group, a binaphthyl group, and the like. The aromatic hydrocarbon group preferably has 6 to 18 carbon atoms, more preferably 6 to 14 carbon atoms, and still more preferably 6 to 10 carbon atoms.

Groups formed by combining aromatic hydrocarbon groups and chain hydrocarbon groups (for example, aromatic hydrocarbon group-alkanediyl group-*, alkyl group-aromatic hydrocarbon group- *, alkyl group - aromatic hydrocarbon group - alkanediyl group -*, -CH ₂ - contained in the alkanediyl group and the alkyl group is -O-, -CO-, -S- or -SO ₂ - ), a group that combines an alicyclic hydrocarbon group and a chain hydrocarbon group (for example, an alicyclic hydrocarbon group - an alkanediyl group - *, an alkyl group - an alicyclic hydrocarbon group) -*, alkyl group - alicyclic hydrocarbon group - alkanediyl group -*, -CH ₂ - contained in the alicyclic hydrocarbon group, the alkanediyl group and the alkyl group is -O-, -CO -, -S- or -SO ₂ -), a group combining an aromatic hydrocarbon group and an alicyclic hydrocarbon group (for example, an aromatic hydrocarbon group - an alicyclic hydrocarbon group) -*, alicyclic hydrocarbon group - aromatic hydrocarbon group -*, -CH ₂ - contained in the alicyclic hydrocarbon group is -O-, -CO-, -S- or -SO ₂ - may be replaced with ). * represents a binding site.
Examples of the aromatic hydrocarbon group -alkanediyl group-* include aralkyl groups such as benzyl group and phenethyl group.
Examples of the alkyl group - aromatic hydrocarbon group - * include tolyl group, xylyl group, cumenyl group and the like.
Alicyclic hydrocarbon group - alkanediyl group - * includes cyclohexylmethyl group, cyclohexylethyl group, 1-(adamantan-1-yl)methyl group, 1-(adamantan-1-yl)-1-methylethyl group Examples include cycloalkylalkyl groups such as.
Examples of the alkyl group-alicyclic hydrocarbon group-* include cycloalkyl groups having an alkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, and 2-alkyladamantane-2-yl group.
Examples of the aromatic hydrocarbon group - alicyclic hydrocarbon group -* include phenylcyclohexyl group and the like.
Examples of the alicyclic hydrocarbon group-aromatic hydrocarbon group-* include cyclohexylphenyl group and the like.
In addition, in the combination, two or more types of each of the alicyclic hydrocarbon group, aromatic hydrocarbon group, and chain hydrocarbon group may be combined. Moreover, any group may be bonded to Ar ¹ .

When -CH ₂ - contained in the haloalkyl group or hydrocarbon group represented by R ⁴ is replaced with -O-, -CO-, -S- or -SO ₂ -, the number of carbon atoms before substitution is The total number of carbon atoms in the haloalkyl group or the hydrocarbon group. Moreover, the number may be one, or two or more.
As a group in which -CH ₂ - contained in a haloalkyl group or a hydrocarbon group is replaced with -O-, -S-, -SO ₂ - or -CO-, a hydroxy group (-CH _{2 -} contained in a methyl group) - is replaced with -O-), thiol group (-CH ₂ - contained in the methyl group is replaced with -S-), carboxy group (-CH ₂ -CH contained in the ethyl group) ₂ - is replaced with -O-CO-), alkoxy group (a group in which -CH ₂ - at any position contained in an alkyl group is replaced with -O-), alkoxycarbonyl group (a group in which -O- is substituted for -CH 2 - contained in an alkyl group), -CH ₂ -CH ₂ - at any position contained in the alkyl group is replaced with -O-CO-), alkylcarbonyl group (-CH ₂ - contained at any position contained in the alkyl group is replaced with -CO- ), alkylcarbonyloxy group (a group in which -CH ₂ -CH 2 - contained in an alkyl group is replaced with -CO-O-), alkylthio group (a group in which -CH 2 -CH ₂ - contained in an alkyl group is replaced with -CO-O-), an alkylthio group (a group contained in an alkyl group) (a group in which -CH ₂ - at any position is replaced by -S-), an alkylsulfonyl group (a group in which -CH ₂ - at any position contained in an alkyl group is replaced by -SO ₂ -), oxy group (a group in which -CH ₂ - contained in a methylene group is replaced with -O-), a carbonyl group (a group in which -CH 2 - contained in a methylene group is replaced by -CO-), a thio group (a group in which -CH ₂ - contained in a methylene group is replaced with -CO-), -CH ₂ - contained in a methylene group is replaced with -S-), sulfonyl group (a group in which -CH ₂ - contained in a methylene group is replaced with -SO ₂ -), alkanediyloxy group (a group in which -CH ₂ - at any position contained in an alkanediyl group is replaced with -O-), an alkanediyloxycarbonyl group (a group in which -CH ₂ -CH ₂ at any position contained in an alkanediyl group) - is replaced with -O-CO-), alkanediylcarbonyl group (a group in which -CH ₂ - at any position contained in the alkanediyl group is replaced with -CO-), alkanediylcarbonyloxy group (a group in which -CH ₂ -CH ₂ - at any position contained in an alkanediyl group is replaced with -CO-O-), an alkanediylthio group (a group in which -CH 2 -CH 2 - at any position contained in an alkanediyl group is replaced with -CO-O-), ₂ - is replaced with -S-), alkanediylsulfonyl group (a group in which -CH ₂ - at any position contained in the alkanediyl group is replaced with -SO ₂ -), cycloalkoxy group, cyclo Alkylalkoxy group, alkoxycarbonyloxy group, aromatic hydrocarbon group-carbonyloxy group, aromatic hydrocarbon group-carbonyl group, aromatic hydrocarbon group-oxy group, haloalkoxy group (any position contained in haloalkyl group) -CH ₂ - is replaced with -O-), haloalkoxycarbonyl group (a group in which -CH ₂ -CH ₂ - at any position contained in the haloalkyl group is replaced with -O-CO-) , haloalkylcarbonyl group (a group in which -CH ₂ - at any position contained in the haloalkyl group is replaced with -CO-), haloalkylcarbonyloxy group (-CH ₂ -CH at any position contained in the haloalkyl group) _Examples include a group in which - is replaced with -CO-O-), a group in which two or more of these groups are combined, and the like.
Examples of the alkoxy group include alkoxy groups having 1 to 17 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, and nonyloxy group. group, decyloxy group, undecyloxy group, etc. The number of carbon atoms in the alkoxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3.
Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group, and the like. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 18 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as an acetyloxy group, a propionyloxy group, a butyryloxy group, and the like. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The alkylcarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3.
Examples of the alkylthio group include alkylthio groups having 1 to 17 carbon atoms, such as methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, hexylthio group, octylthio group, 2-ethylhexylthio group, nonylthio group, and decylthio group. group, undecylthio group, etc. The alkylthio group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 17 carbon atoms, such as methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, butylsulfonyl group, pentylsulfonyl group, hexylsulfonyl group, octylsulfonyl group, -Ethylhexylsulfonyl group, nonylsulfonyl group, decylsulfonyl group, undecylsulfonyl group, etc. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3.
Examples of the alkanediyloxy group include alkanediyloxy groups having 1 to 17 carbon atoms, such as methyleneoxy group, ethyleneoxy group, propanediyloxy group, butanediyloxy group, pentanediyloxy group, and the like. The alkanediyloxy group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the alkanediyloxycarbonyl group include alkanediyloxycarbonyl groups having 2 to 17 carbon atoms, such as methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propanediyloxycarbonyl group, butanediyloxycarbonyl group, etc. . Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 18 carbon atoms, such as methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, pentanediylcarbonyl group, and the like. Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 17 carbon atoms, such as methylenecarbonyloxy group, ethylenecarbonyloxy group, propanediylcarbonyloxy group, butanediylcarbonyloxy group, etc. . The alkanediyloxycarbonyl group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms. The alkanediylcarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms. The alkanediylcarbonyloxy group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms.
Examples of the alkanediylthio group include an alkanediylthio group having 1 to 17 carbon atoms, such as a methylenethio group, an ethylenethio group, a propylenethio group, and the like. The alkanediylthio group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the alkanediylsulfonyl group include an alkanediylsulfonyl group having 1 to 17 carbon atoms, such as a methylenesulfonyl group, an ethylenesulfonyl group, a propylenesulfonyl group, and the like. The alkanediylsulfonyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 17 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include a cycloalkylalkoxy group having 4 to 17 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as butoxycarbonyloxy groups. Examples of the aromatic hydrocarbon group-carbonyloxy group include an aromatic hydrocarbon group-carbonyloxy group having 7 to 17 carbon atoms, such as a benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include an aromatic hydrocarbon group-carbonyl group having 7 to 18 carbon atoms, such as a benzoyl group. The aromatic hydrocarbon group-oxy group includes an aromatic hydrocarbon group-oxy group having 6 to 17 carbon atoms, such as a phenyloxy group.
Examples of the haloalkoxy group, haloalkoxycarbonyl group, haloalkylcarbonyl group, and haloalkylcarbonyloxy group include a haloalkoxy group having 1 to 11 carbon atoms, a haloalkoxycarbonyl group having 2 to 11 carbon atoms, and a haloalkylcarbonyl group having 2 to 12 carbon atoms. , a haloalkylcarbonyloxy group having 2 to 11 carbon atoms, and for example, a group in which one or more hydrogen atoms of the groups exemplified above are replaced with a halogen atom.

In addition, examples of groups in which -CH ₂ - contained in the alicyclic hydrocarbon group are replaced with -O-, -S-, -SO ₂ - or -CO- include the groups shown below. . Also included are groups in which -O- is replaced by -S-, and -CO- is replaced by -SO ₂ -, among the groups shown below. The binding site can be at any position.

Examples of the substituent that the hydrocarbon group of R ⁴ may have include a halogen atom and a cyano group.
Examples of the halogen atom include the same groups as those described above.
The hydrocarbon group may have one substituent or multiple substituents.
R ⁴ is a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms (-CH ₂ - contained in the alkyl group or haloalkyl group is replaced with -O- or -CO-); ), preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms (-CH ₂ - contained in the alkyl group may be replaced with -O- or -CO-). ) or a haloalkyl group having 1 to 4 carbon atoms, such as an iodine atom, a fluorine atom, a hydroxy group, an alkoxy group having 1 to 3 carbon atoms, a hydroxyalkyl group having 1 to 3 carbon atoms, a carboxy group, or a haloalkyl group having 1 to 3 carbon atoms. It is more preferably a fluorinated alkyl group having 1 to 3 carbon atoms, and even more preferably an iodine atom, a fluorine atom, a hydroxy group, a methoxy group, an ethoxy group, a carboxy group, or a perfluoroalkyl group having 1 to 3 carbon atoms. Even more preferred are an iodine atom, a fluorine atom, a hydroxy group, a methoxy group, or a trifluoromethyl group.
Among these, R ⁴ is preferably a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, an iodine atom, or a hydroxy group, and when there are two or more R ⁴ , at least one is a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms. -6 fluorinated alkyl groups are preferred.
m4 is preferably an integer of 0 to 6, more preferably an integer of 0 to 4, and even more preferably 0, 1 or 2. When m4 is 2 or more, two or more R ⁴ 's may be the same or different.

Examples of the anion (I) include anions represented by the following formulas (Ia-1) to (Ia-50). Among these, anions represented by formulas (Ia-1) to (Ia-25) and formulas (Ia-41) to (Ia-50) are preferred.

［式（ｂ２－１）～式（ｂ２－４）中、
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、炭素数１～１８の脂肪族炭化水素基、炭素数１～１２のフッ化アルキル基又は炭素数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、ハロゲン原子、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基、炭素数１～１２のフッ化アルキル基又は炭素数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、該鎖式炭化水素基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、ハロゲン原子、ヒドロキシ基、炭素数１～１２の脂肪族炭化水素基、炭素数１～１２のフッ化アルキル基又は炭素数１～１２のアルコキシ基を表す。
Ｒ^b13とＲ^b14とは、互いに結合してそれらが結合するベンゼン環と一緒になって硫黄原子を含む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。
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。］
ｕ２が０のとき、ｏ２、ｐ２、ｑ２及びｒ２のうちいずれか１つは１以上であり、Ｒ^b13～Ｒ^b1６のうち少なくとも１つはハロゲン原子であることが好ましく、ｕ２が１のとき、ｏ２、ｐ２、ｓ２、ｔ２、ｑ２及びｒ２のうちいずれか１つは１以上であり、Ｒ^b13～Ｒ^b18のうち少なくとも１つはハロゲン原子であることが好ましい。
さらに、ｕ２が０のとき、ｒ２は１以上であることが好ましく、１であることがさらに好ましい。また、ｕ２が０、かつ、ｒ２が１以上のとき、Ｒ^ｂ１６がハロゲン原子であることが好ましい。 [Cation (I)]
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.

[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, such as a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or a fluorinated alkyl group having 1 to 12 carbon atoms. It may be substituted with 1 to 12 alkoxy groups.
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 halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl 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 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. Optionally 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 halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms .
R ^b13 and R ^b14 may be bonded to each other to form a ring containing a sulfur atom together with the benzene ring to which they are bonded, and -CH ₂ - contained in the ring is -O-, It may be replaced with -S- or -CO-.
L ^b31 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represent any integer from 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. ]
When u2 is 0, any one of o2, p2, q2 and r2 is 1 or more, at least one of R ^b13 to R ^b16 is preferably a halogen atom, and when u2 is 1, It is preferable that any one of o2, p2, s2, t2, q2 and r2 is 1 or more, and at least one of R ^b13 to R ^b18 is a halogen atom.
Further, when u2 is 0, r2 is preferably 1 or more, and more preferably 1. Further, when u2 is 0 and r2 is 1 or more, R ^b16 is preferably a halogen atom.

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.

The fluorinated alkyl group refers to an alkyl group having 1 to 12 carbon atoms and having a fluorine atom, and includes a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group, and the like. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 9, more preferably 1 to 6, and still more preferably 1 to 4.

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 (tolyl group, xylyl group, cumenyl group, mesityl group) group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and an aromatic hydrocarbon group having an alicyclic 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 the 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 thiolane-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring, 1,4-oxathian-4-ium ring, and the like.
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.

カチオン（ｂ２－２）としては、以下のカチオンが挙げられる。

カチオン（ｂ２－３）としては、以下のカチオンが挙げられる。

カチオン（ｂ２－４）としては、以下のカチオンが挙げられる。

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.

Specific examples of the salt (I) include salts obtained by arbitrarily combining the above-mentioned cations and anions. Specific examples of salt (I) are shown in the table below.
In the table below, each code represents the code attached to the structure representing the above-mentioned anion or cation, and "~" indicates that the salt (I) and the anion (I) correspond to each other. For example, salt (I-1) is a salt consisting of an anion represented by formula (I-a-1) and a cation represented by formula (b2-c-1), and salt (I-2) is formed by formula ( A salt consisting of an anion represented by I-a-2) and a cation represented by formula (b2-c-1), salt (I-31) is a salt consisting of an anion represented by formula (I-a-1) and a cation represented by formula (b2-c-1) (b2-c-10) represents a salt consisting of the cation shown by (b2-c-10).

Among them, salts (I) include salts (I-1) to salts (I-25), salts (I-31) to salts (I-55), and salts (I-61) to salts (I-85). ), salt (I-91) to salt (I-115), salt (I-121) to salt (I-145), salt (I-151) to salt (I-175), salt (I-181) ~ Salt (I-205), Salt (I-211) ~ Salt (I-235), Salt (I-241) ~ Salt (I-265), Salt (I-271) ~ Salt (I-295), Salt (I-301) ~ Salt (I-325), Salt (I-331) ~ Salt (I-355), Salt (I-361) ~ Salt (I-385), Salt (I-391) ~ Salt (I-415), salt (I-421) to salt (I-445), salt (I-451) to salt (I-475), salt (I-723) to salt (I-882) is preferred.
The salt represented by formula (I) can be produced by a conventionally known method, for example, can be synthesized by the method described in JP 2018-120218A.

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

The compound (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 benzenesulfonyl anion, a sulfonylimide anion, a sulfonylmethide anion, and a carboxylic acid anion.

As the compound (B), JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-Sho. 62-153853, JP 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. Compounds that generate acids upon exposure to radiation can be used. Moreover, you may use the compound manufactured by the well-known method. Compound (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、水素原子、フッ素原子、炭素数１～６のアルキル基又は炭素数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、該飽和炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよく、該飽和炭化水素基に含まれる水素原子は、フッ素原子又はヒドロキシ基で置換されていてもよい。
Ｙは、置換基を有していてもよいメチル基又は置換基を有していてもよい炭素数３～２４の環状炭化水素基を表し、該環状炭化水素基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－、－ＳＯ_２－又は－ＣＯ－に置き換わっていてもよい。
Ｚ１^＋は、有機カチオンを表す。］ Compound (B) is preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "salt (B1)", excluding salt (I)) or a salt represented by formula (B2) (hereinafter sometimes referred to as "salt (B2)").

[In formula (B1),
Q ^b1 and Q ^b2 each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, or a perfluoroalkyl group having 1 to 6 carbon atoms.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, -CH ₂ - contained in the saturated hydrocarbon group may be replaced with -O- or -CO-, and the saturated The hydrogen atom contained in the hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents a methyl group which may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH ₂ - contained in the cyclic hydrocarbon group is , -O-, -S-, -SO ₂ - or -CO-.
Z1 ⁺ represents an organic cation. ]

The perfluoroalkyl groups of 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 perfluorobutyl group. Examples include hexyl group.
Examples of the alkyl group for Q ^b1 and Q ^b2 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, and the like.
Q ^b1 and Q ^b2 preferably contain a fluorine atom or a perfluoroalkyl group in at least one of Q ^b1 and Q ^b2 , each independently more preferably a fluorine atom or a perfluoroalkyl group, and each independently contains a fluorine atom or a perfluoroalkyl group. More preferably, it is a fluoromethyl group, and even 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. The terminal of the branched alkanediyl group may be a methyl group.

As a group in which -CH ₂ - contained in the saturated hydrocarbon group represented by L ^b1 is replaced with -O- or -CO-, for example, any of formulas (b1-1) to (b1-3) Examples include groups represented by: 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; * represents a binding site 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。］

[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. ]

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, a methylene group, -CH(CF ₃ )-, or -C(CF ₃ ) ₂ -.
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, the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, a methylene group, - CH(CF ₃ )- and -C(CF ₃ ) ₂ - are preferred.
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-.

［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。］
Ｌ^ｂ８は、好ましくは炭素数１～４の２価の飽和炭化水素基である。
Ｌ^ｂ９は、好ましくは炭素数１～８の２価の飽和炭化水素基である。
Ｌ^ｂ１０は、好ましくは単結合又は炭素数１～１９の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１～８の２価の飽和炭化水素基である。
Ｌ^ｂ１１は、好ましくは炭素数１～８の２価の飽和炭化水素基である。
Ｌ^ｂ１２は、好ましくは単結合又は炭素数１～８の２価の飽和炭化水素基である。
Ｌ^ｂ１３は、好ましくは炭素数１～１２の２価の飽和炭化水素基である。
Ｌ^ｂ１４は、好ましくは単結合又は炭素数１～６の２価の飽和炭化水素基である。
Ｌ^ｂ１５は、好ましくは単結合又は炭素数１～１８の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１～８の２価の飽和炭化水素基である。
Ｌ^ｂ１６は、好ましくは炭素数１～１２の２価の飽和炭化水素基である。
Ｌ^ｂ１７は、好ましくは炭素数１～６の２価の飽和炭化水素基である。
Ｌ^ｂ１８は、好ましくは単結合又は炭素数１～１７の２価の飽和炭化水素基であり、より好ましくは単結合又は炭素数１～４の２価の飽和炭化水素基である。 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
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. ]
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, 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。］ 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. ]

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.

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

Examples of the group represented by formula (b1-5) include the following.

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

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

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

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

Examples of the group represented by formula (b1-9) include the following.

Examples of the group represented by formula (b1-10) include the following.

Examples of the group represented by formula (b1-11) include the following.

Examples of the cyclic hydrocarbon group represented by Y include an alicyclic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic aromatic hydrocarbon group, or a combination thereof.
Examples of the alicyclic hydrocarbon group represented by Y in which -CH ₂ - contained in the alicyclic hydrocarbon group is not replaced with -O-, -S-, -SO ₂ - or -CO-, Examples 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-, -SO ₂ - or -CO-, the number may be one, or two or more. But that's fine. Examples of such groups include groups represented by formulas (Y12) to (Y35) and formulas (Y39) to (Y43). -O- or -CO- in the groups represented by formulas (Y12) to (Y35) and formulas (Y39) to (Y43) may be replaced with -S- or -SO ₂ -. * represents the binding site with L ^b1 .

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 (Y43), more preferably Formula (Y11), Formula (Y15), Formula (Y16), Formula (Y20), Formula (Y26), Formula (Y27), Formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42), or formula (Y43), more preferably formula (Y11), formula (Y15), or formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43). .
The alicyclic hydrocarbon group represented by Y is a spiro ring having an oxygen atom such as formula (Y28) to formula (Y35), formula (Y39), formula (Y40), formula (Y42) or formula (Y43), In some cases it is preferred that the alkanediyl group between two oxygen atoms 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.
The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 24, more preferably 3 to 20, still more preferably 3 to 18, and even more preferably 3 to 16.

Examples of the aromatic hydrocarbon group represented by Y include phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, and binaphthyl group. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 24, more preferably 6 to 20, still more preferably 6 to 18, even more preferably 6 to 14, and even more preferably It is 6-10.
Examples of the heterocyclic aromatic hydrocarbon group represented by Y include groups derived from a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, and the like. The heterocyclic aromatic hydrocarbon group preferably has 4 to 9 carbon atoms, more preferably 4 to 8 carbon atoms.
The aromatic hydrocarbon group or heterocyclic aromatic hydrocarbon group represented by Y is preferably a group derived from a phenyl group, a naphthyl group, a furan ring or a thiophene ring, and more preferably a phenyl group. preferable.

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, an alkyl group having 3 to 16 carbon atoms, Represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these. ja represents any integer of 0 to 4. The alkyl group and the alicyclic carbon -CH ₂ - contained in the hydrogen group may be replaced with -O-, -SO ₂ - or -CO-, and -CH 2 - contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group The hydrogen atom may be replaced with a hydroxy group or a fluorine atom).
Substituents for the cyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, and an alkyl group having 1 to 16 carbon atoms which may be substituted with a hydroxy group (-CH ₂ - contained in the alkyl group) , -O- or -CO-), alicyclic hydrocarbon group having 3 to 16 carbon atoms, aromatic hydrocarbon group having 6 to 18 carbon atoms, aralkyl group having 7 to 21 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 having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these. ja represents any integer of 0 to 4. The alkyl -CH ₂ - contained in the group and the alicyclic hydrocarbon group may be replaced with -O-, -SO ₂ - or -CO-, and -CH 2 - contained in the alkyl group, the alicyclic hydrocarbon group and the alicyclic hydrocarbon group The hydrogen atom contained in the aromatic hydrocarbon group may be replaced with a hydroxy group or a fluorine atom).

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. The alicyclic hydrocarbon group may have a chain hydrocarbon group, and examples thereof include a methylcyclohexyl group and a dimethylcyclohexyl group. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms, more preferably 3 to 10 carbon atoms.
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 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-methylphenyl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group), and carbon Examples include aromatic hydrocarbon groups having 3 to 18 alicyclic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.). The aromatic hydrocarbon group preferably has 6 to 14 carbon atoms, more preferably 6 to 10 carbon atoms.
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. The alkyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms.
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 aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Groups in which -CH ₂ - contained in an alkyl group is replaced with -O-, -S-, -SO ₂ -, -CO-, etc. include an alkoxy group, an alkylsulfonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkyl Examples include a carbonyloxy group or a combination thereof.
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. The alkoxy group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and still more preferably 1 to 4 carbon atoms.
Examples of the alkylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, and a propylsulfonyl group. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 12, more preferably 1 to 6, and still more preferably 1 to 4.
Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. The alkoxycarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and still more preferably 2 to 4 carbon atoms.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and still more preferably 2 to 4 carbon atoms.
Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, and the like. The alkylcarbonyloxy group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and still more preferably 2 to 4 carbon atoms.
Examples of combined groups include a group that combines an alkoxy group and an alkyl group, a group that combines an alkoxy group and an alkoxy group, a group that combines an alkoxy group and an alkylcarbonyl group, and a group that combines an alkoxy group and an alkylcarbonyloxy group. Examples include groups that combine these.
Examples of the group combining an alkoxy group and an alkyl group include alkoxyalkyl groups such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, and an ethoxymethyl group. The number of carbon atoms in the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4.
Examples of the group combining an alkoxy group and an alkoxy group include alkoxyalkoxy groups such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, and an ethoxyethoxy group. The number of carbon atoms in the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4.
Examples of the group combining an alkoxy group and an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group, and an ethoxypropionyl group. The number of carbon atoms in the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and still more preferably 3 to 5.
Examples of the group combining an alkoxy group and an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, and an ethoxypropionyloxy group. The number of carbon atoms in the alkoxyalkylcarbonyloxy group is preferably 3 to 13, more preferably 3 to 7, and still more preferably 3 to 5.
Groups in which -CH ₂ - contained in the alicyclic hydrocarbon group is replaced with -O-, -SO ₂ -, or -CO-, etc. include formulas (Y12) to (Y35), formulas (Y39) to Examples include a group represented by (Y43).

［式（ｗ１－１）～式（ｗ１－３２）中、
該基に含まれる－ＣＨ₂－は、－Ｏ－、－Ｓ－、－ＣＯ－又は－ＳＯ_２－に置き換わっていてもよい。結合部位は任意の位置である。］ The cyclic hydrocarbon group in Y (-CH ₂ - contained in the cyclic hydrocarbon group may be replaced with -O-, -CO-, -S- or -SO ₂ -) is, among others, An alicyclic hydrocarbon group having 3 to 24 carbon atoms (even if -CH ₂ - contained in the alicyclic hydrocarbon group is replaced with -O-, -CO-, -S- or -SO ₂ -) ) or an aromatic hydrocarbon group having 6 to 24 carbon atoms, and an alicyclic hydrocarbon group having 3 to 20 carbon atoms (-CH ₂ - contained in the alicyclic hydrocarbon group is preferably -O-, -CO-, -S- or -SO ₂ -) or an aromatic hydrocarbon group having 6 to 20 carbon atoms, more preferably an aromatic hydrocarbon group having 3 to 18 carbon atoms. Cyclic hydrocarbon group (-CH ₂ - contained in the alicyclic hydrocarbon group may be replaced with -O-, -CO-, -S- or -SO ₂ -) or carbon number 6 More preferably, it is an aromatic hydrocarbon group of ˜18. Specifically, a group represented by any one of formulas (w1-1) to (w1-32) is preferable, and groups represented by formulas (w1-1) to (w1-6) and formula (w1-32) are preferable. 12) ~Formula (w1-30) It is more preferable to be a group represented by any one of formula (w1-1) ~ formula (w1-3), formula (w1-15) ~ formula (w1-17) ), formula (w1-22), formula (w1-25), and any one of formulas (w1-27) to (w1-29) are more preferable. Here, the cyclic hydrocarbon group may have a substituent.

[In formulas (w1-1) to (w1-32),
-CH ₂ - contained in the group may be replaced with -O-, -S-, -CO- or -SO ₂ -. The binding site can be at any position. ]

Ｙは、なかでも、好ましくはアダマンチル基、ヒドロキシアダマンチル基、オキソアダマンチル基、ノルボルナンラクトン基、フェニル基、これらを含む基又は式（Ｙ４２）、式（Ｙ１００）～式（Ｙ１１４）、式（Ｙ１３４）～式（Ｙ１３９）で表される基であり、特に好ましくは、ヒドロキシアダマンチル基、オキソアダマンチル基、これらを含む基又は式（Ｙ４２）、式（Ｙ１００）～式（Ｙ１１４）、式（Ｙ１３４）～式（Ｙ１３９）で表される基である。
式（Ｂ１）で表される塩におけるアニオンとしては、式（Ｂ１－Ａ－１）～式（Ｂ１－Ａ－８５）で表されるアニオン〔以下、式番号に応じて「アニオン（Ｂ１－Ａ－１）」等という場合がある。〕が好ましく、式（Ｂ１－Ａ－１）～式（Ｂ１－Ａ－４）、式（Ｂ１－Ａ－９）、式（Ｂ１－Ａ－１０）、式（Ｂ１－Ａ－２４）～式（Ｂ１－Ａ－３３）、式（Ｂ１－Ａ－３６）～式（Ｂ１－Ａ－４０）、式（Ｂ１－Ａ－４７）～式（Ｂ１－Ａ－８５）のいずれかで表されるアニオンがより好ましい。

Y is preferably an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent or an aromatic hydrocarbon group having 6 to 24 carbon atoms which may have a substituent, More preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent or an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent. is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, and more preferably , a cycloalkyl group having 5 or 6 carbon atoms, a norbornyl group, an adamantyl group, a norbornane lactone group, an adamantane lactone group, a lipid in which a cycloalkyl group having 5 or 6 carbon atoms and a cycloalkyl group having 5 to 8 carbon atoms are bonded by spiro. Cyclic hydrocarbon group, alicyclic hydrocarbon group in which a norbornyl group and a cycloalkyl group having 5 to 8 carbon atoms are bonded via a spiro, an alicyclic group in which an adamantyl group and a cycloalkyl group having 5 to 8 carbon atoms are bonded via a spiro bond. It is a hydrocarbon group or a phenyl group. Here, the alicyclic hydrocarbon group, the cycloalkyl group, the norbornyl group, the adamantyl group, the norbornane lactone group, the adamantane lactone group, and the phenyl group each may have a substituent. , -CH ₂ - contained in the alicyclic hydrocarbon group, the cycloalkyl group, the norbornyl group and the adamantyl group is replaced with -O-, -S-, -SO ₂ - or -CO-, respectively. You can leave it there.
Specific examples of Y include the following.

Y is, among others, preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, a norbornane lactone group, a phenyl group, a group containing these, or a formula (Y42), a formula (Y100) to a formula (Y114), a formula (Y134) - A group represented by the formula (Y139), particularly preferably a hydroxyadamantyl group, an oxoadamantyl group, a group containing these, or a group containing these, or the formula (Y42), the formula (Y100) - the formula (Y114), the formula (Y134) - It is a group represented by formula (Y139).
Anions in the salt represented by formula (B1) include anions represented by formulas (B1-A-1) to (B1-A-85) [hereinafter referred to as "anion (B1-A-85)" 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-85) 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の鎖式炭化水素基、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^Ａ４１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 a chain 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 ^A41 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-70), respectively.

［式（Ｂ２）中、
ｍ２１は、１～５のいずれかの整数を表し、ｍ２１が２以上のとき、複数の括弧内の基は互いに同一であっても異なってもよい。
Ｒ²¹は、炭素数３～１８の環状炭化水素基を含む炭素数３～４８の炭化水素基を表し、該環状炭化水素基は、置換基を有してもよく、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。
Ｒ^2２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－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
ｍ２２は、０～４のいずれかの整数を表し、ｍ２２が２以上のとき、複数のＲ^2２は互いに同一であっても異なってもよい。
Ｚ１^＋は、有機カチオンを表す。］

[In formula (B2),
m21 represents any integer from 1 to 5, and when m21 is 2 or more, the groups within the parentheses may be the same or different.
R ²¹ represents a hydrocarbon group having 3 to 48 carbon atoms, including a cyclic hydrocarbon group having 3 to 18 carbon atoms, and the cyclic hydrocarbon group may have a substituent, and the cyclic hydrocarbon group may have a substituent. -CH ₂ - may be replaced with -O-, -S-, -SO ₂ - or -CO-.
R ²² 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-.
m22 represents any integer from 0 to 4, and when m22 is 2 or more, a plurality of R ^22s may be the same or different.
Z1 ⁺ represents an organic cation. ]

In formula (B2), the hydrocarbon group containing a cyclic hydrocarbon group in R ²¹ is a cyclic hydrocarbon group such as a monocyclic or polycyclic alicyclic hydrocarbon group and an aromatic hydrocarbon group, or a cyclic hydrocarbon group containing these. A combination of a monocyclic or polycyclic alicyclic hydrocarbon group, a cyclic hydrocarbon group such as an aromatic hydrocarbon group, and a chain hydrocarbon group (alkyl group, alkenyl group, alkynyl group, etc.) is optional. Examples include groups combined with . The number of carbon atoms in the cyclic hydrocarbon group in R ²¹ is, for example, 3 to 24, preferably 3 to 20, more preferably 3 to 18, even more preferably 3 to 16, and even more preferably 5 to 16. The total carbon number of the hydrocarbon groups including the cyclic hydrocarbon group in R ²¹ is, for example, 3 to 48, preferably 3 to 40, more preferably 3 to 36, even more preferably 3 to 30, and 3 to 24. is even more preferred, 3 to 18 is even more preferred, and 3 to 16 is even more preferred.

より具体的に、脂環式炭化水素基としては、以下に表される基等が挙げられる。＊は結合部位を表す。

脂環式炭化水素基の炭素数は、好ましくは３～２４であり、より好ましくは３～１８であり、さらに好ましくは３～１６であり、さらにより好ましくは５～１６である。
芳香族炭化水素基としては、フェニル基、ナフチル基、ビフェニル基、アントリル基、フェナントリル基、ビナフチル基等のアリール基等が挙げられる。芳香族炭化水素基の炭素数は、好ましくは６～２４であり、より好ましくは６～１８であり、さらに好ましくは６～１４であり、さらにより好ましくは６～１０である。 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, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, and cyclododecyl group; Examples include polycyclic cycloalkyl groups such as decahydronaphthyl, norbornyl, and adamantyl groups.
Specifically, examples of the alicyclic hydrocarbon group include the groups shown below. The binding site can be at any position.

More specifically, examples of the alicyclic hydrocarbon group include the groups shown below. * represents a binding site.

The alicyclic hydrocarbon group preferably has 3 to 24 carbon atoms, more preferably 3 to 18 carbon atoms, still more preferably 3 to 16 carbon atoms, and even more preferably 5 to 16 carbon atoms.
Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, and binaphthyl group. The aromatic hydrocarbon group preferably has 6 to 24 carbon atoms, more preferably 6 to 18 carbon atoms, still more preferably 6 to 14 carbon atoms, and even more preferably 6 to 10 carbon atoms.

Examples of alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, and dodecyl group. Examples include alkyl groups such as groups.
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 octenyl group, an isooctenyl 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 number of carbon atoms in the chain hydrocarbon group is preferably 1 to 24, more preferably 1 to 18, even more preferably 1 to 12, even more preferably 1 to 8, and even more preferably The number is 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.

As a combined group,
A group that combines an alicyclic hydrocarbon group and an aromatic hydrocarbon group, a group that combines an alicyclic hydrocarbon group and a chain hydrocarbon group, a group that combines an aromatic hydrocarbon group and a chain hydrocarbon group Examples include groups such as a group consisting of a combination of an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a chain hydrocarbon group. Here, -CH ₂ - contained in the combined group may be replaced with -O-, -S-, -CO- or -SO ₂ -.
In addition, in the combination, two or more types of alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined. Moreover, any group may be bonded to an oxygen atom. Further, the above-mentioned groups may contain groups having different valences (alkanediyl group, alkanetriyl group, cycloalkanediyl group, cycloalkanetriyl group, etc.).

Specific examples of combined groups include:
Alicyclic hydrocarbon groups - chain hydrocarbon groups - * (included in the chain hydrocarbon group and the alicyclic hydrocarbon group) such as adamantylmethyl group, adamantylethyl group, cyclohexylmethyl group, cyclohexylethyl group, etc. -CH ₂ - may be replaced with -O-, -S-, -CO- or -SO ₂ -),
Chain hydrocarbon group - alicyclic hydrocarbon group - * (-CH ₂ - contained in the chain hydrocarbon group and the alicyclic hydrocarbon group) such as methyladamantyl group, methylcyclohexyl group, dimethylcyclohexyl group, etc. may be replaced with -O-, -S-, -CO- or -SO ₂ -.)
Chain hydrocarbon groups such as tolyl group and xylyl group - aromatic hydrocarbon group -* (-CH ₂ - contained in the chain hydrocarbon group is -O-, -S-, -CO- or - may be replaced with SO ₂ -),
Chain hydrocarbon group - alicyclic hydrocarbon group - chain hydrocarbon group - *(-CH ₂ - contained in the chain hydrocarbon group and the alicyclic hydrocarbon group) such as methylcyclohexylmethyl group , -O-, -S-, -CO- or -SO ₂ -).
Aromatic hydrocarbon group - chain hydrocarbon group - such as benzyl group, phenethyl group -* (-CH ₂ - contained in the chain hydrocarbon group is -O-, -S-, -CO- or - may be replaced with SO ₂ -),
Chain hydrocarbon group such as tolylmethyl group - aromatic hydrocarbon group - chain hydrocarbon group -* (-CH ₂ - contained in the chain hydrocarbon group is -O-, -S-, -CO - or -SO ₂ - may be substituted.),
An aromatic hydrocarbon group such as a phenyladamantyl group - an alicyclic hydrocarbon group -* (-CH ₂ - contained in the alicyclic hydrocarbon group is -O-, -S-, -CO- or - may be replaced with SO ₂ -),
Alicyclic hydrocarbon group - aromatic hydrocarbon group - such as cyclohexylphenyl group, adamantyl phenyl group -* (-CH ₂ - contained in the alicyclic hydrocarbon group is -O-, -S-, - may be replaced with CO- or -SO ₂ -),
Chain hydrocarbon group - alicyclic hydrocarbon group - aromatic hydrocarbon group - * (included in the chain hydrocarbon group and the alicyclic hydrocarbon group) such as methylcyclohexylphenyl group and dimethylcyclohexylphenyl group -CH ₂ - may be replaced with -O-, -S-, -CO- or -SO ₂ -),
Chain hydrocarbon group - aromatic hydrocarbon group - alicyclic hydrocarbon group - * (included in the chain hydrocarbon group and the alicyclic hydrocarbon group) such as methylphenylcyclohexyl group and dimethylphenylcyclohexyl group -CH ₂ - may be replaced with -O-, -S-, -CO- or -SO ₂ -),
Alicyclic hydrocarbon group - chain hydrocarbon group - aromatic hydrocarbon group - * (included in the chain hydrocarbon group and the alicyclic hydrocarbon group) such as cyclohexylmethylphenyl group and cyclohexylethylphenyl group -CH ₂ - may be replaced with -O-, -S-, -CO- or -SO ₂ -),
Aromatic hydrocarbon group - Chain hydrocarbon group - Alicyclic hydrocarbon group - * (included in the chain hydrocarbon group and the alicyclic hydrocarbon group) such as phenylmethylcyclohexyl group and phenylethylcyclohexyl group -CH ₂ - may be replaced with -O-, -S-, -CO- or -SO ₂ -),
Alicyclic hydrocarbon group - aromatic hydrocarbon group - chain hydrocarbon group - * (included in the chain hydrocarbon group and the alicyclic hydrocarbon group) such as cyclohexyl phenylmethyl group, cyclohexyl phenylethyl group, etc. -CH ₂ - may be replaced with -O-, -S-, -CO- or -SO ₂ -),
Aromatic hydrocarbon group - alicyclic hydrocarbon group - chain hydrocarbon group - * (included in the chain hydrocarbon group and the alicyclic hydrocarbon group) such as phenylcyclohexylmethyl group and phenylcyclohexylethyl group -CH ₂ - may be replaced with -O-, -S-, -CO- or -SO ₂ -),
etc. Here, * represents a bonding site with an oxygen atom.

より具体的に、脂環式炭化水素基に含まれる－ＣＨ_２－が、－Ｏ－、－Ｓ－、－ＣＯ－又は－ＳＯ_２－で置き換わった基としては、以下に表される基等が挙げられる。＊は結合部位を表す。

When -CH ₂ - contained in the hydrocarbon group represented by R ²¹ is replaced with -O-, -S-, -CO- or -SO ₂ -, the number of carbon atoms before substitution is the same as that of the hydrocarbon group. The total number of carbon atoms is Further, the number may be one, or two or more.
As a group in which -CH ₂ - contained in a hydrocarbon group is replaced with -O-, -S-, -CO- or -SO ₂ -, a hydroxy group (-CH ₂ - contained in a methyl group is replaced with -O-, -S-, -CO- or -SO 2 -) (a group in which -CH 2 - contained in a methyl group is replaced with -S-), a thiol group (a group in which -CH ₂ - contained in a methyl group is replaced with -S-), a carboxy group (a group in which -CH ₂ -CH ₂ - contained in an ethyl group is , -O-CO-), alkoxy groups (groups in which -CH ₂ - at any position in the alkyl group is replaced with -O-), alkylthio groups (any group in the alkyl group, in which -CH 2 - is replaced with -O-), (a group in which -CH ₂ - at the position is replaced with -S-), an alkoxycarbonyl group (a group in which -CH ₂ -CH ₂ - at any position contained in the alkyl group is replaced by -O-CO-) ), alkylcarbonyl group (a group in which -CH ₂ - contained in an alkyl group is replaced with -CO-), an alkylsulfonyl group (a group in which -CH ₂ - contained in an arbitrary position in an alkyl group is replaced with -CO-), , -SO ₂ -), alkylcarbonyloxy group (a group in which -CH ₂ -CH ₂ - at any position in the alkyl group is replaced with -CO-O-), oxy group (methylene (a group in which -CH ₂ - contained in the group is replaced with -O-), a carbonyl group (a group in which -CH ₂ - contained in a methylene group is replaced with -CO-), a thio group (a group in which -CH 2 - contained in a methylene group is replaced with -CO-), -CH ₂ - contained in the methylene group is replaced with -S-), sulfonyl group (a group in which -CH ₂ - contained in the methylene group is replaced with -SO ₂ -), alkanediyloxy group (alkanediyl -CH ₂ - at any position contained in the group is replaced with -O-), alkanediyloxycarbonyl group (-CH ₂ -CH ₂ - contained at any position contained in the alkanediyl group is replaced with -O-, -O-CO-), alkanediylcarbonyl group (group in which -CH ₂ - at any position in the alkanediyl group is replaced with -CO-), alkanediylcarbonyloxy group (alkanediyl -CH ₂ -CH ₂ - at any position contained in the group is replaced with -CO-O-), an alkanediylthio group (a group in which -CH ₂ - contained at any position contained in the alkanediyl group is replaced with -CO-O-) , -S-), alkanediylsulfonyl group (group in which -CH ₂ - at any position contained in the alkanediyl group is replaced with -SO ₂ -), cycloalkoxy group, cycloalkylalkoxy group , an alkoxycarbonyloxy group, an aromatic hydrocarbon group-carbonyloxy group, an aromatic hydrocarbon group-carbonyl group, an aromatic hydrocarbon group-oxy group, and a group combining two or more of these groups. .
Examples of the alkoxy group include alkoxy groups having 1 to 17 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, and nonyloxy group. group, decyloxy group, undecyloxy group, etc. The number of carbon atoms in the alkoxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3.
Examples of the alkylthio group include alkylthio groups having 1 to 17 carbon atoms, such as methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, hexylthio group, octylthio group, 2-ethylhexylthio group, nonylthio group, and decylthio group. group, undecylthio group, etc. The alkylthio group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group, and the like. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 18 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as an acetyloxy group, a propionyloxy group, a butyryloxy group, and the like. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The alkylcarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3.
Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 17 carbon atoms, such as methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, butylsulfonyl group, pentylsulfonyl group, hexylsulfonyl group, octylsulfonyl group, -Ethylhexylsulfonyl group, nonylsulfonyl group, decylsulfonyl group, undecylsulfonyl group, etc. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3.
Examples of the alkanediyloxy group include alkanediyloxy groups having 1 to 17 carbon atoms, such as methyleneoxy group, ethyleneoxy group, propanediyloxy group, butanediyloxy group, pentanediyloxy group, and the like. The alkanediyloxy group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the alkanediyloxycarbonyl group include alkanediyloxycarbonyl groups having 2 to 17 carbon atoms, such as methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propanediyloxycarbonyl group, butanediyloxycarbonyl group, etc. . Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 18 carbon atoms, such as methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, pentanediylcarbonyl group, and the like. Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 17 carbon atoms, such as methylenecarbonyloxy group, ethylenecarbonyloxy group, propanediylcarbonyloxy group, butanediylcarbonyloxy group, etc. . The alkanediyloxycarbonyl group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms. The alkanediylcarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms. The alkanediylcarbonyloxy group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, still more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms.
Examples of the alkanediylthio group include an alkanediylthio group having 1 to 17 carbon atoms, such as a methylenethio group, an ethylenethio group, a propylenethio group, and the like. The alkanediylthio group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the alkanediylsulfonyl group include an alkanediylsulfonyl group having 1 to 17 carbon atoms, such as a methylenesulfonyl group, an ethylenesulfonyl group, a propylenesulfonyl group, and the like. The alkanediylsulfonyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 17 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include a cycloalkylalkoxy group having 4 to 17 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as butoxycarbonyloxy groups. Examples of the aromatic hydrocarbon group-carbonyloxy group include aromatic hydrocarbon group-carbonyloxy groups having 7 to 17 carbon atoms, such as benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 18 carbon atoms, such as a benzoyl group. The aromatic hydrocarbon group-oxy group includes an aromatic hydrocarbon group-oxy group having 6 to 17 carbon atoms, such as a phenyloxy group.
In addition, examples of groups in which -CH ₂ - contained in the alicyclic hydrocarbon group are replaced with -O-, -S-, -CO- or -SO ₂ - include the groups shown below. . -O- or -CO- in the groups shown below may be replaced with -S- or -SO ₂ -. The binding site can be at any position.

More specifically, as the group in which -CH ₂ - contained in the alicyclic hydrocarbon group is replaced with -O-, -S-, -CO- or -SO ₂ -, the following groups etc. can be mentioned. * represents a binding site.

Examples of substituents that the cyclic hydrocarbon group may have include a halogen atom, a cyano group, and an alkyl group having 1 to 12 carbon atoms (-CH ₂ - contained in the alkyl group is -O-, -S- , -CO- or -SO ₂ -). When the cyclic hydrocarbon group has a substituent, the substituent is not included in the total carbon number of the hydrocarbon group including the cyclic hydrocarbon group in R ²¹ .
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group 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, and the like. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 9, still more preferably 1 to 8, even more preferably 1 to 6, and even more preferably 1 to 4. and even more preferably 1 to 3.
When -CH ₂ - contained in an alkyl group is replaced with -O-, -S-, -CO- or -SO ₂ - as a substituent, the number of carbon atoms before substitution is the total number of carbon atoms in the alkyl group. shall be. Substituted groups include a hydroxy group (a group in which -CH ₂ - contained in a methyl group is replaced with -O-), a carboxy group (a group in which -CH 2 -CH ₂ - contained in an ethyl group is replaced with -O-), and a carboxy group (a group in which -CH ₂ - contained in an ethyl group is replaced with -O-) (a group in which -CO- is replaced with -CO-), an alkoxy group (a group in which -CH 2 - at any position contained in an alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -O- is substituted for -CH ₂ - at any position contained in an alkyl group) (a group in which -CH ₂ -CH ₂ - is replaced with -O-CO-), an alkylcarbonyl group (a group in which -CH ₂ - at any position contained in the alkyl group is replaced with -CO-), Examples include alkylcarbonyloxy groups (groups in which -CH ₂ -CH ₂ - contained in an alkyl group is replaced with -CO-O-), groups that combine two or more of these groups, etc. It will be done.
Examples of the alkoxy group include alkoxy groups having 1 to 11 carbon atoms. Examples include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group and the like. The alkoxy group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 11 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group, and examples of the alkylcarbonyl group include alkyl groups having 2 to 12 carbon atoms. Carbonyl groups include, for example, acetyl, propionyl and butyryl groups, and alkylcarbonyloxy groups include alkylcarbonyloxy groups having 2 to 11 carbon atoms, such as acetyloxy, propionyloxy, etc. group, butyryloxy group, etc. The alkoxycarbonyl group preferably has 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms, and still more preferably 2 or 3 carbon atoms. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 6, more preferably 2 to 4, and still more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 6, more preferably 2 to 4, and still more preferably 2 or 3.
The cyclic hydrocarbon group may have one substituent or multiple substituents.
Examples of substituents that the cyclic hydrocarbon group may have include a halogen atom or an alkyl group having 1 to 6 carbon atoms (-CH ₂ - contained in the alkyl group is -O-, -S-, -CO - or -SO ₂ -) is preferable, and a fluorine atom, an iodine atom, or an alkyl group having 1 to 4 carbon atoms (-CH ₂ - contained in the alkyl group is substituted with -O-, -S -, -CO- or -SO ₂ -) is more preferable, and a fluorine atom, an iodine atom, a hydroxy group, an alkoxy group having 1 to 3 carbon atoms, or an alkyl group having 1 to 4 carbon atoms is more preferable. Preferably, a fluorine atom, an iodine atom, a hydroxy group, or an alkyl group having 1 to 4 carbon atoms is even more preferable.

Cyclic hydrocarbon group (The cyclic hydrocarbon group may have a substituent, -CH ₂ - contained in the cyclic hydrocarbon group is -O-, -S-, -SO ₂ - or -CO- ) may be replaced by
An alicyclic hydrocarbon group having 3 to 18 carbon atoms (the alicyclic hydrocarbon group may have a substituent, and -CH ₂ - contained in the alicyclic hydrocarbon group is -O- , -S-, -SO ₂ - or -CO-), or an aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group may be substituted with a substituent) ) is preferable,
An alicyclic hydrocarbon group having 3 to 18 carbon atoms (the alicyclic hydrocarbon group has one or more atoms selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an iodine atom, and a fluorine atom) -CH ₂ - contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -SO ₂ - or -CO-), or a group with 6 carbon atoms. -18 aromatic hydrocarbon group (The aromatic hydrocarbon group may have one or more selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an iodine atom, and a fluorine atom.) It is more preferable that
An alicyclic hydrocarbon group having 5 to 16 carbon atoms (the alicyclic hydrocarbon group has one or more atoms selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an iodine atom, and a fluorine atom) (-CH ₂ - contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -SO ₂ - or -CO-) is more preferable. .

上記式において、Ｒ^21’は、上述したＲ²¹と同じ定義であり、Ｒ²¹と同じであってもよいし異なっていてもよい。 A hydrocarbon group having 3 to 48 carbon atoms including a cyclic hydrocarbon group represented by R ²¹ (the cyclic hydrocarbon group may have a substituent, and the -CH ₂ - contained in the hydrocarbon group is -O-, -S-, -SO ₂ - or -CO- may be substituted).
Preferably, a hydrocarbon group having 3 to 48 carbon atoms including an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the alicyclic hydrocarbon group may have a substituent; -CH ₂ - contained may be replaced with -O-, -S-, -SO ₂ - or -CO-), or a carbon number containing an aromatic hydrocarbon group having 6 to 18 carbon atoms. 6 to 48 hydrocarbon groups (the aromatic hydrocarbon group may have a substituent, -CH ₂ - contained in the hydrocarbon group is -O-, -S-, -SO ₂ - or may be replaced with -CO-),
More preferably, a hydrocarbon group having 3 to 48 carbon atoms including an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the alicyclic hydrocarbon group includes an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an iodine group) It may have one or more atoms selected from the group consisting of atoms and fluorine atoms, and -CH ₂ - contained in the hydrocarbon group is replaced with -O-, -S-, -SO ₂ - or -CO-. ), or a hydrocarbon group having 6 to 48 carbon atoms including an aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group is an alkyl group having 1 to 4 carbon atoms, a hydroxyl group having 1 to 4 carbon atoms, -CH ₂ - contained in the hydrocarbon group may contain -O-, -S-, -SO ₂ - or -CO - may be replaced.),
More preferably, an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the alicyclic hydrocarbon group is one selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an iodine atom, and a fluorine atom) -CH ₂ - contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -SO ₂ - or -CO-), carbon A group consisting of a combination of an alicyclic hydrocarbon group having 3 to 18 carbon atoms and a chain hydrocarbon group having 1 to 6 carbon atoms (the alicyclic hydrocarbon group is an alkyl group having 1 to 4 carbon atoms, a hydroxy group, It may have one or more selected from the group consisting of iodine atoms and fluorine atoms, and -CH ₂ - contained in the combined group is replaced by -O-, -S-, -SO ₂ - or -CO-. ), an aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group is selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an iodine atom, and a fluorine atom) ), or a group combining an aromatic hydrocarbon group having 6 to 18 carbon atoms and a chain hydrocarbon group having 1 to 6 carbon atoms (the aromatic hydrocarbon group may have one or more , an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an iodine atom, and a fluorine atom, and the -CH ₂ - contained in the combined group is -O-, -S-, -SO ₂ - or -CO- may be substituted),
Even more preferably, an alicyclic hydrocarbon group having 5 to 16 carbon atoms (the alicyclic hydrocarbon group is selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an iodine atom, and a fluorine atom) -CH ₂ - contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -SO ₂ - or -CO-), Or, a group consisting of a combination of an alicyclic hydrocarbon group having 5 to 16 carbon atoms and a chain hydrocarbon group having 1 to 4 carbon atoms (the alicyclic hydrocarbon group is an alkyl group having 1 to 4 carbon atoms, It may have one or more selected from the group consisting of a hydroxy group, an iodine atom, and a fluorine atom, and the -CH ₂ - contained in the combined group is -O-, -S-, -SO ₂ - or - may be replaced with CO-).
In addition, a hydrocarbon group having 3 to 48 carbon atoms including a cyclic hydrocarbon group represented by R ²¹ (the cyclic hydrocarbon group may have a substituent, and -CH ₂ - contained in the hydrocarbon group) may be replaced with -O-, -S-, -SO ₂ - or -CO-.)
W ²¹ -L ²¹ -* (W ²¹ represents a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and -CH ₂ - contained in the cyclic hydrocarbon group is -O- , -S-, -SO ₂ - or -CO-. L ²¹ represents a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms, and -CH ₂ - may be replaced by -O-, -S-, -SO ₂ - or -CO-. * is also preferably a bonding site with an oxygen atom).
Examples of the cyclic hydrocarbon group of W ²¹ , the substituent that W ²¹ may have, and the chain hydrocarbon group of L ²¹ include the same groups as mentioned above.
W ²¹ is an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the alicyclic hydrocarbon group may have a substituent, and -CH ₂ - contained in the alicyclic hydrocarbon group is , -O-, -S-, -SO ₂ - or -CO-), or an aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group may be substituted with a substituent ), preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the alicyclic hydrocarbon group may include an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an iodine atom and fluorine atoms, and -CH ₂ - contained in the alicyclic hydrocarbon group is -O-, -S-, -SO ₂ - or -CO- ), or an aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group consists of an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an iodine atom, and a fluorine atom) It is more preferable that it is an alicyclic hydrocarbon group having 5 to 16 carbon atoms (the alicyclic hydrocarbon group may include an alkyl group having 1 to 4 carbon atoms). -CH 2 - contained in the alicyclic hydrocarbon group may have one or more selected from the group consisting of a group consisting of a hydroxyl group, an iodine atom, and a fluorine atom, and -CH ₂ - contained in the alicyclic hydrocarbon group is -O-, -S-, - (may be replaced with SO ₂ - or -CO-) is more preferable.
L ²¹ is a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms (-CH ₂ - contained in the chain hydrocarbon group may be replaced with -O- or -CO-). Preferably, a single bond or a chain hydrocarbon group having 1 to 4 carbon atoms (-CH ₂ - contained in the chain hydrocarbon group may be replaced with -O- or -CO-). More preferably, it is a single bond or a chain hydrocarbon group having 1 to 3 carbon atoms.
m21 is an integer of 1 to 5, preferably an integer of 1 to 4, more preferably an integer of 1 to 3, even more preferably 1 or 2, and even more preferably 2. When m21 is 1 or 2, it is preferable to have the following structure in which m is substituted for SO ₃ ^- .

In the above formula, R ^21' has the same definition as R ²¹ described above, and may be the same as or different from R ²¹ .

Examples of the alkyl group having 1 to 6 carbon atoms for R ²² 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, more preferably 1 to 3.
Examples of the halogen atom for ^R22 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
R ²² is each independently a halogen atom or an alkyl group having 1 to 4 carbon atoms (-CH ₂ - contained in the alkyl group may be replaced with -O- or -CO-); is preferable, and more preferably a fluorine atom, an iodine atom, or an alkyl group having 1 to 3 carbon atoms (-CH ₂ - contained in the alkyl group may be replaced with -O- or -CO-). It is preferably a fluorine atom, an iodine atom, a hydroxy group, a methoxy group, or a methyl group.
m22 is an integer of 0 to 4, preferably an integer of 0 to 3, and more preferably an integer of 0 to 2. In one embodiment, m22 is preferably zero. In another embodiment, m22 is preferably 1 or 2. When m22 is 1, ^R22 is preferably a halogen atom, and more preferably ^R22 is a fluorine atom or an iodine atom. When m22 is 2, one of ^R22 is a halogen atom, the other is preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms, one of ^R22 is a fluorine atom or an iodine atom, and the other is more preferably a fluorine atom, an iodine atom, or an alkyl group having 1 to 3 carbon atoms.

Examples of the anion in the salt represented by formula (B2) include the following anions. Among these, anions represented by formulas (B2a-1) to (B2a-20) are preferable, and anions represented by formulas (B2a-1) to (B2a-11) and formulas (B2a-16) to (B2a-20) are preferred. ) is more preferable.

スルホニルメチドアニオンとしては、以下のものが挙げられる。

カルボン酸アニオンとしては、以下のものが挙げられる。

Among them, formula (B1a-1) to formula (B1a-4), formula (B1a-7) to formula (B1a-11), formula (B1a-14) to formula (B1a-30), and formula (B1a-35) ) to (B1a-65) and formulas (B2a-1) to (B2a-20) are preferred.
In addition, another form of compound (B) is a salt in which the anion in the salt represented by formula (B1) or formula (B2) is replaced with a sulfonylimide anion, a sulfonylmethide anion, a carboxylic acid anion, etc. , is suitably used as compound (B).
Examples of sulfonylimide anions include the following.

Examples of sulfonyl methide anions include the following.

Examples of carboxylic acid anions include the following.

Examples of the organic cation of Z1 ⁺ include those similar to the cation of Z ⁺ in formula (I), including organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. etc. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, similar to Z ⁺ in formula (I), examples include cations represented by any of formulas (b2-1) to (b2-4). Z1 ⁺ in (B2) and Z ⁺ in formula (I) may be the same or different.

Compound (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the compound (B), preferably formulas (B1a-1) to (B1a-4), formulas (B1a-7) to (B1a-11), and formulas (B1a-14) to (B1a-30) and an anion represented by any one of formulas (B1a-35) to (B1a-65) and formulas (B2a-1) to (B2a-20), a cation (b2-1), and a cation (b2-2). ), a combination with a cation (b2-3) or a cation (b2-4).

Preferable examples of the compound (B) include those represented by formulas (B1-1) to (B1-105) and formulas (B2-1) to (B2-20), respectively. 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). ), formula (B1-20) to formula (B1-26), formula (B1-29), formula (B1-31) to formula (B1-105), and formula (B2-1) to formula (B2-20) Those represented by are particularly preferred.

When containing salt (I) and compound (B) as acid generators, the content ratio of salt (I) and compound (B) (mass ratio; salt (I): compound (B)) is usually , 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, even more preferably 10:90 to 90:10, especially Preferably the ratio is 15:85 to 85:15.

In the resist composition of the present invention, the total content of acid generators is preferably 0.1% by mass or more and 99.9% by mass or less, more preferably 1% by mass, based on the solid content of the resist composition. The content is 45% by mass or less, more preferably 1% by mass or more and 40% by mass or less, even more preferably 3% by mass or more and 40% by mass or less. When the resist composition of the present invention contains the resin (A) described below, the total content of the acid generator is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 45 parts by mass or less, based on 100 parts by mass of the resin (A). Preferably it is 1 part by mass or more and 40 parts by mass or less, more preferably 3 parts by mass or more and 40 parts by mass or less.

［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いてもよい炭素数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２～１２のアルコキシアルキル基、炭素数２～１２のアルコキシアルコキシ基、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部位を表す。
Ａ^a52は、炭素数１～８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いてもよい。］ <Resin (A)>
Resin (A) contains a structural unit represented by formula (a2-A). It is preferable that the resin (A) further contains a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"). Further, it may contain a structural unit other than the structural unit represented by formula (a2-A) and 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.
The structural unit represented by formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)") is represented by the following formula.

[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 contain a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, a carbon number Represents an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group.
A ^a50 represents a single bond or *-X ^a51 -(A ^a52 -X ^a52 ) _nb -, and * represents a bonding site with the carbon atom to which -R ^a50 is bonded.
A ^a52 represents an alkanediyl group having 1 to 8 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 and R ^a51 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 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 perfluoro Examples include hexyl group. The alkyl group preferably has 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, and still more preferably 1 or 2 carbon atoms.
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. 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 alkoxy group for R ^a51 include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, and tert-butoxy group. The alkoxy group 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.
Examples of the alkoxyalkyl group for R ^a51 include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group.
Examples of the alkoxyalkoxy group in R ^a51 include methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group, propoxymethoxy group, isopropoxymethoxy group, butoxymethoxy group, sec-butoxymethoxy group, and tert-butoxymethoxy group. Can be mentioned. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group.
Examples of the alkylcarbonyl group for R ^a51 include an acetyl group, a propionyl group, a butyryl group, and the like. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group.
Examples of the alkylcarbonyloxy group for R ^a51 include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group.
R ^a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, and includes a fluorine atom, an iodine atom, a hydroxy group, and a methyl group. A methoxy group, an ethoxy group, an ethoxyethoxy group or an ethoxymethoxy group are more preferable, and a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group are even more preferable.

*-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.
As the alkanediyl group in A ^a52 , 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-1,4-diyl group and 2-methylbutane-1,4-diyl group. The alkanediyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, still more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms.
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.
It is preferable that at least one hydroxy group is bonded to the meta or para position of the benzene ring. When two hydroxy groups are bonded to a phenyl group, each hydroxy group is preferably bonded to the meta and para positions.

Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A No. 2010-204634 and JP-A No. 2012-12577.
Structural units (a2-A) include structural units represented by formulas (a2-2-1) to (a2-2-24) and formulas (a2-2-1) to (a2-2-24). ) Examples include structural units in which the methyl group corresponding to R ^a50 in structural unit (a2-A) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. Structural unit (a2-A) is a structural unit represented by formula (a2-2-1) to formula (a2-2-4), a structural unit represented by formula (a2-2-6), or a structural unit represented by formula (a2-2-6). a2-2-8), structural units represented by formula (a2-2-12) to formula (a2-2-18), and formula (a2-2-1) to formula (a2- 2-4) Structural unit represented by formula (a2-2-6), structural unit represented by formula (a2-2-8), formula (a2-2-12) ~ In the structural unit represented by the formula (a2-2-18), it is preferable that the methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom, and the structural unit represented by the formula (a2-2 -3) Structural unit represented by formula (a2-2-4), structural unit represented by formula (a2-2-8), formula (a2-2-12) to formula The structural unit represented by (a2-2-14), the structural unit represented by formula (a2-2-18) and the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2- 4) Structural unit represented by formula (a2-2-8), structural unit represented by formula (a2-2-12) to formula (a2-2-14), formula ( In the structural unit represented by formula (a2-2-18), it is more preferable that the methyl group corresponding to R ^a50 in structural unit (a2-A) is replaced with a hydrogen atom, and the structural unit represented by formula (a2-2- 3), a structural unit represented by formula (a2-2-4), a structural unit represented by formula (a2-2-8), and a structural unit represented by formula (a2-2-3). In the structural unit represented by the formula (a2-2-4), the structural unit represented by the formula (a2-2-8), a methyl group corresponding to R ^a50 in the structural unit (a2-A) It is more preferable that it is a structural unit in which 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 mol% or more, more preferably 10% by mole or more based on the total structural units. It is mol% or more, more preferably 15 mol% or more, even more preferably 20 mol% or more. Moreover, it is preferably 80 mol% or less, more preferably 70 mol% or less, and still more preferably 65 mol% or less. Specifically, it is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, even more preferably 15 to 65 mol%, and even more preferably 20 to 65 mol%.
The structural unit (a2-A) can be included in the resin (A) by, for example, polymerizing using the structural unit (a1-4) described below and then treating it with an acid such as p-toluenesulfonic acid. can. 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－Ａ１）及び式（ａ２－Ａ２）中、
Ｒ^a50及びＡ^a50は、それぞれ式（ａ２）と同じ意味を表す。
ｍｂ１は、０～４のいずれかの整数を表す。
Ｒ^ａ５２は、ハロゲン原子を表す。
Ｒ^ａ５３は、炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数２～１２のアルコキシアルキル基、炭素数２～１２のアルコキシアルコキシ基、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。
ｍｂ２及びｍｂ３は、それぞれ独立に、０～４のいずれかの整数を表し、ｍｂ２が２以上の場合、複数のＲ^ａ５２は互いに同一であっても異なってもよく、ｍｂ３が２以上の場合、複数のＲ^ａ５３は互いに同一であっても異なってもよく、１≦ｍｂ２＋ｍｂ３≦４を満たす。］
Ｒ^ａ５２のハロゲン原子は、Ｗ^ａ５０の環状炭化水素基の置換基及びＲ^ａ５１におけるハロゲン原子と同じものが挙げられる。Ｒ^ａ５２のハロゲン原子としては、フッ素原子又はヨウ素原子が好ましい。
Ｒ^ａ５３の炭素数１～６のアルキル基、炭素数１～６のアルコキシ基、炭素数２～１２のアルコキシアルキル基、炭素数２～１２のアルコキシアルコキシ基、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としては、それぞれ、Ｗ^ａ５０の環状炭化水素基の置換基及びＲ^ａ５１におけるアルキル基、アルコキシ基、アルコキシアルキル基、アルコキシアルコキシ基、アルキルカルボニル基、アルキルカルボニルオキシ基、アクロイルオキシ基、メタクリロイルオキシ基と同じものが挙げられ、メチル基、メトキシ基、エトキシ基、エトキシエトキシ基又はエトキシメトキシ基がより好ましく、メトキシ基又はエトキシエトキシ基がさらに好ましい。
ｍｂ１は、０～３のいずれかの整数が好ましく、０～２のいずれかの整数がより好ましく、０又は１がさらに好ましい。
ｍｂ２は、０～３のいずれかの整数が好ましく、１～３のいずれかの整数がより好ましく、１又は２がさらに好ましい。
ｍｂ３は、０～３のいずれかの整数が好ましく、０～２のいずれかの整数がより好ましく、０又は１がさらに好ましい。 The structural unit (a2-A) includes a structural unit represented by the following formula (a2-A1) (hereinafter sometimes referred to as "structural unit (a2-A1)") and a structural unit represented by the formula (a2-A2). (hereinafter sometimes referred to as "structural unit (a2-A2)").

[In formula (a2-A1) and formula (a2-A2),
R ^a50 and A ^a50 each represent the same meaning as in formula (a2).
mb1 represents any integer from 0 to 4.
R ^a52 represents a halogen atom.
R ^a53 is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. group, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group.
mb2 and mb3 each independently represent any integer from 0 to 4; when mb2 is 2 or more, the plurality of R ^a52s may be the same or different; when mb3 is 2 or more, The plurality of R ^a53s may be the same or different from each other, and satisfy 1≦mb2+mb3≦4. ]
Examples of the halogen atom in R ^a52 include the same halogen atom as the substituent of the cyclic hydrocarbon group in W ^a50 and the halogen atom in R ^a51 . The halogen atom for R ^a52 is preferably a fluorine atom or an iodine atom.
R ^a53 alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, alkoxyalkyl group having 2 to 12 carbon atoms, alkoxyalkoxy group having 2 to 12 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms , an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group, respectively, a substituent of the cyclic hydrocarbon group in W ^a50 and an alkyl group, an alkoxy group, an alkoxyalkyl group, an alkoxyalkoxy group in R ^a51 . group, alkylcarbonyl group, alkylcarbonyloxy group, acroyloxy group, methacryloyloxy group, methyl group, methoxy group, ethoxy group, ethoxyethoxy group or ethoxymethoxy group are more preferable, methoxy group or ethoxy group. Ethoxy group is more preferred.
mb1 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and even more preferably 0 or 1.
mb2 is preferably an integer of 0 to 3, more preferably 1 to 3, and even more preferably 1 or 2.
mb3 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and even more preferably 0 or 1.

［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２～８のアルケニル基、炭素数３～２０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。
＊は結合部位を表す。］

［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。
＊は結合部位を表す。］ <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 alkenyl group having 2 to 8 carbon atoms, or an alicyclic hydrocarbon having 3 to 20 carbon atoms. group ^, an aromatic hydrocarbon group having 6 to ¹⁸ carbon atoms, or a group combining these; Forms hydrogen groups.
ma and na each independently represent 0 or 1, and at least one of ma and na represents 1.
* represents a binding site. ]

[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 binding site. ]

Ｒ^ａ１、Ｒ^ａ２及びＲ^ａ３における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、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のアルキルシクロアルキル基又は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。
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－との結合部位を表す。

Examples of the alkyl group for R ^a1 , R ^a2 and R ^a3 include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and the like.
Examples of the alkenyl group in R ^a1 , R ^a2 and R ^a3 include ethenyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, tert-butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, isooctenyl group, Examples include nonenyl group.
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 bonding site). The number of carbon atoms in the alicyclic hydrocarbon groups of R ^a1 , R ^a2 and R ^a3 is preferably 3 to 16.

Examples of the aromatic hydrocarbon group for R ^a1 , R ^a2 and R ^a3 include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group.
Examples of combined groups include groups that combine the above-mentioned alkyl groups and alicyclic hydrocarbon groups (for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyl group). dimethyl group, norbornylethyl group, etc.), aralkyl group such as benzyl group, aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group) group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon group having alicyclic hydrocarbon group (p- Examples include aryl-cycloalkyl groups such as cyclohexylphenyl group, p-adamantylphenyl group, phenylcyclohexyl group, etc.
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 bonding site 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, alicyclic hydrocarbon group, aromatic hydrocarbon group, and a combination thereof include the same groups as those listed for R ^a1 , R ^a2 and R ^a3 .
When R ^a2' and R ^a3' combine with each other to form a heterocyclic group together with the carbon atom to which they are bonded and X, -C(R ^a1' ) (R ^a2' ) -X-R ^a3' , The following groups may be mentioned. * represents a binding site.

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 binding site.

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

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－との結合部位を表す。
Ｒ^a01、Ｒ^ａ４及びＲ^ａ５は、それぞれ独立に、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。
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、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２～８のアルケニル基、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 type of structural unit selected from the group consisting of structural unit (a1-0), structural unit (a1-1), and structural unit (a1-2), and more preferably structural unit (a1- 1) and at least one or two structural units selected from the group consisting of structural units (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 binding site with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
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, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or any of these. Represents a combined group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic group having 6 to 18 carbon atoms. Represents a hydrocarbon group 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 a hydrogen atom or a methyl group, more preferably a methyl group.
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, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group and groups combining these in R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 include R ^a1 of formula (1), Examples include the same groups as those listed for R ^a2 and R ^a3 .
The alkyl group in R ^a02 , R ^a03 , and R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and still more preferably a methyl group.
The alkyl group in R ^a6 and R ^a7 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, or a t-butyl group, and even more preferably an ethyl group or an isopropyl group. Or a t-butyl group.
The alkenyl group in R ^a6 and R ^a7 is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably an ethenyl group, a propenyl group, an isopropenyl group or a butenyl group.
The number of carbon atoms in the alicyclic hydrocarbon groups of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 is preferably 5 to 12, more preferably 5 to 10.
The number of carbon atoms in the aromatic hydrocarbon groups R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 is preferably 6 to 12, more preferably 6 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.
In the group that is a combination of an alkyl group and an aromatic hydrocarbon group, it is preferable that the total number of carbon atoms in the combination of these alkyl groups and aromatic hydrocarbon groups is 18 or less.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably a methyl group, ethyl group, phenyl group or naphthyl 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, an alkenyl group having 2 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, An isopropyl group, t-butyl group, ethenyl group, phenyl group or naphthyl group, more preferably an ethyl group, isopropyl group, t-butyl group, ethenyl group or phenyl 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.

The structural unit (a1-0) is, for example, a structural unit represented by any one of formulas (a1-0-1) to (a1-0-18) 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, a halogen atom, a haloalkyl group (alkyl group having a halogen atom), or another alkyl group, and formulas (a1-0-1) to (a1-0-) 10), formula (a1-0-13), or formula (a1-0-14) is preferable.

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 (a1-1-7) and the methyl group corresponding to R ^a4 in the structural unit (a1-1) are hydrogen atoms or halogen atoms. , a haloalkyl group or another alkyl group is preferable, and a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) is more preferable.

The structural unit (a1-2) corresponds to a structural unit represented by any of formulas (a1-2-1) to (a1-2-14) and R ^a5 in the structural unit (a1-2). Examples include structural units in which a methyl group is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group, such as formula (a1-2-2), formula (a1-2-5), formula (a1-2-6) ) and any one of formulas (a1-2-10) to (a1-2-14) 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). Based on the unit, it is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, and even more preferably 30 mol% or more. It is. Further, it may be 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, and still more preferably 70 mol% or less. Specifically, it is 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, still more preferably 25 to 70 mol%, and even more preferably It is 30 to 70 mol%.
When the resin (A) contains the structural unit (a1-0), its content is 5 mol% or more, preferably 10 mol% or more, based on the total structural units of the resin (A). Further, it may be 80 mol% or less, preferably 75 mol% or less, and more preferably 70 mol% or less. Specifically, it is 5 to 80 mol%, preferably 5 to 75 mol%, and more preferably 10 to 70 mol%.
When the resin (A) contains structural units (a1-1) and/or structural units (a1-2), the total content of these units is 10 mol% or more based on the total structural units of the resin (A). It is preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, and even more preferably 30 mol% or more. Further, 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, Even more preferably, it is 70 mol% or less. Specifically, it is 10 to 90 mol%, preferably 15 to 85 mol%, more preferably 15 to 80 mol%, still more preferably 20 to 80 mol%, even more preferably The content is 20 to 75 mol%, and even more preferably 20 to 70 mol%.

［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いてもよい炭素数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２～１２のアルコキシアルキル基、炭素数２～１２のアルコキシアルコキシ基、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^a30は、単結合又は＊－Ｘ^a31－（Ａ^a32－Ｘ^a32）_nc－を表し、＊は－Ｒ^a32が結合する炭素原子との結合部位を表す。
Ａ^a32は、炭素数１～８のアルカンジイル基を表す。
Ｘ^a31及びＸ^a32は、それぞれ独立に、－Ｏ－、－ＣＯ－Ｏ－又は－Ｏ－ＣＯ－を表す。
ｎｃは、０又は１を表す。
ｌａは、０～４のいずれかの整数を表す。ｌａが２以上のいずれかの整数である場合、複数のＲ^a33は互いに同一であっても異なっていてもよい。
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 which may have a halogen atom.
R ^a33 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, a carbon number Represents an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group.
A ^a30 represents a single bond or *-X ^a31 --(A ^a32 --X ^a32 ) _nc --, and * represents a bonding site with the carbon atom to which --R ^a32 is bonded.
A ^a32 represents an alkanediyl group having 1 to 8 carbon atoms.
X ^a31 and X ^a32 each independently represent -O-, -CO-O- or -O-CO-.
nc represents 0 or 1.
la represents any integer from 0 to 4. When la is any integer of 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-. ]

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 in R ^a32 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 perfluoro Examples include hexyl group.
R ^a32 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 ^a33 include a methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, and 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 alkoxy group for R ^a33 include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group, and hexyloxy group. The alkoxy group 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.
Examples of the alkoxyalkyl group for R ^a33 include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group.
Examples of the alkoxyalkoxy group in R ^a33 include methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group, propoxymethoxy group, isopropoxymethoxy group, butoxymethoxy group, sec-butoxymethoxy group, and tert-butoxymethoxy group. Can be mentioned. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group.
Examples of the alkylcarbonyl group for R ^a33 include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group.
Examples of the alkylcarbonyloxy group for R ^a33 include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group.
R ^a33 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, and includes a fluorine atom, an iodine atom, a hydroxy group, and a methyl group. A methoxy group, an ethoxy group, an ethoxyethoxy group or an ethoxymethoxy group are more preferable, and a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group are even more preferable.

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、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のアルキルシクロアルキル基又は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。 *-X ^a31 -(A ^a32 -X ^a32 ) _nc - includes *-O-, *-CO-O-, *-O-CO-, *-CO-O-A ^a32 -CO-O-, *-O-CO-A ^a32 -O-, *-O-A ^a32 -CO-O-, *-CO-O-A ^a32 -O-CO-, *-O-CO-A ^a32 -O-CO -. Among these, *-CO-O-, *-CO-O-A ^a32 -CO-O-, or *-O-A ^a32 -CO-O- is preferred.
As the alkanediyl group in A ^a32 , 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-1,4-diyl group and 2-methylbutane-1,4-diyl group.
A ^a32 is preferably a methylene group or an ethylene group.
A ^a30 is preferably a single bond, *-CO-O- or *-CO-O-A ^a32 -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.
la is preferably 0, 1 or 2, more preferably 0 or 1, even more preferably 0.
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 that combine the above-mentioned alkyl groups and alicyclic hydrocarbon groups (for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyl group). dimethyl group, norbornylethyl group, etc.), aralkyl group such as benzyl group, aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group) group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon group having alicyclic hydrocarbon group (p- Examples include aryl-cycloalkyl groups such as cyclohexylphenyl group, p-adamantylphenyl group, phenylcyclohexyl group, etc. 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.

R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and 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.
--OC(R ^a34 )(R ^a35 )-O-R ^a36 is preferably bonded to the o-position or p-position of the benzene ring, and more preferably to the p-position.

Examples of the structural unit (a1-4) include structural units derived from monomers described in JP-A No. 2010-204646. Preferably, the hydrogen atom corresponding to R ^a32 in the structural units represented by formulas (a1-4-1) to (a1-4-24) and structural unit (a1-4), respectively, is a halogen atom or a haloalkyl group. or a structural unit substituted with an alkyl group, more preferably formulas (a1-4-1) to (a1-4-5), formula (a1-4-10), and formula (a1-4-13). ), formula (a1-4-14), formula (a1-4-19), and formula (a1-4-20), respectively.

When the resin (A) contains the structural unit (a1-4), the content thereof is preferably 10 to 95 mol%, and 15 to 90% by mole based on the total of all structural units of the resin (A). It is more preferably mol%, even more preferably 20 to 85 mol%, even more preferably 20 to 70 mol%, and even more preferably 20 to 60 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との結合部位を表す。
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 binding site 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) contains the 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.

樹脂（Ａ）が、式（ａ１－３－１）～（ａ１－３－７）で表される構造単位を含む場合、その含有率は、樹脂（Ａ）の全構造単位に対して、１０～９５モル％が好ましく、１５～９０モル％がより好ましく、２０～８５モル％がさらに好ましく、２０～７０モル％がさらにより好ましく、２０～６０モル％が特に好ましい。 Moreover, as the structural unit (a1), the following structural units can also be mentioned.

When the resin (A) contains structural units represented by formulas (a1-3-1) to (a1-3-7), the content thereof is 10% relative to the total structural units of the resin (A). It is preferably from 95 mol%, more preferably from 15 to 90 mol%, even more preferably from 20 to 85 mol%, even more preferably from 20 to 70 mol%, and particularly preferably from 20 to 60 mol%.

<Structural unit (s)>
The structural unit (s) is derived from a monomer that does not have an acid-labile group (hereinafter sometimes referred to as "monomer (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 If a resin containing the unit (hereinafter sometimes referred to as "structural unit (a3)") is used in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

［式（ａ２）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いてもよい炭素数１～６のアルキル基を表す。
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部位を表す。
Ａ^a52は、炭素数１～８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。
Ｗ^ａ５０は、置換基を有してもよい炭素数５～１２の環状炭化水素基を表す。
Ｌ^ａ５０は、単結合又はフッ素原子を有してもよい炭素数１～１２の鎖状炭化水素基を表す。
ｍａ５０は、１～５のいずれかの整数を表す。］
Ｒ^a50におけるハロゲン原子としては、フッ素原子、塩素原子及び臭素原子等が挙げられる。
Ｒ^a50におけ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、トリフルオロメチル基、ジフルオロメチル基、メチル基、ペルフルオロエチル基、２，２，２－トリフルオロエチル基、１，１，２，２－テトラフルオロエチル基、エチル基、ペルフルオロプロピル基、２，２，３，３，３－ペンタフルオロプロピル基、プロピル基、ペルフルオロブチル基、１，１，２，２，３，３，４，４－オクタフルオロブチル基、ブチル基、ペルフルオロペンチル基、２，２，３，３，４，４，５，５，５－ノナフルオロペンチル基、ペンチル基、ヘキシル基、ペルフルオロヘキシル基、トリブロモメチル基、トリクロロメチル基、トリヨードメチル基等が挙げられる。アルキル基の炭素数は、好ましくは１～４であり、より好ましくは１～３であり、さらに好ましくは１又は２である。
Ｒ^a50は、水素原子又は炭素数１～４のアルキル基が好ましく、水素原子、メチル基又はエチル基がより好ましく、水素原子又はメチル基がさらに好ましい。 <Structural unit (a2)>
Structural unit (a2) is a structural unit represented by formula (a2), and has an alcoholic hydroxy group or a phenolic hydroxy group.

[In formula (a2),
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.
A ^a50 represents a single bond or *-X ^a51 --(A ^a52 --X ^a52 ) _nb --, and * represents a bonding site with the carbon atom to which --R ^a50 is bonded.
A ^a52 represents an alkanediyl group having 1 to 8 carbon atoms.
X ^a51 and X ^a52 each independently represent -O-, -CO-O- or -O-CO-.
nb represents 0 or 1.
W ^a50 represents a cyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent.
L ^a50 represents a chain hydrocarbon group having 1 to 12 carbon atoms which may have a single bond or a fluorine atom.
ma50 represents any integer from 1 to 5. ]
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, perfluoro Examples include hexyl group, tribromomethyl group, trichloromethyl group, triiodomethyl group, and the like. The alkyl group preferably has 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms, and still more preferably 1 or 2 carbon atoms.
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.

The alkanediyl group of A ^a52 in A ^a50 includes 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, butane-1,3-diyl group, 2-methylpropane-1,3- Examples include diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group. The alkanediyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, still more preferably 1 to 3 carbon atoms, and even more preferably 1 or 2 carbon atoms.
A ^a52 is preferably a methylene group or an ethylene 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.
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.

Examples of the cyclic hydrocarbon group of W ^a50 include a divalent alicyclic hydrocarbon group and a divalent aromatic hydrocarbon group.
Examples of the monocyclic divalent alicyclic hydrocarbon group in W ^a50 include monocyclic divalent alicyclic hydrocarbon groups such as cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group. Examples include cyclic cycloalkanediyl groups. Examples of polycyclic divalent alicyclic hydrocarbon groups include norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group. Examples include polycyclic cycloalkanediyl groups such as groups. The alicyclic hydrocarbon group preferably has 6 to 12 carbon atoms, more preferably 6 to 10 carbon atoms.
Examples of the divalent aromatic hydrocarbon group in W ^a50 include a phenylene group and a naphthylene group. The aromatic hydrocarbon group preferably has 6 to 12 carbon atoms, more preferably 6 to 10 carbon atoms.
Examples of substituents that the cyclic hydrocarbon group having 5 to 12 carbon atoms in W ^a50 may include halogen atoms, hydroxy groups, alkyl groups having 1 to 12 carbon atoms, haloalkyl groups having 1 to 12 carbon atoms, and Alkoxy group having 1 to 12 carbon atoms, alkoxyalkyl group having 2 to 12 carbon atoms, alkoxyalkoxy group having 2 to 12 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyloxy group or methacryloyloxy group. The number of substituents that W ^a50 has may be one or two or more.
Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.
Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group. The alkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 to 3 carbon atoms. 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 haloalkyl groups include trifluoromethyl group, difluoromethyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, perfluoropropyl group, 2,2, 3,3,3-pentafluoropropyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluoropentyl group, 2,2,3,3,4, Examples include 4,5,5,5-nonafluoropentyl group, perfluorohexyl group, chloromethyl group, bromomethyl group, and iodomethyl group. The haloalkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, and tert-butoxy group. The alkoxy group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms. The alkoxy group 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.
Examples of the alkoxyalkyl group include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group.
Examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group.
Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group.
As the substituent for the cyclic hydrocarbon group of W ^a50 , a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms are preferable, and fluorine Atom, iodine atom, hydroxy group, methyl group, methoxy group, ethoxy group, ethoxyethoxy group or ethoxymethoxy group are more preferred, and fluorine atom, iodine atom, hydroxy group, methyl group, methoxy group or ethoxyethoxy group is even more preferred.

Examples of the chain hydrocarbon group having 1 to 12 carbon atoms in L ^a50 include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, 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 group such as dodecane-1,12-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane- 1,2-diyl group, propane-2,2-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group group, 1-dimethylpropane-1,3-diyl group, pentane-2,4-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, pentane-2,4-diyl group and branched alkanediyl groups such as pentane-1,4-diyl group and 2-methylbutane-1,4-diyl group.
The chain hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms.
The number of fluorine atoms that L ^a50 has may be one or two or more.
ma50 is preferably an integer of 1 to 4, more preferably an integer of 1 to 3.

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 , a structural unit (a2) having a phenolic hydroxy group is preferable, and it is more preferable to use a structural unit (a2-A) described below. 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（ａ２－１）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－との結合部位を表す。
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 binding site 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 preferably 1 mol% or more, preferably 2 mol% or more, based on the total structural units of the resin (A). Furthermore, the amount is 45 mol% or less, preferably 40 mol% or less, more preferably 35 mol% or less, still more preferably 20 mol% or less, and even more preferably 10 mol% or less. Specifically, it is 1 to 45 mol%, preferably 1 to 40 mol%, more preferably 1 to 35 mol%, even more preferably 1 to 20 mol%, and even more preferably It is 1 to 10 mol%.

［式（ａ２－Ｂ）中、
Ｒ^a50及びＡ^a50は、それぞれ式（ａ２）と同じ意味を表す。
Ｒ^ａ５４及びＲ^ａ５５は、それぞれ独立に、炭素数１～４のフッ化アルキル基を表す。
Ｌ^ａ５１は、単結合又は炭素数１～３のアルカンジイル基を表し、該アルカンジイル基はフッ素原子が置換されていてもよい。
Ｒ^ａ５６は、ハロゲン原子、ヒドロキシ基、炭素数１～４のハロアルキル基又は炭素数１～１２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－で置き換わっていてもよい。
ｍｂ４は、１～３のいずれかの整数を表し、ｍｂ４が２以上のとき、複数のＲ^ａ５４、Ｒ^ａ５５及びＬ^ａ５１は、それぞれ互いに同一であっても異なってもよい。
ｍｂ５は、０～４のいずれかの整数を表し、ｍｂ５が２以上のとき、複数のＲ^ａ５６は互いに同一であっても異なってもよい。但し、１≦ｍｂ４＋ｍｂ５≦５である。］
Ｒ^ａ５４及びＲ^ａ５５の炭素数１～４のフッ化アルキル基としては、それぞれ独立に、トリフルオロメチル基、２，２，２－トリフルオロエチル基、３，３，３－トリフルオロプロピル基、４，４，４－トリフルオロブチル基等が挙げられる。Ｒ^ａ５４及びＲ^ａ５５としては、トリフルオロメチル基が好ましい。
Ｌ^ａ５１の炭素数１～３のアルカンジイル基としては、メチレン基、エタン－１，１－ジイル基、プロパン－１，１－ジイル基、プロパン－２，２－ジイル基等が挙げられる。Ｌ^ａ５１としては、単結合又はメチレン基が好ましい。
Ｒ^ａ５６の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^ａ５６における炭素数１～４のハロアルキル基とは、ハロゲン原子を有する炭素数１～４のアルキル基を表し、クロロメチル基、ブロモメチル基、フルオロメチル基、ジフルオロメチル基、トリフルオロメチル基、ペルフルオロブチル等が挙げられである。
Ｒ^ａ５６における炭素数１～１２のアルキル基としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、ｔｅｒｔ－ブチル基、ペンチル基、ヘキシル基、オクチル基、ノニル基等のアルキル基が挙げられる。アルキル基の炭素数は、好ましくは１～９であり、より好ましくは１～６であり、さらに好ましくは１～４である。
Ｒ^ａ５６で表されるアルキル基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっている場合、置き換わる前の炭素数を該アルキル基の総炭素数とする。また、Ｒ^ａ５６は、ヒドロキシ基（メチル基中に含まれる－ＣＨ_２－が、－Ｏ－に置き換わった基）、カルボキシル基（エチル基中に含まれる－ＣＨ_２－ＣＨ_２－が、－Ｏ－ＣＯ－に置き換わった基）、炭素数１～１１のアルコキシ基（炭素数２～１２のアルキル基中に含まれる－ＣＨ_２－が、－Ｏ－に置き換わった基）、炭素数２～１１のアルコキシカルボニル基（炭素数３～１２のアルキル基中に含まれる－ＣＨ_２－ＣＨ_２－が、－Ｏ－ＣＯ－に置き換わった基）、炭素数２～１２のアルキルカルボニル基（炭素数２～１２のアルキル基中に含まれる－ＣＨ_２－が、－ＣＯ－に置き換わった基）、炭素数２～１１のアルキルカルボニルオキシ基（炭素数３～１２のアルキル基中に含まれる－ＣＨ_２－ＣＨ_２－が、－ＣＯ－Ｏ－に置き換わった基）を有していてもよい。
Ｒ^ａ５６としては、なかでも、ハロゲン原子、炭素数１～４のハロアルキル基又は炭素数１～１２のアルキル基（該アルキル基に含まれる－ＣＨ_２－は、－Ｏ－又は－ＣＯ－で置き換わっていてもよい。）であることが好ましい。
ｍｂ４は、好ましくは、１又は２であり、より好ましくは１である。さらに好ましくは、ｍｂ４が１であり、かつ括弧内の基がパラ位に結合するものである。
ｍｂ５は、好ましくは０～２のいずれかの整数であり、より好ましくは０又は１であり、さらに好ましくは０である。
構造単位（ａ２－Ｂ）としては、以下の式（ａ２－Ｂ１）で表される構造単位（以下、「構造単位（ａ２－Ｂ１）」という場合がある。）であることがより好ましい。

［式（ａ２－Ｂ１）中、
Ｒ^ａ５７は、水素原子又はメチル基を表す。
Ａ^ａ５３は、単結合又は＊－ＣＯ－Ｏ－を表し、＊は－Ｒ^ａ５７が結合する炭素原子との結合部位を表す。
Ｒ^ａ５６、ｍｂ４及びｍｂ５は、それぞれ式（ａ２－Ｂ）と同じ意味を表す。］ Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include a structural unit represented by formula (a2-B) (hereinafter sometimes referred to as "structural unit (a2-B)").

[In formula (a2-B),
R ^a50 and A ^a50 each represent the same meaning as in formula (a2).
R ^a54 and R ^a55 each independently represent a fluorinated alkyl group having 1 to 4 carbon atoms.
L ^a51 represents a single bond or an alkanediyl group having 1 to 3 carbon atoms, and the alkanediyl group may be substituted with a fluorine atom.
R ^a56 represents a halogen atom, a hydroxy group, a haloalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 12 carbon atoms, and -CH ₂ - contained in the alkyl group is -O- or -CO-. May be replaced.
mb4 represents any integer from 1 to 3, and when mb4 is 2 or more, the plurality of R ^a54 , R ^a55 and L ^a51 may be the same or different from each other.
mb5 represents any integer from 0 to 4, and when mb5 is 2 or more, a plurality of R ^a56 may be the same or different. However, 1≦mb4+mb5≦5. ]
The fluorinated alkyl groups having 1 to 4 carbon atoms in R ^a54 and R ^a55 each independently include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 3,3,3-trifluoropropyl group, Examples include 4,4,4-trifluorobutyl group. As R ^a54 and R ^a55 , a trifluoromethyl group is preferred.
Examples of the alkanediyl group having 1 to 3 carbon atoms for L ^a51 include a methylene group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-2,2-diyl group, and the like. L ^a51 is preferably a single bond or a methylene group.
Examples of the halogen atom for R ^a56 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The haloalkyl group having 1 to 4 carbon atoms in R ^a56 represents an alkyl group having 1 to 4 carbon atoms having a halogen atom, and includes chloromethyl group, bromomethyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, perfluoromethyl group, Examples include butyl.
Examples of the alkyl group having 1 to 12 carbon atoms in R ^a56 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group, nonyl group, etc. Examples include alkyl groups. The alkyl group preferably has 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms, and still more preferably 1 to 4 carbon atoms.
When the -CH ₂ - contained in the alkyl group represented by R ^a56 is replaced with -O- or -CO-, the number of carbon atoms before being replaced is the total number of carbon atoms in the alkyl group. In addition, R ^a56 is a hydroxy group (a group in which -CH ₂ - contained in a methyl group is replaced with -O-), a carboxyl group (a group in which -CH 2 -CH ₂ - contained in an ethyl group is replaced with -O-), a carboxyl group (a group in which -CH ₂ - contained in an ethyl group is replaced with -O-) -CO-), alkoxy group having 1 to 11 carbon atoms (a group in which -CH ₂ - contained in an alkyl group having 2 to 12 carbon atoms is replaced with -O-), carbon number 2 to 11 an alkoxycarbonyl group (a group in which -CH ₂ -CH ₂ - contained in an alkyl group having 3 to 12 carbon atoms is replaced with -O-CO-), an alkylcarbonyl group having 2 to 12 carbon atoms (a group in which -O-CO- is substituted for an alkyl group having 3 to 12 carbon atoms), A group in which -CH ₂ - contained in an alkyl group of ~12 carbon atoms is replaced with -CO-), an alkylcarbonyloxy group of 2 to 11 carbon atoms (a group in which -CH ₂ - contained in an alkyl group of 3 to 12 carbon atoms) -CH ₂ - may have a group in which -CO-O- is replaced with -CO-O-.
R ^a56 is, among others, a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 12 carbon atoms (-CH ₂ - contained in the alkyl group is replaced with -O- or -CO-). ) is preferable.
mb4 is preferably 1 or 2, more preferably 1. More preferably, mb4 is 1 and the group in parentheses is bonded to the para position.
mb5 is preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0.
The structural unit (a2-B) is more preferably a structural unit represented by the following formula (a2-B1) (hereinafter sometimes referred to as "structural unit (a2-B1)").

[In formula (a2-B1),
R ^a57 represents a hydrogen atom or a methyl group.
A ^a53 represents a single bond or *-CO-O-, and * represents a bonding site with the carbon atom to which -R ^a57 is bonded.
R ^a56 , mb4 and mb5 each represent the same meaning as in formula (a2-B). ]

In formula (a2-B1), R ^a57 is preferably a hydrogen atom.
A ^a53 is preferably a single bond.

Examples of the structural unit (a2-B) include the structural units described below.

In the structural units represented by formulas (a2-B-1) to (a2-B-8), the structural unit in which the hydrogen atom corresponding to R ^a57 is replaced with a methyl group also has the formula (a2-B-9). A structural unit in which the methyl group corresponding to R ^a57 in the structural unit represented by formula (a2-B-16) is replaced with a hydrogen atom can also be cited as a specific example of the structural unit (a2-B). Among these, structural units represented by formulas (a2-B-1) to (a2-B-8) are preferred, and structural units represented by formulas (a2-B-1) to (a2-B-4) are preferred. A structural unit is more preferable, and a structural unit represented by formula (a2-B-1) is even more preferable.

When the resin (A) contains the structural unit (a2-B), its content is preferably 3 mol% or more, more preferably 5 mol% or more, based on the total structural units of the resin (A). and more preferably 10 mol% or more. Moreover, it is preferably 80 mol% or less, more preferably 75 mol% or less, still more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, it is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, still more preferably 10 to 70 mol%, even more preferably 10 to 65 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 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、Ｒ^ａ２０及びＲ^ａ２４は、それぞれ独立に、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。
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 , R ^a20 and R ^a24 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have 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 in R ^a18 , R ^a19 , R ^a20 and R ^a24 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkyl group in R ^a18 , R ^a19 , R ^a20 and R ^a24 include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group. and preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom in R ^a18 , R ^a19 , R ^a20 and R ^a24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert group. -butyl group, perfluoropentyl group, perfluorohexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group, etc.
Examples of the alkanediyl group 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 1 mol% or more, preferably 3 mol% or more, and more Preferably it is 5 mol% or more, more preferably 10 mol% or more. Further, it may be 70 mol% or less, preferably 65 mol% or less, and more preferably 60 mol% or less. Specifically, it is 1 to 70 mol%, preferably 3 to 65 mol%, and more preferably 5 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 content is preferably 1 mol% or more, more preferably 3 mol% or more, and even more preferably 5 mol% or more. Moreover, it is preferably 60 mol% or less, more preferably 55 mol% or less, and still more preferably 50 mol% or less. Specifically, it is preferably 1 to 60 mol%, more preferably 3 to 55 mol%, even more preferably 5 to 50 mol%, and even more preferably 10 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 bonding site).

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.

［式（ａ４－０）中、
Ｒ⁵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２価の脂肪族飽和炭化水素基を表す。
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。
Ｒ⁶は、水素原子又はフッ素原子を表す。］ The structural unit (a4) is preferably a structural unit having a fluorine atom, such as formula (a4-0), formula (a4-1), formula (a4-2), formula (a4-3) and formula ( Examples include structural units represented by at least one selected from the group consisting of a4-4).

[In formula (a4-0),
R ⁵ represents a hydrogen atom or a methyl group.
L ^4a represents a single bond or a divalent aliphatic saturated hydrocarbon 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 ⁶ represents a hydrogen atom or a fluorine atom. ]

Examples of the divalent aliphatic saturated hydrocarbon group in L ^4a include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, and ethane-1 , 1-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, and 2-methylpropane-1,2-diyl group, etc. and alkanediyl groups.
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 ⁵ 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。〕
＊は結合部位であり、右側の＊が－Ｏ－ＣＯ－Ｒ^a42との結合部位である。］

[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 binding site, and the * on the right side is a binding site with -O-CO-R ^a42 . ]

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以上の脂環式飽和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－脂環式飽和炭化水素基、－脂環式飽和炭化水素基－アルキル基、－アルカンジイル基－脂環式飽和炭化水素基－アルキル基等が挙げられる。 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.
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 bonding site).

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 alicyclic saturated hydrocarbon groups, and -alkanediyl groups -Alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, -alkanediyl group-alicyclic saturated 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。
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Ｒ^a42との結合部位を表す。］
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 halogen atoms and groups represented by formulas (ag3). 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-.
A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. * represents the binding site with R ^a42 . ]
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 groups in A ^a45 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 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 the bonding site) ) 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 thereof include alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, more preferably an aliphatic hydrocarbon group having an alkyl group having a halogen atom and/or a group represented by formula (a-g3) .
When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, and still more preferably a carbon number A perfluoroalkyl group having 1 to 6 carbon atoms, 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 an aliphatic hydrocarbon group having a group represented by formula (a-g3), the total number of R ^a42 including the number of carbon atoms contained in the group represented by formula (a-g3) The number of carbon atoms 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価の脂肪族炭化水素基を表す。
Ｘ^a44は、＊＊－Ｏ－ＣＯ－又は＊＊－ＣＯ－Ｏ－を表す（＊＊はＡ^a46との結合部位を表す）。
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部位を表す。］ When R ^a42 is an aliphatic 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 aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
X ^a44 represents **-O-CO- or **-CO-O- (** represents the binding site 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 bonding site with a carbonyl group. ]

The aliphatic 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 bonding site 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 Straight chain 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, Branched alkanediyl groups such as 2-methylbutane-1,4-diyl group can be mentioned.
Examples of the substituent on the alkanediyl group of 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 of 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 binding site, and ** is a binding site 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 having 1 to 6 carbon atoms in L ⁴⁴ include the same groups as those exemplified for the alkanediyl group in A ^a41 .
Examples of the saturated hydrocarbon group for R ^f6 include the same groups as exemplified for R ^a42 .
The alkanediyl group having 1 to 6 carbon atoms 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 the 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との結合部位を表す。）。
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。］ Examples of the structural unit (a4) include a structural unit represented by formula (a4-3).

[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 binding site 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 those exemplified for the alkanediyl group for the divalent saturated hydrocarbon group of 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 saturated 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, Examples include perfluoroalkanediyl groups such as perfluoropropanediyl group, perfluorobutanediyl group, and perfluoropentanediyl group.
The divalent alicyclic saturated 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-type saturated hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, A divalent chain-type saturated hydrocarbon group having 2 to 3 carbon atoms is more preferred.
The saturated hydrocarbon group of A ^f14 is preferably a group containing a chain saturated hydrocarbon group having 3 to 12 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and a chain saturated hydrocarbon group having 3 to 10 carbon atoms. More preferred are groups containing a hydrocarbon group and an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms. Among these, A ^f14 is preferably a group containing an alicyclic saturated 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) contains the 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との結合部位を表す。）。
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 can be mentioned. In the following formula, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom.

[In formula (L1-1),
X ^x1 represents *-O-CO- or *-CO-O- (* represents a binding site 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.

式（Ｌ１－２）で表される基としては、例えば、以下に示す２価の基が挙げられる。

式（Ｌ１－３）で表される基としては、例えば、以下に示す２価の基が挙げられる。

式（Ｌ１－４）で表される基としては、例えば、以下に示す２価の基が挙げられる。

Ｌ⁵⁵は、好ましくは、単結合又は式（Ｌ１－１）で表される基である。 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 following divalent groups.

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）を含む場合、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) contains the 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 (a6)>
The structural unit (a6) is a structural unit having an -SO ₂ - group, and preferably has an -SO ₂ - group in its side chain.
The structural unit having a -SO ₂ - group may have a linear structure having an -SO ₂ - group, a branched structure having a -SO ₂ - group, It may have a cyclic structure (monocyclic or polycyclic structure) having a -SO ₂ - group. Preferably, it is a structural unit having a cyclic structure having a -SO ₂ - group, and more preferably a structural unit having a cyclic structure (sultone ring) containing -SO ₂ -O-.

Examples of the sultone ring include rings represented by the following formulas (T ¹ -1), (T ¹ -2), (T ¹ -3) and (T ¹ -4). The binding site can be at any position. Although the sultone ring may be monocyclic, it is preferably polycyclic. The polycyclic sultone ring means a bridged ring containing -SO ₂ -O- as an atomic group constituting the ring, and is represented by formula (T ¹ -1) and formula (T ¹ -2). Examples include rings. The sultone ring, like the ring represented by formula (T ¹ -2), may further contain a heteroatom in addition to -SO ₂ -O- as an atomic group constituting the ring. Examples of the heteroatom include an oxygen atom, a sulfur atom, or a nitrogen atom, and preferably an oxygen atom.

The sultone ring may have a substituent, and examples of the substituent include an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, and a cyano group having 1 carbon atom. Examples include alkoxy groups having ~12 carbon atoms, aryl groups having 6 to 12 carbon atoms, aralkyl groups having 7 to 12 carbon atoms, glycidyloxy groups, alkoxycarbonyl groups having 2 to 12 carbon atoms, and alkylcarbonyl groups having 2 to 4 carbon atoms. It will be done.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group include a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, octyl group, and decyl group, preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group. It is.
Examples of the alkyl group having a halogen atom include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluorohexyl group, Examples include trichloromethyl group, tribromomethyl group and triiodomethyl group, preferably trifluoromethyl group.
Examples of the alkyl group having a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a 2-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.
Aryl groups include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumyl group, mesityl group, biphenyl group, phenanthryl group. 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl group.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group and naphthylethyl group.
Examples of the alkoxycarbonyl group include groups in which an alkoxy group and a carbonyl group are bonded, such as a methoxycarbonyl group and an ethoxycarbonyl group, preferably an alkoxycarbonyl group having 6 or less carbon atoms, and more preferably a methoxycarbonyl group. Can be mentioned.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.
From the viewpoint of easy production of a monomer leading to the structural unit (a6), a sultone ring having no substituents is preferred.

［式（Ｔ１’）中、
Ｘ^１１は、酸素原子、硫黄原子又はメチレン基を表す。
Ｒ^４１は、ハロゲン原子もしくはヒドロキシ基を有していてもよい炭素数１～１２のアルキル基、ハロゲン原子、ヒドロキシ基、シアノ基、炭素数１～１２のアルコキシ基、炭素数６～１２のアリール基、炭素数７～１２のアラルキル基、グリシジルオキシ基、炭素数２～１２のアルコキシカルボニル基又は炭素数２～４のアルキルカルボニル基を表す。
ｍａは、０～９のいずれかの整数を表す。ｍａが２以上のとき、複数のＲ^４１は同一であっても異なってもよい。
結合部位は任意の位置である。］
Ｘ^１１は、好ましくは酸素原子又はメチレン基であり、より好ましくはメチレン基である。
Ｒ^４１としては、上述したスルトン環の置換基と同様のものが挙げられ、ハロゲン原子又はヒドロキシ基を有していてもよい炭素数１～１２のアルキル基が好ましい。
ｍａは、好ましくは０又は１であり、より好ましくは０である。 As the sultone ring, a ring represented by the following formula (T1') is preferable.

[In formula (T1'),
X ¹¹ represents an oxygen atom, a sulfur atom, or a methylene group.
R ⁴¹ is an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms; group, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms.
ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R ^41s may be the same or different.
The binding site can be at any position. ]
X ¹¹ is preferably an oxygen atom or a methylene group, more preferably a methylene group.
Examples of R ⁴¹ include the same substituents as the above-mentioned sultone ring substituents, and preferably an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group.
ma is preferably 0 or 1, more preferably 0.

Examples of the ring represented by formula (T1') include the following rings. The binding site can be at any position. Among these, those whose binding site is at the 1st or 3rd position are preferred.

The structural unit having the -SO ₂ - group preferably further has a group derived from a polymerizable group. Examples of the polymerizable group include a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, a methacryloylthio group, and the like.
Among these, the monomer leading to the structural unit (a6) is preferably a monomer having an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer.

［式（ａ６－０）中、
Ｒ^ｘは、ハロゲン原子を有してもよい炭素数１～６のアルキル基、水素原子又はハロゲン原子を表す。
Ａ^ｘｘは、酸素原子、－Ｎ（Ｒ^ｃ）－又は硫黄原子を表す。
Ａ^ｘ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－、－ＣＯ－又は－Ｎ（Ｒ^ｄ）－に置き換わっていてもよい。
Ｘ^１１、Ｒ^４１及びｍａは、上記と同じ意味を表す。
Ｒ^ｃ及びＲ^ｄは、互いに独立に、水素原子又は炭素数１～６のアルキル基を表す。］ Structural unit (a6) is preferably a structural unit represented by formula (a6-0).

[In formula (a6-0),
R ^x represents an alkyl group having 1 to 6 carbon atoms that may have a halogen atom, a hydrogen atom, or a halogen atom.
A ^xx represents an oxygen atom, -N(R ^c )- or a sulfur atom.
A ^x 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 is -O-, -CO- or -N(R ^d )- may be replaced.
X ¹¹ , R ⁴¹ and ma represent the same meanings as above.
R ^c and R ^d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. ]

Examples of the halogen atom for R ^x include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group for R ^x include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, and n-hexyl group. preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group.
^R , perfluorohexyl group, trichloromethyl group, tribromomethyl group, and triiodomethyl group.
R ^x is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and still more preferably a hydrogen atom or a methyl group.
Examples of the divalent saturated hydrocarbon group of A ^x include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. A combination of two or more of these groups may also 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 , 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, heptadecane-1, Straight chain alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group;
Butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4- Branched alkanediyl groups such as diyl groups;
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.
The bonding position of A ^x to the sultone ring can be any position, but the 1st position is preferable.

Examples of the structural unit (a6-0) include the following structural units.

Among them, structural units represented by formula (a6-1), formula (a6-2), formula (a6-6), formula (a6-7), formula (a6-8) and formula (a6-12) is preferred, and structural units represented by formula (a6-1), formula (a6-2), formula (a6-7) and (a6-8) are more preferred.
When the resin (A) contains the structural unit (a6), its content is preferably 1 to 50 mol%, more preferably 2 to 40 mol%, and 3 to 40 mol%, based on the total structural units of the resin (A). More preferably 30 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 and an organic cation 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 thing 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.
The optionally substituted perfluoroalkyl group having 1 to 6 carbon atoms in ^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 binding site 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 Z1 ⁺ in the salt represented by formula (B1).

［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、ｚ２Ａ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 ⁺ represent 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 z2A 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ｎＡは、互いに独立に、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 ⁺ represent the same meanings as above.
m and nA 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。
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は、上記と同様のものが挙げられる。
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 alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and groups formed by combining these groups are the same as those mentioned above.
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 a hydrogen atom, a halogen atom (for example, a fluorine atom), or a halogen atom. Structural units substituted with an alkyl group having 1 to 6 carbon atoms (eg, trifluoromethyl group, etc.) which may have an atom may be mentioned.

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 sulfonic acid anion. Examples of the sulfonic acid anion include those similar to those exemplified as the anion contained in the salt (I) or the anion contained in the compound (B). Examples of the sulfonylimide anion, sulfonylmethide anion, and carboxylic acid anion include the same anions exemplified as the anions contained in compound (B).

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) is preferably a resin consisting of a structural unit (a1) and a structural unit (s), that is, a copolymer of a monomer (a1) and a monomer (s).
The structural unit (a1) is preferably a group consisting of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group). At least one kind selected from, more preferably at least two kinds, still more preferably at least two kinds selected from the group consisting of structural unit (a1-1) and structural unit (a1-2).
The structural unit (s) is preferably at least one selected from the group consisting of the structural unit (a2-A), other structural units (a2), and structural units (a3). Structural unit (a2) is preferably structural unit (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 is 15,000 or less), but an oligomer having a weight average molecular weight of 2,000 or more and less than 2,000 may be included. 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).
Examples of resins other than resin (A) include, for example, resins having the same structural units as resin (A) except that resin (A) does not contain the structural unit (a2-A) (hereinafter referred to as resin (AX)). Examples include resins containing structural unit (a4) and/or structural unit (a5) (hereinafter sometimes referred to as resin (X)).
Examples of the resin (AX) include resins containing the structural unit (a1).
Structural units that the resin (X) may further include include structural units (a1), 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).
When the resin (X) contains a structural unit (a4), the content of the structural unit (a4) in the resin (X) is 20 mol% or more based on the total of all structural units of the resin (X). The content is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more. Furthermore, the content may be 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, even more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, it is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, even more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. When the resin (X) contains a structural unit (a5), the content of the structural unit (a5) is 20 mol% or more, and 30 mol% or more, based on the total of all structural units of the resin (X). is preferable, 40 mol% or more is more preferable, and even more preferably 45 mol% or more. Furthermore, the content may be 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, even more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, it is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, even more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. In addition, when the resin (X) contains the structural unit (a4) and the structural unit (a5), the total content of the structural unit (a4) and the structural unit (a5) is the sum of all the structural units of the resin (X). On the other hand, it is 40 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more. Moreover, 100 mol% or less is mentioned. Specifically, the amount is 40 to 100 mol%, preferably 60 to 100 mol%, more preferably 70 to 100 mol%, and even more preferably 80 to 100 mol%. Further, structural unit (a4):structural unit (a5) may be 0:100 to 100:0, preferably 10:90 to 90:10, 30:70 to 70:30 or 40:60 to 60: 40 is more preferable.
Resin (AX) and each structural unit constituting resin (X) may be used alone or in combination of two or more, and monomers that induce these structural units may be used by known polymerization methods (for example, radical polymerization method). The content of each structural unit in resin (AX) and resin (X) can be adjusted by adjusting the amount of monomer used for polymerization.
Examples of the weight average molecular weight of the resin (AX) include those similar to those of the resin (A).
The weight average molecular weight of resin (AX) and 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), but the weight average Oligomers with a molecular weight of less than 6,000 may be included. The means for measuring the weight average molecular weight of resin (X) is the same as that for resin (A).

When the resist composition of the present invention contains resin (X), the content thereof is preferably 1 to 60 parts by mass, and more preferably 1 to 60 parts by mass based on 100 parts by mass of resin (A) and/or resin (AX). The amount is preferably 1 to 50 parts by weight, more preferably 1 to 40 parts by weight, even more preferably 1 to 30 parts by weight, and even more preferably 1 to 8 parts by weight.

When the resist composition contains a resin (A), the content of the resin (A) is preferably 80% by mass or more and 99% by mass or less, and 90% by mass or more based on the solid content of the resist composition. More preferably, it is 99% by mass or less. In addition, when a resin other than the resin (A) is included, the total content of the resin (A) and/or 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. 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 salts that generate an acid that is weaker in acidity than the acid generated from a basic nitrogen-containing organic compound and an acid generator (salt (I) or compound (B)). When the resist composition contains a quencher (C), the content of the quencher (C) is preferably about 0.01 to 15% by mass, based on the solid content of the resist composition. It is more preferably about 0.01 to 10% by mass, even more preferably about 0.1 to 8% by mass, and even more preferably about 0.1 to 7% by mass.
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, 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. Diisopropylaniline is preferred, and 2,6-diisopropylaniline is more preferred.

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 less acidic than the acid generated from the acid generator 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 is a salt in which the acid dissociation constant of the acid generated from the salt is usually -3<pKa, preferably -1<pKa<7. , more preferably a salt with a pKa of 0<pKa<5.
Examples of the salt that generates an acid with weaker acidity than the acid generated from the acid generator include a salt represented by the following formula, a salt represented by the formula (D) described in JP-A-2015-147926 (hereinafter referred to as ), as well as JP2012-229206A, JP2012-6908A, JP2012-72109A, JP2011-39502A, and Examples include salts described in JP-A No. 2011-191745. The salt that generates an acid that is weaker in acidity than the acid generated from the acid generator is preferably a salt that generates a carboxylic acid that is weaker in acidity than the acid generated from the acid generator (salt that has a carboxylic acid anion). More preferably, it is a weak acid inner salt (D), and even more preferably a diphenyliodonium salt containing a phenyl group substituted with a carboxylic acid anion among the weak acid inner salts (D).

［式（Ｄ）中、
Ｒ^D1及びＲ^D2は、それぞれ独立に、炭素数１～１２の炭化水素基、炭素数１～６のアルコキシ基、炭素数２～７のアシル基、炭素数２～７のアシルオキシ基、炭素数２～７のアルコキシカルボニル基、ニトロ基又はハロゲン原子を表す。
ｍ’及びｎ’は、それぞれ独立に、０～４のいずれかの整数を表し、ｍ’が２以上の場合、複数のＲ^D1は同一であっても異なってもよく、ｎ’が２以上の場合、複数のＲ^D2は同一であっても異なってもよい。］
Ｒ^D1及びＲ^D2の炭化水素基としては、鎖式炭化水素基、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。
鎖式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、イソブチル基、ｔｅｒｔ－ブチル基、ペンチル基、ヘキシル基、ノニル基等のアルキル基が挙げられる。
脂環式炭化水素基としては、単環式及び多環式のいずれでもよく、飽和及び不飽和のいずれでもよい。シクロプロピル基、シクロブチル基、シクロペンチル基、シクロへキシル基、シクロノニル基、シクロドデシル基等のシクロアルキル基、ノルボニル基、アダマンチル基等が挙げられる。
芳香族炭化水素基としては、フェニル基、１－ナフチル基、２－ナフチル基、２－メチルフェニル基、３－メチルフェニル基、４－メチルフェニル基、４－エチルフェニル基、４－プロピルフェニル基、４－イソプロピルフェニル基、４－ブチルフェニル基、４－ｔ－ブチルフェニル基、４－ヘキシルフェニル基、４－シクロヘキシルフェニル基、アントリル基、ｐ－アダマンチルフェニル基、トリル基、キシリル基、クメニル基、メシチル基、ビフェニル基、フェナントリル基、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のアリール基等が挙げられる。
これらを組み合わせることにより形成される基としては、アルキル－シクロアルキル基、シクロアルキル－アルキル基、アラルキル基（例えば、フェニルメチル基、１－フェニルエチル基、２－フェニルエチル基、１－フェニル－１－プロピル基、１－フェニル－２－プロピル基、２－フェニル－２－プロピル基、３－フェニル－１－プロピル基、４－フェニル－１－ブチル基、５－フェニル－１－ペンチル基、６－フェニル－１－ヘキシル基等）等が挙げられる。
アルコキシ基としては、メトキシ基、エトキシ基等が挙げられる。
アシル基としては、アセチル基、プロパノイル基、ベンゾイル基、シクロヘキサンカルボニル基等が挙げられる。
アシルオキシ基としては、上記アシル基にオキシ基（－Ｏ－）が結合した基等が挙げられる。
アルコキシカルボニル基としては、上記アルコキシ基にカルボニル基（－ＣＯ－）が結合した基等が挙げられる。
ハロゲン原子としては、フッ素原子、塩素原子、臭素原子等が挙げられる。
Ｒ^D1及びＲ^D2は、それぞれ独立に、炭素数１～８のアルキル基、炭素数３～１０のシクロアルキル基、炭素数１～６のアルコキシ基、炭素数２～４のアシル基、炭素数２～４のアシルオキシ基、炭素数２～４のアルコキシカルボニル基、ニトロ基又はハロゲン原子が好ましい。
ｍ’及びｎ’は、それぞれ独立に、０～２のいずれかの整数であることが好ましく、０であることがより好ましい。ｍ’が２以上の場合、複数のＲ^D1は同一であっても異なってもよく、ｎ’が２以上の場合、複数のＲ^D2は同一であっても異なってもよい。 The weak acid inner salt (D) is diphenyliodonium having an iodonium cation to which two phenyl groups are bonded, and a carboxylic acid anion substituted with at least one of the two phenyl groups bonded to the iodonium cation. Salts are preferred, and specific examples include salts represented by the following formulas.

[In formula (D),
R ^D1 and R ^D2 each independently represent a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, or Represents 2 to 7 alkoxycarbonyl groups, nitro groups, or halogen atoms.
m' and n' each independently represent any integer from 0 to 4, and when m' is 2 or more, the plurality of R ^D1s may be the same or different, and n' is 2 or more. In the case of , the plurality of R ^D2 may be the same or different. ]
Examples of the hydrocarbon groups R ^D1 and R ^D2 include chain hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these.
Examples of the chain hydrocarbon 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, and nonyl group.
The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and may be saturated or unsaturated. Examples include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group, and cyclododecyl group, norbornyl group, and adamantyl group.
Examples of aromatic hydrocarbon groups include phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-propylphenyl group. , 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group , mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, and other aryl groups.
Groups formed by combining these groups include alkyl-cycloalkyl groups, cycloalkyl-alkyl groups, aralkyl groups (for example, phenylmethyl groups, 1-phenylethyl groups, 2-phenylethyl groups, 1-phenyl-1 -propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6 -phenyl-1-hexyl group, etc.).
Examples of the alkoxy group include a methoxy group and an ethoxy group.
Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, and a cyclohexanecarbonyl group.
Examples of the acyloxy group include a group in which an oxy group (-O-) is bonded to the above-mentioned acyl group.
Examples of the alkoxycarbonyl group include a group in which a carbonyl group (-CO-) is bonded to the above-mentioned alkoxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and the like.
R ^D1 and R ^D2 each independently represent an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyl group having 2 to 4 carbon atoms; An acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group, or a halogen atom is preferred.
m' and n' are each independently preferably an integer of 0 to 2, and more preferably 0. When m' is 2 or more, multiple R ^D1s may be the same or different; when n' is 2 or more, multiple R ^D2s may be the same or different.

More specifically, the following salts may be mentioned.

<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) and, if necessary, a resin (A), 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. The mixing means is also 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 an inorganic substrate such as a silicon wafer, and an organic substrate on which a resist film or the like is formed on the surface. 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. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid state laser light source (YAG or semiconductor laser). etc.) 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 ultraviolet light (EUV). I can do it. 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. A chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the heated composition. Furthermore, before development, the steps of applying a resist composition, drying, exposing, and heating may be repeated on the exposed composition layer.
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, and alcohol solvents or ester solvents are preferable.
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）で表される塩６．１７部及びアセトニトリル３０部を混合し、５０℃で１時間攪拌した。得られた混合物に、５０℃で、式（Ｉ－１－ｂ）で表される化合物１．６２部を添加し、５０℃で２時間撹拌した後、式（Ｉ－１－ｃ）で表される化合物２．３０部を添加し、５０℃で３時間撹拌した。得られた混合物に、クロロホルム１００部及び５％シュウ酸水３９部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水５０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を５回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル５０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－１）で表される塩６．８８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５６５．１ Synthesis Example 1: Synthesis of salt represented by formula (I-1)

6.17 parts of the salt represented by formula (I-1-a) and 30 parts of acetonitrile were mixed and stirred at 50°C for 1 hour. To the resulting mixture, 1.62 parts of the compound represented by formula (I-1-b) was added at 50°C, and after stirring at 50°C for 2 hours, the compound represented by formula (I-1-c) was added. 2.30 parts of the compound to be used was added, and the mixture was stirred at 50°C for 3 hours. To the resulting mixture were added 100 parts of chloroform and 39 parts of 5% oxalic acid water, stirred at 23°C for 30 minutes, allowed to stand, and separated. 50 parts of ion-exchanged water was added to the collected organic layer, stirred at 23° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This water washing operation was repeated five times. The collected organic layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained concentrate, and the mixture was stirred and the supernatant liquid was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 6.88 parts of a salt represented by formula (I-1).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI(-)Spectrum): M ^- 565.1

式（Ｉ－２－ａ）で表される塩６．１７部及びアセトニトリル３０部を混合し、５０℃で１時間攪拌した。得られた混合物に、５０℃で、式（Ｉ－１－ｂ）で表される化合物１．６２部を添加し、５０℃で２時間撹拌した後、式（Ｉ－１－ｃ）で表される化合物２．３０部を添加し、５０℃で３時間撹拌した。得られた混合物に、クロロホルム１００部及び５％シュウ酸水３９部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水５０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を５回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル５０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－２）で表される塩６．８８部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ２６３．１
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５６５．１ Synthesis Example 2: Synthesis of salt represented by formula (I-2)

6.17 parts of the salt represented by formula (I-2-a) and 30 parts of acetonitrile were mixed and stirred at 50°C for 1 hour. To the resulting mixture, 1.62 parts of the compound represented by formula (I-1-b) was added at 50°C, and after stirring at 50°C for 2 hours, the compound represented by formula (I-1-c) was added. 2.30 parts of the compound to be used was added thereto, and the mixture was stirred at 50°C for 3 hours. To the resulting mixture were added 100 parts of chloroform and 39 parts of 5% oxalic acid water, stirred at 23°C for 30 minutes, allowed to stand, and separated. 50 parts of ion-exchanged water was added to the collected organic layer, stirred at 23° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This water washing operation was repeated five times. The collected organic layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained concentrate, and the mixture was stirred and the supernatant liquid was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 6.88 parts of a salt represented by formula (I-2).
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI(-)Spectrum): M ^- 565.1

式（Ｉ－３３１－ａ）で表される塩８．７９部及びアセトニトリル３０部を混合し、５０℃で１時間攪拌した。得られた混合物に、５０℃で、式（Ｉ－１－ｂ）で表される化合物１．６２部を添加し、５０℃で２時間撹拌した後、式（Ｉ－１－ｃ）で表される化合物２．３０部を添加し、５０℃で３時間撹拌した。得られた混合物に、クロロホルム１００部及び５％シュウ酸水３９部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水５０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を５回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル５０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－３３１）で表される塩９．９６部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ５２５．０
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５６５．１ Synthesis Example 3: Synthesis of salt represented by formula (I-331)

8.79 parts of the salt represented by formula (I-331-a) and 30 parts of acetonitrile were mixed and stirred at 50°C for 1 hour. To the resulting mixture, 1.62 parts of the compound represented by formula (I-1-b) was added at 50°C, and after stirring at 50°C for 2 hours, the compound represented by formula (I-1-c) was added. 2.30 parts of the compound to be used was added, and the mixture was stirred at 50°C for 3 hours. To the resulting mixture were added 100 parts of chloroform and 39 parts of 5% oxalic acid water, stirred at 23°C for 30 minutes, allowed to stand, and separated. 50 parts of ion-exchanged water was added to the collected organic layer, stirred at 23° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This water washing operation was repeated five times. The collected organic layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained concentrate, and the mixture was stirred and the supernatant liquid was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 9.96 parts of a salt represented by formula (I-331).
MASS (ESI (+) Spectrum): M ⁺ 525.0
MASS (ESI(-)Spectrum): M ^- 565.1

式（Ｉ－８３３－ｃ）で表される化合物３．８４部及びアセトニトリル３０部を混合し、５０℃で１時間攪拌した。得られた混合物に、５０℃で、式（Ｉ－１－ｂ）で表される化合物１．６２部を添加し、５０℃で２時間撹拌した後、式（Ｉ－８３３－ａ）で表される塩６．８６部を添加し、５０℃で３時間撹拌した。得られた混合物に、クロロホルム１００部及び５％シュウ酸水３９部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水５０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を５回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル５０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－８３３）で表される塩９．５２部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ５２５．０
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５２７．０ Synthesis Example 4: Synthesis of salt represented by formula (I-833)

3.84 parts of the compound represented by formula (I-833-c) and 30 parts of acetonitrile were mixed and stirred at 50°C for 1 hour. To the resulting mixture was added 1.62 parts of a compound represented by formula (I-1-b) at 50°C, and after stirring at 50°C for 2 hours, a compound represented by formula (I-833-a) was added. 6.86 parts of salt was added thereto, and the mixture was stirred at 50°C for 3 hours. To the resulting mixture were added 100 parts of chloroform and 39 parts of 5% oxalic acid water, stirred at 23°C for 30 minutes, allowed to stand, and separated. 50 parts of ion-exchanged water was added to the collected organic layer, stirred at 23° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This water washing operation was repeated five times. The collected organic layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained concentrate, and the mixture was stirred and the supernatant liquid was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 9.52 parts of a salt represented by formula (I-833).
MASS (ESI (+) Spectrum): M ⁺ 525.0
MASS (ESI (-) Spectrum): M ^- 527.0

式（Ｉ－８３４－ｃ）で表される化合物３．７８部及びアセトニトリル３０部を混合し、５０℃で１時間攪拌した。得られた混合物に、５０℃で、式（Ｉ－１－ｂ）で表される化合物１．６２部を添加し、５０℃で２時間撹拌した後、式（Ｉ－８３３－ａ）で表される塩６．８６部を添加し、５０℃で３時間撹拌した。得られた混合物に、クロロホルム１００部及び５％シュウ酸水３９部を加え、２３℃で３０分間攪拌し、静置、分液した。回収された有機層に、イオン交換水５０部を加え、２３℃で３０分間攪拌し、静置、分液することにより有機層を水洗した。この水洗操作を５回繰り返した。回収された有機層を濃縮し、得られた濃縮物に、ｔｅｒｔ－ブチルメチルエーテル５０部を加えて攪拌し、上澄液を除去した。得られた残渣をアセトニトリルに溶解し、濃縮することにより、式（Ｉ－８３４）で表される塩９．４０部を得た。
ＭＡＳＳ（ＥＳＩ（＋）Ｓｐｅｃｔｒｕｍ）：Ｍ^＋ ５２５．０
ＭＡＳＳ（ＥＳＩ（－）Ｓｐｅｃｔｒｕｍ）：Ｍ^－ ５２１．０ Synthesis Example 5: Synthesis of salt represented by formula (I-834)

3.78 parts of the compound represented by formula (I-834-c) and 30 parts of acetonitrile were mixed and stirred at 50°C for 1 hour. To the resulting mixture was added 1.62 parts of a compound represented by formula (I-1-b) at 50°C, and after stirring at 50°C for 2 hours, a compound represented by formula (I-833-a) was added. 6.86 parts of salt was added thereto, and the mixture was stirred at 50°C for 3 hours. To the resulting mixture were added 100 parts of chloroform and 39 parts of 5% oxalic acid water, stirred at 23°C for 30 minutes, allowed to stand, and separated. 50 parts of ion-exchanged water was added to the collected organic layer, stirred at 23° C. for 30 minutes, allowed to stand, and separated to wash the organic layer with water. This water washing operation was repeated five times. The collected organic layer was concentrated, 50 parts of tert-butyl methyl ether was added to the obtained concentrate, and the mixture was stirred and the supernatant liquid was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 9.40 parts of a salt represented by formula (I-834).
MASS (ESI (+) Spectrum): M ⁺ 525.0
MASS (ESI(-)Spectrum): M ^- 521.0

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 6 [Synthesis of resin A1]
As monomers, monomer (a1-1-3), monomer (a1-2-6), monomer (a2-1-3), monomer (a3-4-2) and monomer (a1-4-2) are used, The molar ratio [monomer (a1-1-3): monomer (a1-2-6): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-2)] is , 20:35:3:15:27, and methyl isobutyl ketone was added to this monomer mixture in an amount of 1.5 times the total weight of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were added at 73 mol%. It was heated at ℃ for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5% by weight) was added to the polymerization reaction solution in an amount of 2.0 times the total mass of all monomers, stirred for 12 hours, and then separated. The collected organic layer was poured into a large amount of n-heptane to precipitate the resin, which was then filtered and collected to obtain resin A1 with a weight average molecular weight of approximately 5.3×10 ³ in a yield of 63%. This resin A1 has the following structural units.

Synthesis Example 7 [Synthesis of resin A2]
As monomers, monomer (a1-1-3), monomer (a1-2-5), monomer (a2-1-3), monomer (a3-4-2) and monomer (a1-4-2) are used, The molar ratio [monomer (a1-1-3): monomer (a1-2-5): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-2)] is , 45:14:2.5:11.5:27, and further mixed with this monomer mixture 1.5 times the mass of methyl isobutyl ketone based on the total mass of all monomers. did. To the obtained mixture, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were added at 73 mol%. It was heated at ℃ for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5% by weight) was added to the polymerization reaction solution in an amount of 2.0 times the total mass of all monomers, stirred for 12 hours, and then separated. The collected organic layer was poured into a large amount of n-heptane to precipitate the resin, which was filtered and collected to obtain resin A2 with a weight average molecular weight of approximately 5.9×10 ³ in a yield of 63%. This resin A2 has the following structural units.

Synthesis Example 8 [Synthesis of resin AX1]
As monomers, monomer (a1-1-3), monomer (a1-2-5), monomer (a2-1-3), and monomer (a3-4-2) were used, and their molar ratio [monomer (a1-1 -3): Monomer (a1-2-5): Monomer (a2-1-3): Monomer (a3-4-2)] so that the ratio is 45:14:2.5:38.5. This monomer mixture was further mixed with 1.5 times the mass of methyl isobutyl ketone based on the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were added to 73 mol%. It was heated at ℃ for about 5 hours. Thereafter, the polymerization reaction solution was poured into a large amount of methanol/water mixed solvent to precipitate the resin, and by filtering and recovering, resin AX1 with a weight average molecular weight of about 6.0 x ¹⁰³ was obtained in a yield of 63%. Ta. This resin AX1 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.

＜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
A2: Resin A2
AX1: Resin AX1
<Salt (I)>
I-1: Salt represented by formula (I-1) I-2: Salt represented by formula (I-2) I-331: Salt represented by formula (I-331) I-833: Formula Salt represented by (I-833) I-834: Salt represented by formula (I-834) IX-1: Synthesized by the method described in JP2018-120218A

<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 on a hot plate for 60 seconds at the temperature shown in the "PEB" column of Table 2. Next, the composition layer on the silicon wafer was developed by a dynamic dispensing method at 23° C. for 20 seconds using butyl acetate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as a developer to obtain a resist pattern. .

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 and 2, Compositions 1 to 6 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 (8)

A resist composition containing an acid generator containing a salt represented by formula (I) and a resin containing a structural unit represented by formula (a2-A).

[In formula (I),
Q ¹ and Q ² each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, or a perfluoroalkyl group having 1 to 6 carbon atoms.
R ¹ and R ² each independently represent a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, 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 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, and * represents C(R ¹ )(R ² ) or C(Q ¹ ) represents the binding site with (Q ² ).
L ¹ and L ² each independently represent a single bond or an aliphatic hydrocarbon group having 1 to 12 carbon atoms which may have a fluorine atom, and -CH ₂ - contained in the aliphatic hydrocarbon group may be replaced with -O- or -CO-.
A ¹ represents a single bond or a cyclic hydrocarbon group having 3 to 36 carbon atoms which may have a substituent, and -CH ₂ - contained in the cyclic hydrocarbon group is -O-, -CO-, -S- or -SO ₂ - may be substituted.
m1 represents an integer of 1 to 3.
Ar ¹ represents an aromatic hydrocarbon group having 6 to 10 carbon atoms or a heterocyclic aromatic hydrocarbon group having 4 to 9 carbon atoms.
Rf ¹ represents a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms.
R ⁴ represents a halogen atom, a haloalkyl group having 1 to 12 carbon atoms, or a hydrocarbon group having 1 to 18 carbon atoms, and the hydrocarbon group may have a substituent, and the haloalkyl group and the hydrocarbon group -CH ₂ - contained in the group may be replaced with -O-, -CO-, -S- or -SO ₂ -.
m4 represents any integer from 0 to 8, and when m4 is 2 or more, a plurality of R ⁴ may be the same or different.
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 contain a halogen atom.
R ^a51 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, a carbon number Represents an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group.
A ^a50 represents a single bond or *-X ^a51 --(A ^a52 --X ^a52 ) _nb --, and * represents a bonding site with the carbon atom to which --R ^a50 is bonded.
A ^a52 represents an alkanediyl group having 1 to 8 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. ] The resist composition according to claim 1, wherein Ar ¹ is a group derived from a benzene ring, a naphthalene ring, a furan ring, or a thiophene ring. 3. The resist composition according to claim 1, wherein X ¹ is *-CO-O- or *-O-CO-. A ¹ is a cyclic hydrocarbon group having 3 to 36 carbon atoms which may have a substituent (-CH ₂ - contained in the cyclic hydrocarbon group is -O-, -CO-, -S- or - 3. The resist composition according to claim 1, wherein SO ₂ - may be substituted. The resin is at least one type selected from the group consisting of a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), and a structural unit represented by formula (a1-2). The resist composition according to claim 1 or 2, comprising:

[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 binding site with -CO-.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
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, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or any of these. Represents a combined group.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic group having 6 to 18 carbon atoms. Represents a hydrocarbon group 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. ] 3. The resist composition according to claim 1, wherein the resin contains a structural unit represented by formula (a3-4)'.

[In formula (a3-4)',
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 ^a24 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms that may have a halogen atom. ] 3. The resist composition according to claim 1, further comprising a salt that generates an acid less acidic than the acid generated from the acid generator. (1) a step of applying the resist composition according to claim 1 or 2 onto 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.
A method for manufacturing a resist pattern including: