JP7841968B2 - Carboxylate salt, carboxylic acid generator, resist composition, and method for producing resist patterns - Google Patents

Description

This invention relates to carboxylate salts, carboxylic acid generators, resist compositions, and methods for producing resist patterns.

Patent Document 1 describes a carboxylate salt represented by the following formula and a resist composition containing the carboxylate salt as a carboxylic acid generator.
Patent Document 2 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator.
Patent Document 3 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator.
Patent Document 4 describes a carboxylate salt represented by the following formula and a resist composition containing the carboxylate salt as a carboxylic acid generator.

Japanese Patent Publication No. 2011-039502 Japanese Patent Publication No. 2011-006402 Japanese Patent Publication No. 2020-015713 Japanese Patent Publication No. 2020-046662

The present invention provides a carboxylate salt that forms a resist pattern with better line edge roughness (LER) than a resist pattern formed by a resist composition containing the above-mentioned salt.

This invention includes the following inventions.
[1] A carboxylic acid generator containing a carboxylic acid salt represented by formula (I).
[In formula (I),
^R1 , ^R2 , and ^R3 each independently represent *-O-R ¹⁰ , *-O-CO-R ¹⁰ , *-O-CO-O-R ¹⁰ , or *-O-L ¹⁰ -CO-O-R ¹⁰ , where * represents the bonding site with the benzene ring.
^L10 represents an alkanediyl group with 1 to 6 carbon atoms.
R ¹⁰ represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, which may have substituents, and one of the _-CH2- groups in the alicyclic hydrocarbon group is replaced by -CO- or a group represented by formula (R ^10-1 ).
[In formula (R ¹⁰ -1),
R ^f1 and R ^f2 each independently represent a hydrogen atom, a fluorine atom, or a C1-C6 alkyl fluoride.
s represents an integer between 0 and 10, and when s is 2 or greater, multiple R ^f1 and R ^f2 are either identical or distinct.
^R4 , ^R5 , ^R6 , ^R7 , ^R8 , and ^R9 each independently represent a halogen atom, a C1-C12 haloalkyl group, or a C1-C18 hydrocarbon group, the hydrocarbon group may have substituents, and the _-CH2- contained in the haloalkyl group and the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
^A1 , ^A2 , and ^A3 each independently represent a hydrocarbon group having 2 to 20 carbon atoms, and the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- .
m1 represents an integer from 1 to 5, and when m1 is 2 or greater, the bases within the parentheses may be the same or different.
m² represents an integer between 0 and 5, and when m² is 2 or greater, the bases within the parentheses may be the same or different.
m3 represents an integer between 0 and 5, and when m3 is 2 or greater, the bases within the parentheses may be the same or different.
m4 represents an integer between 0 and 4, and when m4 is 2 or greater, multiple ^R4s may be the same or different from each other.
m5 represents an integer between 0 and 4, and when m5 is 2 or greater, multiple ^R5s may be the same or different from each other.
m6 represents an integer between 0 and 4, and when m6 is 2 or greater, multiple ^R6s may be the same or different from each other.
m7 represents an integer between 0 and 4, and when m7 is 2 or greater, multiple ^R7s may be the same or different from each other.
m8 represents an integer between 0 and 5, and when m8 is 2 or greater, multiple ^R8s may be the same or different from each other.
m9 represents an integer between 0 and 5, and when m9 is 2 or greater, multiple ^R9s may be the same or different from each other.
However, 1 ≤ m1 + m7 ≤ 5, 0 ≤ m2 + m8 ≤ 5, and 0 ≤ m3 + m9 ≤ 5.
^X0 represents a hydrocarbon group having 1 to 72 carbon atoms, which may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
[2] ^A1 is *-X01-L01- or * ^-L01 - ^X01- , ^A2 is * ^-X02 - ^L02- or *-L02- ^X02- , and ^A3 is * ^{-X03 - L03-} or * ^{-L03 - X03-} ( ^X01 , ^X02 and ^X03 each independently represent -O-, -CO-, -S- or ^-SO2- . ^L01 , ^L02 and ^L03 each independently represent a hydrocarbon group having ₁ to 19 carbon atoms, the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S- or _-SO2- . * is ^R1 , ^R2 or R ³ represents the bonding site with the benzene ring to which it is bonded.) The carboxylic acid generator described in [1].
[3] The carboxylic acid generator according to [2], wherein ^X01 , ^X02 , and ^X03 are each independently -O- or -S-.
[4] The carboxylic acid generator according to [2] or [3], wherein ^L01 , ^L02 and ^L03 are each independently an alkanediyl group having 1 to 6 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-).
[5] R ¹⁰ represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have substituents, and one of the _-CH2- contained in the alicyclic hydrocarbon group is replaced by a group represented by formula (R ^10-1 ), and R ^f1 and R ^f2 are fluorine atoms, according to any one of [1] to [4].
[6] A carboxylic acid generator according to any one of [1] to [5], wherein ^X0 is an aliphatic hydrocarbon group having 1 to ₇₂ carbon atoms which may have substituents (the _-CH2- contained in the aliphatic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-), an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents, a group represented by formula (aa), or a group represented by formula (bb).
[In formula (aa),
X ^a and X ^b each independently represent -O- or -S-.
^X1a represents a hydrocarbon group having 1 to 24 carbon atoms, which may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
^X2a represents a hydrocarbon group having 1 to 48 carbon atoms, which may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
* indicates the bond site with the carbon atom of ^-COO- .
[In formula (bb),
L ^A represents a C1-C6 alkanediyl group which may have a fluorine atom, or a C6-C14 aromatic hydrocarbon group which may have a halogen atom or a C1-C4 perfluoroalkyl group.
L ^B represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the _-CH2- contained in the alkanediyl group may be replaced with -O-, -S-, -CO-, or _-SO2- .
R ^A represents a hydrocarbon group having 1 to 36 carbon atoms, which may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
* indicates the bond site with the carbon atom in ^-COO- .
[7] ^X0 may have a fluorine atom, a perfluoroalkyl group having 1 to 4 carbon atoms, or a cycloidal hydrocarbon group having 3 to 36 carbon atoms (the _-CH2- contained in the cycloidal hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ), or a group combining a cycloidal hydrocarbon group having 3 to 36 carbon atoms and a chain hydrocarbon group having 1 to 18 carbon atoms (the _-CH2- contained in the cycloidal hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- , and the _-CH2- contained in the chain hydrocarbon group The - may be replaced with -O- or -CO-, and the alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, a C1-C4 perfluoroalkyl group or a hydroxyl group.), a C6-C36 aromatic hydrocarbon group which may have a fluorine atom, a C1-C4 perfluoroalkyl group or a hydroxyl group, a group represented by formula (aa) or a group represented by formula (bb) [6] is the carboxylic acid generator.
A resist composition containing a carboxylic acid generator according to any one of [8] [1] to [7], an acid generator other than the carboxylic acid generator, and a resin having an acid-unstable group.
[9] The resist composition according to [8], wherein the resin having an acid-unstable group comprises at least one 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).
[In formulas (a1-0), (a1-1), and (a1-2),
L ^a01 , L ^a1 , and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, where k1 is an integer from 1 to 7, and * represents the bond site with -CO-.
^Ra01 , ^Ra4 , and ^Ra5 each independently represent a hydrogen atom, a halogen atom, or a C1-C6 alkyl group which may contain a halogen atom.
^Ra02 , ^Ra03 , and ^Ra04 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 a combination thereof.
^Ra6 and ^Ra7 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, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by a combination of these.
m1 represents an integer between 0 and 14.
n1 represents an integer between 0 and 10.
n1' represents an integer between 0 and 3.
[10] The resist composition according to [8] or [9], further comprising a resin containing a structural unit having a fluorine atom.
[11] (1) A step of applying the resist composition described in any of [8] to [10] onto a substrate,
(2) A step of drying the coated composition to form a composition layer,
(3) Exposure step of the composition layer,
A method for manufacturing a resist pattern, comprising the steps of (4) heating the composition layer after exposure and (5) developing the composition layer after heating.
[12] Carboxylate salt represented by formula (I).
[In formula (I),
^R1 , ^R2 , and ^R3 each independently represent *-O-R ¹⁰ , *-O-CO-R ¹⁰ , *-O-CO-O-R ¹⁰ , or *-O-L ¹⁰ -CO-O-R ¹⁰ , where * represents the bonding site with the benzene ring.
^L10 represents an alkanediyl group with 1 to 6 carbon atoms.
R ¹⁰ represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, which may have substituents, and one of the _-CH2- groups in the alicyclic hydrocarbon group is replaced by -CO- or a group represented by formula (R ^10-1 ).
[In formula (R ¹⁰ -1),
R ^f1 and R ^f2 each independently represent a hydrogen atom, a fluorine atom, or a C1-C6 alkyl fluoride.
s represents an integer between 0 and 10, and when s is 2 or greater, multiple R ^f1 and R ^f2 are either identical or distinct.
^R4 , ^R5 , ^R6 , ^R7 , ^R8 , and ^R9 each independently represent a halogen atom, a C1-C12 haloalkyl group, or a C1-C18 hydrocarbon group, the hydrocarbon group may have substituents, and the _-CH2- contained in the haloalkyl group and the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
^A1 , ^A2 , and ^A3 each independently represent a hydrocarbon group having 2 to 20 carbon atoms, and the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- .
m1 represents an integer from 1 to 5, and when m1 is 2 or greater, the bases within the parentheses may be the same or different.
m² represents an integer between 0 and 5, and when m² is 2 or greater, the bases within the parentheses may be the same or different.
m3 represents an integer between 0 and 5, and when m3 is 2 or greater, the bases within the parentheses may be the same or different.
m4 represents an integer between 0 and 4, and when m4 is 2 or greater, multiple ^R4s may be the same or different from each other.
m5 represents an integer between 0 and 4, and when m5 is 2 or greater, multiple ^R5s may be the same or different from each other.
m6 represents an integer between 0 and 4, and when m6 is 2 or greater, multiple ^R6s may be the same or different from each other.
m7 represents an integer between 0 and 4, and when m7 is 2 or greater, multiple ^R7s may be the same or different from each other.
m8 represents an integer between 0 and 5, and when m8 is 2 or greater, multiple ^R8s may be the same or different from each other.
m9 represents an integer between 0 and 5, and when m9 is 2 or greater, multiple ^R9s may be the same or different from each other.
However, 1 ≤ m1 + m7 ≤ 5, 0 ≤ m2 + m8 ≤ 5, and 0 ≤ m3 + m9 ≤ 5.
^X0 represents a hydrocarbon group having 1 to 72 carbon atoms, which may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
[13] ^A1 is *-X01-L01- or * ^-L01 - ^X01- , ^A2 is *-X02- ^L02- or * ^-L02 - ^X02- , and ^A3 is * ^{-X03 - L03-} or * ^{-L03 - X03-} ( ^X01 , ^X02 and ^X03 each independently represent -O-, -CO-, -S- or ^-SO2- . ^L01 , ^L02 and ^L03 each independently represent a hydrocarbon group having ₁ to 19 carbon atoms, the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S- or _-SO2- . * is ^R1 , R ² or R ³ represents the bonding site with the benzene ring.) The carboxylate salt described in [12].
[14] The carboxylate salt according to [13], wherein ^X01 , ^X02 , and ^X03 are each independently -O- or -S-.
[15] The carboxylate salt according to [13] or [14], wherein ^L01 , ^L02 , and ^L03 are each independently an alkanediyl group having 1 to 6 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-).
[16] R ¹⁰ represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have substituents, and one of the _-CH2- contained in the alicyclic hydrocarbon group is replaced by a group represented by formula (R ^10-1 ), and R ^f1 and R ^f2 are fluorine atoms, according to any one of [12] to [15].
[17] A carboxylate salt according to any one of [12] to [16], wherein ^X0 is an aliphatic hydrocarbon group having 1 to 72 carbon atoms which may have substituents (the _-CH2- contained in the aliphatic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ), an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents, a group represented by formula (aa), or a group represented by formula (bb).
[In formula (aa),
X ^a and X ^b each independently represent -O- or -S-.
^X1a represents a hydrocarbon group having 1 to 24 carbon atoms, which may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
^X2a represents a hydrocarbon group having 1 to 48 carbon atoms, which may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
* indicates the bond site with the carbon atom of ^-COO- .
[In formula (bb),
L ^A represents a C1-C6 alkanediyl group which may have a fluorine atom, or a C6-C14 aromatic hydrocarbon group which may have a halogen atom or a C1-C4 perfluoroalkyl group.
L ^B represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the _-CH2- contained in the alkanediyl group may be replaced with -O-, -S-, -CO-, or _-SO2- .
R ^A represents a hydrocarbon group having 1 to 36 carbon atoms, which may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
* indicates the bond site with the carbon atom of ^-COO- .
[18] ^X0 may have a fluorine atom, a perfluoroalkyl group having 1 to 4 carbon atoms, or a cycloidal hydrocarbon group having 3 to 36 carbon atoms (the _-CH2- contained in the cycloidal hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ), or a group combining a cycloidal hydrocarbon group having 3 to 36 carbon atoms and a chain hydrocarbon group having 1 to 18 carbon atoms (the _-CH2- contained in the cycloidal hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- , and the _-CH2- contained in the chain hydrocarbon group The - may be replaced with -O- or -CO-, and the alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, a C1-C4 perfluoroalkyl group or a hydroxyl group.), a C6-C36 aromatic hydrocarbon group which may have a fluorine atom, a C1-C4 perfluoroalkyl group or a hydroxyl group, a group represented by formula (aa), or a group represented by formula (bb) [17] carboxylate salt.

By using the resist composition containing the carboxylate salt of the present invention, resist patterns with good line edge roughness (LER) can be manufactured.

In this specification, "(meth)acrylic monomer" means "at least one of acrylic monomers and methacrylic monomers." The notations "(meth)acrylate" and "(meth)acrylic acid" also have the same meaning. For groups described herein that can take both linear and branched structures, either is acceptable. When the _-CH2- contained in hydrocarbon groups, etc., is replaced by -O-, -S-, -CO- or _-SO2- , the same example shall apply to each group. "Combined group" means a group formed by bonding two or more of the exemplified groups, and the valencies of these groups may be appropriately changed depending on the bonding configuration. "Derived from" or "induced" means that the polymerizable C=C bond contained in the molecule becomes a -C-C- group (single bond) through polymerization. If stereoisomers exist, all stereoisomers are included.
In this specification, "solid content of the resist composition" means the total amount of the resist composition excluding the solvent (E) described later.

[Carboxylate salt represented by formula (I)]
The present invention relates to a carboxylate salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)" or "carboxylate salt (I)").
In carboxylate salts (I), the negatively charged side is sometimes called the "anion (I)," and the positively charged side is sometimes called the "cation (I)."
[In the formula, all signs have the same meaning as described above.]

[Cation (I)]
The cation (I) of the carboxylate salt represented by formula (I) is the cation represented by formula (I-C).
[In equation (I-C), all signs have the same meaning as in equation (I).]

In formula (I), examples of alkanediyl groups in ^L10 contained in ^R1 , ^R2 , and ^R3 include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, and hexane-1,6-diyl group; and branched alkanediyl groups such as 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, and 2-methylbutane-1,4-diyl group.
^L10 is preferably an alkanediyl group having 1 to 3 carbon atoms, and more preferably a methylene group.

The alicyclic hydrocarbon group ^R10 contained in ^R1 , ^R2 , and ^R3 may be either monocyclic or polycyclic. Examples of alicyclic hydrocarbon groups include the groups shown below. The bonding site can be at any position.
Specifically, monocyclic alicyclic hydrocarbon groups include monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl. Polycyclic alicyclic hydrocarbon groups include polycyclic cycloalkyl groups such as decahydronaphthyl, adamantyl, and norbornyl; cycloalkyl groups such as spirocyclohexane-1,2'-cyclopentane and spiroadamantane-2,3'-cyclopentane; and spiro rings having cycloalkyl groups spiro-bonded to norvonyl or adamantyl groups. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, and even more preferably 3 to 12.
The alicyclic hydrocarbon group of R ¹⁰ is preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms, more preferably an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and even more preferably an adamantyl group.

Substituents for a C3- to C18 alicyclic hydrocarbon group that may have substituents include halogen atoms or C1- to C18 hydrocarbon groups (where the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- ).
Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
Examples of hydrocarbon groups having 1 to 18 carbon atoms include chain-type hydrocarbon groups such as alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these.
Examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, and dodecyl group.
The number of carbon atoms in the chain-like hydrocarbon group is preferably 1 to 12, more preferably 1 to 9, even 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. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, and norbornyl. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, and even more preferably 3 to 12.
Specifically, examples of alicyclic hydrocarbon groups include the same groups as those described above.
Examples of aromatic hydrocarbon groups include phenyl groups, naphthyl groups, biphenyl groups, anthryl groups, phenanthryl groups, and binaphthyl groups. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and even more preferably 6 to 10.

Groups formed by combining these groups include groups formed by combining an aromatic hydrocarbon group with a chain hydrocarbon group (e.g., aromatic hydrocarbon group-alkanediyl group-*, alkyl group-aromatic hydrocarbon group-*), groups formed by combining an alicyclic hydrocarbon group with a chain hydrocarbon group (e.g., alicyclic hydrocarbon group-alkanediyl group-*, alkyl group-alicyclic hydrocarbon group-*), and groups formed by combining an aromatic hydrocarbon group with an alicyclic hydrocarbon group (e.g., aromatic hydrocarbon group-alicyclic hydrocarbon group-*, alicyclic hydrocarbon group-aromatic hydrocarbon group-*). * indicates the bonding site.
Examples of aromatic hydrocarbon groups—alkanediyl groups—* include aralkyl groups such as benzyl and phenethyl groups.
Examples of alkyl groups—aromatic hydrocarbon groups—* include tolyl groups, xylyl groups, and cumenyl groups.
Examples of alicyclic hydrocarbon groups - alkanediyl groups - * include cyclohexylmethyl group, cyclohexylethyl group, 1-(adamantan-1-yl)methyl group, 1-(adamantan-1-yl)-1-methylethyl, and other cycloalkylalkyl groups.
Examples of alkyl groups—alicyclic hydrocarbon groups—* include methylcyclohexyl groups, dimethylcyclohexyl groups, 2-alkyladamantan-2-yl groups, and other cycloalkyl groups having alkyl groups.
Examples of aromatic hydrocarbon groups—alicyclic hydrocarbon groups—* include phenylcyclohexyl groups.
Examples of alicyclic hydrocarbon groups—aromatic hydrocarbon groups—* include cyclohexylphenyl groups.
In addition, two or more types of alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined. Furthermore, _{the -CH2-} contained in alicyclic hydrocarbon groups and chain hydrocarbon groups (alkanediyl groups, alkyl groups) may be replaced with -O-, -CO-, -S-, or _-SO2- . Any of the combined groups may be bonded to the alicyclic hydrocarbon group.

Groups in which the _-CH2- contained in a hydrocarbon group is replaced with -O-, -S-, -CO-, or _-SO2- include: hydroxyl group (a group in which the _-CH2- contained in a methyl group is replaced with -O-), carboxyl group (a group in which the _-CH2 - _CH2- contained in an ethyl group is replaced with -O-CO-), thiol group (a group in which the _-CH2- contained in a methyl group is replaced with -S-), alkoxy group (a group in which the _-CH2- at any position in an alkyl group is replaced with -O-), alkoxycarbonyl group (a group in which the _-CH2 - _CH2- at any position in an alkyl group is replaced with -O-CO-), alkylthio group (a group in which the _-CH2- at any position in an alkyl group is replaced with -S-), alkylcarbonyl group (a group in which the -CH2- at any position in an alkyl group is replaced with -O- ₎ Examples include groups in which - is replaced by -CO-), alkylcarbonyloxy groups (groups in which _{-CH2- CH2-} at any position in the alkyl group is replaced by -CO-O-), alkylsulfonyl groups (groups in which _-CH2- at any position in the alkyl group is replaced by _-SO2- ), cycloalkoxy groups, cycloalkylalkoxy groups, alkoxycarbonyloxy groups, aromatic hydrocarbon group-carbonyloxy groups, and groups that combine two or more of these groups.
Examples of alkoxy groups include alkoxy groups having 1 to 17 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, and undecyloxy groups. The number of carbon atoms in the alkoxy group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Alkoxycarbonyl groups, alkylcarbonyl groups, and alkylcarbonyloxy groups represent groups in which a carbonyl group or carbonyloxy group is bonded to an alkyl group or alkoxy group as described above.
Examples of alkoxycarbonyl groups include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, and butoxycarbonyl groups. Examples of alkylcarbonyl groups include alkylcarbonyl groups having 2 to 18 carbon atoms, such as acetyl, propionyl, and butyryl groups. Examples of alkylcarbonyloxy groups include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as acetyloxy, propionyloxy, and butyryloxy groups. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 to 3. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 to 3. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 to 3.
Examples of alkylthio groups include alkylthio groups having 1 to 17 carbon atoms, such as methylthio groups, ethylthio groups, and propylthio groups. The number of carbon atoms in the alkylthio group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of alkylsulfonyl groups include alkylsulfonyl groups having 1 to 17 carbon atoms, such as methylsulfonyl groups, ethylsulfonyl groups, and propylsulfonyl groups. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of cycloalkoxy groups include cycloalkoxy groups having 3 to 17 carbon atoms, such as the cyclohexyloxy group. Examples of cycloalkylalkoxy groups include cycloalkylalkoxy groups having 4 to 17 carbon atoms, such as the cyclohexylmethoxy group. Examples of alkoxycarbonyloxy groups include alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as the butoxycarbonyloxy group. Examples of aromatic hydrocarbon group-carbonyloxy groups include aromatic hydrocarbon group-carbonyloxy groups having 7 to 17 carbon atoms, such as the benzoyloxy group.
Furthermore, groups in which the _-CH2- contained in an alicyclic hydrocarbon group is replaced with -O-, -S-, -CO-, or _-SO2- include the groups shown below. The -O- or -CO- in the groups shown below may be replaced with -S- or _-SO2- . The bonding site can be at any position.
If the _-CH2- contained in a hydrocarbon group is replaced by -O-, -S-, -CO-, or _-SO2- , the number of carbon atoms before the replacement is considered the total number of carbon atoms in the hydrocarbon group. This number may be one or two or more.

One of the _-CH2- groups in the alicyclic hydrocarbon group of ^R10 is replaced by -CO- or a group represented by formula ( ^R10-1 ).
[In formula (R ¹⁰ -1),
R ^f1 and R ^f2 each independently represent a hydrogen atom, a fluorine atom, or a C1-C6 alkyl fluoride.
s represents an integer between 0 and 10, and when s is 2 or greater, multiple R ^f1 and R ^f2 are either identical or distinct.

Examples of fluoride alkyl groups for R ^f1 and R ^f2 include difluoromethyl group, trifluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1-(trifluoromethyl)-1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis( Examples include trifluoro)methyl-2,2,2-trifluoroethyl group, 2-(perfluoropropyl)ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2-(perfluorobutyl)ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group, and perfluorohexyl group. Among these, trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, etc. are preferred. The number of carbon atoms in the alkyl fluoride is preferably 1 to 4, and more preferably 1 to 3.
R ^f1 and R ^f2 are preferably, independently, a hydrogen atom, a fluorine atom, or a C1-C3 alkyl fluoride, more preferably a hydrogen atom or a fluorine atom, and even more preferably a fluorine atom.

s is preferably an integer from 0 to 8, more preferably an integer from 0 to 6, even more preferably an integer from 0 to 4, and even more preferably an integer from 1 to 3.
In other words, the following groups, which are rings containing -O-C-O-,
The following are even more preferable.
^R1 , ^R2 , and ^R3 are preferably *-O-CO-R ¹⁰ , *-O-CO-O-R ¹⁰ , or *-O-L ¹⁰ -CO-O-R ¹⁰ , and more preferably *-O-CO-R ¹⁰ or *-O-L ¹⁰ -CO-O-R ^10. * represents the bonding site with the benzene ring.
The bonding positions of ^R1 , ^R2 , and ^R3 to the benzene ring can be independently any of the ortho, meta, or para positions relative to the bonding positions of ^A1 , ^A2 , and ^A3 . In particular, it is preferable that ^R1 , ^R2 , and ^R3 are independently bonded to the para or meta positions relative to the bonding positions of ^A1 , ^A2 , and ^A3 , and more preferably bonded to the para position.

Examples of halogen atoms for ^R4 , ^R5 , ^R6 , ^R7 , ^R8 , and ^R9 include fluorine, chlorine, bromine, and iodine atoms.
The C1-C12 haloalkyl groups ^R4 , ^R5 , ^R6 , ^R7 , ^R8 , and ^R9 represent C1-C12 alkyl groups having a halogen atom, and include C1-C12 alkyl fluorides, C1-C12 alkyl chlorides, C1-C12 alkyl bromides, and C1-C12 alkyl iodides. Examples of haloalkyl groups include C1-C12 perfluoroalkyl groups (trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, etc.), 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, and 3,3,4,4,4-pentafluorobutyl group, chloromethyl group, bromomethyl group, and iodomethyl group. The number of carbon atoms in the haloalkyl group is preferably 1-9, more preferably 1-6, even more preferably 1-4, and even more preferably 1-3.
Examples of hydrocarbon groups having 1 to 18 carbon atoms in ^R4 , ^R5 , ^R6 , ^R7 , ^R8 , and ^R9 include chain-type hydrocarbon groups such as alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these.
Examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, and dodecyl group.
The number of carbon atoms in the chain-like hydrocarbon group is preferably 1 to 12, more preferably 1 to 9, even 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 bonding site can be at any position.
Specifically, monocyclic alicyclic hydrocarbon groups include monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl. Polycyclic alicyclic hydrocarbon groups include polycyclic cycloalkyl groups such as decahydronaphthyl, adamantyl, and norbornyl. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, and even more preferably 3 to 12.
Examples of aromatic hydrocarbon groups include phenyl groups, naphthyl groups, biphenyl groups, anthryl groups, phenanthryl groups, and binaphthyl groups. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and even more preferably 6 to 10.
Groups formed by combination include groups formed by combining an aromatic hydrocarbon group and a chain hydrocarbon group (e.g., aromatic hydrocarbon group-alkanediyl group-*, alkyl group-aromatic hydrocarbon group-*), groups formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group (e.g., alicyclic hydrocarbon group-alkanediyl group-*, alkyl group-alicyclic hydrocarbon group-*), and groups formed by combining an aromatic hydrocarbon group and an alicyclic hydrocarbon group (e.g., aromatic hydrocarbon group-alicyclic hydrocarbon group-*, alicyclic hydrocarbon group-aromatic hydrocarbon group-*). * indicates a bonding site. Here, the _-CH2- contained in chain hydrocarbon groups such as alkanediyl groups and alkyl groups, aromatic hydrocarbon groups, and alicyclic hydrocarbon groups may be replaced with -O-, -CO-, -S-, or _-SO2- .
Examples of aromatic hydrocarbon groups—alkanediyl groups—* include aralkyl groups such as benzyl and phenethyl groups.
Examples of alkyl groups—aromatic hydrocarbon groups—* include tolyl groups, xylyl groups, and cumenyl groups.
Examples of alicyclic hydrocarbon groups - alkanediyl groups - * include cyclohexylmethyl group, cyclohexylethyl group, 1-(adamantan-1-yl)methyl group, 1-(adamantan-1-yl)-1-methylethyl group, and other cycloalkylalkyl groups.
Examples of alkyl groups—alicyclic hydrocarbon groups—* include methylcyclohexyl groups, dimethylcyclohexyl groups, 2-alkyladamantan-2-yl groups, and other cycloalkyl groups having alkyl groups.
Examples of aromatic hydrocarbon groups—alicyclic hydrocarbon groups—* include phenylcyclohexyl groups.
Examples of alicyclic hydrocarbon groups—aromatic hydrocarbon groups—* include cyclohexylphenyl groups.
In addition, in the combinations, two or more types of alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined. Furthermore, any of these groups may be bonded to a benzene ring.
Groups in which the _-CH2- contained in haloalkyl groups and hydrocarbon groups are replaced with -O-, -S-, -CO-, or _-SO2- include: hydroxyl group (a group in which the _-CH2- contained in a methyl group is replaced with -O-), thiol group (a group in which the _-CH2- contained in a methyl group is replaced with -S-), carboxyl group (a group in which the _-CH2 - _CH2- contained in an ethyl group is replaced with -O-CO-), alkoxy group (a group in which the _-CH2- at any position in an alkyl group is replaced with -O-), alkylthio group (a group in which the _-CH2- at any position in an alkyl group is replaced with -S-), alkoxycarbonyl group (a group in which the _-CH2 - _CH2- at any position in an alkyl group is replaced with -O-CO-), alkylcarbonyl group (a group in which the _-CH2- at any position in an alkyl group is replaced with -O-CO-) －, a group in which - is replaced by -CO-), alkylsulfonyl group (a group in which _-CH2- at any position in the alkyl group is replaced by _-SO2- ), alkylcarbonyloxy group (a group in which _-CH2 - _CH2- at any position in the alkyl group is replaced by -CO-O-), oxy group (a group in which _-CH2- in the methylene group is replaced by -O-), carbonyl group (a group in which _-CH2- in the methylene group is replaced by -CO-), thio group (a group in which _-CH2- in the methylene group is replaced by -S-), sulfonyl group (a group in which _-CH2- in the methylene group is replaced by _-SO2- ), alkanediyloxy group (a group in which -CH2- at any position in the alkanediyl group is replaced by -CO- ₎ (A group in which - is replaced by -O-), Alkanediyloxycarbonyl group (A group in which _-CH2 - _CH2- at any position in the alkanediyl group is replaced by -O-CO-), Alkanediylcarbonyl group (A group in which _-CH2- at any position in the alkanediyl group is replaced by -CO-), Alkanediylcarbonyloxy group (A group in which _-CH2 - _CH2- at any position in the alkanediyl group is replaced by -CO-O-), Alkanediylthio group (A group in which _-CH2- at any position in the alkanediyl group is replaced by -S-), Alkanediylsulfonyl group (A group in which _-CH2- at any position in the alkanediyl group is replaced by _-SO2 Examples include groups in which - is replaced by -), cycloalkoxy groups, cycloalkylalkoxy groups, alkoxycarbonyloxy groups, aromatic hydrocarbon group-carbonyloxy groups, aromatic hydrocarbon group-carbonyl groups, aromatic hydrocarbon group-oxy groups, haloalkoxy groups (groups in which _-CH2- at any position in a haloalkyl group is replaced by -O-), haloalkoxycarbonyl groups (groups in which _-CH2 - _CH2- at any position in a haloalkyl group is replaced by -O-CO-), haloalkylcarbonyl groups (groups in which _-CH2- at any position in a haloalkyl group is replaced by -CO-), haloalkylcarbonyloxy groups (groups in which _{-CH2- CH2-} at any position in a haloalkyl group is replaced by -CO-O-), and groups that combine two or more of these groups.
Examples of alkoxy groups include alkoxy groups having 1 to 17 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, and undecyloxy groups. The number of carbon atoms in the alkoxy group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of alkylthio groups 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, decylthio group, and undecylthio group. The number of carbon atoms in the alkylthio group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Alkoxycarbonyl groups, alkylcarbonyl groups, and alkylcarbonyloxy groups represent groups in which a carbonyl group or carbonyloxy group is bonded to an alkyl group or alkoxy group as described above.
Examples of alkoxycarbonyl groups include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as methoxycarbonyl groups, ethoxycarbonyl groups, and butoxycarbonyl groups. Examples of alkylcarbonyl groups include alkylcarbonyl groups having 2 to 18 carbon atoms, such as acetyl groups, propionyl groups, and butyryl groups. Examples of alkylcarbonyloxy groups include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as acetyloxy groups, propionyloxy groups, and butyryloxy groups. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3.
Examples of alkylsulfonyl groups 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, 2-ethylhexylsulfonyl group, nonylsulfonyl group, decylsulfonyl group, and undecylsulfonyl group. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of alkanediyloxy groups include alkanediyloxy groups having 1 to 17 carbon atoms, such as methyleneoxy, ethyleneoxy, propanediyloxy, butanediyloxy, and pentanediyloxy groups. The number of carbon atoms in the alkanediyloxy group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of alkanediyloxycarbonyl groups include alkanediyloxycarbonyl groups having 2 to 17 carbon atoms, such as methyleneoxycarbonyl groups, ethyleneoxycarbonyl groups, propanediyloxycarbonyl groups, and butanediyloxycarbonyl groups. Examples of alkanediylcarbonyl groups include alkanediylcarbonyl groups having 2 to 18 carbon atoms, such as methylenecarbonyl groups, ethylenecarbonyl groups, propanediylcarbonyl groups, butanediylcarbonyl groups, and pentanediylcarbonyl groups. Examples of alkanediylcarbonyloxy groups include alkanediylcarbonyloxy groups having 2 to 17 carbon atoms, such as methylenecarbonyloxy groups, ethylenecarbonyloxy groups, propanediylcarbonyloxy groups, and butanediylcarbonyloxy groups. The number of carbon atoms in the alkanediyloxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3.
Examples of alkanediylthio groups include alkanediylthio groups having 1 to 17 carbon atoms, such as methylenethio groups, ethylenethio groups, and propylenethio groups. The number of carbon atoms in the alkanediylthio group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of alkanediylsulfonyl groups include alkanediylsulfonyl groups having 1 to 17 carbon atoms, such as methylenesulfonyl groups, ethylenesulfonyl groups, and propylenesulfonyl groups. The number of carbon atoms in the alkanediylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of cycloalkoxy groups include cycloalkoxy groups having 3 to 17 carbon atoms, such as the cyclohexyloxy group. Examples of cycloalkylalkoxy groups include cycloalkylalkoxy groups having 4 to 17 carbon atoms, such as the cyclohexylmethoxy group. Examples of alkoxycarbonyloxy groups include alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as the butoxycarbonyloxy group. Examples of aromatic hydrocarbon group-carbonyloxy groups include aromatic hydrocarbon group-carbonyloxy groups having 7 to 17 carbon atoms, such as the benzoyloxy group. Examples of aromatic hydrocarbon group-carbonyl groups include aromatic hydrocarbon group-carbonyl groups having 7 to 17 carbon atoms, such as the benzoyl group. Examples of aromatic hydrocarbon group-oxy groups include aromatic hydrocarbon group-oxy groups having 6 to 16 carbon atoms, such as the phenyloxy group.
Examples of haloalkoxy groups, haloalkoxycarbonyl groups, haloalkylcarbonyl groups, and haloalkylcarbonyloxy groups include haloalkoxy groups having 1 to 11 carbon atoms, haloalkoxycarbonyl groups having 2 to 11 carbon atoms, haloalkylcarbonyl groups having 2 to 12 carbon atoms, and haloalkylcarbonyloxy groups having 2 to 11 carbon atoms. For example, groups obtained by replacing one or more hydrogen atoms of the above-mentioned groups with halogen atoms are also included.
Furthermore, groups in which the _-CH2- contained in an alicyclic hydrocarbon group is replaced with -O-, -S-, -CO-, or _-SO2- include the groups shown below. The -O- or -CO- in the groups shown below may be replaced with -S- or _-SO2- . The bonding site can be at any position.
If the _-CH2- contained in the haloalkyl group and hydrocarbon group is replaced by -O-, -S-, -CO-, or _-SO2- , the number of carbon atoms before replacement shall be the total number of carbon atoms in the hydrocarbon group. This number may be one or two or more.
Substituents that the hydrocarbon groups ^R4 , ^R5 , ^R6 , ^R7 , ^R8 , and ^R9 may have include halogen atoms, cyano groups, and C1-C12 alkyl groups (the _-CH2- contained in the alkyl group may be replaced with -O- or -CO-).
Examples of halogen atoms include the same groups as those described above.
Examples of alkyl groups having 1 to 12 carbon atoms include the same groups as those described above.
If the _-CH2- group in an alkyl group is replaced with -O- or -CO- as a substituent, the number of carbon atoms before the replacement shall be the total number of carbon atoms in the alkyl group. Examples of the replaced group include hydroxyl group, carboxyl group, alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, alkylcarbonyloxy group, etc.
Examples of alkoxy groups, alkoxycarbonyl groups, alkylcarbonyl groups, and alkylcarbonyloxy groups include alkoxy groups having 1 to 11 carbon atoms, alkoxycarbonyl groups having 2 to 11 carbon atoms, alkylcarbonyl groups having 2 to 12 carbon atoms, and alkylcarbonyloxy groups having 2 to 11 carbon atoms, and are the same groups as those described above.
The hydrocarbon group may have one substituent or more substituents.

Examples of hydrocarbon groups in ^A1 , ^A2 , and ^A3 include linear or branched chain hydrocarbon groups (e.g., alkanediyl groups), monocyclic or polycyclic alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. Two or more of these groups may be combined. The number of carbon atoms in the hydrocarbon group is preferably 2 to 19, more preferably 2 to 18, even more preferably 2 to 16, even more preferably 2 to 14, and even more preferably 2 to 12.
Examples of chain-like hydrocarbon groups include linear alkane diyl groups such as 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, and Examples of branched alkanediyl groups include 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, and 2-methylbutane-1,4-diyl group.
The number of carbon atoms in the chain-like hydrocarbon group is preferably 2 to 18, more preferably 2 to 12, even more preferably 2 to 9, even more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples include the groups shown below. The bonding site can be at any position.
Specifically, examples include monocyclic alicyclic hydrocarbon groups such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl, as well as polycyclic alicyclic hydrocarbon groups such as norbornane-1,4-diyl, norbornane-2,5-diyl, adamantane-1,5-diyl, and adamantane-2,6-diyl.
The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, even more preferably 3 to 12, and even more preferably 3 to 10.
Examples of aromatic hydrocarbon groups include phenylene groups, naphthylene groups, anthrylene groups, biphenylene groups, phenanthrylene groups, and other arylene groups. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and even more preferably 6 to 10.
Groups formed by combination include groups formed by combining an alicyclic hydrocarbon group and an alkanediyl group, groups formed by combining an aromatic hydrocarbon group and an alkanediyl group, and groups formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group. Here, the alkanediyl group in combination with an alicyclic hydrocarbon group and/or an aromatic hydrocarbon group may contain a methylene group. In the combination, two or more types of chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups may be combined. Furthermore, any of the groups may be bonded to the benzene ring to which ^R1 , ^R2 , or ^R3 is attached.
Examples of groups combining an alicyclic hydrocarbon group and an alkanediyl group include -divalent alicyclic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent alicyclic hydrocarbon group-alkanediyl group-, and -alkanediyl group-divalent alicyclic hydrocarbon group-.
Examples of groups combining an aromatic hydrocarbon group and an alkanediyl group include -divalent aromatic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent aromatic hydrocarbon group-alkanediyl group-, and -alkanediyl group-divalent aromatic hydrocarbon group-.
Examples of groups combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group include -aromatic hydrocarbon group-alicyclic hydrocarbon group-, -alicyclic hydrocarbon group-aromatic hydrocarbon group-, and -alicyclic hydrocarbon group-aromatic hydrocarbon group-alicyclic hydrocarbon group-.

If the _-CH2- contained in a hydrocarbon group is replaced by -O-, -CO-, -S-, or _-SO2- , the number of carbon atoms before the replacement is considered the total number of carbon atoms in the hydrocarbon group. This number may be one or two or more.
Groups in which the _-CH2- contained in a hydrocarbon group is replaced with -O-, -CO-, -S-, or _-SO2- include: hydroxyl group (a group in which the _-CH2- contained in a methyl group is replaced with -O-), carboxyl group (a group in which the _-CH2 - _CH2- contained in an ethyl group is replaced with -O-CO-), thiol group (a group in which the _-CH2- contained in a methyl group is replaced with -S-), alkoxy group (a group in which the _-CH2- at any position in an alkyl group is replaced with -O-), alkoxycarbonyl group (a group in which the _-CH2 - _CH2- at any position in an alkyl group is replaced with -O-CO-), alkylcarbonyl group (a group in which the _-CH2- at any position in an alkyl group is replaced with -CO-), alkylcarbonyloxy group (a group in which the -CH2 _- CH2- at any position in an alkyl group is replaced with -O- ₎ －, a group in which - is replaced by -CO-O-), alkylthio group (a group in which _-CH2- at any position in the alkyl group is replaced by -S-), alkylsulfonyl group (a group in which _-CH2- at any position in the alkyl group is replaced by _-SO2- ), oxy group (a group in which _-CH2- in the methylene group is replaced by -O-), carbonyl group (a group in which _-CH2- in the methylene group is replaced by -CO-), thio group (a group in which _-CH2- in the methylene group is replaced by -S-), sulfonyl group (a group in which _-CH2- in the methylene group is replaced by _-SO2- ), alkanediyloxy group (a group in which -CH2- at any position in the alkanediyl group is replaced by -CO- ₎ (A group in which - is replaced by -O-), Alkanediyloxycarbonyl group (A group in which -CH2 _{-CH2- at} any position in the alkanediyl group is replaced by -O-CO-), Alkanediylcarbonyl group (A group in which _-CH2- at any position in the alkanediyl group is replaced by -CO-), Alkanediylcarbonyloxy group (A group in which _-CH2 - _CH2- at any position in the alkanediyl group is replaced by -CO-O-), Alkanediylsulfonyl group (A group in which _-CH2- at any position in the alkanediyl group is replaced by _-SO2- ), Alkanediylthio group (A group in which -CH2- at any position in the alkanediyl group is replaced by _-SO2-) Examples include groups in which - is replaced by -S-, cycloalkoxy groups, cycloalkylalkoxy groups, alkoxycarbonyloxy groups, aromatic hydrocarbon group-carbonyloxy groups, aromatic hydrocarbon group-carbonyl groups, aromatic hydrocarbon group-oxy groups, and groups that combine two or more of these groups.
Examples of alkoxy groups include alkoxy groups having 1 to 17 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, and undecyloxy groups. The number of carbon atoms in the alkoxy group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Alkoxycarbonyl groups, alkylcarbonyl groups, and alkylcarbonyloxy groups represent groups in which a carbonyl group or carbonyloxy group is bonded to an alkyl group or alkoxy group as described above.
Examples of alkoxycarbonyl groups include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as methoxycarbonyl groups, ethoxycarbonyl groups, and butoxycarbonyl groups. Examples of alkylcarbonyl groups include alkylcarbonyl groups having 2 to 18 carbon atoms, such as acetyl groups, propionyl groups, and butyryl groups. Examples of alkylcarbonyloxy groups include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as acetyloxy groups, propionyloxy groups, and butyryloxy groups. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3.
Examples of alkylthio groups 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, decylthio group, and undecylthio group. The number of carbon atoms in the alkylthio group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of alkylsulfonyl groups 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, 2-ethylhexylsulfonyl group, nonylsulfonyl group, decylsulfonyl group, and undecylsulfonyl group. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of alkanediyloxy groups include alkanediyloxy groups having 1 to 17 carbon atoms, such as methyleneoxy, ethyleneoxy, propanediyloxy, butanediyloxy, and pentanediyloxy groups. The number of carbon atoms in the alkanediyloxy group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of alkanediyloxycarbonyl groups include alkanediyloxycarbonyl groups having 2 to 17 carbon atoms, such as methyleneoxycarbonyl groups, ethyleneoxycarbonyl groups, propanediyloxycarbonyl groups, and butanediyloxycarbonyl groups. Examples of alkanediylcarbonyl groups include alkanediylcarbonyl groups having 2 to 18 carbon atoms, such as methylenecarbonyl groups, ethylenecarbonyl groups, propanediylcarbonyl groups, butanediylcarbonyl groups, and pentanediylcarbonyl groups. Examples of alkanediylcarbonyloxy groups include alkanediylcarbonyloxy groups having 2 to 17 carbon atoms, such as methylenecarbonyloxy groups, ethylenecarbonyloxy groups, propanediylcarbonyloxy groups, and butanediylcarbonyloxy groups. The number of carbon atoms in the alkanediyloxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3.
Examples of alkanediylsulfonyl groups include alkanediylsulfonyl groups having 1 to 17 carbon atoms, such as methylenesulfonyl groups, ethylenesulfonyl groups, and propylenesulfonyl groups. The number of carbon atoms in the alkanediylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of alkanediylthio groups include alkanediylthio groups having 1 to 17 carbon atoms, such as methylenethio groups, ethylenethio groups, and propylenethio groups. The number of carbon atoms in the alkanediylthio group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.
Examples of cycloalkoxy groups include cycloalkoxy groups having 3 to 17 carbon atoms, such as the cyclohexyloxy group. Examples of cycloalkylalkoxy groups include cycloalkylalkoxy groups having 4 to 17 carbon atoms, such as the cyclohexylmethoxy group. Examples of alkoxycarbonyloxy groups include alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as the butoxycarbonyloxy group. Examples of aromatic hydrocarbon group-carbonyloxy groups include aromatic hydrocarbon group-carbonyloxy groups having 7 to 17 carbon atoms, such as the benzoyloxy group. Examples of aromatic hydrocarbon group-carbonyl groups include aromatic hydrocarbon group-carbonyl groups having 7 to 17 carbon atoms, such as the benzoyl group. Examples of aromatic hydrocarbon group-oxy groups include aromatic hydrocarbon group-oxy groups having 6 to 16 carbon atoms, such as the phenyloxy group.

Furthermore, the following groups are examples of groups in which the _-CH2- contained in an alicyclic hydrocarbon group is replaced with -O-, -CO-, -S-, or _-SO2- . The -O- or -CO- in the following groups may be replaced with -S- or _-SO2- . The bonding site can be at any position.
The substituents that the hydrocarbon groups ^A1 , ^A2 , and ^A3 may have include the same groups as those listed in ^R4 to ^R9 .

Preferably, ^A1 , ^A2 , and ^A3 are each independently a hydrocarbon group having 2 to 20 carbon atoms (the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- ; however, at least one of the _-CH2- contained in the hydrocarbon group is replaced with _-O- , -CO-, -S-, or -SO2-). Specifically, ^A1 is * ^-L011 - ^X01 -L012-, ^A2 is * ^-L021 -X02- ^L022- , and ^A3 is * ^-L031 - ^X03 - ^L032- ( ^X01 , ^X02 and ^X03 each independently represent -O-, -CO-, -S- or ^-SO2- ). ^L011 , ^L012 , ^L021 , ^L022 , ^{L031 and L032} each independently represent a single bond or a hydrocarbon group having 1 to 19 carbon atoms, and the hydrocarbon group may have substituents, and _{the -CH2- contained} in the hydrocarbon group may be replaced with -O-, -CO-, -S- or _-SO2- . However, L The total number of carbon atoms in ⁰¹¹ and L ⁰¹² is 1 to 19, the total number of carbon atoms in L ⁰²¹ and L ⁰²² is 1 to 19, and the total number of carbon atoms in L ⁰³¹ and L ⁰³² is 1 to 19. (* represents the bonding site with the benzene ring to which R ¹ , R ² , or R ³ is bonded.) It is more preferable that A ¹ is *-X ⁰¹ -L ^01- or *-L ⁰¹ -X ^01- , A ² is *-X ⁰² -L ^02- or *-L ⁰² -X ^02- , and A ³ is *-X ⁰³ -L ^03- or *-L ⁰³ -X ^03- (X ⁰¹ , X ⁰² , and X ⁰³ are each independently -O-, -CO-, -S-, or -SO2 ₎ ^L01 , ^L02 , and ^L03 each independently represent a hydrocarbon group having 1 to 19 carbon atoms, and the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- . * represents the bonding site with the benzene ring to which ^R1 , ^R2 , or ^R3 is bonded.) It is even more preferable that this is the case.
The hydrocarbon groups having 1 to 19 carbon atoms in ^L011 , ^L012 , ^L021 , ^L022 , ^L031 , ^L032 , ^L01 , ^L02 , and ^L03 (the hydrocarbon groups may have substituents, and the _-CH2- contained in the hydrocarbon groups may be replaced with -O-, -CO-, -S-, or _-SO2- ) include groups in the range of 1 to 19 carbon atoms, similar to the groups listed in ^A1 , ^A2 , and ^A3 .
^X01 , ^X02 , and ^X03 are each preferably -O- or -S-, and more preferably -O-.
^L011 , ^L012 , ^L021 , ^L022 , ^L031 and ^L032 are each preferably independently single bonds or hydrocarbon groups having 1 to 18 carbon atoms (the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- ), more preferably single bonds or hydrocarbon groups having 1 to 14 carbon atoms (the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- ), and more preferably single bonds, chain hydrocarbon groups having 1 to 9 carbon atoms, alicyclic hydrocarbon groups having 3 to 12 carbon atoms, or groups combining chain hydrocarbon groups having 1 to 4 carbon atoms and alicyclic hydrocarbon groups having 3 to 10 carbon atoms (the _-CH2- contained in the chain hydrocarbon group and the alicyclic hydrocarbon group may be replaced with -O-, -CO-, -S-, or -SO2- ₎ It is even more preferable that it is a single bond or an alkanediyl group having 1 to 6 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-), it is even more preferable that it is a single bond or an alkanediyl group having 1 to 4 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-), and it is even more preferable that it is a single bond or an alkanediyl group having 1 to 3 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-). In particular, it is preferable that the group is a single bond, a methylene group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-2,2-diyl group, a carbonyl group, a carbonyloxy group, a carbonyloxymethylene group, an ethyleneoxy group, a methylenecarbonyloxymethylene group, or an ethyleneoxycarbonyl group, and more preferably a single bond, a methylene group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-2,2-diyl group, or a carbonyl group. However, the total number of carbon atoms in L ⁰¹¹ and L ⁰¹² is 1 to 19, the total number of carbon atoms in L ⁰²¹ and L ⁰²² is 1 to 19, and the total number of carbon atoms in L ⁰³¹ and L ⁰³² is 1 to 19.
^L01 , ^L02 , and ^L03 are each preferably, independently, a hydrocarbon group having 1 to 18 carbon atoms (the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- ), more preferably a hydrocarbon group having 1 to 14 carbon atoms (the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- ), and a group consisting of a chain hydrocarbon group having 1 to 9 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or a combination of a chain hydrocarbon group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 3 to 10 carbon atoms (the _-CH2- contained in the chain hydrocarbon group and the alicyclic hydrocarbon group may be replaced with -O-, -CO-, -S-, or -SO2- _). It is even more preferable that the group is an alkanediyl group having 1 to 6 carbon atoms (where the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-), it is even more preferable that the group is an alkanediyl group having 1 to 4 carbon atoms (where the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-), and it is even more preferable that the group is an alkanediyl group having 1 to 3 carbon atoms (where the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-). In particular, it is preferable that the group is a methylene group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-2,2-diyl group, a carbonyl group, a carbonyloxy group, a carbonyloxymethylene group, an ethyleneoxy group, a methylenecarbonyloxymethylene group, or an ethyleneoxycarbonyl group, and more preferably a methylene group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-2,2-diyl group, or a carbonyl group.

The bonding positions of ^A1 , ^A2 , and ^A3 to the benzene ring where the S ⁺ is bonded can be independently any of the ortho, meta, or para positions relative to the S ⁺ bonding position. In particular, when there is 1 m1, m2, and m3, it is preferable that ^A1 , ^A2 , and ^A3 are independently bonded to the para or meta position relative to the S ⁺ bonding position, and more preferably to the para position. When there are 2 m1, m2, and m3, it is preferable that ^{one A1} , ^A2 , and ^A3 are independently bonded to the ortho or meta position relative to the S ⁺ bonding position, one A1, A2, and A3 are independently bonded to the ortho or meta position, and more preferably two A1, A2, and A3 are bonded to the meta position. When m1, m2, and m3 are 3, it is preferable that ^A1 , ^A2 , and ^A3 , independently, have two bonded to the oro or m position and one bonded to the p or m position relative to the S ⁺ bond site, and it is more preferable that two bonded to the m position and one bonded to the p position. When m1, m2, and m3 are 4, it is preferable that ^A1 , ^A2 , and ^A3 , independently, have two bonded to the oro or m position and two bonded to the p or m position relative to the S ⁺ bond site, and it is more preferable that two bonded to the oro position and two bonded to the m position.
m1 is preferably 1, 2, 3, or 4, more preferably 1, 2, or 3, even more preferably 1 or 2, and even more preferably 1.
m2 is preferably 0, 1, 2, 3, or 4, more preferably 0, 1, 2, or 3, even more preferably 0, 1, or 2, and even more preferably 0 or 1.
m3 is preferably 0, 1, 2, 3, or 4, more preferably 0, 1, 2, or 3, even more preferably 0, 1, or 2, and even more preferably 0 or 1.
m4 is preferably 0, 1, 2, or 4, and more preferably 0, 1, or 2.
m5 is preferably 0, 1, 2, or 4, and more preferably 0, 1, or 2.
m6 is preferably 0, 1, 2, or 4, and more preferably 0, 1, or 2.
m7 is preferably 0, 1, 2, or 3, more preferably 0, 1, or 2, and even more preferably 0 or 1.
m8 is preferably 0, 1, 2, or 3, more preferably 0, 1, or 2, and even more preferably 0 or 1.
m9 is preferably 0, 1, 2, or 3, more preferably 0, 1, or 2, and even more preferably 0 or 1.
In particular, it is preferable that at least one of m8 and m9 is an integer of 1 or more, and it is more preferable that both m8 and m9 are integers of 1 or more.
^R4 , ^R5 , and ^R6 are each preferably, independently, a halogen atom, a C1-C6 fluorinated alkyl group, or a C1-C6 alkyl group (where the _-CH2- group in the alkyl group may be replaced with -O- or -CO-); more preferably a halogen atom, a C1-C4 fluorinated alkyl group, or a C1-C4 alkyl group (where the _-CH2- group in the alkyl group may be replaced with -O- or -CO-); even more preferably a fluorine atom, an iodine atom, a C1-C4 perfluoroalkyl group, or a C1-C4 alkyl group (where the _-CH2- group in the alkyl group may be replaced with -O- or -CO-); and even more preferably a fluorine atom, an iodine atom, a hydroxyl group, a methoxy group, or a trifluoromethyl group.
The bonding positions of ^R4 , ^R5 , and ^R6 to the benzene ring can be independently any of the ortho, meta, or para positions relative to the bonding positions of ^A1 , ^A2 , and ^A3 . In particular, when there is one m4, m5, and m6, it is preferable that ^R4 , ^R5 , and ^R6 are independently bonded to the para or meta positions relative to the bonding positions of ^A1 , ^A2 , and ^A3 , and more preferably to the meta positions. When there are two m4, m5, and m6, it is preferable that ^{one R4} , ^R5 , and ^R6 are independently bonded to the ortho or meta positions, one R4, R5, and R6 are independently bonded to the para or meta positions relative to the bonding positions of ^A1 , ^A2 , and ^A3 , and more preferably that both R4, R5, and R6 are independently bonded to the meta positions. When m4, m5, and m6 are 3, it is preferable that two ^R4 , ^R5 , and ^R6 are independently bonded to the bond sites of ^A1 , ^A2 , and ^A3 at the o or m position, and one at the p or m position, and it is more preferable that one is bonded at the o position and two are bonded at the m position. When m4, m5, and m6 are 4, it is preferable that two ^R4 , ^R5 , and ^R6 are independently bonded to the bond sites of ^A1 , ^A2 , and ^A3 at the o or m position, and two are bonded at the p or m position, and it is more preferable that two are bonded at the o position and two are bonded at the m position.
^R7 , ^R8 , and ^R9 are each preferably, independently, a halogen atom, a C1-C6 fluorinated alkyl group, or a C1-C6 alkyl group (where the _-CH2- contained in the alkyl group may be replaced with -O- or -CO-), more preferably a halogen atom, a C1-C4 fluorinated alkyl group, or a C1-C4 alkyl group (where the _-CH2- contained in the alkyl group may be replaced with -O- or -CO-), even more preferably a fluorine atom, an iodine atom, a C1-C4 perfluoroalkyl group, or a C1-C4 alkyl group (where the _-CH2- contained in the alkyl group may be replaced with -O- or -CO-), and even more preferably a fluorine atom, an iodine atom, a trifluoromethyl group, a hydroxyl group, a methoxy group, a methyl group, or a t-butyl group.
The bonding positions of ^R7 , ^R8 , and ^R9 to the benzene ring can be independently any of the ortho, meta, or para positions relative to the S ⁺ bonding position. In particular, when there is one m7, m8, and m9, it is preferable that each of ^R7 , ^R8 , and ^R9 is independently bonded to the para or meta position relative to the S ⁺ bonding position, and more preferably bonded to the para position. When there are two m7, m8, and m9, it is preferable that one of ^R7 , ^R8 , and ^R9 is independently bonded to the ortho ^{or meta} position, one is bonded to the para or meta position, one is bonded to the meta position, and one is bonded to the para or meta position relative to the S+ bonding position, and more preferably one is bonded to the para or meta position. When m7, m8, and m9 are 3, it is preferable that two ^R7 , ^R8 , and ^R9 are independently bonded to the S ⁺ bond site at the oro or m position, and one at the p or m position, and it is more preferable that two are bonded to the m position and one at the p position. When m7, m8, and m9 are 4, it is preferable that two ^R7 , ^R8 , and ^R9 are independently bonded to the S ⁺ bond site at the oro or m position, and two are bonded to the p or m position, and it is more preferable that two are bonded to the m position, one is bonded to the oro position and one at the p position.

Examples of cation (I) represented by formula (I-C) include the cation represented by formula (I-C-1) (hereinafter sometimes referred to as "cation (I-C-1)").
[In formula (IC-1),
^R1 , ^R2 , ^R3 , ^R4 , ^R5 , ^R6 , ^R7 , ^R8 , ^R9 , m1, m2, m3, m4, m5, m6, m7, m8, and m9 have the same meaning as in equation (I).
^L1 , ^L2 , and ^L3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- .
^X1 , ^X2 , and ^X3 each independently represent -O- or -S-.

Examples of ^L1 , ^L2 , and ^L3 are hydrocarbon groups having 1 to 18 carbon atoms (the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- ). These include groups having 1 to 18 carbon atoms, similar to the groups listed in ^A1 , ^A2 , and ^A3 .
^X1 is preferably -O-.
^X2 is preferably -O-.
^X3 is preferably -O-.
The bonding positions of ^X1 , ^X2 , and ^X3 to the benzene ring can be independently any of the ortho, meta, or para positions relative to the S ⁺ bonding position. In particular, it is preferable that the bonding positions are the same as those of ^A1 , ^A2 , and ^A3 to the benzene ring to which the S ⁺ is bonded.
^L1 , ^L2 , and ^L3 are each preferably independently a hydrocarbon group having 1 to 16 carbon atoms (the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- ), more preferably a hydrocarbon group having 1 to 14 carbon atoms (the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- ), even more preferably a chain hydrocarbon group having 1 to 9 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or a group combining a chain hydrocarbon group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 3 to 10 carbon atoms (the _-CH2- contained in the chain hydrocarbon group and the alicyclic hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- ), and further preferably an alkanediyl group having 1 to 6 carbon atoms (the -CH2- contained in the alkanediyl group ₂ - may be replaced with -O- or -CO-.) It is even more preferable that it is an alkanediyl group having 1 to 4 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-), and it is even more preferable that it is an alkanediyl group having 1 to 3 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-). In particular, it is preferable that the group is a methylene group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-2,2-diyl group, a carbonyl group, a carbonyloxy group, a carbonyloxymethylene group, an ethyleneoxy group, a methylenecarbonyloxymethylene group, or an ethyleneoxycarbonyl group, and more preferably a methylene group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-2,2-diyl group, or a carbonyl group.

Examples of cations (I) in the carboxylate salt (I) include cations represented by the following formulas (I-c-1) to (I-c-73).

[Anion (I)]
The anion (I) of the carboxylate salt represented by formula (I) is the anion represented as ^X₀ - ^COO- .
In formula (I), the hydrocarbon group represented by ^X0 includes aliphatic hydrocarbon groups (chain hydrocarbon groups such as alkyl groups, alkenyl groups, and alkynyl groups, and alicyclic hydrocarbon groups), aromatic hydrocarbon groups, and groups combining these. The _-CH2- contained in the aliphatic hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- . In the hydrocarbon group, the atom adjacent ^to _CO2- is preferably a carbon atom, and in the aliphatic hydrocarbon group, the atom adjacent ^to _CO2- is more preferably a carbon atom.
Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, octyl, and nonyl groups. The number of carbon atoms in the alkyl group is preferably 1 to 18, more preferably 1 to 12, even more preferably 1 to 9, even more preferably 1 to 6, and even more preferably 1 to 4.
Examples of alkenyl groups include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, tert-butenyl, pentenyl, hexenyl, heptenyl, octenyl, isooctenyl, and nonenyl groups.
Examples of alkynyl groups include ethynyl, propynyl, isopropynyl, butynyl, isobutynyl, tert-butynyl, pentynyl, hexynyl, octinyl, and noninyl groups.
Groups in which the _-CH2- contained in a chain hydrocarbon group is replaced with -O-, -S-, -CO-, or _-SO2- include: hydroxyl group (a group in which the _-CH2- contained in a methyl group is replaced with -O-), carboxyl group (a group in which the _-CH2 - _CH2- contained in an ethyl group is replaced with -O-CO-), thiol group (a group in which the _-CH2- contained in a methyl group is replaced with -S-), alkoxy group (a group in which the _-CH2- at any position in an alkyl group is replaced with -O-), carbonyl group (a group in which the _-CH2- contained in a methylene group is replaced with -CO-), thio group (a group in which the _-CH2- contained in a methylene group is replaced with -S-), and sulfonyl group (a group in which the _-CH2- contained in a methylene group is replaced with _-SO2- ) groups (groups in which _-CH2- in a methylene group is replaced with -O-), oxy groups (groups in which -CH2- _CH2- in an alkyl group is replaced with -O-), alkoxycarbonyl groups (groups in which _-CH2 -CH2- at any position in an alkyl group is replaced with -O-CO-), alkylcarbonyl groups (groups in which _-CH2- at any position in an alkyl group is replaced with -CO-), alkylcarbonyloxy groups (groups in which _-CH2 - _CH2- at any position in an alkyl group is replaced with -CO-O-), alkylthio groups (groups in which _-CH2- at any position in an alkyl group is replaced with -S-), alkylsulfonyl groups (groups in which _-CH2- at any position in an alkyl group is replaced with _-SO2- ), alkanediyloxy groups (groups in which -CH2- at any position in an alkanediyl group is replaced with -S- ₎ Examples include groups in which - is replaced by -O-), alkanediyloxycarbonyl groups (groups in which _-CH2 - _CH2- at any position in an alkanediyl group is replaced by -O-CO-), alkanediylcarbonyl groups (groups in which _-CH2- at any position in an alkanediyl group is replaced by -CO-), alkanediylcarbonyloxy groups (groups in which _-CH2 - _CH2- at any position in an alkanediyl group is replaced by -CO-O-), alkanediylsulfonyl groups (groups in which _-CH2- at any position in an alkanediyl group is replaced by _-SO2- ), and alkanediylthio groups (groups in which _-CH2- at any position in an alkanediyl group is replaced by -S-).
Examples of alkoxy groups include alkoxy groups having 1 to 17 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, undecyloxy, and phenyloxy groups. The number of carbon atoms in the alkoxy group is preferably 1 to 11, more preferably 1 to 6, and even more preferably 1 to 4.
Examples of alkoxycarbonyl groups include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, and butoxycarbonyl groups. Examples of alkylcarbonyl groups include alkylcarbonyl groups having 2 to 18 carbon atoms, such as acetyl, propionyl, and butyryl groups. Examples of alkylcarbonyloxy groups include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as acetyloxy, propionyloxy, and butyryloxy groups.
Examples of alkylthio groups include alkylthio groups having 1 to 17 carbon atoms, such as methylthio groups, ethylthio groups, and propylthio groups. The number of carbon atoms in the alkylthio group is preferably 1 to 11, more preferably 1 to 6, and even more preferably 1 to 4.
Examples of alkylsulfonyl groups include alkylsulfonyl groups having 1 to 17 carbon atoms, such as methylsulfonyl groups, ethylsulfonyl groups, and propylsulfonyl groups. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, and even more preferably 1 to 4.
Examples of alkanediyloxy groups, alkanediyloxycarbonyl groups, alkanediylcarbonyl groups, alkanediylcarbonyloxy groups, alkanediylsulfonyl groups, and alkanediylthio groups include alkanediyloxy groups having 1 to 17 carbon atoms, alkanediyloxycarbonyl groups having 2 to 17 carbon atoms, alkanediylcarbonyl groups having 2 to 18 carbon atoms, alkanediylcarbonyloxy groups having 2 to 17 carbon atoms, alkanediylsulfonyl groups having 1 to 17 carbon atoms, and alkanediylthio groups having 1 to 17 carbon atoms, as well as the same groups as described above.
Furthermore, the substitutions in alkenyl and alkynyl groups may include carbon-carbon double or carbon-carbon triple bonds at any position, as exemplified by the substitutions in alkyl groups described above.

The alicyclic hydrocarbon group may be monocyclic, polycyclic, or spirocyclic, and may be saturated or unsaturated. Examples of alicyclic hydrocarbon groups include the following groups. The bonding site can be at any position.
Specifically, examples include monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclononyl, cyclodecyl, and cyclododecyl groups, and polycyclic cycloalkyl groups such as norbornyl and adamantyl groups.
The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 36, more preferably 3 to 24, even more preferably 3 to 18, even more preferably 3 to 16, and even more preferably 3 to 12.
Examples of groups in which the _-CH2- contained in an alicyclic hydrocarbon group is replaced with -O-, -S-, -CO-, or _-SO2- include the following groups. The bonding site can be at any position.
As the alicyclic hydrocarbon group, a group represented by any of formulas (y1) to (y11), (y44) to (y48), or (y59) to (y61) is preferred, and a group represented by any of formulas (y3), (y4), (y9), or (y11) is more preferred.
The groups in which the _-CH2- contained in the alicyclic hydrocarbon group is replaced with -O-, -S-, -CO-, or _-SO2- are preferably groups represented by any of the formulas (y12) to (y20), (y26), (y27), (y30), (y31), (y39) to (y43), and (y49) to (y71), and more preferably groups represented by any of the formulas (y14), (y15), (y16), (y20), (y26), (y27), (y30), (y31), (y39), (y40), (y42), (y43), (y49) to (y58), and (y62) to (y71).

Examples of aromatic hydrocarbon groups include phenyl groups, naphthyl groups, biphenyl groups, anthryl groups, phenanthryl groups, binaphthyl groups, and other aryl groups. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 36, more preferably 6 to 24, even more preferably 6 to 18, even more preferably 6 to 14, and even more preferably 6 to 10.
In the case of combined groups, the above-mentioned groups may include groups with different valencies (such as alkanediyl groups, alkanetriyl groups, alkanetetrayl groups, cycloalkanediyl groups, cycloalkanetriyl groups, cycloalkanetetrayl groups, etc.).

The combined bases are,
A group combining an alicyclic hydrocarbon group and a chain hydrocarbon group (the chain hydrocarbon group and the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- ),
This represents a group formed by combining a chain hydrocarbon group and an aromatic hydrocarbon group (where the _-CH2- contained in the chain hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- ), and a group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group (where the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- ).
In addition, in the combinations, two or more types of alicyclic hydrocarbon groups, chain hydrocarbon groups, and aromatic hydrocarbon groups may be combined.
Specifically, the combined bases are:
Alicyclic hydrocarbon groups such as adamantylmethylene groups and cyclohexylmethylene groups - chain hydrocarbon groups - *, (alicyclic hydrocarbon group) ₂ - chain hydrocarbon groups - * (the _-CH2- contained in the chain hydrocarbon group and the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ),
Chain hydrocarbon groups such as methyladamantyl groups and dimethyladamantyl groups - alicyclic hydrocarbon groups - *, (chain hydrocarbon group) ₂ - alicyclic hydrocarbon groups - * (the _-CH2- contained in the chain hydrocarbon group and the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ),
Chain-type hydrocarbon groups such as tolyl groups and xylyl groups - aromatic hydrocarbon groups - * (the _-CH2- contained in the chain-type hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ),
Chain hydrocarbon group such as methylcyclohexylmethylene group - alicyclic hydrocarbon group - chain hydrocarbon group - *, (chain hydrocarbon group) ₂ - alicyclic hydrocarbon group - chain hydrocarbon group - *, (chain hydrocarbon group - alicyclic hydrocarbon group) ₂ - chain hydrocarbon group - * (the _-CH2- contained in the chain hydrocarbon group and the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ),
Aromatic hydrocarbon group such as a benzyl group - chain hydrocarbon group - * (the _-CH2- contained in the chain hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ),
A chain-like hydrocarbon group such as a tolylmethyl group - aromatic hydrocarbon group - chain-like hydrocarbon group - * (the _-CH2- contained in the chain-like hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ),
Chain hydrocarbon group such as methyladamantanemethyleneadamantyl group, di(methyladamantanemethylene)adamantyl group - alicyclic hydrocarbon group - chain hydrocarbon group - alicyclic hydrocarbon group - *, (chain hydrocarbon group - alicyclic hydrocarbon group - chain hydrocarbon group) ₂ - alicyclic hydrocarbon group - *, (chain hydrocarbon group - alicyclic hydrocarbon group) ₂ - chain hydrocarbon group - alicyclic hydrocarbon group - *, (chain hydrocarbon group) ₂ - alicyclic hydrocarbon group - chain hydrocarbon group - alicyclic hydrocarbon group - * (the _-CH2- contained in the chain hydrocarbon group and the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ),
Alicyclic hydrocarbon group - chain hydrocarbon group - alicyclic hydrocarbon group - chain hydrocarbon group - *, (alicyclic hydrocarbon group) ₂ - chain hydrocarbon group - alicyclic hydrocarbon group - chain hydrocarbon group - *, (alicyclic hydrocarbon group - chain hydrocarbon group) ₂ - alicyclic hydrocarbon group - chain hydrocarbon group - *, (alicyclic hydrocarbon group - chain hydrocarbon group - alicyclic hydrocarbon group) ₂ - chain hydrocarbon group - * (the _-CH2- contained in the chain hydrocarbon group and the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ),
Chain hydrocarbon group - alicyclic hydrocarbon group - chain hydrocarbon group - alicyclic hydrocarbon group - chain hydrocarbon group - *, (chain hydrocarbon group) ₂ - alicyclic hydrocarbon group - chain hydrocarbon group - alicyclic hydrocarbon group - chain hydrocarbon group - *, (chain hydrocarbon group - alicyclic hydrocarbon group) ₂ - chain hydrocarbon group - alicyclic hydrocarbon group - chain hydrocarbon group - *, (chain hydrocarbon group - alicyclic hydrocarbon group - chain hydrocarbon group) ₂ - alicyclic hydrocarbon group - chain hydrocarbon group - *, (chain hydrocarbon group - alicyclic hydrocarbon group - chain hydrocarbon group - alicyclic hydrocarbon group) ₂ - chain hydrocarbon group - * (the _-CH2- contained in the chain hydrocarbon group and the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ),
These are some examples. Here, * represents the bonding site between the carbonyl group and the carbon atom.

If the _-CH2- contained in the hydrocarbon group represented by ^X0 is replaced by -O-, -S-, -CO-, or _-SO2- , the number of carbon atoms before the replacement shall be considered the total number of carbon atoms in the hydrocarbon group. Also, if a substituent is attached to the hydrocarbon group represented by ^X0 , the number of carbon atoms before the substitution shall be considered the total number of carbon atoms in the hydrocarbon group.
The hydrocarbon group represented by ^X0 may have one or more substituents.
Examples of substituents include hydroxyl groups, halogen atoms, cyano groups, C1-C12 alkyl groups, C1-C12 alkoxy groups, C2-C13 alkoxycarbonyl groups, C2-C13 alkylcarbonyl groups, C2-C13 alkylcarbonyloxy groups, C3-C12 alicyclic hydrocarbon groups, C6-C10 aromatic hydrocarbon groups, or combinations thereof.
Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
Examples of alkyl groups having 1 to 12 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, octyl, and nonyl groups.
Examples of alkoxy groups having 1 to 12 carbon atoms include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, undecyloxy, and dodecyloxy groups.
The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group having 2 to 13 carbon atoms represent groups in which a carbonyl group or carbonyloxy group is bonded to the alkyl group or alkoxy group described above.
Examples of alkoxycarbonyl groups having 2 to 13 carbon atoms include methoxycarbonyl, ethoxycarbonyl, and butoxycarbonyl groups. Examples of alkylcarbonyl groups having 2 to 13 carbon atoms include acetyl, propionyl, and butyryl groups. Examples of alkylcarbonyloxy groups having 2 to 13 carbon atoms include acetyloxy, propionyloxy, and butyryloxy groups.
Examples of alicyclic hydrocarbon groups having 3 to 12 carbon atoms are listed below. ** indicates the bonding site with ^X0 .
Examples of aromatic hydrocarbon groups having 6 to 10 carbon atoms include aryl groups such as phenyl groups and naphthyl groups.
Examples of combined groups include groups combining a hydroxyl group with an alkyl group having 1 to 12 carbon atoms, groups combining an alkyl group having 1 to 12 carbon atoms with an aromatic hydrocarbon group having 6 to 10 carbon atoms, groups combining an alicyclic hydrocarbon group having 3 to 12 carbon atoms with an aromatic hydrocarbon group having 6 to 10 carbon atoms, and groups combining a halogen atom with an alkyl group having 1 to 12 carbon atoms.
Examples of groups combining a hydroxyl group with an alkyl group having 1 to 12 carbon atoms include hydroxymethyl groups, hydroxyethyl groups, and other hydroxyalkyl groups having 1 to 12 carbon atoms.
Examples of groups combining an alkyl group having 1 to 12 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms include aralkyl groups having 7 to 22 carbon atoms, such as the benzyl group, and alkylaryl groups having 7 to 22 carbon atoms, such as the tolyl group and the xylyl group.
Examples of groups combining an alicyclic hydrocarbon group having 3 to 12 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms include the cyclohexylphenyl group.
Examples of groups combining a halogen atom with an alkyl group having 1 to 12 carbon atoms include perfluoroalkyl groups having 1 to 12 carbon atoms such as trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, and nonafluorobutyl group.

The hydrocarbon group represented by ^X0 is preferably an aliphatic hydrocarbon group having 1 to 72 carbon atoms which may have substituents (the _-CH2- contained in the aliphatic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ), an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents, a group represented by formula (aa), or a group represented by formula (bb).
More preferably, an alicyclic hydrocarbon group which may have a fluorine atom, a C1-C4 alkyl group, a C1-C4 perfluoroalkyl group or a hydroxyl group (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ), a group which is a combination of an alicyclic hydrocarbon group and a chain hydrocarbon group (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- , and the _-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-, and the alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, a C1-C4 alkyl group, a C1-C4 perfluoroalkyl group or a hydroxyl group), an aromatic hydrocarbon group which may have a fluorine atom, a C1-C4 alkyl group, a C1-C4 perfluoroalkyl group or a hydroxyl group, a group which is represented by formula (aa) or a group which is represented by formula (bb),
More preferably, *-alicyclic hydrocarbon group (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- , and the alicyclic hydrocarbon group may have a fluorine atom, a perfluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group. * represents the bonding site with the carbon atom of ^-COO- ), *-alicyclic hydrocarbon group-chain hydrocarbon group (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- , and the _-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-, and the alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, a perfluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group. * represents the bonding site with the carbon atom of ^-COO- ), *-chain hydrocarbon group-alicyclic hydrocarbon group (the _-CH2- contained in the chain hydrocarbon group - may be replaced by -O- or -CO-, and _-CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or _-SO2- , and the chain hydrocarbon group and the alicyclic hydrocarbon group may have a fluorine atom, a perfluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group. * represents the bonding site with the carbon atom of ^-COO- ., ), an aromatic hydrocarbon group which may have a fluorine atom, a perfluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group, a group represented by formula (aa) or a group represented by formula (bb),
More preferably, * - polycyclic alicyclic hydrocarbon group (the _-CH2- contained in the polycyclic alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- , and the polycyclic alicyclic hydrocarbon group may have a fluorine atom, a C1-C4 perfluoroalkyl group or a hydroxyl group. * represents the bonding site with the carbon atom of -COO- ⁾ , * - polycyclic alicyclic hydrocarbon group-chain hydrocarbon group (the _-CH2- contained in the polycyclic alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- , and the _-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-, and the polycyclic alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, a C1-C4 perfluoroalkyl group or a hydroxyl group. * represents -COO ^- Represents the bonding site with the carbon atom.), * - Chain hydrocarbon group - Polycyclic alicyclic hydrocarbon group (the _-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-, and the _-CH2- contained in the polycyclic alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- , and the chain hydrocarbon group and the polycyclic alicyclic hydrocarbon group may have a fluorine atom, a perfluoroalkyl group having 1 to 4 carbon atoms or a hydroxyl group. * represents the bonding site with the carbon atom of ^-COO- ), aromatic hydrocarbon group which may have a fluorine atom, a perfluoroalkyl group having 1 to 4 carbon atoms or a hydroxyl group, a group represented by formula (aa) or a group represented by formula (bb),
Particularly preferred are an adamantanone group, a hydroxyadamantyl group, a group combining an adamantyl group and an alkyl group (the _-CH2- contained in the alkyl group may be replaced with -O- or -CO-), a group represented by formula (Y30F), a fluorine atom, a phenyl group having a perfluoroalkyl group or hydroxyl group having 1 to 4 carbon atoms, a group represented by formula (aa), or a group represented by formula (bb).
In the above groups, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 36, more preferably 3 to 24, even more preferably 3 to 18, even more preferably 3 to 16, and even more preferably 3 to 12. The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 18, more preferably 1 to 12, even more preferably 1 to 9, even more preferably 1 to 6, and even more preferably 1 to 4. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 36, more preferably 6 to 24, even more preferably 6 to 18, even more preferably 6 to 14, and even more preferably 6 to 10.
[In formula (aa),
X ^a and X ^b each independently represent -O- or -S-.
^X1a represents a hydrocarbon group having 1 to 24 carbon atoms, which may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
^X2a represents a hydrocarbon group having 1 to 48 carbon atoms, which may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
* indicates the bond site with the carbon atom in ^-COO- .
[In formula (bb),
L ^A represents a C1-C6 alkanediyl group which may have a fluorine atom, or a C6-C14 aromatic hydrocarbon group which may have a halogen atom or a C1-C4 perfluoroalkyl group.
L ^B represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the _-CH2- contained in the alkanediyl group may be replaced with -O-, -S-, -CO-, or _-SO2- .
R ^A represents a hydrocarbon group having 1 to 36 carbon atoms, which may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
* indicates the bond site with the carbon atom in ^-COO- .

X ^a and X ^b are preferably the same atom, and more preferably both are oxygen atoms.

Examples of hydrocarbon groups represented by ^X1a and ^X2a include aliphatic hydrocarbon groups, aromatic hydrocarbon groups, or groups formed by combining two or more of these. These hydrocarbon groups may have substituents. Furthermore, the _-CH2- contained in these hydrocarbon groups may be replaced with -O-, -S-, -CO-, or _-SO2- . Here, the number of carbon atoms in the hydrocarbon group refers to the number of carbon atoms in the hydrocarbon group that does not have substituents and is not replaced.

Examples of the aliphatic hydrocarbon group of ^X1a include chain hydrocarbon groups such as alkanetriyl groups, alicyclic hydrocarbon groups, or combinations thereof.
Examples of alkanetriyl groups include methine, ethanetriyl, propanetriyl, butanetriyl, pentanetriyl, hexanetriyl, heptanetriyl, octantriyl, nonanetriyl, decanetriyl, undecanetriyl, and dodecanetriyl groups.

The alicyclic hydrocarbon group may be monocyclic or polycyclic.
Examples of monocyclic alicyclic hydrocarbon groups include cyclobutanetriyl, cyclopentanetriyl, cyclohexanetriyl, and cyclooctanetriyl groups.
Examples of polycyclic alicyclic hydrocarbon groups include norbornanetriyl groups and adamantanetriyl groups.
Examples of aromatic hydrocarbon groups include benzenetriyl groups, naphthalentriyl groups, and anthracetriyl groups.
In the case of combined groups, the above-mentioned groups may include groups with different valencies (alkyl groups, alkanediyl groups, alkanetetrayl groups, cycloalkyl groups, cycloalkanediyl groups, cycloalkanetetrayl groups, etc.).

The hydrocarbon group represented by ^X1a has 1 to 24 carbon atoms and may further have one or more substituents. Examples of substituents include hydroxyl groups, halogen atoms, cyano groups, C1-C12 alkyl groups, C1-C12 alkoxy groups, C2-C13 alkoxycarbonyl groups, C2-C13 alkylcarbonyl groups, C2-C13 alkylcarbonyloxy groups, C3-C12 alicyclic hydrocarbon groups, C6-C10 aromatic hydrocarbon groups, or groups combining these.
Examples of halogen atoms, alkyl groups, alkoxy groups, alkoxycarbonyl groups, alkylcarbonyl groups and alkylcarbonyloxy groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups and groups combining these are the same groups as described above.

The hydrocarbon group represented by ^X1a is preferably an alkanetriyl group having 1 to 6 carbon atoms that may have substituents, or an alicyclic hydrocarbon group having 3 to 18 carbon atoms that may have substituents, more preferably an alkanetriyl group having 1 to 6 carbon atoms, or a group represented by formulas (w1-1) to (w1-11), and even more preferably an alkanetriyl group having 1 to 6 carbon atoms, a polycyclic hydrocarbon group such as a group represented by formula (w1-1) or a group represented by formula (w1-3), or a monocyclic hydrocarbon group such as a group represented by formula (w1-2) or a group represented by formula (w1-6).
[In formulas (w1-1) to (w1-11),
The ring may have a hydroxyl group, a halogen atom, a cyano group, a C1-C12 alkyl group, a C1-C12 alkoxy group, a C2-C13 alkoxycarbonyl group, a C2-C13 alkylcarbonyl group, a C2-C13 alkylcarbonyloxy group, a C3-C12 alicyclic hydrocarbon group, a C6-C10 aromatic hydrocarbon group, or a group having a combination thereof.
* indicates a connection site.

The number of carbon atoms in the hydrocarbon group represented by X ^2a is preferably 2 to 48, more preferably 4 to 48, even more preferably 6 to 44, even more preferably 8 to 40, and even more preferably 10 to 38.

Substituents that the hydrocarbon group in X ^2a may have include hydroxyl groups, halogen atoms, cyano groups, C1-C12 alkyl groups, C1-C12 alkoxy groups, C2-C13 alkoxycarbonyl groups, C2-C13 alkylcarbonyl groups, C2-C13 alkylcarbonyloxy groups, C3-C12 alicyclic hydrocarbon groups, C6-C10 aromatic hydrocarbon groups, or groups combining these.
Examples of halogen atoms, alkyl groups, alkoxy groups, alkoxycarbonyl groups, alkylcarbonyl groups, alkylcarbonyloxy groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups combining these are the same as those described above.
The substituents that the hydrocarbon group in X ^2a may have are preferably a fluorine atom, a C1-C4 alkyl group, a C1-C4 perfluoroalkyl group, or a hydroxyl group.
The hydrocarbon group having 1 to 48 carbon atoms represented by X ^2a may have one substituent or multiple substituents.

Examples of hydrocarbon groups in X ^2a include linear or branched chain hydrocarbon groups (e.g., alkanediyl groups), monocyclic or polycyclic alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. Two or more of these groups may be combined.
Specifically, linear alkanediyl groups such as 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, and octane-1,8-diyl group;
Branched alkanediyl groups such as 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, and 2-methylbutane-1,4-diyl group;
Monocyclic alicyclic hydrocarbon groups, such as monocyclic cycloalkanediyl groups like cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl;
Polycyclic alicyclic hydrocarbon groups, 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 aromatic hydrocarbon groups such as phenylene groups, naphthylene groups, biphenylene groups, anthrylene groups, phenanthrylene groups, and binaphthylene groups.
In the case of combined groups, the above-mentioned groups may include groups with different valencies (alkyl groups, alkanetriyl groups, alkanetetrayl groups, cycloalkyl groups, cycloalkanetriyl groups, cycloalkanetetrayl groups, etc.).
Examples of combined groups include groups combining a chain hydrocarbon group and an alicyclic hydrocarbon group, groups combining a chain hydrocarbon group and an aromatic hydrocarbon group, and groups combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group. Specifically, examples include groups in which one or more alicyclic hydrocarbon groups are bonded to a chain hydrocarbon group (e.g., -chain hydrocarbon group-alicyclic hydrocarbon group, -chain hydrocarbon group-(alicyclic hydrocarbon group) ₂ , etc.), groups in which one or more chain hydrocarbon groups are bonded to an alicyclic hydrocarbon group (e.g., -alicyclic hydrocarbon group-chain hydrocarbon group, -alicyclic hydrocarbon group-(chain hydrocarbon group) ₂ , etc.), and groups in which one or more alicyclic hydrocarbon groups and a chain hydrocarbon group are bonded to a chain hydrocarbon group (e.g., -chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group, -chain hydrocarbon group-(alicyclic hydrocarbon group-chain hydrocarbon group) ₂ , etc.).

The hydrocarbon group in X ^2a is,
A chain-like hydrocarbon group having 2 to 18 carbon atoms (the _-CH2- contained in the chain-like hydrocarbon group may be replaced with -O- or -CO-, and the chain-like hydrocarbon group may have substituents),
A cycloaliphatic hydrocarbon group having 3 to 18 carbon atoms (the _-CH2- contained in the cycloaliphatic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- , and the cycloaliphatic hydrocarbon group may have substituents), or
Preferably, the group is a combination of a chain hydrocarbon group having 1 to 12 carbon atoms (the _-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-) and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ) (the group may have substituents).
A chain-like hydrocarbon group having 4 to 18 carbon atoms (the _-CH2- contained in the chain-like hydrocarbon group may be replaced with -O- or -CO-, and the chain-like hydrocarbon group may have substituents), or
It is more preferable that the group is a combination of a chain hydrocarbon group having 1 to 12 carbon atoms (the _-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-) and an alicyclic hydrocarbon group having 3 to 16 carbon atoms (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ) (the group may have substituents).
A chain-like hydrocarbon group having 6 to 14 carbon atoms (the _-CH2- contained in the chain-like hydrocarbon group may be replaced with -O- or -CO-, and the chain-like hydrocarbon group may have substituents), or
It is even more preferable that the group is a combination of a chain-like hydrocarbon group having 1 to 12 carbon atoms (the _-CH2- contained in the chain-like hydrocarbon group may be replaced with -O- or -CO-) and an alicyclic hydrocarbon group having 5 to 14 carbon atoms (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ) (the group may have substituents).

Specifically, examples of hydrocarbon groups in X ^2a include:
Alkanediyl groups having 2 to 18 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-, and the alkanediyl group may have substituents),
A cycloaliphatic hydrocarbon group having 3 to 18 carbon atoms (the _-CH2- contained in the cycloaliphatic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- , and the cycloaliphatic hydrocarbon group may have substituents),
A group consisting of an alkanediyl group having 1 to 12 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-) and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ) (the group may have substituents), or
Preferably, the group consists of an alkanediyl group having 1 to 12 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-), an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and an alkyl group having 1 to 12 carbon atoms (the _-CH2- contained in the alkyl group may be replaced with -O- or -CO-) (the group may have substituents).
Alkanediyl groups having 4 to 18 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-, and the alkanediyl group may have substituents),
A group consisting of an alkanediyl group having 1 to 12 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-) and an alicyclic hydrocarbon group having 3 to 16 carbon atoms (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ) (the group may have substituents), or
It is more preferable that the group consists of a carbon-1 to carbon-12 alkanediyl group (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-), a carbon-3 to carbon-16 alicyclic hydrocarbon group, and a carbon-1 to carbon-12 alkyl group (the _-CH2- contained in the alkyl group may be replaced with -O- or -CO-) (the group may have substituents).
Alkanediyl groups having 6 to 14 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-, and the alkanediyl group may have substituents),
A group consisting of an alkanediyl group having 1 to 12 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-) and an adamantanediyl group (the _-CH2- contained in the adamantanediyl group may be replaced with -O- or -CO-) (the group may have substituents), or
It is even more preferable that the group consists of a carbon-1 to carbon-12 alkanediyl group (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-), an adamantanediyl group, and a carbon- ₁ to carbon-12 alkyl group (the -CH2- contained in the alkyl group may be replaced with -O- or -CO-) (the group may have substituents).

More specifically, ^X2a is preferably a group represented by formula ( ^X2-1 ), a group represented by formula ( ^X2-2 ), a group represented by formula ( ^X2-3 ), or a group represented by formula ( ^X2-4 ).
[In the formula,
^R1x , ^R2x , ^R3x , ^R4x , ^R5x , and ^R6x each independently represent an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group consisting of two or more of these groups, wherein the _-CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- , and the alkyl group and the alicyclic hydrocarbon group may have substituents.
* indicates the bonding site with X ^a and X ^b .
The combined group may be a combination of one alkyl group and one alicyclic hydrocarbon group as described above, or a group consisting of two or more of either or two or more of both. In this case, the number of carbon atoms in the combined group is 39 or less, preferably 37 or less.

In particular, ^R1x , ^R2x , ^R3x , ^R4x , ^R5x and ^R6x may be an alkyl group having 1 to 6 carbon atoms (the _-CH2- contained in the alkyl group may be replaced with -O- or -CO-, and the alkyl group may have substituents), an alicyclic hydrocarbon group having 5 to 12 carbon atoms (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- , and the alicyclic hydrocarbon group may have substituents), or an alkyl group having 1 to 6 carbon atoms (the _-CH2- contained in the alkyl group may be replaced with -O- or -CO-) and an alicyclic hydrocarbon group having 5 to 12 carbon atoms (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- It is preferable that the group is a combination of a methoxy group, an adamantyl group (the _-CH2- contained in the adamantyl group may be replaced with -O- or -CO-, and the adamantyl group may have substituents), or a group that is a combination of a methoxy group, an adamantyl group ( _{the -CH2-} contained in the alkyl group may be replaced with -O- or -CO-), and an adamantyl group (the group may have substituents).
The group represented by formula (aa) is more preferably a group represented by any of the following formulas (aa1), (aa2), (aa3), and (aa4).
[In equations (aa1) to (aa4),
^W1a represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms.
X ^a and X ^b each independently represent -O- or -S-.
^R1x , ^R2x , ^R3x , ^R4x , ^R5x , and ^R6x each independently represent the same meaning as equations ( ^X² -1), ( ^X² -2), ( ^X² -3), and ( ^X² -4).
* indicates the bond site with the carbon atom in ^-COO- .
In formulas (aa1) to (aa4), the alicyclic hydrocarbon group of ^W1a is more preferably a group represented by formulas (w1-1) to (w1-11), and even more preferably a polycyclic hydrocarbon group such as the group represented by formula (w1-1) or the group represented by formula (w1-3), or a monocyclic hydrocarbon group such as the group represented by formula (w1-2) or the group represented by formula (w1-6).

In formula (bb), examples of C1-C6 alkanediyl groups in L ^A and L ^B include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, and hexane-1,6-diyl group; and branched alkanediyl groups such as propane-1,2-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, and 2-methylbutane-1,4-diyl group. The number of carbon atoms in the alkanediyl group is preferably 1 to 4, and more preferably 1 to 3.
Examples of alkanediyl groups that may contain a fluorine atom include perfluoroalkanediyl groups such as difluoromethylene group, perfluoroethylene group, perfluoropropanediyl group, perfluorobutanediyl group, and perfluoropentanediyl group.
If the _-CH2- contained in the alkanediyl group is replaced by -O-, -S-, -CO-, or _-SO2- , the number of carbon atoms before the replacement shall be the total number of carbon atoms in the alkanediyl group. Alkanediyl groups include hydroxyl groups (groups in which the _-CH2- in a methyl group is replaced with -O-), carboxyl groups (groups in which the _-CH2 - _CH2- in an ethyl group is replaced with -O-CO-), thiol groups (groups in which the _-CH2- in a methyl group is replaced with -S-), alkoxy groups (groups in which any position of _-CH2- in an alkyl group is replaced with -O-), alkoxycarbonyl groups (groups in which any position of _-CH2 - _CH2- in an alkyl group is replaced with -O-CO-), alkylcarbonyl groups (groups in which any position of _-CH2- in an alkyl group is replaced with -CO-), alkylcarbonyloxy groups (groups in which any position of -CH2 _{- CH2-} in an alkyl group is replaced with -CO-O-), and alkylthio groups (groups in which any position of -CH2- in an alkyl group is replaced with _{-CO- عالالاللاللاللاللاللاللاللاللالللاللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللالللعاللعالالللللعالالللللعالالللللعالالللللعالالللللعالالللللعالالللللعالالللللعالالللللعالالللللعالاللللللعالاللللللعالاللللللعالاللللللعالاللللللعالالللللللعالالللللللعالاللللللللعالالللللل ​ ​ ​ ​ ​ ​ ​ ​} It may also have a group in which - is replaced by -CO-, or an alkanediylcarbonyloxy group (a group in which _-CH2 - _CH2- at any position in the alkanediyl group is replaced by -CO-O-).
Examples of alkoxy groups, alkoxycarbonyl groups, alkylcarbonyl groups, alkylcarbonyloxy groups, alkylthio groups, and alkylsulfonyl groups are the same as those listed above.
Examples of alkanediyloxy groups include methyleneoxy, ethyleneoxy, propanediyloxy, butanediyloxy, and pentanediyloxy groups.
Examples of alkanediylthio groups include methylenethio, ethylenethio, propanediylthio, butanediylthio, and pentanediylthio groups.
Examples of alkanediylsulfonyl groups include methylenesulfonyl groups, ethylenesulfonyl groups, propanediylsulfonyl groups, butanediylsulfonyl groups, and pentanediylsulfonyl groups.
Examples of alkanediyloxycarbonyl groups include methyleneoxycarbonyl groups, ethyleneoxycarbonyl groups, propanediyloxycarbonyl groups, and butanediyloxycarbonyl groups.
Examples of alkanediylcarbonyl groups include methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, and pentanediylcarbonyl group.
Examples of alkanediylcarbonyloxy groups include methylenecarbonyloxy groups, ethylenecarbonyloxy groups, propanediylcarbonyloxy groups, and butanediylcarbonyloxy groups.
Examples of aromatic hydrocarbon groups having 6 to 14 carbon atoms in L ^A include aromatic hydrocarbon groups such as phenylene groups, naphthylene groups, anthrylene groups, biphenylene groups, and arylene groups such as phenanthrylene groups. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 10, and more preferably 6.
Examples of halogen atoms that L ^A may contain include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.
Examples of C1-C4 perfluoroalkyl groups that L ^A may have include trifluoromethyl, pentafluoroethyl, heptafluoropropyl, and nonafluorobutyl groups.
L ^A is preferably a C1-C4 alkanediyl group which may have a fluorine atom, or a C6-C10 aromatic hydrocarbon group which may have a halogen atom or a C1-C4 perfluoroalkyl group, and more preferably a C1-C3 alkanediyl group which has a fluorine atom, or a phenylene group which may have a fluorine atom, an iodine atom, or a C1-C3 perfluoroalkyl group.
L ^B is preferably a single bond or an alkanediyl group having 1 to 3 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-), and more preferably a single bond, a methylene group, or an ethylene group.

Examples of hydrocarbon groups in R ^A include aliphatic hydrocarbon groups (chain hydrocarbon groups such as alkyl groups, alkenyl groups, and alkynyl groups, as well as alicyclic hydrocarbon groups), aromatic hydrocarbon groups, and groups formed by combining these.
Examples of alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, 2-ethylhexyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, and n-dodecyl group. The number of carbon atoms in the alkyl group is preferably 1 to 18, more preferably 1 to 12, even more preferably 1 to 9, even more preferably 1 to 6, and even more preferably 1 to 4.
Examples of alkenyl groups include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, tert-butenyl, pentenyl, hexenyl, heptenyl, octenyl, isooctenyl, and nonenyl groups.
Examples of alkynyl groups include ethynyl, propynyl, isopropynyl, butynyl, isobutynyl, tert-butynyl, pentynyl, hexynyl, octinyl, and noninyl groups.
Groups in which the _-CH2- contained in a chain-like hydrocarbon group is replaced with -O-, -S-, -CO-, or _-SO2- include hydroxyl groups, carboxyl groups, alkoxy groups, alkoxycarbonyl groups, alkylcarbonyl groups, alkylcarbonyloxy groups, alkylsulfonyl groups, and alkylthio groups.
Examples of alkoxy groups, alkoxycarbonyl groups, alkylcarbonyl groups, alkylcarbonyloxy groups, alkylsulfonyl groups, and alkylthio groups include alkoxy groups having 1 to 17 carbon atoms, alkoxycarbonyl groups having 2 to 17 carbon atoms, alkylcarbonyl groups having 2 to 18 carbon atoms, alkylcarbonyloxy groups having 2 to 17 carbon atoms, alkylsulfonyl groups having 1 to 17 carbon atoms, and alkylthio groups having 1 to 17 carbon atoms, which are the same groups as those described above.
The alicyclic hydrocarbon group may be monocyclic, polycyclic, or spirocyclic, and may be saturated or unsaturated. Examples of monocyclic alicyclic hydrocarbon groups include monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and cyclododecyl. Examples of polycyclic alicyclic hydrocarbon groups include polycyclic cycloalkyl groups such as decahydronaphthyl, adamantyl, and norbornyl.
Examples of alicyclic hydrocarbon groups and groups in which the _-CH2- contained in the alicyclic hydrocarbon group is replaced with -O-, -S-, -CO-, or _-SO2- include the groups represented by formulas (y1) to (y71) above. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 36, more preferably 3 to 24, even more preferably 3 to 18, even more preferably 3 to 16, and even more preferably 3 to 12.
Examples of aromatic hydrocarbon groups include phenyl groups, naphthyl groups, biphenyl groups, anthryl groups, phenanthryl groups, binaphthyl groups, and other aryl groups. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 36, more preferably 6 to 24, even more preferably 6 to 18, even more preferably 6 to 14, and even more preferably 6 to 10.
In the case of combined groups, the above-mentioned groups may include groups with different valencies (alkanediyl group, alkanetriyl group, cycloalkanediyl group, cycloalkanetriyl group, etc.).
Groups formed by combining these groups include groups formed by combining an aromatic hydrocarbon group with a chain hydrocarbon group (e.g., aromatic hydrocarbon group-alkanediyl group-*, alkyl group-aromatic hydrocarbon group-*), groups formed by combining an alicyclic hydrocarbon group with a chain hydrocarbon group (e.g., alicyclic hydrocarbon group-alkanediyl group-*, alkyl group-alicyclic hydrocarbon group-*), and groups formed by combining an aromatic hydrocarbon group with an alicyclic hydrocarbon group (e.g., aromatic hydrocarbon group-alicyclic hydrocarbon group-*, alicyclic hydrocarbon group-aromatic hydrocarbon group-*). * indicates the bonding site.
Examples of aromatic hydrocarbon groups—alkanediyl groups—* include aralkyl groups such as benzyl and phenethyl groups.
Examples of alkyl groups—aromatic hydrocarbon groups—* include tolyl groups, xylyl groups, and cumenyl groups.
Examples of alicyclic hydrocarbon groups - alkanediyl groups - * include cyclohexylmethyl group, cyclohexylethyl group, 1-(adamantan-1-yl)methyl group, 1-(adamantan-1-yl)-1-methylethyl group, and other cycloalkylalkyl groups.
Examples of alkyl groups—alicyclic hydrocarbon groups—* include methylcyclohexyl groups, dimethylcyclohexyl groups, 2-alkyladamantan-2-yl groups, and other cycloalkyl groups having alkyl groups.
Examples of aromatic hydrocarbon groups—alicyclic hydrocarbon groups—* include the phenyladamantyl group.
Examples of alicyclic hydrocarbon groups—aromatic hydrocarbon groups—* include the adamantylphenyl group.
Furthermore, in the combinations, two or more types of alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain-like hydrocarbon groups may be combined. Also, any of the groups may be bonded to L ^B.
In addition to the groups mentioned above, other examples of groups in which the _-CH2- contained in a hydrocarbon group is replaced with -O-, -S-, -CO-, or _-SO2- include cycloalkoxy groups, cycloalkylalkoxy groups, alkoxycarbonyloxy groups, aromatic hydrocarbon group-carbonyloxy groups, and groups that combine two or more of these groups.
Examples of cycloalkoxy groups include cycloalkoxy groups having 3 to 17 carbon atoms, such as the cyclohexyloxy group. Examples of cycloalkylalkoxy groups include cycloalkylalkoxy groups having 4 to 17 carbon atoms, such as the cyclohexylmethoxy group. Examples of alkoxycarbonyloxy groups include alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as the butoxycarbonyloxy group. Examples of aromatic hydrocarbon group-carbonyloxy groups include aromatic hydrocarbon group-carbonyloxy groups having 7 to 17 carbon atoms, such as the benzoyloxy group.
If the _-CH2- contained in a hydrocarbon group is replaced by -O-, -S-, _-SO2- , or -CO-, the number of carbon atoms before the replacement is considered the total number of carbon atoms in the hydrocarbon group. This number may be one or two or more.

Substituents that the hydrocarbon group of R ^A may have include halogen atoms, cyano groups, and C1-C12 alkyl groups (the _-CH2- contained in the alkyl group may be replaced with -O-, -S-, -CO-, or _-SO2- ).
Examples of halogen atoms include the same groups as those described above.
Examples of alkyl groups having 1 to 12 carbon atoms include the same groups as those described above.
Examples of groups in which the _-CH2- contained in an alkyl group is replaced with -O- or -CO- include hydroxyl groups, carboxyl groups, alkoxy groups, alkoxycarbonyl groups, alkylcarbonyl groups, and alkylcarbonyloxy groups.
Examples of alkoxy groups, alkoxycarbonyl groups, alkylcarbonyl groups, and alkylcarbonyloxy groups include alkoxy groups having 1 to 11 carbon atoms, alkoxycarbonyl groups having 2 to 11 carbon atoms, alkylcarbonyl groups having 2 to 12 carbon atoms, and alkylcarbonyloxy groups having 2 to 11 carbon atoms. For example, the same groups as those described above can be included.
The hydrocarbon group in R ^A may have one substituent or multiple substituents.

The hydrocarbon group in R ^A is preferably a C1-C12 alkyl group which may have substituents (however, the _-CH2- contained in the alkyl group may be replaced with -O-, -S-, -CO- or _-SO2- ) or a C3-C18 cyclic hydrocarbon group which may have substituents (however, the _-CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ), and preferably a C3-C18 cyclic hydrocarbon group which may have a fluorine atom, a hydroxyl group, a C1-C6 alkyl group or a C1-C6 perfluoroalkyl group (however, the _-CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ).

Examples of cyclic hydrocarbon groups include monocyclic or polycyclic alicyclic hydrocarbon groups having 3 to 18 carbon atoms, aromatic hydrocarbon groups having 6 to 18 carbon atoms, and other cyclic hydrocarbon groups, or groups that combine these.
Examples of alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and combined groups include those similar to those mentioned above.
Furthermore, in the combination, two or more types of alicyclic hydrocarbon groups and aromatic hydrocarbon groups may be combined. Also, any of the groups may be bonded to L ^B.

A cyclic hydrocarbon group having 3 to 18 carbon atoms (the cyclic hydrocarbon group may have a fluorine atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, or a perfluoroalkyl group having 1 to 6 carbon atoms, and the _-CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ) is,
A fluorine atom, a hydroxyl group, a C1-C4 alkyl group, or a C3-C18 alicyclic hydrocarbon group which may have a C1-C4 perfluoroalkyl group (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ), or
It is preferable that the atom is a fluorine atom, a hydroxyl group, or a C6-C18 aromatic hydrocarbon group (for example, a phenyl group or a naphthyl group) which may have a C1-C4 alkyl group.
The group represented by formula (bb) is more preferably the group represented by formula (bb1).
[In formula (bb1),
L ^A and L ^B have the same meaning as equation (bb).
^W1a represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and this alicyclic hydrocarbon group may have a fluorine atom, an alkyl group having 1 to 4 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, or a hydroxyl group, and the _-CH2- contained in this alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
* indicates the bond site with the carbon atom of ^-COO- .
In formula (bb1), ^W1a is more preferably a 3-18 carbon alicyclic hydrocarbon group which may have a fluorine atom, a hydroxyl group, a carbon 1-4 alkyl group, or a carbon 1-4 perfluoroalkyl group (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -CO-, or _-SO2- ).
In formula (bb1), the alicyclic hydrocarbon group of ^W1a is preferably a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, or one of the following groups (the bond site is at any position).

Examples of carboxylate anions in the carboxylate salt represented by formula (I) include the carboxylate anions listed below.

Examples of carboxylate salts (I) include salts obtained by arbitrarily combining the cations and anions mentioned above. Specific examples of carboxylate salts (I) are shown in the table below.
In the table below, each symbol represents the symbol attached to the structure representing the anion or cation described above, and "~" indicates that the carboxylate salt (I) corresponds to the anion (I) or cation (I). For example, carboxylate salt (I-1) is a salt consisting of the anion represented by formula (I-a-1) and the cation represented by formula (I-c-1), carboxylate salt (I-2) is a salt consisting of the anion represented by formula (I-a-2) and the cation represented by formula (I-c-1), and carboxylate salt (I-96) is a salt consisting of the anion represented by formula (I-a-1) and the cation represented by formula (I-c-2). Furthermore, salt (I-6936) represents a salt composed of an anion represented by formula (I-a-96) and a cation represented by formula (I-c-1), salt (I-6937) represents a salt composed of an anion represented by formula (I-a-96) and a cation represented by formula (I-c-2), and salt (I-7009) represents a salt composed of an anion represented by formula (I-a-97) and a cation represented by formula (I-c-1).

In particular, as carboxylate salt (I), salts combining an anion represented by any of formulas (I-a-1) to (I-a-5), (I-a-10) to (I-a-21), and (I-a-57) to (I-a-66) with a cation represented by any of formulas (I-c-1) to (I-c-73) are preferred. Specifically, carboxylate salt (I-1) to carboxylate salt (I-5), carboxylate salt (I-10) to carboxylate salt (I-21), carboxylate salt (I-57) to carboxylate salt (I-66), carboxylate salt (I-96) to carboxylate salt (I-100), carboxylate salt (I-105) to carboxylate salt (I-116), carboxylate salt (I-152) to carboxylate salt (I-161), carboxylate salt (I-191) to carboxylate salt (I-191) Bonate (I-195), carboxylate (I-200) to carboxylate (I-211), carboxylate (I-247) to carboxylate (I-256), carboxylate (I-286) to carboxylate (I-290), carboxylate (I-295) to carboxylate (I-306), carboxylate (I-342) to carboxylate (I-351), carboxylate (I-381) to carboxylate (I-385), carboxylate (I-390) to carboxylate (I-401), carboxylate (I-437) to carboxylate (I-446), carboxylate (I-476) to carboxylate (I-480), carboxylate (I-485) to carboxylate (I-496), carboxylate (I-532) to carboxylate (I-541), Bonate (I-571) to carboxylate (I-575), carboxylate (I-580) to carboxylate (I-591), carboxylate (I-627) to carboxylate (I-636), carboxylate (I-666) to carboxylate (I-670), carboxylate (I-675) to carboxylate (I-686), carboxylate (I-722) to carboxylate (I-731), carboxylate (I-761) to carboxylate (I-765), carboxylate (I-770) to carboxylate (I-781), carboxylate (I-817) to carboxylate (I-826), carboxylate (I-856) to carboxylate (I-860), carboxylate (I-865) to carboxylate (I-876), carboxylate (I-912) to Carboxylate (I-921), Carboxylate (I-951) to Carboxylate (I-955), Carboxylate (I-960) to Carboxylate (I-971), Carboxylate (I-1007) to Carboxylate (I-1016), Carboxylate (I-1046) to Carboxylate (I-1050), Carboxylate (I-1055) to Carboxylate (I-1066), Carboxylate (I-1102) to Carboxylate (I-1111), Carboxylate (I-1141) to Carboxylate (I-1145), Carboxylate (I-1150) to Carboxylate (I-1161), Carboxylate (I-1197) to Carboxylate (I-1206), Carboxylate (I-1236) to Carboxylate (I-1240), Carboxylate (I-1 245) - Carboxylate (I-1256), Carboxylate (I-1292) - Carboxylate (I-1301), Carboxylate (I-1331) - Carboxylate (I-1335), Carboxylate (I-1340) - Carboxylate (I-1351), Carboxylate (I-1387) - Carboxylate (I-1396), Carboxylate (I-1426) - Carboxylate (I-1430), Carboxylate (I-1435) - Carboxylate (I-1446), Carboxylate (I-1482) - Carboxylate (I-1491), Carboxylate (I-1521) - Carboxylate (I-1525), Carboxylate (I-1530) - Carboxylate (I-1541), Carboxylate (I-1577) - Carboxylate (I-1586), Carboxylate salt (I-1616) to carboxylate salt (I-1620), carboxylate salt (I-1625) to carboxylate salt (I-1636), carboxylate salt (I-1672) to carboxylate salt (I-1681), carboxylate salt (I-1711) to carboxylate salt (I-1715), carboxylate salt (I-1720) to carboxylate salt (I-1731), carboxylate salt (I-1767) to carboxylate salt (I-1776), carboxylate salt (I-1806) to carboxylate salt (I-1810), carboxylate salt (I-1815) to carboxylate salt (I-1826), carboxylate salt (I-1862) to carboxylate salt (I-1871), carboxylate salt (I-1901) to carboxylate salt (I-1905), carboxylate salt (I-1910) to carboxylate Salt (I-1921), carboxylate salt (I-1957) ~ carboxylate salt (I-1966), carboxylate salt (I-1996) ~ carboxylate salt (I-2000), carboxylate salt (I-2005) ~ carboxylate salt (I-2016), carboxylate salt (I-2052) ~ carboxylate salt (I-2061), carboxylate salt (I-2091) ~ carboxylate salt (I-2095), carboxylate salt (I-2100) ~ carboxylate salt (I-2111), carboxylate salt (I-2147) ~ carboxylate salt (I-2156), carboxylate salt (I-2186) ~ carboxylate salt (I-2190), carboxylate salt (I-2195) ~ carboxylate salt (I-2206), carboxylate salt (I-2242) ~ carboxylate salt (I-2251), carboxylate salt (I-2 281) ~Carboxylate (I-2285), Carboxylate (I-2290) ~Carboxylate (I-2301), Carboxylate (I-2337) ~Carboxylate (I-2346), Carboxylate (I-2376) ~Carboxylate (I-2380), Carboxylate (I-2385) ~Carboxylate (I-2396), Carboxylate (I-2432) ~Carboxylate (I-2441), Carboxylate (I-2471) ~Carboxylate (I-2475), Carboxylate (I-2480) ~Carboxylate (I-2491), Carboxylate (I-2527) ~Carboxylate (I-2536), Carboxylate (I-2566) ~Carboxylate (I-2570), Carboxylate (I-2575) ~Carboxylate (I-2586), Carboxylate salt (I-2622) to carboxylate salt (I-2631), carboxylate salt (I-2661) to carboxylate salt (I-2665), carboxylate salt (I-2670) to carboxylate salt (I-2681), carboxylate salt (I-2717) to carboxylate salt (I-2726), carboxylate salt (I-2756) to carboxylate salt (I-2760), carboxylate salt (I-2765) to carboxylate salt (I-2776), carboxylate salt (I-2812) to carboxylate salt (I-2821), carboxylate salt (I-2851) to carboxylate salt (I-2855), carboxylate salt (I-2860) to carboxylate salt (I-2871), carboxylate salt (I-2907) to carboxylate salt (I-2916), carboxylate salt (I-2946) to carboxylate Salt (I-2950), carboxylate (I-2955) ~ carboxylate (I-2966), carboxylate (I-3002) ~ carboxylate (I-3011), carboxylate (I-3041) ~ carboxylate (I-3045), carboxylate (I-3050) ~ carboxylate (I-3061), carboxylate (I-3097) ~ carboxylate (I-3106), carboxylate (I-3136) ~ carboxylate (I-3140), carboxylate (I-3145) ~ carboxylate (I-3156), carboxylate (I-3192) ~ carboxylate (I-3201), carboxylate (I-3231) ~ carboxylate (I-3235), carboxylate (I-3240) ~ carboxylate (I-3251), carboxylate (I-3 287) ~Carboxylate (I-3296), Carboxylate (I-3326) ~Carboxylate (I-3330), Carboxylate (I-3335) ~Carboxylate (I-3346), Carboxylate (I-3382) ~Carboxylate (I-3391), Carboxylate (I-3421) ~Carboxylate (I-3425), Carboxylate (I-3430) ~Carboxylate (I-3441), Carboxylate (I-3477) ~Carboxylate (I-3486), Carboxylate (I-3516) ~Carboxylate (I-3520), Carboxylate (I-3525) ~Carboxylate (I-3536), Carboxylate (I-3572) ~Carboxylate (I-3581), Carboxylate (I-3611) ~Carboxylate (I-3615), Carboxylate salt (I-3620) to carboxylate salt (I-3631), carboxylate salt (I-3667) to carboxylate salt (I-3676), carboxylate salt (I-3706) to carboxylate salt (I-3710), carboxylate salt (I-3715) to carboxylate salt (I-3726), carboxylate salt (I-3762) to carboxylate salt (I-3771), carboxylate salt (I-3801) to carboxylate salt (I-3805), carboxylate salt (I-3810) to carboxylate salt (I-3821), carboxylate salt (I-3857) to carboxylate salt (I-3866), carboxylate salt (I-3896) to carboxylate salt (I-3900), carboxylate salt (I-3905) to carboxylate salt (I-3916), carboxylate salt (I-3952) to carboxylate Salt (I-3961), carboxylate salt (I-3991) to carboxylate salt (I-3995), carboxylate salt (I-4000) to carboxylate salt (I-4011), carboxylate salt (I-4047) to carboxylate salt (I-4056), carboxylate salt (I-4086) to carboxylate salt (I-4090), carboxylate salt (I-4095) to carboxylate salt (I-4106), carboxylate salt (I-4142) to carboxylate salt (I-4151), carboxylate salt (I-4181) to carboxylate salt (I-4185), carboxylate salt (I-4190) to carboxylate salt (I-4201), carboxylate salt (I-4237) to carboxylate salt (I-4246), carboxylate salt (I-4276) to carboxylate salt (I-4280), carboxylate salt (I-4 285) ~Carboxylate (I-4296), Carboxylate (I-4332) ~Carboxylate (I-4341), Carboxylate (I-4371) ~Carboxylate (I-4375), Carboxylate (I-4380) ~Carboxylate (I-4391), Carboxylate (I-4427) ~Carboxylate (I-4436), Carboxylate (I-4466) ~Carboxylate (I-4470), Carboxylate (I-4475) ~Carboxylate (I-4486), Carboxylate (I-4522) ~Carboxylate (I-4531), Carboxylate (I-4561) ~Carboxylate (I-4565), Carboxylate (I-4570) ~Carboxylate (I-4581), Carboxylate (I-4617) ~Carboxylate (I-4626), Carboxylate salt (I-4656) to carboxylate salt (I-4660), carboxylate salt (I-4665) to carboxylate salt (I-4676), carboxylate salt (I-4712) to carboxylate salt (I-4721), carboxylate salt (I-4751) to carboxylate salt (I-4755), carboxylate salt (I-4760) to carboxylate salt (I-4771), carboxylate salt (I-4807) to carboxylate salt (I-4816), carboxylate salt (I-4846) to carboxylate salt (I-4850), carboxylate salt (I-4855) to carboxylate salt (I-4866), carboxylate salt (I-4902) to carboxylate salt (I-4911), carboxylate salt (I-4941) to carboxylate salt (I-4945), carboxylate salt (I-4950) to carboxylate Salt (I-4961), carboxylate (I-4997) ~ carboxylate (I-5006), carboxylate (I-5036) ~ carboxylate (I-5040), carboxylate (I-5045) ~ carboxylate (I-5056), carboxylate (I-5092) ~ carboxylate (I-5101), carboxylate (I-5131) ~ carboxylate (I-5135), carboxylate (I-5140) ~ carboxylate (I-5151), carboxylate (I-5187) ~ carboxylate (I-5196), carboxylate (I-5226) ~ carboxylate (I-5230), carboxylate (I-5235) ~ carboxylate (I-5246), carboxylate (I-5282) ~ carboxylate (I-5291), carboxylate (I-5
321) - Carboxylate (I-5325), Carboxylate (I-5330) - Carboxylate (I-5341), Carboxylate (I-5377) - Carboxylate (I-5386), Carboxylate (I-5416) - Carboxylate (I-5420), Carboxylate (I-5425) - Carboxylate (I-5436), Carboxylate (I-5472) - Carboxylate (I-5481), Carboxylate (I-5511) - Carboxylate Salt (I-5515), carboxylate salt (I-5520) to carboxylate salt (I-5531), carboxylate salt (I-5567) to carboxylate salt (I-5576), carboxylate salt (I-5606) to carboxylate salt (I-5610), carboxylate salt (I-5615) to carboxylate salt (I-5626), carboxylate salt (I-5662) to carboxylate salt (I-5671), carboxylate salt (I-5701) to carboxylate salt (I-5705), Rubonate (I-5710) to carboxylate (I-5721), carboxylate (I-5757) to carboxylate (I-5766), carboxylate (I-5796) to carboxylate (I-5800), carboxylate (I-5805) to carboxylate (I-5816), carboxylate (I-5852) to carboxylate (I-5861), carboxylate (I-5891) to carboxylate (I-5895), carboxylate (I-59 00) ~Carboxylate (I-5911), Carboxylate (I-5947) ~Carboxylate (I-5956), Carboxylate (I-5986) ~Carboxylate (I-5990), Carboxylate (I-5995) ~Carboxylate (I-6006), Carboxylate (I-6042) ~Carboxylate (I-6051), Carboxylate (I-6081) ~Carboxylate (I-6085), Carboxylate (I-6090) ~Carboxylate ( I-6101), carboxylate (I-6137) to carboxylate (I-6146), carboxylate (I-6176) to carboxylate (I-6180), carboxylate (I-6185) to carboxylate (I-6196), carboxylate (I-6232) to carboxylate (I-6241), carboxylate (I-6271) to carboxylate (I-6275), carboxylate (I-6280) to carboxylate (I-6291), Bonate (I-6327) to carboxylate (I-6336), carboxylate (I-6366) to carboxylate (I-6370), carboxylate (I-6375) to carboxylate (I-6386), carboxylate (I-6422) to carboxylate (I-6431), carboxylate (I-6461) to carboxylate (I-6465), carboxylate (I-6470) to carboxylate (I-6481), carboxylate (I-6517) ) ~Carboxylate (I-6526), Carboxylate (I-6556) ~Carboxylate (I-6560), Carboxylate (I-6565) ~Carboxylate (I-6576), Carboxylate (I-6612) ~Carboxylate (I-6621), Carboxylate (I-6651) ~Carboxylate (I-6655), Carboxylate (I-6660) ~Carboxylate (I-6671), Carboxylate (I-6707) ~Carboxylate (I- Preferably, the following are carboxylates (I-6716), carboxylate (I-6746) to carboxylate (I-6750), carboxylate (I-6755) to carboxylate (I-6766), carboxylate (I-6802) to carboxylate (I-6811), carboxylate (I-6841) to carboxylate (I-6845), carboxylate (I-6850) to carboxylate (I-6861), and carboxylate (I-6897) to carboxylate (I-6906).

<Method for producing carboxylate salt (I)>
Carboxylate salt (I) can be produced by reacting a salt represented by formula (I-a) with a salt represented by formula (I-b) in a solvent.
[In the formula, all signs have the same meaning as described above.]
R ^A , R ^B , and R ^C each independently represent a hydrocarbon group having 1 to 12 carbon atoms, or R ^A , R ^B , and R ^C together may form an aromatic ring. R ^D represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
Examples of solvents used in this reaction include chloroform, acetonitrile, and deionized water.
The reaction temperature is typically between 15°C and 80°C, and the reaction time is typically between 0.5 and 24 hours.

The salt represented by formula (I-b) can be synthesized by referring to the methods described in Japanese Patent Publication No. 2011-39502 and Japanese Patent Publication No. 2014-88367, and examples include the salts represented below.

In salt (I-a), a salt in which ^R1 , ^R2 , and ^R3 are *-O- ^L10 -CO-O- ^R10 (a salt represented by formula (I-a1)) can be produced by reacting a salt represented by formula (I-c) with a compound represented by formula (I-d) in a solvent in the presence of a base catalyst.
[In the formula, all signs have the same meaning as described above.]
Examples of bases include potassium carbonate, potassium iodide, pyridine, and triethylamine.
Examples of solvents include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, and water.
The reaction temperature is typically between 15°C and 80°C, and the reaction time is typically between 0.5 and 24 hours.

Compounds represented by formula (I-d) include, for example, the compounds shown below, which are readily available on the market and can also be easily manufactured by known methods.

The salt represented by formula (I-c) can be produced by reacting the salt represented by formula (I-e), the compound represented by formula (I-f1), the compound represented by formula (I-f2), and the compound represented by formula (I-f3) in a solvent in the presence of a catalyst.
[In the formula, all signs have the same meaning as described above.]
Potassium carbonate and sodium hydride are examples of catalysts.
Examples of solvents include chloroform, monochlorobenzene, acetonitrile, and water.
The reaction temperature is typically between 15°C and 100°C, and the reaction time is typically between 0.5 and 24 hours.

Examples of salts represented by formula (I-e) include those represented by the following formula, and they are readily available from the market.

Examples of compounds represented by formula (I-f1), formula (I-f2), and formula (I-f3) include the compounds shown below, which are readily available from the market.

The salt represented by formula (I-c) can also be produced by reacting the salt represented by formula (I-e), the compound represented by formula (I-f4), the compound represented by formula (I-f5), and the compound represented by formula (I-f6) in a solvent in the presence of potassium carbonate, followed by acid treatment.
[In the formula, all signs have the same meaning as described above.]
R ^ac represents an acid-unstable group.
Examples of solvents include chloroform, monochlorobenzene, acetonitrile, and water.
The reaction temperature is typically between 15°C and 100°C, and the reaction time is typically between 0.5 and 24 hours.
Examples of acids include p-toluenesulfonic acid and hydrochloric acid.

Examples of compounds represented by formula (I-f4), formula (I-f5), and formula (I-f6) include the compounds shown below, which are readily available from the market.

In salt (I-a), a salt in which ^R1 , ^R2 , and ^R3 are *-O- ^R10 (a salt represented by formula (I-a2)) can be produced by reacting a salt represented by formula (I-c) with a compound represented by formula (I-d2) in a solvent in the presence of a base catalyst.
[In the formula, all signs have the same meaning as described above.]
Examples of bases include sodium hydroxide and potassium hydroxide.
Examples of solvents include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, and water.
The reaction temperature is typically between 15°C and 80°C, and the reaction time is typically between 0.5 and 24 hours.

Compounds represented by formula (I-d2) include, for example, the compounds shown below, which are readily available on the market and can also be easily manufactured by known methods.

In salt (I-a), a salt in which ^R1 , ^R2 , and ^R3 are *-O-CO-O- ^R10 (a salt represented by formula (I-a3)) can be produced by reacting a salt represented by formula (I-c) with a compound represented by formula (I-d2) in a solvent in the presence of carbonyldiimidazole.
[In the formula, all signs have the same meaning as described above.]
Examples of solvents include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, and water.
The reaction temperature is typically between 15°C and 80°C, and the reaction time is typically between 0.5 and 24 hours.

In salt (I-a), a salt in which ^R1 , ^R2 , and ^R3 are *-O-CO- ^R10 (salt represented by formula (I-a4)) can be produced by reacting the compound represented by formula (I-d4) with carbonyldiimidazole in a solvent, and then further reacting it with the salt represented by formula (I-c).
[In the formula, all signs have the same meaning as described above.]
Examples of solvents include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, and water.
The reaction temperature is typically between 15°C and 80°C, and the reaction time is typically between 0.5 and 24 hours.

Compounds represented by formula (I-d4) include, for example, the compounds shown below, which are readily available on the market and can also be easily manufactured by known methods.

In salt (I-a), a salt in which ^R1 , ^R2 , and ^R3 are *-O-CO- ^R10 (a salt represented by formula (I-a4)) can also be produced by reacting a salt represented by formula (I-c) with a compound represented by formula (I-d5) in a solvent in the presence of a base catalyst.
[In the formula, all signs have the same meaning as described above.]
Examples of bases include potassium carbonate, potassium iodide, pyridine, and triethylamine.
Examples of solvents include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, and water.
The reaction temperature is typically between 15°C and 80°C, and the reaction time is typically between 0.5 and 24 hours.

Compounds represented by formula (I-d5) include, for example, the compounds shown below, which are readily available on the market and can also be easily manufactured by known methods.

[Carboxylic acid generator]
The carboxylic acid generator of the present invention is an acid generator containing a carboxylate salt (I). The carboxylate salt (I) of the present invention can be used as an acid generator in a resist composition. When the carboxylate salt (I) is used as an acid generator in a resist composition, the acid generator may contain only one type or two or more types of carboxylate salts (I).
Furthermore, as described later, the acid generator of the present invention may further contain an acid generator known in the resist field other than carboxylate salt (I) (hereinafter sometimes referred to as "acid generator (B)") and/or a carboxylic acid generator known in the resist field other than carboxylate salt (I). Acid generator (B) may be used alone or in combination of two or more types.
When the carboxylic acid generator of the present invention contains an acid generator (B), etc., the ratio of the content of the carboxylic acid salt (I) to the acid generator (B), etc. (mass ratio; carboxylic acid salt (I): acid generator (B)) is usually 1:99 to 100:0, preferably 1:99 to 99:1, more preferably 2:98 to 98:2, and even more preferably 5:95 to 95:5.

[Resist composition]
The resist composition contains a carboxylic acid generator containing the carboxylic acid salt (I) of the present invention, an acid generator (B) other than the carboxylic acid salt (I), and a resin having an acid-unstable group (hereinafter sometimes referred to as "resin (A)"). Here, "acid-unstable group" means a group that has a leaving group, and upon contact with an acid, the leaving group is removed to form a hydrophilic group (for example, a hydroxyl group or a carboxyl group).
The resist composition preferably further contains a quencher (hereinafter sometimes referred to as "quencher (C)") and/or a solvent (hereinafter sometimes referred to as "solvent (E)").
In the resist composition of the present invention, the content of carboxylate salt (I) is preferably 0.1% by mass or more and 35% by mass or less, more preferably 0.5% by mass or more and 30% by mass or less, and even more preferably 1% by mass or more and 25% by mass or less, based on the solid content of the resist composition.

<Acid Generator (B)>
The acid generator (B) may be either nonionic or ionic. Examples of nonionic acid generators include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxiimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate) and sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane). Typical ionic acid generators include onium salts containing onium cations (e.g., diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). Examples of onium salt anions include sulfonic acid anions, sulfonylimide anions, and sulfonylmethide anions.

As the acid generator (B), compounds that generate acid by radiation as described in Japanese Patent Publication Nos. 63-26653, 55-164824, 62-69263, 63-146038, 63-163452, 62-153853, 63-146029, U.S. Patent Nos. 3,779,778 and 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc., can be used. Compounds manufactured by known methods may also be used. Two or more types of acid generators (B) may be used in combination.

The acid generator (B) is preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)").
[In formula (B1),
Q ^b1 and Q ^b2 each independently represent a hydrogen atom, a fluorine atom, a C1-C6 alkyl group, or a C1-C6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and the _-CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group.
Y represents a methyl group which may have substituents or an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have substituents, and the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, _-SO2- , or -CO-.
Z1 ⁺ represents an organic cation.

Examples of perfluoroalkyl groups for 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 perfluorohexyl group.

Examples of alkyl groups for Q ^b1 and Q ^b2 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, and hexyl groups.
Q ^b1 and Q ^b2 preferably contain at least one fluorine atom or a perfluoroalkyl group, more preferably at least one is a fluorine atom or a perfluoroalkyl group, more preferably each is independently a fluorine atom or a trifluoromethyl group, and even more preferably both are fluorine atoms.

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

Examples of groups in which the _-CH2- contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced with -O- or -CO- include the group represented by any of the formulas (b1-1) to (b1-3). In the groups represented by formulas (b1-1) to (b1-3) and their specific examples, the groups represented by formulas (b1-4) to (b1-11), * and ** represent bonding sites, and * represents the bonding site with -Y.

[In formula (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atoms in the saturated hydrocarbon group may be substituted with fluorine atoms.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atoms in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxyl groups, and the _-CH2- in the saturated hydrocarbon group may be replaced with -O- or -CO-.
However, the total number of carbon atoms in L ^b2 and L ^b3 must be 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 atoms in the saturated hydrocarbon group may be substituted with fluorine atoms.
L ^b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atoms in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxyl groups, and the _-CH2- in the saturated hydrocarbon group may be replaced with -O- or -CO-.
However, the total number of carbon atoms in L ^b4 and L ^b5 must be 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 atoms in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxyl groups.
L ^b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atoms in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxyl groups, and the _-CH2- in the saturated hydrocarbon group may be replaced with -O- or -CO-.
However, the total number of carbon atoms in L ^b6 and L ^b7 is 23 or less.

In the groups represented by formulas (b1-1) to (b1-3), if the _-CH2- contained in the saturated hydrocarbon group is replaced by -O- or -CO-, the number of carbon atoms before the replacement shall be the number of carbon atoms of the saturated hydrocarbon group.
Examples of divalent saturated hydrocarbon groups include those similar to the divalent saturated hydrocarbon group of L ^b1 .

L ^b2 is preferably a single bond, a methylene group, -CH( _CF3 )-, or -C( _CF3 ) _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, and the hydrogen atoms in the divalent saturated hydrocarbon group may be substituted with fluorine atoms, and more preferably a methylene group, -CH( _CF3 )-, or -C( _CF3 ) _2- .
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 atoms in the saturated hydrocarbon group may be substituted with fluorine atoms.
L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atoms in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxyl groups, and _{the -CH2-} in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-.

As for the group in which the _-CH2- contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced with -O- or -CO-, the group represented by formula (b1-1) or formula (b1-3) is preferred.

The group represented by formula (b1-1) includes the 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 atoms in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxyl groups.
In formula (b1-5),
L ^b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the _-CH2- 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 atoms in the divalent saturated hydrocarbon group may be substituted with fluorine atoms or hydroxyl groups.
However, the total number of carbon atoms in L ^b9 and L ^b10 must be 20 or less.
In formula (b1-6),
L ^b11 represents a divalent saturated hydrocarbon group with 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 atoms in the divalent saturated hydrocarbon group may be substituted with fluorine atoms or hydroxyl groups.
However, the total number of carbon atoms in L ^b11 and L ^b12 must be 21 or less.
In formula (b1-7),
L ^b13 represents a divalent saturated hydrocarbon group with 1 to 19 carbon atoms.
L ^b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and _{the -CH2-} contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atoms in the divalent saturated hydrocarbon group may be substituted with fluorine atoms or hydroxyl groups.
However, the total number of carbon atoms in 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 the _-CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-.
L ^b17 represents a divalent saturated hydrocarbon group with 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 atoms in the divalent saturated hydrocarbon group may be substituted with fluorine atoms or hydroxyl groups.
However, the total number of carbon atoms in 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, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

The groups represented by formula (b1-3) include those 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 atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms.
L ^b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atoms in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group, or an alkylcarbonyloxy group. The _-CH2- in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atoms in the alkylcarbonyloxy group may be substituted with a hydroxyl group.
However, the total number of carbon atoms in L ^b19 and L ^b20 must be 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 atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms.
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 atoms in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group, or an alkylcarbonyloxy group. The _-CH2- in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atoms in the alkylcarbonyloxy group may be substituted with a hydroxyl group.
However, the total number of carbon atoms in 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 atoms in the saturated hydrocarbon group may be substituted with fluorine atoms.
L ^b25 represents a divalent saturated hydrocarbon group with 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 atoms in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group, or an alkylcarbonyloxy group. The _-CH2- in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atoms in the alkylcarbonyloxy group may be substituted with a hydroxyl group.
However, the total number of carbon atoms in L ^b24 , L ^b25 , and L ^b26 is 21 or less.

Furthermore, in the transition from the group represented by formula (b1-9) to the group represented by formula (b1-11), if a hydrogen atom in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the number of carbon atoms before the substitution shall be considered the number of carbon atoms in the saturated hydrocarbon group.

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

The following are examples of bases represented by formula (b1-4):

The following are examples of bases represented by formula (b1-5):

The following are examples of bases represented by formula (b1-6):

The following are examples of bases represented by formula (b1-7):

The following are examples of bases represented by formula (b1-8):

The following are examples of bases represented by formula (b1-2):

The following are examples of bases represented by formula (b1-9):

The following are examples of bases represented by formula (b1-10):

The following are examples of bases represented by formula (b1-11):

Examples of alicyclic hydrocarbon groups represented by Y in which the _-CH2- contained in the alicyclic hydrocarbon group is not replaced by -O-, -S-, _-SO2- , or -CO- include the groups represented by formulas (Y1) to (Y11) and (Y36) to (Y38).
When the _-CH2- contained in the alicyclic hydrocarbon group represented by Y is replaced by -O-, -S-, _-SO2- , or -CO-, the number of such replacements may be one or two or more. Examples of such groups include those represented by formulas (Y12) to (Y35) and (Y39) to (Y43). The -O- or -CO- in the groups represented by formulas (Y12) to (Y35) and (Y39) to (Y43) may also be replaced by -S- or _-SO2- . * indicates the bonding site with L ^b1 .

The alicyclic hydrocarbon group represented by Y is preferably a group represented by any of the formulas (Y1) to (Y20), (Y26), (Y27), (Y30), (Y31), (Y39) to (Y43), more preferably a group represented by formula (Y11), (Y15), (Y16), (Y20), (Y26), (Y27), (Y30), (Y31), (Y39), (Y40), (Y42), or (Y43), and even more preferably a group represented by formula (Y11), (Y15), (Y20), (Y26), (Y27), (Y30), (Y31), (Y39), (Y40), (Y42), or (Y43).
When the alicyclic hydrocarbon group represented by Y is a spiro ring containing an oxygen atom, such as formulas (Y28) to (Y35), (Y39), (Y40), (Y42), or (Y43), it is preferable that the alkanediyl group between the two oxygen atoms has one or more fluorine atoms. Furthermore, it is preferable that the methylene group adjacent to the oxygen atom among the alkanediyl groups contained in the ketal structure is not substituted with a fluorine atom.

Substituents for the methyl group represented by Y include halogen atoms, hydroxyl groups, alicyclic hydrocarbon groups having 3 to 16 carbon atoms, aromatic hydrocarbon groups having 6 to 18 carbon atoms, glycidyloxy groups, -( _CH2 ) _ja- CO-O-R ^b1 groups or -( _CH2 ) _ja -O-CO-R ^b1 groups (wherein R ^b1 represents an alkyl group having 1 to 16 carbon atoms, 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 an integer from 0 to 4. The _-CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced with -O-, _-SO2- , or -CO-, and the hydrogen atoms contained in the alkyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may be replaced with hydroxyl groups or fluorine atoms).
Substituents for the alicyclic hydrocarbon group represented by Y include halogen atoms, hydroxyl groups, C1-C16 alkyl groups which may be substituted with hydroxyl groups (the _-CH2- contained in the alkyl group may be replaced with -O- or -CO-), C3-C16 alicyclic hydrocarbon groups, C6-C18 aromatic hydrocarbon groups, C7-C21 aralkyl groups, glycidyloxy groups, -( _CH2 ) _ja- CO-O-R ^b1 groups, or -( _CH2 ) _ja -O-CO-R ^b1 groups (wherein R ^b1 represents an alkyl group with 1-C16, a C3-C16 alicyclic hydrocarbon group, a C6-C18 aromatic hydrocarbon group, or a combination thereof. ja represents an integer from 0 to 4. The _-CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be -O- or _-SO2 Examples include: - or -CO-, and the hydrogen atoms contained in the alkyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may be replaced with hydroxyl groups or fluorine atoms.

Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
Examples of alicyclic hydrocarbon groups include cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, norbornyl group, and adamantyl group. Alicyclic hydrocarbon groups may also have chain hydrocarbon groups, such as methylcyclohexyl group and dimethylcyclohexyl group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 12, and more preferably 3 to 10.
Examples of aromatic hydrocarbon groups include phenyl groups, naphthyl groups, anthryl groups, biphenyl groups, phenanthryl groups, and other aryl groups. Aromatic hydrocarbon groups may have a chain-type hydrocarbon group or an alicyclic hydrocarbon group, and examples include aromatic hydrocarbon groups having a chain-type hydrocarbon group with 1 to 18 carbon atoms (tolyl group, xylyl group, cumenyl group, mesityl group, p-methylphenyl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), and aromatic hydrocarbon groups having an alicyclic hydrocarbon group with 3 to 18 carbon atoms (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.). The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 14, and more preferably 6 to 10.
Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, 2-ethylhexyl, octyl, nonyl, decyl, undecyl, and dodecyl groups. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4.
Examples of alkyl groups substituted with a hydroxyl group include hydroxymethyl groups, hydroxyethyl groups, and other hydroxyalkyl groups.
Examples of aralkyl groups include benzyl groups, phenethyl groups, phenylpropyl groups, naphthylmethyl groups, and naphthylethyl groups.
Groups in which the _-CH2- contained in an alkyl group is replaced with -O-, _-SO2- , or -CO- include alkoxy groups, alkylsulfonyl groups, alkoxycarbonyl groups, alkylcarbonyl groups, alkylcarbonyloxy groups, or groups that combine these.
Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy, and dodecyloxy groups. The number of carbon atoms in the alkoxy group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4.
Examples of alkylsulfonyl groups include methylsulfonyl groups, ethylsulfonyl groups, and propylsulfonyl groups. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4.
Examples of alkoxycarbonyl groups include methoxycarbonyl groups, ethoxycarbonyl groups, and butoxycarbonyl groups. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4.
Examples of alkylcarbonyl groups include acetyl groups, propionyl groups, and butyryl groups. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4.
Examples of alkylcarbonyloxy groups include acetyloxy groups, propionyloxy groups, and butyryloxy groups. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4.
Examples of combined groups include groups combining an alkoxy group and an alkyl group, groups combining two alkoxy groups, groups combining an alkoxy group and an alkylcarbonyl group, and groups combining an alkoxy group and an alkylcarbonyloxy group.
Examples of groups combining an alkoxy group and an alkyl group include alkoxyalkyl groups such as methoxymethyl, methoxyethyl, ethoxyethyl, and ethoxymethyl groups. The number of carbon atoms in the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4.
Examples of groups formed by combining alkoxy groups include alkoxyalkoxy groups such as methoxymethoxy, methoxyethoxy, ethoxymethoxy, and ethoxyethoxy. The number of carbon atoms in the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4.
Examples of groups combining an alkoxy group and an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as methoxyacetyl group, methoxypropionyl group, ethoxyacetyl group, and ethoxypropionyl group. The number of carbon atoms in the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and even more preferably 3 to 5.
Examples of groups combining an alkoxy group and an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as methoxyacetyloxy group, methoxypropionyloxy group, ethoxyacetyloxy group, and ethoxypropionyloxy group. The number of carbon atoms in the alkoxyalkylcarbonyloxy group is preferably 3 to 13, more preferably 3 to 7, and even more preferably 3 to 5.
Groups in which the _-CH2- contained in an alicyclic hydrocarbon group is replaced with -O-, _-SO2- , or -CO-, etc., include the groups represented by formulas (Y12) to (Y35) and (Y39) to (Y43).

Y is preferably a cyclic hydrocarbon group having 3 to 24 carbon atoms, which may have substituents; more preferably a cyclic hydrocarbon group having 3 to 20 carbon atoms, which may have substituents; even more preferably a cyclic hydrocarbon group having 3 to 18 carbon atoms, which may have substituents; and even more preferably a substituted adamantyl group or a substituted norbornyl group, wherein the _-CH2- constituting the cyclic hydrocarbon group, adamantyl group or norbornyl group may be replaced with -O-, -S-, _-SO2- , or -CO-. Specifically, the following are examples.

In particular, Y is preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, a norbornane lactone group, or a group represented by formulas (Y42), (Y100) to (Y114), (Y134) to (Y139), and especially preferably a hydroxyadamantyl group, an oxoadamantyl group, a group containing these, or a group represented by formulas (Y42), (Y100) to (Y114), (Y134) to (Y139).

The anions in the salt represented by formula (B1) are preferably those represented by formulas (B1-A-1) to (B1-A-65) [hereinafter, they may be referred to as "anion (B1-A-1)," etc., depending on the formula number], and more preferably those represented by any of formulas (B1-A-1) to (B1-A-4), (B1-A-9), (B1-A-10), (B1-A-24) to (B1-A-33), (B1-A-36) to (B1-A-40), or (B1-A-47) to (B1-A-65).

Here, R ⁱ² to R ⁱ⁷ are each independently, for example, C1-C4 alkyl groups, preferably methyl or ethyl groups. ^{R i8} is, for example, a C1-C12 chain hydrocarbon group, preferably a C1-C4 alkyl group, a C5-C12 alicyclic hydrocarbon group, or a group formed by a combination thereof, more preferably a methyl group, ethyl group, cyclohexyl group, or adamantyl group. ^{L A4} is a single bond or a C1-C4 alkanediyl group. ^{Q b1} and Q ^b2 have the same meaning as above.
Specific examples of anions in the salt represented by formula (B1) include the anions described in Japanese Patent Publication No. 2010-204646.

Preferred anions in the salt represented by formula (B1) include the anions represented by formulas (B1a-1) to (B1a-43), respectively.

Among these, anions represented by any of the following formulas are preferred: (B1a-1) to (B1a-4), (B1a-7) to (B1a-11), (B1a-14) to (B1a-30), and (B1a-35) to (B1a-41).

Furthermore, the following are examples of sulfonylimid anions.
Examples of sulfonylmethide anions include the following:

Examples of Z1 ⁺ organic cations 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 aryl sulfonium cations are more preferred. Specifically, examples include cations represented by any of formulas (b2-1) to (b2-4) (hereinafter, depending on the formula number, they may be referred to as "cation (b2-1)," etc.).
In equations (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 atoms in the chain hydrocarbon group may be substituted with a hydroxyl 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 atoms 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 atoms in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkyl fluoride group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may bond to each other and form a ring together with the sulfur atom to which they are bonded, and the _-CH2- contained in the ring may be replaced with -O-, -S-, or -CO-.
R ^b7 and R ^b8 each independently represent a halogen atom, a hydroxyl 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 an integer between 0 and 5.
When m2 is 2 or greater, multiple R ^b7s may be the same or different, and when n2 is 2 or greater, multiple R ^b8s may be the same or different.
R ^b9 and R ^b10 each independently represent a chain-type 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 the _-CH2- contained in the ring may be replaced with -O-, -S-, or -CO-.
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 atoms in the chain hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atoms in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms.
R ^b11 and R ^b12 may bond to each other and form a ring including the -CH-CO- to which they are bonded, and the _-CH2- contained in the ring may be replaced with -O-, -S-, or -CO-.
R ^b13 to R ^b18 each independently represent a halogen atom, a hydroxyl 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 bond to each other and, together with the benzene ring to which they are bonded, form a ring containing a sulfur atom, and the _-CH2- contained in the ring may be replaced with -O-, -S-, or -CO-.
L ^b31 represents a sulfur atom or an oxygen atom.
o2, p2, s2, and t2 each independently represent an integer between 0 and 5.
q2 and r2 each independently represent an integer between 0 and 4.
u2 represents either 0 or 1.
When o2 is 2 or more, multiple R ^b13 are the same or different; when p2 is 2 or more, multiple R ^b14 are the same or different; when q2 is 2 or more, multiple R ^b15 are the same or different; when r2 is 2 or more, multiple R ^b16 are the same or different; when s2 is 2 or more, multiple R ^b17 are the same or different; when t2 is 2 or more, multiple R ^b18 are the same or different.
When u2 is 0, it is preferable that one of o2, p2, q2, and r2 is 1 or more, and at least one of R ^b13 to R ^b16 is a halogen atom. When u2 is 1, it is preferable that 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.
Furthermore, when u2 is 0, r2 is preferably 1 or greater, and more preferably 1. Also, when u2 is 0 and r2 is 1 or greater, R ^b16 is preferably a halogen atom.
Aliphatic hydrocarbon groups refer to both chain-type hydrocarbon groups and alicyclic hydrocarbon groups.
Examples of chain-type hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl.
In particular, the chain-like hydrocarbon groups R ^b9 to R ^b12 preferably have 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, norbornyl, and the following groups.
In particular, the alicyclic hydrocarbon groups R ^b9 to R ^b12 preferably have 3 to 18 carbon atoms, and more preferably 4 to 12 carbon atoms.
Examples of alicyclic hydrocarbon groups in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include methylcyclohexyl group, dimethylcyclohexyl group, 2-methyladamantan-2-yl group, 2-ethyladamantan-2-yl group, 2-isopropyladamantan-2-yl group, methylnorbornyl group, and isobornyl group. In alicyclic hydrocarbon groups 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.
A fluorinated alkyl group refers to an alkyl group having 1 to 12 carbon atoms and containing a fluorine atom, such as a fluoromethyl group, difluoromethyl group, trifluoromethyl group, or perfluorobutyl group. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 9, more preferably 1 to 6, and even more preferably 1 to 4.
Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, biphenyl, naphthyl, and phenanthryl groups. Aromatic hydrocarbon groups may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples include aromatic hydrocarbon groups having a chain hydrocarbon group with 1 to 18 carbon atoms (tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), and aromatic hydrocarbon groups having an alicyclic hydrocarbon group with 3 to 18 carbon atoms (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.).
Furthermore, if the aromatic hydrocarbon group has a chain-type hydrocarbon group or an alicyclic hydrocarbon group, a chain-type hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms are preferred.
Examples of aromatic hydrocarbon groups in which a hydrogen atom is substituted with an alkoxy group include the p-methoxyphenyl group.
Examples of chain-like hydrocarbon groups in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl, and naphthylethyl groups.
Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy, and dodecyloxy groups.
Examples of alkylcarbonyl groups include acetyl, propionyl, and butyryl groups.
Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.
Examples of alkylcarbonyloxy groups include methylcarbonyloxy group, ethylcarbonyloxy group, propylcarbonyloxy group, isopropylcarbonyloxy group, butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, pentylcarbonyloxy group, hexylcarbonyloxy group, octylcarbonyloxy group, and 2-ethylhexylcarbonyloxy group.
The ring formed by R ^b4 and R ^b5 bonding to each other and together with the sulfur atom to which they are bonded may be monocyclic, polycyclic, aromatic, non-aromatic, saturated, or unsaturated. This ring may have 3 to 18 carbon atoms, preferably 4 to 18 carbon atoms. The ring containing the sulfur atom may have 3 to 12 membered rings, preferably 3 to 7 membered rings, and examples of such rings are shown below. * indicates a bonding site.
The ring formed by R ^b9 and R ^b10 together may be monocyclic, polycyclic, aromatic, non-aromatic, saturated, or unsaturated. This ring may be a 3-membered to 12-membered ring, preferably a 3-membered to 7-membered ring. Examples include a thioran-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring.
The ring formed by R ^b11 and R ^b12 together may be monocyclic, polycyclic, aromatic, non-aromatic, saturated, or unsaturated. This ring may be a 3-membered to 12-membered ring, preferably a 3-membered to 7-membered ring. Examples include oxocycloheptane rings, oxocyclohexane rings, oxonorbornane rings, and oxoadamantane rings.

Among cations (b2-1) to (b2-4), cation (b2-1) is preferred.
The following cations can be considered as cations (b2-1):
Examples of cations (b2-2) include the following cations.
Examples of cations (b2-3) include the following:
Examples of cations (b2-4) include the following cations.

The acid generator (B) is a combination of the anion and the organic cation described above, and these can be combined arbitrarily. Preferred examples of the acid generator (B) include a combination of an anion represented by any of the formulas (B1a-1) to (B1a-4), (B1a-7) to (B1a-11), (B1a-14) to (B1a-30), or (B1a-35) to (B1a-41) and a cation (b2-1), cation (b2-2), cation (b2-3), or cation (b2-4).

Preferably, the acid generator (B) is represented by formulas (B1-1) to (B1-60). Among these, those containing arylsulfonium cations are preferred, and those represented by formulas (B1-1) to (B1-3), (B1-5) to (B1-7), (B1-11) to (B1-14), (B1-20) to (B1-26), (B1-29), and (B1-31) to (B1-60) are particularly preferred.

In the resist composition of the present invention, the content of the acid generator (B) is preferably 1 to 45 parts by mass, more preferably 1 to 40 parts by mass, and even more preferably 3 to 35 parts by mass, per 100 parts by mass of resin (A). The resist composition of the present invention may contain one type of acid generator (B) alone, or multiple types.

<Resin (A)>
Resin (A) contains structural units having acid-unstable groups (hereinafter sometimes referred to as "structural unit (a1)"). Preferably, resin (A) further contains structural units other than structural unit (a1). Examples of structural units other than structural unit (a1) include structural units that do not have acid-unstable groups (hereinafter sometimes referred to as "structural unit (s)"), structural units other than structural unit (a1) and structural unit (s) (for example, structural units having halogen atoms as described later (hereinafter sometimes referred to as "structural unit (a4)"), structural units having non-eliminating hydrocarbon groups as described later (hereinafter sometimes referred to as "structural unit (a5)"), and structural units derived from other monomers known in the art.

<Structural unit (a1)>
The structural unit (a1) is derived from a monomer having an acid-unstable group (hereinafter sometimes referred to as "monomer (a1)").
The acid-unstable group contained in resin (A) is preferably the group represented by formula (1) (hereinafter also referred to as group (1)) and/or the group represented by formula (2) (hereinafter also referred to as group (2)).
[In formula (1), ^Ra1 , ^Ra2 , and ^Ra3 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 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group having a combination thereof. Alternatively, ^Ra1 and ^Ra2 are bonded to each other to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
ma and na each independently represent either 0 or 1, and at least one of ma and na represents 1.
* indicates a connection 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, R ^a3' represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^a2' and R ^a3' are bonded to each other to form a heterocyclic group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded and X, and the _-CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced with -O- or -S-.
X represents either an oxygen atom or a sulfur atom.
'na' represents 0 or 1.
* indicates a connection site.

Examples of alkyl groups in R ^a1 , R ^a2 , and R ^a3 include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl groups.
Examples of alkenyl groups in R ^a1 , R ^a2 , and R ^a3 include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, tert-butenyl, pentenyl, hexenyl, heptenyl, octenyl, isooctenyl, and nonenyl groups.
The alicyclic hydrocarbon groups in R ^a1 , R ^a2 , and R ^a3 may be monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, norbornyl, and the following groups (* indicates 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.
Aromatic hydrocarbon groups in R ^a1 , R ^a2 , and R ^a3 include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl groups.
Examples of combined groups include groups that combine alkyl groups and alicyclic hydrocarbon groups as described above (for example, alkylcycloalkyl groups or cycloalkylalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having alkyl groups (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having alicyclic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), and aryl-cycloalkyl groups such as phenylcyclohexyl group.
Preferably, ma is 0 and na is 1.
When R ^a1 and R ^a2 bond to each other to form an alicyclic hydrocarbon group, the following groups are examples of -C(R ^a1 )(R ^a2 )(R ^a3 ). The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * indicates the bond site with -O-.

Examples of hydrocarbon groups in R ^a1' , R ^a2' , and R ^a3' include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these.
Examples of alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and combined groups are the same as those listed in ^Ra1 , ^Ra2 , and ^Ra3 .
When R ^a2' and R ^a3' bond to each other and form a heterocyclic group with the carbon atom to which they are bonded and X, the following groups can be considered as -C(R ^a1' )(R ^a2' )-X-R ^a3' . * indicates a bonding site.
It is preferable that at least one of R ^a1' and R ^a2' is a hydrogen atom.
na' is preferably 0.

The following are examples of base (1):
In formula (1), ^Ra1 , ^Ra2 , and ^Ra3 are alkyl groups, with ma = 0 and na = 1. A tert-butoxycarbonyl group is preferred as the group.
In formula (1), ^Ra1 and ^Ra2 , together with the carbon atoms to which they are bonded, form an adamantyl group, and ^Ra3 is an alkyl group with ma = 0 and na = 1.
In formula (1), ^Ra1 and ^Ra2 are each independently alkyl groups, and ^Ra3 is an adamantyl group with ma = 0 and na = 1.
The following are specific examples of group (1). * indicates a bonding site.

The following are specific examples of group (2). * indicates a bonding site.

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

Among (meth)acrylic monomers having acid-unstable groups, those having alicyclic hydrocarbon groups with 5 to 20 carbon atoms are preferred. Using a resin (A) having structural units derived from a monomer (a1) with a bulky structure such as an alicyclic hydrocarbon group in the resist composition can improve the resolution of the resist pattern.

Structural units derived from (meth)acrylic monomers having group (1) include structural units represented by formula (a1-0) (hereinafter sometimes referred to as structural unit (a1-0)), structural units represented by formula (a1-1) (hereinafter sometimes referred to as structural unit (a1-1)), or structural units represented by formula (a1-2) (hereinafter sometimes referred to as structural unit (a1-2)). Preferably, at least one or two structural units selected from the group consisting of structural unit (a1-0), structural unit (a1-1), and structural unit (a1-2), and more preferably, at least one or two structural units selected from the group consisting of structural unit (a1-1) and structural unit (a1-2). These may be used individually or in combination of two or more.
[In formulas (a1-0), (a1-1), and (a1-2),
L ^a01 , L ^a1 , and L ^a2 each independently represent -O- or ^* -O-(CH ₂ ) _k1 -CO-O-, where k1 is an integer from 1 to 7, and * represents the bonding site with -CO-.
^Ra01 , ^Ra4 , and ^Ra5 each independently represent a hydrogen atom, a halogen atom, or a C1-C6 alkyl group 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 a combination thereof.
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, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by a combination of these.
m1 represents an integer between 0 and 14.
n1 represents an integer between 0 and 10.
n1' represents an integer between 0 and 3.

R ^a01 , R ^a4 , and R ^a5 are preferably hydrogen atoms or methyl groups, and more preferably methyl groups.
L ^a01 , L ^a1 , and L ^a2 are preferably oxygen atoms or *-O-( _CH2 ) _k01 -CO-O- (wherein k01 is preferably an integer from 1 to 4, more preferably 1), and more preferably oxygen atoms.
Examples of alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and combinations thereof in R ^a02 , R ^a03 , and R ^a04 include the same groups as those listed in R ^a1 , R ^a2 , and R ^a3 of formula (1).
Examples of alkyl groups, alkenyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and combinations thereof in R ^a6 and R ^a7 include the same groups as those listed in R ^a1 , R ^a2 , and R ^a3 of formula (1).
The alkyl groups in R ^a02 , R ^a03 , and R ^a04 are preferably alkyl groups having 1 to 6 carbon atoms, more preferably methyl or ethyl groups, and even more preferably methyl groups.
The alkyl groups in R ^a6 and R ^a7 are preferably alkyl groups having 1 to 6 carbon atoms, more preferably methyl, ethyl, isopropyl, or t-butyl groups, and even more preferably ethyl, isopropyl, or t-butyl groups.
The alkenyl group in R ^a6 and R ^a7 is preferably an alkenyl group having 2 to 6 carbon atoms, and more preferably an ethenyl group, propenyl group, isopropenyl group, or butenyl group.
The number of carbon atoms in the alicyclic hydrocarbon groups of ^{Ra02, Ra03 , Ra04} , ^Ra6 , and ^Ra7 is preferably 5 to 12, and more preferably 5 to 10.
The number of carbon atoms in ^the aromatic hydrocarbon groups of Ra02, ^Ra03 , ^Ra04 , ^Ra6 , and ^Ra7 is preferably 6 to 12, and more preferably 6 to 10.
In groups formed by combining an alkyl group and an alicyclic hydrocarbon group, it is preferable that the total number of carbon atoms in the combined alkyl group and alicyclic hydrocarbon group is 18 or less.
In groups formed by combining an alkyl group and an aromatic hydrocarbon group, it is preferable that the total number of carbon atoms in the combined alkyl group and aromatic hydrocarbon group is 18 or less.
R ^a02 and R ^a03 are preferably C1-C6 alkyl groups or C6-C12 aromatic hydrocarbon groups, and more preferably methyl, ethyl, phenyl, or naphthyl groups.
R ^a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group.
R ^a6 and R ^a7 are preferably C1-C6 alkyl groups, C2-C6 alkenyl groups, or C6-C12 aromatic hydrocarbon groups, more preferably methyl groups, ethyl groups, isopropyl groups, t-butyl groups, ethenyl groups, phenyl groups, or naphthyl groups, and even more preferably ethyl groups, isopropyl groups, t-butyl groups, ethenyl groups, or phenyl groups.
m1 is preferably an integer from 0 to 3, and more preferably 0 or 1.
n1 is preferably an integer from 0 to 3, and more preferably 0 or 1.
n1' is preferably 0 or 1.

Examples of structural units (a1-0) include structural units represented by any of the formulas (a1-0-1) to (a1-0-18) and structural units in which the methyl group corresponding to R ^a01 in structural unit (a1-0) is replaced by a hydrogen atom, a halogen atom, a haloalkyl group (an alkyl group having a halogen atom), or another alkyl group. Structural units represented by any of the formulas (a1-0-1) to (a1-0-10), (a1-0-13), or (a1-0-14) are preferred.

Examples of structural units (a1-1) include structural units derived from monomers described in Japanese Patent Publication No. 2010-204646. Among these, structural units represented by any of formulas (a1-1-1) to (a1-1-7) and structural units in which the methyl group corresponding to R ^a4 in structural unit (a1-1) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group are preferred, and structural units represented by any of formulas (a1-1-1) to (a1-1-4) are more preferred.

Examples of structural units (a1-2) include structural units represented by any of formulas (a1-2-1) to (a1-2-14) and structural units in which the methyl group corresponding to R ^a5 in structural unit (a1-2) is replaced by a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. Structural units represented by any of formulas (a1-2-2), (a1-2-5), (a1-2-6), and (a1-2-10) to (a1-2-14) are preferred.
When resin (A) contains structural units (a1-0) and/or structural units (a1-1) and/or structural units (a1-2), the total content of these is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, and even more preferably 30 mol% or more, relative to the total structural units of resin (A). Alternatively, it may be 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, and even more preferably 70 mol% or less. Specifically, it may be 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, even more preferably 25 to 70 mol%, and even more preferably 30 to 70 mol%.
When resin (A) contains structural units (a1-0), the content is 5 mol% or more, preferably 10 mol% or more, relative to the total structural units of resin (A). Alternatively, it can be 80 mol% or less, preferably 75 mol% or less, and more preferably 70 mol% or less. Specifically, it can be 5 to 80 mol%, preferably 5 to 75 mol%, and more preferably 10 to 70 mol%.
When resin (A) contains structural unit (a1-1) and/or structural unit (a1-2), the total content of these is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, relative to the total structural units of resin (A). Alternatively, it may be 90 mol% or less, preferably 85 mol% or less, more preferably 80 mol% or less, even more preferably 75 mol% or less, and even more preferably 70 mol% or less. Specifically, it is 10 to 90 mol%, preferably 15 to 85 mol%, more preferably 20 to 80 mol%, even more preferably 20 to 75 mol%, and even more preferably 20 to 70 mol%.

Examples of structural units having a base (2) in structural unit (a1) include the structural unit represented by formula (a1-4) (hereinafter sometimes referred to as "structural unit (a1-4)").
[In formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms that may contain a halogen atom.
R ^a33 represents a halogen atom, a hydroxyl group, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C2-C12 alkoxyalkyl group, a C2-C12 alkoxyalkoxy group, a C2-C4 alkylcarbonyl group, a C2-C4 alkylcarbonyloxy group, an acryloyloxy group, or a methacryloyloxy group.
A ^a30 represents a single bond or ^* -X ^a31- (A ^a32 -X ^a32 ) _nc- , where * represents the bonding site with the carbon atom to which -R ^a32 is bonded.
A ^a32 represents an alkanediyl group with 1 to 6 carbon atoms.
X ^a31 and X ^a32 independently represent -O-, -CO-O-, or -O-CO-, respectively.
nc represents 0 or 1.
'la' represents an integer between 0 and 4. If 'la' is an integer greater than or equal to 2, multiple R ^a33s may be identical or different from one another.
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 -CH2-} contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced with -O- or -S-.

Examples of halogen atoms in R ^a32 and R ^a33 include fluorine atoms, chlorine atoms, and bromine atoms.
Examples of C1-C6 alkyl groups that may have halogen atoms in R ^a32 include trifluoromethyl, difluoromethyl, methyl, perfluoroethyl, 2,2,2-trifluoroethyl, 1,1,2,2-tetrafluoroethyl, ethyl, perfluoropropyl, 2,2,3,3,3-pentafluoropropyl, propyl, perfluorobutyl, 1,1,2,2,3,3,4,4-octafluorobutyl, butyl, perfluoropentyl, 2,2,3,3,4,4,5,5,5-nonafluoropentyl, pentyl, hexyl, and perfluorohexyl groups.
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 alkyl groups in R ^a33 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, and hexyl groups. The alkyl group is preferably a C1-C4 alkyl group, more preferably a methyl or ethyl group, and even more preferably a methyl group.
Examples of alkoxy groups in R ^a33 include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, tert-butoxy, pentyloxy, and hexyloxy groups. The alkoxy group is preferably a carbon-1 to carbon-4 alkoxy group, more preferably a methoxy or ethoxy group, and even more preferably a methoxy group.
Examples of alkoxyalkyl groups in R ^a33 include methoxymethyl group, ethoxyethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, sec-butoxymethyl group, and 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 alkoxyalkoxy groups 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. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group.
Examples of alkylcarbonyl groups in R ^a33 include acetyl groups, propionyl groups, and butyryl groups. The alkylcarbonyl group is preferably one having 2 to 3 carbon atoms, and more preferably an acetyl group.
Examples of alkylcarbonyloxy groups in R ^a33 include acetyloxy groups, propionyloxy groups, and butyryloxy groups. 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 hydroxyl group, a C1-C4 alkyl group, a C1-C4 alkoxy group, or a C2-C8 alkoxyalkoxy group; more preferably a fluorine atom, an iodine atom, a hydroxyl group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group; and even more preferably a fluorine atom, an iodine atom, a hydroxyl group, a methyl group, a methoxy group, or an ethoxyethoxy group.

Examples of *-X ^a31- (A ^a32 -X ^a32 ) _nc- include *-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-, and *-O-CO-A ^a32 -O-CO-. Among these, *-CO-O-, *-CO-O-A ^a32 -CO-O-, or *-O-A ^a32 -CO-O- are preferred.

Examples of alkanediyl groups in A ^a32 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-1,4-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-, more preferably a single bond, *-CO-O- or *-CO-O- _CH2 -CO-O-, and even more preferably a single bond or *-CO-O-.

la is preferably 0, 1, or 2, more preferably 0 or 1, and even more preferably 0.
Examples of hydrocarbon groups in R ^a34 , R ^a35 , and R ^a36 include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups combining these.
Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl groups.
Alicyclic hydrocarbon groups may be monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, norbornyl, and the following groups (* indicates a bonding site).
Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl groups.
Examples of combined groups include groups that combine the alkyl group and alicyclic hydrocarbon group as described above (for example, alkylcycloalkyl groups or cycloalkylalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having alkyl groups (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having alicyclic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), and aryl-cycloalkyl groups such as phenylcyclohexyl group. In particular, R ^a36 can be alkyl groups having 1 to 18 carbon atoms, alicyclic hydrocarbon groups having 3 to 18 carbon atoms, aromatic hydrocarbon groups having 6 to 18 carbon atoms, or groups formed by combining these.

R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably a hydrogen atom, a C1-C12 alkyl group, or a C3-C12 alicyclic hydrocarbon group, 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 group formed by a combination thereof, and more preferably 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 in ^{R a36} is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

In structural units (a1-4), -OC(R ^a34 )(R ^a35 )-O-R ^a36 is eliminated upon contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxyl group.
-OC(R ^a34 )(R ^a35 )-O-R ^a36 is preferably bonded to the ortho- or para-position of the benzene ring, and more preferably bonded to the para-position.

Examples of structural units (a1-4) include monomer-derived structural units described in Japanese Patent Publication No. 2010-204646. Preferably, examples include structural units represented by formulas (a1-4-1) to (a1-4-24) and structural units in which the hydrogen atom corresponding to R ^a32 in structural unit (a1-4) is replaced by a halogen atom, a haloalkyl group, or an alkyl group. More preferably, examples include structural units represented by formulas (a1-4-1) to (a1-4-5), (a1-4-10), (a1-4-13), (a1-4-14), (a1-4-19), and (a1-4-20).
If resin (A) contains structural units (a1-4), the content of these units is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, and even more preferably 10 to 40 mol%, relative to the total amount of all structural units in resin (A).

Structural units derived from (meth)acrylic monomers having group (2) include the structural unit represented by formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)").
In formula (a1-5),
R ^a8 represents a C1-C6 alkyl group, which may contain a halogen atom, a hydrogen atom, or a halogen atom.
Z ^a1 represents a single bond or *-( _CH2 ) _h3 -CO- ^L54- , h3 represents an integer from 1 to 4, and * represents the bond site with ^L51 .
L ⁵¹ , L ⁵² , L ⁵³ , and L ⁵⁴ each independently represent -O- or -S-.
s1 represents an integer between 1 and 3.
s1' represents an integer between 0 and 3.

Examples of halogen atoms include fluorine atoms and chlorine atoms, with fluorine atoms being preferred.
C1-C6 alkyl groups that may have halogen atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, fluoromethyl, and trifluoromethyl groups.
In formula (a1-5), ^Ra8 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 between 0 and 2.
Z ^a1 is preferably a single bond or * _-CH2 -CO-O-.

Examples of structural units (a1-5) include monomer-derived structural units described in Japanese Patent Publication No. 2010-61117. Among these, structural units represented by formulas (a1-5-1) to (a1-5-4) are preferred, and structural units represented by formula (a1-5-1) or formula (a1-5-2) are more preferred.
If resin (A) contains structural units (a1-5), the content of these units is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, even more preferably 5 to 40 mol%, and even more preferably 5 to 30 mol%, relative to the total structural units of resin (A).

Furthermore, the following structural units can also be listed as structural units (a1).
If resin (A) contains the above structural units, the content is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, and even more preferably 10 to 40 mol%, relative to the total structural units of resin (A).

<Structural unit (s)>
The structural unit (s) is derived from a monomer that does not have an acid-unstable group (hereinafter sometimes referred to as "monomer (s)"). The monomer used to derive the structural unit (s) can be any monomer known in the resist field that does not have an acid-unstable group.
The structural unit (s) preferably has a hydroxyl group or a lactone ring. If a resin containing a structural unit having a hydroxyl group and not having an acid-unstable group (hereinafter sometimes referred to as "structural unit (a2)") and/or a structural unit having a lactone ring and not having an acid-unstable group (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.

<Structural Unit (a2)>
The hydroxyl group in structural unit (a2) may be either an alcoholic hydroxyl group or a phenolic hydroxyl group.
When manufacturing a resist pattern from the resist composition of the present invention, if a high-energy beam such as a KrF excimer laser (248 nm), electron beam, or EUV (ultra-ultraviolet light) is used as the exposure light source, a structural unit (a2) having a phenolic hydroxyl group is preferred, and it is more preferable to use the structural unit (a2-A) described later. Furthermore, if an ArF excimer laser (193 nm) or the like is used, a structural unit (a2) having an alcoholic hydroxyl group is preferred, and it is more preferable to use the structural unit (a2-1) described later. The structural unit (a2) may consist of one type alone, or it may consist of two or more types.

A structural unit having a phenolic hydroxyl group in structural unit (a2) is the structural unit represented by formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)").
[In formula (a2-A),
R ^a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms that may contain a halogen atom.
R ^a51 represents a halogen atom, a hydroxyl group, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C2-C12 alkoxyalkyl group, a C2-C12 alkoxyalkoxy group, a C2-C4 alkylcarbonyl group, a C2-C4 alkylcarbonyloxy group, an acryloyloxy group, or a methacryloyloxy group.
A ^a50 represents a single bond or *-X ^a51- (A ^a52 -X ^a52 ) _nb- , where * represents the bonding site with the carbon atom to which -R ^a50 is bonded.
A ^a52 represents an alkanediyl group with 1 to 6 carbon atoms.
X ^a51 and X ^a52 independently represent -O-, -CO-O-, or -O-CO-, respectively.
nb represents either 0 or 1.
mb represents an integer between 0 and 4. If mb is an integer greater than or equal to 2, multiple R ^a51s may be identical or different from each other.

Examples of halogen atoms in R ^a50 and R ^a51 include fluorine atoms, chlorine atoms, and bromine atoms.
Examples of C1-C6 alkyl groups that may have halogen atoms in R ^a50 include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, and perfluorohexyl group.
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 alkyl groups in R ^a51 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, and hexyl groups. The alkyl group is preferably a C1-C4 alkyl group, more preferably a methyl or ethyl group, and even more preferably a methyl group.
Examples of alkoxy groups in R ^a51 include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, and tert-butoxy groups. The alkoxy group is preferably a carbon-1 to carbon-4 alkoxy group, more preferably a methoxy or ethoxy group, and even more preferably a methoxy group.
Examples of alkoxyalkyl groups in R ^a51 include methoxymethyl group, ethoxyethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, sec-butoxymethyl group, and 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 alkoxyalkoxy groups 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. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group.
Examples of alkylcarbonyl groups in R ^a51 include acetyl groups, propionyl groups, and butyryl groups. The alkylcarbonyl group is preferably one having 2 to 3 carbon atoms, and more preferably an acetyl group.
Examples of alkylcarbonyloxy groups in R ^a51 include acetyloxy groups, propionyloxy groups, and butyryloxy groups. 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 hydroxyl group, a C1-C4 alkyl group, a C1-C4 alkoxy group, or a C2-C8 alkoxyalkoxy group; more preferably a fluorine atom, an iodine atom, a hydroxyl group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group; and even more preferably a fluorine atom, an iodine atom, a hydroxyl group, a methyl group, a methoxy group, or an ethoxyethoxy group.

Examples of *-X ^a51- (A ^a52 -X ^a52 ) _nb- include *-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-, and *-O-CO-A ^a52 -O-CO-. Among these, *-CO-O-, *-CO-O-A ^a52 -CO-O-, or *-O-A ^a52 -CO-O- are preferred.
Examples of alkanediyl groups in A ^a52 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-1,4-diyl group, and 2-methylbutane-1,4-diyl group.
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-, more preferably a single bond, *-CO-O- or *-CO-O- _CH2 -CO-O-, and even more preferably a single bond or *-CO-O-.
MB is preferably 0, 1, or 2, more preferably 0 or 1, and even more preferably 0.
Preferably, at least one hydroxyl group is bonded to the meta or para position of the benzene ring, and more preferably to the meta position. If the phenyl group has two or more hydroxyl groups, it is preferable that the two hydroxyl groups are bonded to the meta and para positions, respectively.

Examples of structural units (a2-A) include monomer-derived structural units described in Japanese Patent Publication No. 2010-204634 and Japanese Patent Publication No. 2012-12577.
Examples of structural units (a2-A) include structural units represented by formulas (a2-2-1) to (a2-2-24) and 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. The structural unit (a2-A) is a structural unit represented by formulas (a2-2-1) to (a2-2-4), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), a structural unit represented by formulas (a2-2-12) to (a2-2-18), and a structural unit represented by formulas (a2-2-1) to (a2-2-4), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), and a structural unit represented by formulas (a2-2-12) to (a2-2-18), in which R Preferably, the structural unit is one in which the methyl group corresponding to ^a50 is replaced by a hydrogen atom, and in the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-4), the structural unit represented by formula (a2-2-8), the structural unit represented by formulas (a2-2-12) to (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), the structural unit represented by formula (a2-2-8), the structural unit represented by formulas (a2-2-12) to (a2-2-14), and the structural unit represented by formula (a2-2-18), R in structural unit (a2-A) It is more preferable that the structural unit is one in which the methyl group corresponding to ^a50 is replaced by a hydrogen atom, and in the structural units represented by formula (a2-2-3), formula (a2-2-4), formula (a2-2-8), and the structural units represented by formula (a2-2-3), formula (a2-2-4), and formula (a2-2-8), it is even more preferable that the structural unit is one in which the methyl group corresponding to R ^a50 in structural unit (a2-A) is replaced by a hydrogen atom.
When the resin (A) contains structural units (a2-A), the content of structural units (a2-A) is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and even more preferably 20 mol% or more, relative to the total structural units. Furthermore, it is preferably 80 mol% or less, more preferably 70 mol% or less, and even 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 incorporated into resin (A) by polymerizing using structural unit (a1-4), for example, and then treating with an acid such as p-toluenesulfonic acid. Alternatively, the structural unit (a2-A) can be incorporated into resin (A) by polymerizing using acetoxystyrene, for example, and then treating with an alkali such as tetramethylammonium hydroxide.

A structural unit having an alcoholic hydroxyl group in structural unit (a2) is the 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-( _CH2 ) _k2 -CO-O-,
k2 represents an integer between 1 and 7. * represents a bond 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 hydroxyl group.
o1 represents an integer between 0 and 10.

In formula (a2-1), L ^a3 is preferably -O-, -O-( _CH2 ) _f1 -CO-O- (where f1 represents an integer from 1 to 4), and 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 hydroxyl group.
o1 is preferably an integer from 0 to 3, more preferably 0 or 1.

Examples of structural units (a2-1) include structural units derived from monomers described in Japanese Patent Publication No. 2010-204646. Structural units represented by any of formulas (a2-1-1) to (a2-1-6) are preferred, structural units represented by any of formulas (a2-1-1) to (a2-1-4) are more preferred, and structural units represented by formula (a2-1-1) or (a2-1-3) are even more preferred.
When resin (A) contains structural units (a2-1), the content is preferably 1 mol% or more, and more preferably 2 mol% or more, relative to the total structural units of resin (A). Also, it is preferably 45 mol% or less, more preferably 40 mol% or less, more preferably 35 mol% or less, even more preferably 20 mol% or less, and even more preferably 10 mol% or less. Specifically, it is preferably 1 to 45 mol%, more preferably 1 to 40 mol%, more preferably 1 to 35 mol%, even more preferably 2 to 20 mol%, and even more preferably 2 to 10 mol%.

<Structural Unit (a3)>
The lactone ring of 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 it may be a fused ring of a monocyclic lactone ring and another ring. Preferably, it may be a γ-butyrolactone ring, an adamantane lactone ring, or a bridging ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)).
The structural unit (a3) is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3), or formula (a3-4). One of these may be included alone, or two or more may be included.
[In formulas (a3-1), (a3-2), (a3-3), and (a3-4),
L ^a4 , L ^a5 , and L ^a6 each independently represent a base represented by -O- or *-O-( _CH2 ) _k3 -CO-O- (where k3 is an integer from 1 to 7).
L ^a7 represents -O-, *-OL ^a8 -O-, *-OL ^a8 -CO-O-, *-OL ^a8 -CO-O-L ^a9 -CO-O-, or *-OL ^a8 -O-CO-L ^a9 -O-.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms.
* indicates a bonding site with a carbonyl group.
R ^a18 , R ^a19 , and R ^a20 each independently represent a hydrogen atom or a methyl group.
R ^a24 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms that may contain a halogen atom.
X ^a3 represents _-CH2- or an oxygen atom.
R ^a21 represents an aliphatic hydrocarbon group with 1 to 4 carbon atoms.
^Ra22 , ^Ra23 , and ^Ra25 each independently represent a carboxyl group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer between 0 and 5.
q1 represents an integer between 0 and 3.
r1 represents an integer between 0 and 3.
w1 represents an integer between 0 and 8.
When p1, q1, r1 and/or w1 are 2 or more, the multiple R ^a21 , R ^a22 , R ^a23 and/or R ^a25 may be the same or different from each other.

Examples of aliphatic hydrocarbon groups in ^Ra21 , ^Ra22 , ^Ra23 , and ^Ra25 include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, and tert-butyl groups.
Examples of halogen atoms in R ^a24 include fluorine, chlorine, bromine, and iodine atoms.
Examples of alkyl groups in R ^a24 include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, and hexyl groups, with alkyl groups having 1 to 4 carbon atoms being preferred, and methyl or ethyl groups being more preferred.
Examples of alkyl groups having a halogen atom in R ^a24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluorohexyl group, trichloromethyl group, tribromomethyl group, and triiodomethyl group.

Examples of alkanediyl groups in L ^a8 and L ^a9 include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-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-( _CH2 ) _k3 -CO-O-, where k3 is an integer from 1 to 4, more preferably -O- and *-O- _CH2 -CO-O-, and even more preferably an oxygen atom.
R ^a18 to R ^a21 are preferably methyl groups.
^Ra22 and ^Ra23 are each independently preferably a carboxyl group, a cyano group, or a methyl group.
p1, q1, and r1 are each independently, preferably integers from 0 to 2, and more preferably 0 or 1.

In formula (a3-4), R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.
R ^a25 is preferably a carboxyl group, a cyano group, or a methyl group.
L ^a7 is preferably -O- or *-O-L ^a8 -CO-O-, and more preferably -O-, -O- _CH2 -CO-O- or -O- _{C2H4 -CO} -O-.
w1 is preferably an integer between 0 and 2, and more preferably 0 or 1.
In particular, formula (a3-4) is preferred over formula (a3-4)'.
(In the formula, R ^a24 and L ^a7 have the same meaning as above.)

Examples of structural units (a3) include those derived from monomers described in Japanese Patent Publication No. 2010-204646, Japanese Patent Publication No. 2000-122294, and Japanese Patent Publication No. 2012-41274. Preferred structural units (a3) include those represented by any of the formulas (a3-1-1), (a3-1-2), (a3-2-1), (a3-2-2), (a3-3-1), (a3-3-2), and (a3-4-1) to (a3-4-12), and structural units in which the methyl groups corresponding to R ^a18 , R ^a19 , R ^a20 , and R ^a24 in formulas (a3-1) to (a3-4) are replaced with hydrogen atoms.
When resin (A) contains structural units (a3), the total content is 1 mol% or more, preferably 3 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, relative to the total structural units of resin (A). Alternatively, it can be 70 mol% or less, preferably 65 mol% or less, and more preferably 60 mol% or less. Specifically, it can be 1 to 70 mol%, preferably 3 to 65 mol%, and more preferably 5 to 60 mol%.
Furthermore, the content of structural unit (a3-1), structural unit (a3-2), structural unit (a3-3), or structural unit (a3-4) is preferably 1 mol% or more, more preferably 3 mol% or more, and even more preferably 5 mol% or more, relative to the total structural units of resin (A). Also preferably 60 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less. Specifically, 1 to 60 mol% is preferred, 3 to 55 mol% is more preferred, and 5 to 50 mol% is even more preferred.

<Structural Unit (a4)>
The following structural units (a4) can be considered:
[In formula (a4),
R ⁴¹ represents a hydrogen atom or a methyl group.
R ⁴² represents a saturated hydrocarbon group having 1 to 24 fluorine atoms, and the _-CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.
The saturated hydrocarbon group represented by R ⁴² includes chain-type hydrocarbon groups, monocyclic or polycyclic alicyclic hydrocarbon groups, and groups formed by combining these.

Examples of chain-like hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl groups.
Examples of monocyclic or polycyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups; and polycyclic alicyclic hydrocarbon groups such as decahydronaphthyl, adamantyl, norbornyl, and the following groups (* indicates the bonding site).
Examples of groups formed by combinations include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

The structural unit (a4) is preferably a structural unit having a fluorine atom, and examples include structural units represented by at least one selected from the group consisting of formulas (a4-0), (a4-1), (a4-2), (a4-3), and (a4-4).
[In formula (a4-0),
R ^5a represents a hydrogen atom or a methyl group.
L ^4a represents a single bond or an alkanediyl group having 1 to 4 carbon atoms.
^L3a represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms.
R ^6a represents a hydrogen atom or a fluorine atom.

Examples of alkanediyl groups in L ^4a include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, and butane-1,4-diyl group, and branched alkanediyl groups such as 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.

In L ^3a , the perfluoroalkanediyl group is a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, a perfluoropropane-2,2-diyl group, a perfluorobutane-1,4-diyl group, a perfluorobutane-2,2-diyl group, a perfluorobutane-1,2-diyl group, a perfluoropentane-1,5-diyl group, a perfluoropentane-2,2-diyl group, a perfluoropentane- Examples include 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, and perfluorooctane-4,4-diyl group.
Examples of perfluorocycloalkanediyl groups in L ^3a include perfluorocyclohexanediyl group, perfluorocyclopentanediyl group, perfluorocycloheptanediyl group, and perfluoroadamantanediyl group.

L ^4a is preferably a single bond, a methylene group, or an ethylene group, and more preferably a single bond or a methylene group.
^L3a is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

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

An example of a structural unit (a4) is the structural unit represented by formula (a4-1).
[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 substituents, and the _-CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.
A ^a41 represents an alkanediyl group having 1 to 6 carbon atoms, which may have substituents, 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 either 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 substituents.
A ^a43 represents a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms, which may have a single bond or substituents.
X ^a41 and X ^a42 independently represent -O-, -CO-, -CO-O-, or -O-CO-, respectively.
However, the total number of carbon atoms in A ^a42 , A ^a43 , A ^a44 , X ^a41 , and X ^a42 is 7 or less.
* indicates a binding site, and the * on the right is the binding site with -O-CO-R ^a42 .

Examples of saturated hydrocarbon groups in R ^a42 include chain-type saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these.

Examples of chain-type saturated hydrocarbon groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl groups.
Examples of monocyclic or polycyclic alicyclic saturated hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups; and polycyclic alicyclic saturated hydrocarbon groups such as decahydronaphthyl, adamantyl, norbornyl, and the following groups (* indicates the bonding site).
Examples of groups formed by combinations include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group.

The substituents on R ^a42 include at least one selected from the group consisting of halogen atoms and groups represented by formula (a-g3). Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms 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 contain a halogen atom.
* indicates the binding site with R ^a42 .
However, in R ^a42 -X ^a43 - ^{A a45} , if R ^a42 does not have a halogen atom, then A ^a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms and having at least one halogen atom.

A ^a45 includes alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl;
Examples include monocyclic alicyclic hydrocarbon groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups, as well as polycyclic alicyclic hydrocarbon groups such as decahydronaphthyl, adamantyl, norbornyl, and the following groups (* indicates the bonding site).
Examples of groups formed by combinations include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

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

If R ^a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), then R ^a42 is more preferably a group represented by formula (a-g2).
[In formula (a-g2),
A ^a46 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, which may contain a halogen atom.
X ^a44 represents **-O-CO- or **-CO-O- (where ** represents the bonding site with A ^a46 ).
A ^a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms, which may contain a halogen atom.
However, the total number of carbon atoms in A ^a46 , A ^a47 , and X ^a44 is 18 or less, and at least one of A ^a46 and A ^a47 has at least one halogen atom.
* indicates the bonding site with the carbonyl group.

The saturated hydrocarbon group of A ^a46 preferably has 1 to 6 carbon atoms, and 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, and A ^a47 is even more preferably a cyclohexyl group or an adamantyl group.

The preferred structure of the group represented by formula (a-g2) is as follows (* indicates the bonding site with the carbonyl group).

Examples of alkanediyl groups in A ^a41 include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, and hexane-1,6-diyl group; and branched 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, and 2-methylbutane-1,4-diyl group.
Examples of substituents on the alkanediyl group represented by A ^a41 include hydroxyl groups and alkoxy groups 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.

Examples of 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 alicyclic saturated hydrocarbon groups, as well as groups formed by combining alkanediyl groups and divalent alicyclic saturated hydrocarbon groups. Specifically, examples include methylene groups, ethylene groups, propane-1,3-diyl groups, propane-1,2-diyl groups, butane-1,4-diyl groups, 1-methylpropane-1,3-diyl groups, 2-methylpropane-1,3-diyl groups, and 2-methylpropane-1,2-diyl groups.
Examples of substituents on the divalent saturated hydrocarbon groups represented by A ^a42 , A ^a43 , and A ^a44 include hydroxyl groups and alkoxy groups having 1 to 6 carbon atoms.
s is preferably 0.

In the group represented by formula (a-g1), the following groups are examples of groups where X ^a42 is -O-, -CO-, -CO-O-, or -O-CO-. In the following examples, * and ** represent bonding sites, respectively, where ** is the bonding site with -O-CO-R ^a42 .

Structural units represented by formula (a4-1) include the structural units shown below and structural units in which the methyl group corresponding to R ^a41 in the structural unit represented by formula (a4-1) below is replaced by a hydrogen atom.

An example of a structural unit (a4) is the 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 the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-.
R ^f6 represents a saturated hydrocarbon group having 1 to 20 fluorine atoms.
However, the upper limit for the total number of carbon atoms in L ⁴⁴ and R ^f6 is 21.

The alkanediyl group of L ⁴⁴ is similar to the group exemplified in A ^a41 .
The saturated hydrocarbon group of R ^f6 is similar to the group exemplified in R ^a42 .
In L ⁴⁴ , an alkanediyl group having 2 to 4 carbon atoms is preferred, and an ethylene group is more preferred.

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

An example of a structural unit (a4) is the structural unit represented by formula (a4-3).
[In formula (a4-3),
R ^f7 represents a hydrogen atom or a methyl group.
^L5 represents an alkanediyl group with 1 to 6 carbon atoms.
A ^f13 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, which may contain a fluorine atom.
X ^f12 represents *-O-CO- or *-CO-O- (where * represents the bonding site with A ^f13 ).
A ^f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms, which may contain 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 alkanediyl groups in L ⁵ include those similar to those exemplified in the alkanediyl group of A ^a41 .
In A ^f13 , the optionally fluorine-containing divalent saturated hydrocarbon group is preferably an optionally fluorine-containing divalent chain-type saturated hydrocarbon group and an optionally fluorine-containing divalent alicyclic saturated hydrocarbon group, and more preferably a perfluoroalkanediyl group.
Examples of divalent chain-type saturated hydrocarbon groups that may contain a fluorine atom include methylene groups, ethylene groups, propanediyl groups, butanediyl groups, and pentanediyl groups, as well as perfluoroalkanediyl groups such as difluoromethylene groups, perfluoroethylene groups, perfluoropropanediyl groups, perfluorobutanediyl groups, and perfluoropentanediyl groups.
The divalent alicyclic saturated hydrocarbon group, which may contain a fluorine atom, may be monocyclic or polycyclic. Examples of monocyclic groups include cyclohexanediyl and perfluorocyclohexanediyl groups. Examples of polycyclic groups include adamantanediyl, norbornanediyl, and perfluoroadamantanediyl groups.

A ^f14 may have saturated hydrocarbon groups and saturated hydrocarbon groups having fluorine atoms, and these may be the same groups as those exemplified in R ^a42 . Among them are 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, Preferred groups include alkyl fluorides such as hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group, and perfluorooctyl 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, and perfluoroadamantylmethyl group.

In formula (a4-3), ^L5 is preferably an ethylene group.
The divalent saturated hydrocarbon group of A ^f13 is preferably a group containing a divalent chain saturated hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a divalent chain saturated hydrocarbon group having 2 to 3 carbon atoms.
The saturated hydrocarbon group of A ^f14 is preferably a group containing a chain-type saturated hydrocarbon group having 3 to 12 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a group containing a chain-type saturated hydrocarbon group having 3 to 10 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms. In particular, 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 structural units represented by formula (a4-3) include those represented by formulas (a4-1'-1) to (a4-1'-11), respectively. Structural units in which the methyl group corresponding to R ^f7 in structural unit (a4-3) is replaced with a hydrogen atom can also be cited as structural units represented by formula (a4-3).

Another example of a structural unit (a4) is the structural unit represented by formula (a4-4).
[In formula (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 represents -( _CH2 ) _j1- , -( _CH2 ) _j2 -O-( _CH2 ) _j3- , or -( _CH2 ) _j4 -CO-O-( _CH2 ) _j5- .
j1 through j5 each independently represent an integer from 1 to 6.
R ^f22 represents a saturated hydrocarbon group having 1 to 10 carbon atoms and containing a fluorine atom.

The saturated hydrocarbon group of R ^f22 is the same as the saturated hydrocarbon group represented by R ^a42 . ^{R f22} is preferably an alkyl group having 1 to 10 carbon atoms and a fluorine atom, or an alicyclic saturated hydrocarbon group having 1 to 10 carbon atoms and a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms and a fluorine atom, and even more preferably an alkyl group having 1 to 6 carbon atoms and a fluorine atom.
In formula (a4-4), A ^f21 is preferably -( _CH2 ) _j1- , more preferably an ethylene group or a methylene group, and even more preferably a methylene group.

Examples of structural units represented by formula (a4-4) include the following structural units and structural units in which the methyl group corresponding to R ^f21 in structural unit (a4-4) is replaced by a hydrogen atom.
If resin (A) contains structural units (a4), the content of these units is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and even more preferably 3 to 10 mol%, relative to the total structural units of resin (A).

<Structural Unit (a5)>
Examples of non-eliminating hydrocarbon groups in structural unit (a5) include groups having linear, branched, or cyclic hydrocarbon groups. Among these, structural unit (a5) is preferably a group having an alicyclic hydrocarbon group.
An example of a structural unit (a5) is the 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 atoms 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 the _-CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.

The alicyclic hydrocarbon group in R ⁵² may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. Examples of polycyclic alicyclic hydrocarbon groups include adamantyl and norbornyl groups.
Examples of aliphatic hydrocarbon groups having 1 to 8 carbon atoms include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl.
Examples of alicyclic hydrocarbon groups having substituents include the 3-methyladamantyl group.
R ⁵² is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group, or a cyclohexyl group.

Examples of divalent saturated hydrocarbon groups in L ⁵⁵ include divalent chain saturated hydrocarbon groups and divalent alicyclic saturated hydrocarbon groups, with divalent chain saturated hydrocarbon groups being preferred.
Examples of divalent chain-type saturated hydrocarbon groups include methylene groups, ethylene groups, propanediyl groups, butanediyl groups, and pentanediyl groups, as well as other alkanediyl groups.
The divalent alicyclic saturated hydrocarbon group may be monocyclic or polycyclic. Examples of monocyclic alicyclic saturated hydrocarbon groups include cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl. Examples of polycyclic divalent alicyclic saturated hydrocarbon groups include adamantanediyl and norbornanediyl.

Groups in which the _-CH2- contained in the divalent saturated hydrocarbon group represented by L ⁵⁵ is replaced with -O- or -CO- include, for example, the groups represented by formulas (L1-1) to (L1-4). In the following formulas, * and ** represent bonding sites, and * represents the bonding site with the oxygen atom.
In formula (L1-1),
X ^x1 represents *-O-CO- or *-CO-O- (where * represents the bond position 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 number of carbon atoms in L ^x1 and L ^x2 must be 16 or less.
In formula (L1-2),
L ^x3 represents a divalent aliphatic saturated hydrocarbon group with 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 number of carbon atoms in L ^x3 and L ^x4 must be 17 or less.
In formula (L1-3),
L ^x5 represents a divalent aliphatic saturated hydrocarbon group with 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 number of carbon atoms in L ^{x 5} , L ^{x 6} , and L ^{x 7} must be 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 number of carbon atoms in L ^x8 , L ^x9 , and W ^x1 is 15 or less.

L ^x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond.
L ^x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
L ^x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
W ^x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

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

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

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

Examples of groups 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).

Examples of structural units (a5-1) include the structural units shown below and structural units in which the methyl group corresponding to R ⁵¹ in structural unit (a5-1) below is replaced by a hydrogen atom.
If the resin (A) contains structural units (a5), the content of these units is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and even more preferably 3 to 15 mol%, relative to the total structural units of the resin (A).

<Structural Unit (a6)>
The structural unit (a6) is a structural unit having a _-SO₂- group, and it is preferable that the _-SO₂- group is present in the side chain.
A structural unit having an _-SO₂- group may have a linear structure having an _-SO₂- group, a branched structure having an _-SO₂- group, or a cyclic structure (monocyclic and polycyclic) having an _-SO₂- group. Preferably, it is a structural unit having a cyclic structure having an _-SO₂- group, and more preferably, it is a structural unit having a cyclic structure (sultone ring) containing _-SO₂- O-.

Examples of sultone rings include those represented by the following formulas ( ^T1-1 ), ( ^T1-2 ), ( ^T1-3 ), and ( ^T1-4 ). The bonding site can be at any position. The sultone ring may be monocyclic, but it is preferably polycyclic. A polycyclic sultone ring means a bridging ring containing -SO₂ _- O- as the atomic group constituting the ring, and examples include the rings represented by formulas ( ^T1-1 ) and ( ^T1-2 ). The sultone ring, as in the ring represented by formula ( ^T1-2 ), may also contain heteroatoms in addition to _-SO₂- O- as the atomic group constituting the ring. Examples of heteroatoms include oxygen atoms, sulfur atoms, or nitrogen atoms, and oxygen atoms are preferred.

The sultone ring may have substituents. Examples of substituents include C1-C12 alkyl groups (which may have a halogen atom or a hydroxyl group), halogen atoms, hydroxyl groups, cyano groups, C1-C12 alkoxy groups, C6-C12 aryl groups, C7-C12 aralkyl groups, glycidyloxy groups, C2-C12 alkoxycarbonyl groups, and C2-C4 alkylcarbonyl groups.

Examples of halogen atoms include fluorine, chlorine, bromine, and iodine.
Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, and decyl groups, preferably alkyl groups having 1 to 6 carbon atoms, and more preferably methyl groups.
Examples of alkyl groups having a halogen atom include trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluorosec-butyl, perfluorotert-butyl, perfluoropentyl, perfluorohexyl, trichloromethyl, tribromomethyl, and triiodomethyl, with trifluoromethyl being preferred.
Examples of alkyl groups having a hydroxyl group include hydroxymethyl groups and 2-hydroxyethyl groups.
Examples of alkoxy groups include methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, decyloxy, and dodecyloxy groups.
Examples of aryl groups include phenyl, naphthyl, anthryl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumyl, mesityl, biphenyl, phenanthryl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl.
Examples of aralkyl groups include benzyl, phenethyl, phenylpropyl, naphthylmethyl, and naphthylethyl groups.
Examples of alkoxycarbonyl groups include groups in which an alkoxy group such as a methoxycarbonyl group or an ethoxycarbonyl group is bonded to a carbonyl group, preferably an alkoxycarbonyl group having 6 or fewer carbon atoms, and more preferably a methoxycarbonyl group.
Examples of alkylcarbonyl groups include acetyl, propionyl, and butyryl groups.

From the viewpoint of ease of producing monomers that lead to structural unit (a6), a sultone ring without substituents is preferred.
As the sultone ring, the ring represented by the following formula (T1') is preferred.
[In formula (T1'),
^X11 represents an oxygen atom, a sulfur atom, or a methylene group.
R ⁴¹ represents a C1-C12 alkyl group which may have a halogen atom or a hydroxyl group, a halogen atom, a hydroxyl group, a cyano group, a C1-C12 alkoxy group, a C6-C12 aryl group, a C7-C12 aralkyl group, a glycidyloxy group, a C2-C12 alkoxycarbonyl group, or a C2-C4 alkylcarbonyl group.
ma represents an integer from 0 to 9. When ma is 2 or greater, multiple R ^41s may be the same or different.
The connection site can be at any position.
X ¹¹ is preferably an oxygen atom or a methylene group, and more preferably a methylene group.
Examples of R ⁴¹ include substituents similar to those of the sultone ring, and a C1 to C12 alkyl group which may have a halogen atom or a hydroxyl group is preferred.

As the sultone ring, the ring represented by formula (T1) is more preferable.
[In formula (T1),
^R8 represents a C1-C12 alkyl group which may have a halogen atom or a hydroxyl group, a halogen atom, a hydroxyl group, a cyano group, a C1-C12 alkoxy group, a C6-C12 aryl group, a C7-C12 aralkyl group, a glycidyloxy group, a C2-C12 alkoxycarbonyl group, or a C2-C4 alkylcarbonyl group.
m represents an integer from 0 to 9. When m is 2 or greater, multiple ^R8s may be the same or different.
The connection site can be at any position.

R ⁸ is similar to R ⁴¹ .
In formula (T1'), ma and in formula (T1), m are preferably 0 or 1, and more preferably 0.

The following rings are examples of rings represented by formula (T1') and formula (T1). The bonding site is at an arbitrary position.
Structural units having a sultone ring preferably have the following groups. * in the following groups indicates a bonding site.

The structural unit having the _-SO₂- group preferably further has a group derived from a polymerizable group. Examples of polymerizable groups include vinyl group, acryloyl group, methacryloyl group, acryloyloxy group, methacryloyloxy group, acryloylamino group, methacryloylamino group, acryloylthio group, and methacryloylthio group.
In particular, the monomer that leads to the structural unit (a6) is preferably a monomer having an ethylenically unsaturated bond, and more preferably a (meth)acrylic monomer.

The structural unit (a6) is preferably a structural unit represented by formula (Ix).
[In formula (Ix), ^Rx represents a C1-C6 alkyl group, a hydrogen atom, or a halogen atom which may have a halogen atom.
^Axx represents an oxygen atom, a -N( ^Rc )- atom, or a sulfur atom.
^Ax represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and _{the -CH2-} contained in the saturated hydrocarbon group may be replaced with -O-, -CO-, or -N( ^Rd )-.
^X11 represents an oxygen atom, a sulfur atom, or a methylene group.
R ⁴¹ represents a C1-C12 alkyl group which may have a halogen atom or a hydroxyl group, a halogen atom, a hydroxyl group, a cyano group, a C1-C12 alkoxy group, a C6-C12 aryl group, a C7-C12 aralkyl group, a glycidyloxy group, a C2-C12 alkoxycarbonyl group, or a C2-C4 alkylcarbonyl group.
ma represents an integer from 0 to 9. When ma is 2 or greater, multiple R ^41s may be the same or different.
^Rc and ^Rd independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

Examples of halogen atoms in ^Rx include fluorine, chlorine, bromine, and iodine.
Examples of alkyl groups 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 alkyl groups having 1 to 4 carbon atoms, and more preferably methyl group or ethyl group.
Examples of alkyl groups having a halogen atom of R ^x include trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluorosec-butyl, perfluorotert-butyl, perfluoropentyl, perfluorohexyl, trichloromethyl, tribromomethyl, and triiodomethyl.
^Rx 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 divalent saturated hydrocarbon group A ^x include linear alkanediyl groups, branched alkanediyl groups, and monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and combinations of two or more of these groups are also acceptable.
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 alkane diyl groups such as 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-1,17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, and propane-2,2-diyl group;
Branched alkanediyl groups such as 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;
Monocyclic, divalent, alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, cyclobutane-1,3-diyl groups, cyclopentane-1,3-diyl groups, cyclohexane-1,4-diyl groups, and cyclooctane-1,5-diyl groups;
Examples include polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.

R ⁴¹ , X ¹¹ , and ma are the same as those in formula (T1').
Examples of sultone rings include those mentioned above, and among them, those with specified bonding positions are preferred.

The following structural units (a6) are examples of structural units:

In particular, structural units represented by formulas (a6-1), (a6-2), (a6-6), (a6-7), (a6-8), and (a6-12) are preferred, and structural units represented by formulas (a6-1), (a6-2), (a6-7), and (a6-8) are more preferred.
If the resin (A) has structural units (a6), the content of these units is preferably 1 to 50 mol%, more preferably 2 to 40 mol%, and even more preferably 3 to 30 mol%, relative to the total structural units of the resin (A).

<Structural Unit (II)>
The resin (A) may further contain structural units that decompose upon exposure to generate acid (hereinafter sometimes referred to as "structural unit (II)"). Specifically, structural unit (II) is the structural unit described in Japanese Patent Application Publication No. 2016-79235, and is preferably a structural unit having a sulfonate group or carboxylate group and an organic cation in its side chain, or a structural unit having a sulfonio group and an organic anion in its side chain.

The structural unit having a sulfonate group or carboxylate group and an organic cation in its side chain is preferably the 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, wherein the _-CH2- contained in the saturated hydrocarbon group may be replaced with -O-, -S-, or -CO-, and 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 hydroxyl group.
A ^x1 represents an alkanediyl group having 1 to 8 carbon atoms, and the hydrogen atoms contained in the alkanediyl group may be substituted with fluorine atoms or perfluoroalkyl groups 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 that may contain a halogen atom.
ZA ⁺ represents an organic cation.

Examples of halogen atoms represented by R ^III3 include fluorine, chlorine, bromine, and iodine atoms.
Examples of C1-C6 alkyl groups that may have a halogen atom represented by R ^III3 are the same as those of C1-C6 alkyl groups that may have a halogen atom represented by R ^a8 .
Examples of ^C1 -C1 alkanediyl groups include methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, 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, and 2-methylbutane-1,4-diyl group.
Examples of ^C1 -C1 perfluoroalkyl groups that may be substituted include trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluorosec-butyl, perfluorotert-butyl, perfluoropentyl, and perfluorohexyl groups.
Examples of divalent saturated hydrocarbon groups having 1 to 18 carbon atoms represented by X ^III3 include linear or branched alkanediyl groups, monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and combinations thereof.
Specifically, linear alkane diyl groups such as 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, etc.; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane Examples include branched alkanediyl groups such as pan-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group; cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group; and divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.
Examples of groups in which the _-CH2- contained in a saturated hydrocarbon group is replaced by -O-, -S-, or -CO- include the divalent groups represented by formulas (X1) to (X53). However, the number of carbon atoms before the _-CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S-, or -CO- is 17 or less. In the following formulas, * and ** represent bonding sites, and * represents the bonding site with A ^x1 .

^X3 represents a divalent saturated hydrocarbon group with 1 to 16 carbon atoms.
^X4 represents a divalent saturated hydrocarbon group with 1 to 15 carbon atoms.
^X5 represents a divalent saturated hydrocarbon group with 1 to 13 carbon atoms.
^X6 represents a divalent saturated hydrocarbon group with 1 to 14 carbon atoms.
^X7 represents a trivalent saturated hydrocarbon group with 1 to 14 carbon atoms.
^X8 represents a divalent saturated hydrocarbon group with 1 to 13 carbon atoms.

In formula (II-2-A'), ZA ⁺ is similar to the cation Z1 ⁺ in the acid generator (B1).

The structural unit represented by formula (II-2-A') is preferably the structural unit represented by formula (II-2-A).
[In formula (II-2-A),
R ^III3 , X ^III3 , and ZA ⁺ have the same meaning as above.
z2A represents an integer between 0 and 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, multiple R ^III2 and R ^III4 may be the same or different from each other.
Q ^a and Q ^b each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
Examples of perfluoroalkyl groups having 1 to 6 carbon atoms represented by R ^III2 , R ^III4 , Q ^a , and Q ^b include the same perfluoroalkyl groups having 1 to 6 carbon atoms represented by Q ^b1 mentioned above.

The structural unit represented by formula (II-2-A) is preferably the 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 ⁺ have the same meaning as above.
R ^III5 represents a saturated hydrocarbon group with 1 to 12 carbon atoms.
z2A1 represents an integer between 0 and 6.
X ^I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, and the _-CH2- contained in the saturated hydrocarbon group may be replaced with -O-, -S-, or -CO-, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with halogen atoms or hydroxyl groups.
Examples of saturated hydrocarbon groups having 1 to 12 carbon atoms represented by R ^III5 include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and dodecyl groups.
Examples of divalent saturated hydrocarbon groups represented by X ^I2 include those similar to the divalent saturated hydrocarbon groups represented by X ^III3 .

The structural unit represented by formula (II-2-A-2) is preferred over the structural unit represented by formula (II-2-A-1).
[In formula (II-2-A-2),
R ^III3 , R ^III5 , and ZA ⁺ have the same meaning as above.
mA and nA each independently represent 1 or 2.

Examples of structural units represented by formula (II-2-A') include the following structural units, structural units in which the group corresponding to the methyl group of R ^III3 is replaced by a hydrogen atom, a halogen atom (e.g., a fluorine atom), or a C1-C6 alkyl group which may have a halogen atom (e.g., a trifluoromethyl group), and structural units described in International Publication No. 2012/050015. ZA ⁺ represents an organic cation.

The structural unit having a sulfonio group and an organic anion in its side chain is preferably the 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 that may contain a halogen atom.
^A- represents an organic anion.
Examples of divalent aromatic hydrocarbon groups having 6 to 18 carbon atoms represented by R ^II1 include phenylene groups and naphthylene groups.
Examples of hydrocarbon groups represented by R ^II2 and R ^II3 include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these.
Examples of alkyl groups and alicyclic hydrocarbon groups are the same as those described above.
Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl groups.
Examples of combined groups include groups combining alkyl groups and alicyclic hydrocarbon groups as described above, aralkyl groups such as benzyl groups, aromatic hydrocarbon groups having alkyl groups (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having alicyclic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), and aryl-cycloalkyl groups such as phenylcyclohexyl groups.
Examples of halogen atoms represented by R ^{II 4} include fluorine, chlorine, bromine, and iodine atoms.
Examples of C1-C6 alkyl groups that may have a halogen atom represented by R ^II4 include the same C1-C6 alkyl groups that may have a halogen atom represented by R ^a8 .
Examples of the divalent linking group represented by A ^II1 include divalent saturated hydrocarbon groups having 1 to 18 carbon atoms, and the _-CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O-, -S-, or -CO-. Specifically, the same as the divalent saturated hydrocarbon groups having 1 to 18 carbon atoms represented by X ^III3 can be mentioned.

Examples of structural units containing the cation in formula (II-1-1) include the structural unit represented below and structural units in which the group corresponding to the methyl group of R ^II4 is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or a C1-C6 alkyl group which may have a halogen atom (e.g., a trifluoromethyl group).

Examples of organic anions 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, and more preferably a sulfonic acid anion that is included in the salt represented by formula (B1) above. The sulfonylimide anions and sulfonylmethide anions are more preferably the anions exemplified in the acid generator (B) above. Furthermore, the carboxylic acid anions are more preferably anions included in the carboxylic acid salt represented by formula (I) above, and may also be the following.

Examples of structural units represented by formula (II-1-1) include the following structural units:
When resin (A) contains structural unit (II), the content of structural unit (II) is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and even more preferably 3 to 10 mol%, relative to the total structural units of resin (A).

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

Each structural unit constituting resin (A) may be used individually or in combination of two or more types, and these structural units can be produced by known polymerization methods (e.g., radical polymerization) using monomers that derive these structural units. The content of each structural unit in resin (A) can be adjusted by the amount of monomer used in polymerization.
The weight-average molecular weight of resin (A) is preferably 2,000 or more (more preferably 2,500 or more, even more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, even more preferably 15,000 or less). In this specification, the weight-average molecular weight is the value obtained by gel permeation chromatography under the conditions described in the examples.

<Resins other than resin (A)>
The resist composition of the present invention may also contain resins other than resin (A).
Examples of resins other than resin (A) include resins containing structural unit (a4) or structural unit (a5) (hereinafter sometimes referred to as resin (X)).
Among the resins (X), resins containing structural units (a4) are preferred.
In resin (X), the content of structural units (a4) is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more, relative to the total amount of all structural units in resin (X).
Structural units that resin (X) may further have include structural unit (a2), structural unit (a3), and structural units derived from other known monomers. In particular, resin (X) is preferably a resin consisting only of structural unit (a4) and/or structural unit (a5), and more preferably a resin consisting only of structural unit (a4).
Each structural unit constituting the resin (X) may be used individually or in combination of two or more types, and these structural units can be produced by known polymerization methods (e.g., radical polymerization) using monomers that induce these structural units. The content of each structural unit in the resin (X) can be adjusted by the amount of monomer used in polymerization.
The weight-average molecular weight of resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight-average molecular weight of resin (X) is the same as in the case of resin (A).
Furthermore, if the resist composition contains resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, even more preferably 1 to 40 parts by mass, even more preferably 1 to 30 parts by mass, and even more preferably 1 to 8 parts by mass, per 100 parts by mass of resin (A).

The content of resin (A) in the resist composition is preferably 80% to 99% by mass, and more preferably 90% to 99% by mass, relative to the solid content of the resist composition. Furthermore, if resins other than resin (A) are included, the total content of resin (A) and the other resins is preferably 80% to 99% by mass, and more preferably 90% to 99% by mass, relative to the solid content of the resist composition. The solid content of the resist composition and the resin content thereto can be measured using known analytical means such as liquid chromatography or gas chromatography.

<Solvent (E)>
The solvent (E) content 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 solvent (E) content can be measured by known analytical means such as liquid chromatography or gas chromatography.
Examples of 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; esters such as ethyl lactate, butyl acetate, amyl acetate, and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone; and cyclic esters such as γ-butyrolactone. One of solvents (E) may be used alone, or two or more may be used.

<Quencher (C)>
Quencher (C) is a basic nitrogen-containing organic compound or a salt that generates an acid weaker than the acid generated from an acid generator (excluding carboxylate salts represented by formula (I)). When the resist composition contains quencher (C), the content of quencher (C) is preferably about 0.01 to 15% by mass, 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, based on the solid content of the resist composition.
Basic nitrogen-containing organic compounds include amines and ammonium salts. Amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines, and tertiary amines.
Examples of amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-,3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, and tributylamine. Amine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methylddecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethylddecylamine Mine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridyl)ethanol Examples include 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, and the like. Preferably, aromatic amines such as diisopropylaniline are included, and more preferably, 2,6-diisopropylaniline is included.
Examples of ammonium salts include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate, and choline.

The acidity of a salt that generates an acid weaker than the acid generated by an acid generator is indicated by its acid dissociation constant (pKa). A salt that generates an acid weaker than the acid generated by an acid generator is a salt whose acid dissociation constant is usually -3 < pKa, preferably -1 < pKa < 7, and more preferably 0 < pKa < 5.
Examples of salts that generate an acid weaker in acidity than the acid generated from the acid generator include the salt represented by the following formula, the salt represented by formula (D) described in Japanese Patent Publication No. 2015-147926 (hereinafter sometimes referred to as "weak acid intramolecular salt (D)"), and the salts described in Japanese Patent Publication Nos. 2012-229206, 2012-6908, 2012-72109, 2011-39502, and 2011-191745. The salt that generates an acid weaker in acidity than the acid generated from the acid generator is preferably a salt that generates a carboxylic acid weaker in acidity than the acid generated from the acid generator (a salt having a carboxylic acid anion), more preferably a weak acid intramolecular salt (D), and even more preferably a diphenyliodonium salt containing a phenyl group substituted with a carboxylic acid anion among the weak acid intramolecular salts (D).

The weak acid intramolecular salt (D) is preferably a diphenyliodonium salt having an iodonium cation to which two phenyl groups are bonded, and a carboxylic acid anion to which at least one of the two phenyl groups bonded to the iodonium cation is substituted. Specifically, examples include salts represented by the following formula.

[In formula (D),
^RD1 and ^RD2 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, an alkoxycarbonyl group having 2 to 7 carbon atoms, a nitro group, or a halogen atom.
m' and n' each independently represent an integer between 0 and 4. If m' is 2 or greater, multiple R ^D1s may be the same or different. If n' is 2 or greater, multiple R ^D2s may be the same or different.
Examples of hydrocarbon groups in ^RD1 and ^RD2 include chain hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these.
Examples of chain-type hydrocarbon groups include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, and nonyl groups.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and may be saturated or unsaturated. Examples include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclononyl, and cyclododecyl groups, as well as norbonyl and adamantyl groups.
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, anthyl 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 include alkyl-cycloalkyl groups, cycloalkyl-alkyl groups, and aralkyl groups (for example, phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl-1-propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, etc.).
Examples of alkoxy groups include methoxy groups and ethoxy groups.
Examples of acyl groups include acetyl groups, propanoyl groups, benzoyl groups, and cyclohexanecarbonyl groups.
Examples of acyloxy groups include groups in which an oxy group (-O-) is bonded to the above-mentioned acyl group.
Examples of alkoxycarbonyl groups include groups in which a carbonyl group (-CO-) is bonded to the above-mentioned alkoxy group.
Examples of halogen atoms include fluorine, chlorine, and bromine atoms.
^RD1 and ^RD2 are each preferably 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, an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group, or a halogen atom.
m' and n' are each independently preferably integers from 0 to 2, and more preferably 0. If m' is 2 or greater, multiple R ^D1s may be the same or different, and if n' is 2 or greater, multiple R ^D2s may be the same or different.

More specifically, the following salts are examples:

<Other ingredients>
The resist composition of the present invention may optionally contain components other than those described above (hereinafter sometimes referred to as "other components (F)"). There are no particular limitations on other components (F), 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 can be prepared by mixing a carboxylate (I), a resin (A), an acid generator (B), and, if necessary, a resin other than resin (A), a solvent (E), a quencher (C), and other components (F). The mixing order is arbitrary and not particularly limited. The mixing temperature can be selected from 10 to 40°C, depending on the type of resin, the solubility of the resin in the solvent (E), etc. The mixing time can be selected from 0.5 to 24 hours, depending on the mixing temperature. There are no particular restrictions on the mixing method, and stirring or other methods can be used.
After mixing the components, it is preferable to filter the mixture using a filter with a pore size of approximately 0.003 to 0.2 μm.

<Method for manufacturing resist patterns>
The method for manufacturing a resist pattern of the present invention is:
(1) A step of applying the resist composition of the present invention onto a substrate,
(2) A step of drying the coated composition to form a composition layer,
(3) Exposure step of the composition layer,
(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 to a substrate using commonly used equipment such as a spin coater. Examples of substrates include inorganic substrates such as silicon wafers, and organic substrates with a resist film or the like formed on their surface. Before applying the resist composition, the substrate may be cleaned, or an anti-reflective film or the like may be formed on the substrate.
The solvent is removed and a composition layer is formed by drying the coated composition. 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 vacuum device. The heating temperature is preferably 50 to 200°C, and the heating time is preferably 10 to 180 seconds. Furthermore, the pressure during vacuum drying is preferably about 1 to 1.0 × ^10⁵ Pa.
The resulting composition layer is typically exposed using an exposure machine. The exposure machine may be an immersion exposure machine. Various types of exposure light sources can be used, including those that emit ultraviolet laser light such as KrF excimer lasers (wavelength 248 nm), ArF excimer lasers (wavelength 193 nm), and _F2 excimer lasers (wavelength 157 nm); those that emit far-ultraviolet or vacuum-ultraviolet harmonic laser light by wavelength conversion of laser light from a solid-state laser light source (such as a YAG or semiconductor laser); electron beams; and those that irradiate with ultra-ultraviolet (EUV) light. In this specification, the irradiation of these radiations is sometimes collectively referred to as "exposure." During exposure, exposure is usually performed through a mask corresponding to the desired pattern. If the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask.
The composition layer after exposure is subjected to heat treatment (so-called post-exposure bake) to promote the deprotection reaction at acid-unstable groups. The heating temperature is usually around 50 to 200°C, preferably around 70 to 150°C. Chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the composition after heating. Alternatively, before development, the process of coating the resist composition, drying, exposure, and heating may be repeated on the composition layer after exposure.
The heated composition layer is typically developed using a developing device and a developing solution. Development methods include the dip method, paddle method, spray method, and dynamic dispensing method. The development temperature is preferably, for example, 5 to 60°C, and the development time is preferably, for example, 5 to 300 seconds. By selecting the type of developing solution as described below, a positive-type resist pattern or a negative-type 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 can be any alkaline aqueous solution used in this field. For example, aqueous solutions of tetramethylammonium hydroxide or (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline) can be used. The alkaline developer may also contain a surfactant.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove any remaining water on the substrate and pattern.
When manufacturing a negative-type 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; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; and aromatic hydrocarbon solvents such as anisole.
In the organic developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and even more preferably substantially composed of only organic solvents.
Among these, organic developers containing butyl acetate and/or 2-heptanone are 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 even more preferably substantially only butyl acetate and/or 2-heptanone.
Organic developers may contain surfactants. Furthermore, organic developers may contain trace amounts of water.
During development, the development process may be stopped by substituting a different type of solvent for the organic developer.
It is preferable to wash the developed resist pattern with a rinsing solution. The rinsing solution is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent.
After cleaning, it is preferable to remove any remaining rinse solution from the substrate and patterns.

<Application>
The resist composition of the present invention is suitable as 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, and is particularly suitable as a resist composition for ArF excimer laser exposure, and is useful for microfabrication of semiconductors.

The present invention will be described in more detail with reference to examples. In the examples, "%" and "parts" representing the content or amount used are based on mass unless otherwise specified.
The weight-average molecular weight was determined by gel permulation chromatography. The analytical conditions for gel permulation chromatography are as follows:
Column: TSKgel Multipore HXL-M x 3 + guard column (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min
Detector: RI detector; Column temperature: 40°C
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: Agilent 1100, MASS: Agilent LC/MSD). In the following examples, the value of this molecular ion peak is indicated as "MASS".

Example 1: Synthesis of the salt represented by formula (I-2)
22.55 parts of the compound represented by formula (I-2-a), 4.56 parts of the compound represented by formula (I-2-c), 150 parts of ethyl acetate, and 15 parts of tetrahydrofuran were mixed and stirred at 23°C for 30 minutes. 13.10 parts of the compound represented by formula (I-2-b) were added to the resulting mixed solution and stirred at 23°C for 18 hours. 50 parts of n-heptane and 70 parts of deionized water were added to the resulting reaction mass and stirred at 23°C for 30 minutes, after which the organic layer was separated. 70 parts of deionized water were added to the recovered organic layer and stirred at 23°C for 30 minutes, after which the organic layer was separated. This washing procedure was repeated four times. The obtained organic layer was concentrated, and the concentrated mass was fractionated using a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: n-heptane/ethyl acetate = 1/1) to obtain 8.91 parts of the compound represented by formula (I-2-d).
1.02 parts of the compound represented by formula (I-2-d) and 10 parts of tetrahydrofuran were mixed and stirred at 23°C for 30 minutes, then cooled to 5°C, and 0.14 parts of sodium hydride were added. 1.82 parts of the salt represented by formula (I-2-e) were added to the resulting mixture and stirred at 5°C for 3 hours. 6.30 parts of 1N hydrochloric acid were added to the resulting mixture, then the temperature was raised to 23°C and stirred at 23°C for 6 hours. 30 parts of chloroform and 15 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. The obtained organic layer was concentrated, and to the concentrated residue, 1 part of acetonitrile and 30 parts of tert-butyl methyl ether were added and stirred at 23°C for 30 minutes, then the supernatant was removed and concentrated to obtain 1.55 parts of the salt represented by formula (I-2-f).
0.98 parts of the salt represented by formula (I-2-f) and 30 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes. Then, 0.16 parts of potassium carbonate and 0.05 parts of potassium iodide were added, and the temperature was raised to 75°C. 1.08 parts of the compound represented by formula (I-2-g) were added to the resulting mixture and stirred at 75°C for 5 hours, then cooled to 23°C. 50 parts of chloroform and 20 parts of 5% aqueous oxalic acid solution were added to the resulting mixture and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. 20 parts of deionized water were added to the obtained organic layer and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. This washing procedure was repeated five times. The obtained organic layer was concentrated to obtain 1.33 parts of the salt represented by formula (I-2-h).
1.23 parts of the salt represented by formula (I-2-h), 0.47 parts of the salt represented by formula (I-2-i), and 30 parts of chloroform were mixed and stirred at 23°C for 2 hours. 20 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. This washing procedure was repeated five times. The resulting organic layer was concentrated to obtain 1.38 parts of the salt represented by formula (I-2).
MASS (ESI (+) Spectrum): M ⁺ 735.2
MASS (ESI(-)Spectrum): M ^- 193.1

Example 2: Synthesis of the salt represented by formula (I-4)
1.23 parts of the salt represented by formula (I-2-h), 0.70 parts of the salt represented by formula (I-4-i), and 30 parts of chloroform were mixed and stirred at 23°C for 2 hours. 20 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. This washing procedure was repeated five times. The resulting organic layer was concentrated to obtain 1.59 parts of the salt represented by formula (I-4).
MASS (ESI (+) Spectrum): M ⁺ 735.2
MASS (ESI(-)Spectrum): M ^- 337.1

Example 3: Synthesis of the salt represented by formula (I-669)
1.02 parts of the compound represented by formula (I-2-d) and 20 parts of tetrahydrofuran were mixed and stirred at 23°C for 30 minutes, then cooled to 5°C, and 0.14 parts of sodium hydride were added. 2.60 parts of the salt represented by formula (I-669-e) were added to the resulting mixture and stirred at 5°C for 3 hours. 6.30 parts of 1N hydrochloric acid were added to the resulting mixture, then the temperature was raised to 23°C and stirred at 23°C for 6 hours. 30 parts of chloroform and 15 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. The obtained organic layer was concentrated, and to the concentrated residue, 1 part of acetonitrile and 30 parts of tert-butyl methyl ether were added and stirred at 23°C for 30 minutes, then the supernatant was removed and concentrated to obtain 1.95 parts of the salt represented by formula (I-669-f).
1.30 parts of the salt represented by formula (I-669-f) and 30 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes. Then, 0.16 parts of potassium carbonate and 0.05 parts of potassium iodide were added, and the temperature was raised to 75°C. 1.08 parts of the compound represented by formula (I-2-g) were added to the resulting mixture and stirred at 75°C for 5 hours, then cooled to 23°C. 50 parts of chloroform and 20 parts of 5% oxalic acid aqueous solution were added to the resulting mixture and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. 20 parts of deionized water were added to the obtained organic layer and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. This washing procedure was repeated five times. The obtained organic layer was concentrated to obtain 1.64 parts of the salt represented by formula (I-669-h).
1.45 parts of the salt represented by formula (I-669-h), 0.70 parts of the salt represented by formula (I-4-i), and 30 parts of chloroform were mixed and stirred at 23°C for 2 hours. 20 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. This washing procedure was repeated five times. The resulting organic layer was concentrated to obtain 1.62 parts of the salt represented by formula (I-669).
MASS (ESI (+) Spectrum): M ⁺ 871.2
MASS (ESI(-)Spectrum): M ^- 337.1

Example 4: Synthesis of the salt represented by formula (I-384)
0.98 parts of the salt represented by formula (I-2-f) and 30 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes. Then, 0.16 parts of potassium carbonate and 0.05 parts of potassium iodide were added, and the temperature was raised to 75°C. 0.68 parts of the compound represented by formula (I-384-g) were added to the resulting mixture and stirred at 75°C for 5 hours, then cooled to 23°C. 50 parts of chloroform and 20 parts of 5% aqueous oxalic acid solution were added to the resulting mixture and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. 20 parts of deionized water were added to the obtained organic layer and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. This washing procedure was repeated five times. The obtained organic layer was concentrated to obtain 1.19 parts of the salt represented by formula (I-384-h).
0.50 parts of the salt represented by formula (I-384-h), 0.45 parts of the salt represented by formula (I-4-i), and 30 parts of chloroform were mixed and stirred at 23°C for 2 hours. 20 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. This washing procedure was repeated five times. By concentrating the resulting organic layer, 0.67 parts of the salt represented by formula (I-384) were obtained.
MASS (ESI (+) Spectrum): M ⁺ 591.2
MASS (ESI(-)Spectrum): M ^- 337.1

Example 5: Synthesis of the salt represented by formula (I-3234)
1.77 parts of the compound represented by formula (I-3234-b) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.46 parts of carbonyldiimidazole were added to the resulting mixture and stirred at 50°C for 2 hours. 2.84 parts of the salt represented by formula (I-3234-a) were added to the resulting mixture and stirred at 50°C for 3 hours, after which it was cooled to 23°C. 6.30 parts of 1N hydrochloric acid were added to the resulting mixture, the temperature was raised to 23°C, and the mixture was stirred at 23°C for 6 hours. 50 parts of chloroform and 25 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. After concentrating the obtained organic layer, 1 part acetonitrile and 30 parts tert-butyl methyl ether were added to the concentration residue, and the mixture was stirred at 23°C for 30 minutes. The supernatant was then removed and the mixture was concentrated to obtain 2.52 parts of the salt represented by formula (I-3234-c).
0.60 parts of the salt represented by formula (I-3234-c) and 30 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes. Then, 0.08 parts of potassium carbonate and 0.03 parts of potassium iodide were added, and the temperature was raised to 75°C. 0.81 parts of the compound represented by formula (I-3234-g) were added to the resulting mixture and stirred at 75°C for 5 hours, then cooled to 23°C. 50 parts of chloroform and 20 parts of 5% oxalic acid aqueous solution were added to the resulting mixture and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. 20 parts of deionized water were added to the obtained organic layer and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. This washing procedure was repeated five times. The obtained organic layer was concentrated to obtain 1.09 parts of the salt represented by formula (I-3234-h).
0.60 parts of the salt represented by formula (I-3234-h), 0.35 parts of the salt represented by formula (I-4-i), and 30 parts of chloroform were mixed and stirred at 23°C for 2 hours. 20 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. This washing procedure was repeated five times. By concentrating the resulting organic layer, 0.78 parts of the salt represented by formula (I-3234) were obtained.
MASS (ESI (+) Spectrum): M ⁺ 719.2
MASS (ESI(-)Spectrum): M ^- 337.1

Example 6: Synthesis of the salt represented by formula (I-4469)
4.34 parts of the compound represented by formula (I-4469-b) and 30 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes. After the resulting mixture was cooled to 0°C, 0.30 parts of sodium hydride were mixed and stirred at 0°C for 4 hours. 3.17 parts of the salt represented by formula (I-2-e) were added to the resulting mixture at 0°C and stirred at 0°C for 3 hours to obtain a mixture containing the salt represented by formula (I-4469-c). The resulting mixture was heated to 23°C, 7.00 parts of 1N hydrochloric acid were added, and the mixture was heated to 23°C and stirred at 23°C for 6 hours. 50 parts of chloroform and 25 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. After concentrating the obtained organic layer, 30 parts of tert-butyl methyl ether were added to the concentration residue, and the mixture was stirred at 23°C for 30 minutes. The supernatant was then removed and the mixture was concentrated to obtain 4.82 parts of the salt represented by formula (I-4469-f).
1.57 parts of the salt represented by formula (I-4469-f) and 30 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes. Then, 0.16 parts of potassium carbonate and 0.05 parts of potassium iodide were added, and the temperature was raised to 75°C. 0.90 parts of the compound represented by formula (I-2-g) were added to the resulting mixture and stirred at 75°C for 5 hours, then cooled to 23°C. 50 parts of chloroform and 20 parts of 5% aqueous oxalic acid solution were added to the resulting mixture and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. 20 parts of deionized water were added to the obtained organic layer and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. This washing procedure was repeated five times. The obtained organic layer was concentrated to obtain 1.99 parts of the salt represented by formula (I-4469-h).

0.81 parts of the salt represented by formula (I-4469-h), 0.35 parts of the salt represented by formula (I-4-i), 30 parts of chloroform, and 15 parts of ethyl acetate were mixed and stirred at 23°C for 2 hours. 20 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. This washing procedure was repeated five times. The resulting organic layer was concentrated, and 30 parts of tert-butyl methyl ether were added to the concentrated residue and stirred at 23°C for 30 minutes, after which the mixture was filtered to obtain 0.99 parts of the salt represented by formula (I-4469).
MASS (ESI (+) Spectrum): M ⁺ 987.0
MASS (ESI(-)Spectrum): M ^- 337.1

Example 7: Synthesis of the salt represented by formula (I-5324)
4.34 parts of the compound represented by formula (I-5324-b) and 30 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes. After the resulting mixture was cooled to 0°C, 0.30 parts of sodium hydride were mixed and stirred at 0°C for 4 hours. 3.17 parts of the salt represented by formula (I-2-e) were added to the resulting mixture at 0°C and stirred at 0°C for 3 hours to obtain a mixture containing the salt represented by formula (I-5324-c). The resulting mixture was heated to 23°C, 7.00 parts of 1N hydrochloric acid were added, and the mixture was heated to 23°C and stirred at 23°C for 6 hours. 50 parts of chloroform and 25 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. After concentrating the obtained organic layer, 30 parts of tert-butyl methyl ether were added to the concentration residue, and the mixture was stirred at 23°C for 30 minutes. The supernatant was then removed and the mixture was concentrated to obtain 4.66 parts of the salt represented by formula (I-5324-f).
1.57 parts of the salt represented by formula (I-5324-f) and 30 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes. Then, 0.16 parts of potassium carbonate and 0.05 parts of potassium iodide were added, and the temperature was raised to 75°C. 0.90 parts of the compound represented by formula (I-2-g) were added to the resulting mixture and stirred at 75°C for 5 hours, then cooled to 23°C. 50 parts of chloroform and 20 parts of 5% oxalic acid aqueous solution were added to the resulting mixture and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. 20 parts of deionized water were added to the obtained organic layer and stirred at 23°C for 30 minutes. The organic layer was then separated by liquid-liquid extraction. This washing procedure was repeated five times. The obtained organic layer was concentrated to obtain 1.62 parts of the salt represented by formula (I-5324-h).
0.81 parts of the salt represented by formula (I-5324-h), 0.35 parts of the salt represented by formula (I-4-i), 30 parts of chloroform, and 15 parts of ethyl acetate were mixed and stirred at 23°C for 2 hours. 20 parts of deionized water were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. This washing procedure was repeated five times. The resulting organic layer was concentrated, and 30 parts of tert-butyl methyl ether were added to the concentrated residue and stirred at 23°C for 30 minutes, followed by filtration to obtain 0.93 parts of the salt represented by formula (I-5324).
MASS (ESI (+) Spectrum): M ⁺ 987.0
MASS (ESI(-)Spectrum): M ^- 337.1

Synthesis Example 1: Synthesis of the salt represented by formula (IX-6)
2.25 parts of the compound represented by formula (IX-6-b) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 0.73 parts of carbonyldiimidazole were added to the resulting mixed solution and stirred at 50°C for 2 hours. 1.42 parts of the salt represented by formula (IX-6-a) were added to the resulting mixed solution and stirred at 50°C for 3 hours, then cooled to 23°C. 15 parts of 5% aqueous oxalic acid solution were added to the resulting mixture and stirred at 23°C for 30 minutes, after which the organic layer was separated. 15 parts of deionized water were added to the resulting organic layer and stirred at 23°C for 30 minutes, after which the organic layer was separated. 1.21 parts of the salt represented by formula (I-2-i) were added to the resulting organic layer and stirred at 23°C for 2 hours. 30 parts of chloroform and 30 parts of deionized water were added to the resulting reaction product and stirred at 23°C for 30 minutes, after which the organic layer was separated. Thirty parts of deionized water were added to the recovered organic layer, and the mixture was stirred at 23°C for 30 minutes. The organic layer was then separated and removed. This washing procedure was repeated seven times. The obtained organic layer was concentrated, and the concentrated mixture was fractionated using a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: methanol/chloroform = 1/1) to obtain 1.48 parts of the salt represented by formula (IX-6).
MASS (ESI (+) Spectrum): M ⁺ 760.8
MASS (ESI(-)Spectrum): M ^- 193.1

Synthesis Example 2: Synthesis of the salt represented by formula (IX-7)
1.43 parts of the salt represented by formula (I-2-e), 2.11 parts of the compound represented by formula (IX-7-b), and 10 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes. 0.40 parts of potassium carbonate were added to the resulting mixture and stirred at 23°C for 30 minutes, then stirred at 90°C for 20 hours to obtain a mixture containing the salt represented by formula (IX-7-c). After cooling the resulting mixture to 23°C, 11 parts of 5% aqueous oxalic acid solution were added and stirred at 23°C for 30 minutes, then 1.21 parts of the salt represented by formula (I-2-i) were added and stirred at 23°C for 7 hours. 30 parts of chloroform and 30 parts of deionized water were added to the resulting reaction product and stirred at 23°C for 30 minutes, then the organic layer was separated. 30 parts of deionized water were added to the recovered organic layer and stirred at 23°C for 30 minutes, then the organic layer was separated. This washing procedure was repeated seven times. The obtained organic layer was concentrated, and the concentrated mixture was parsed using a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Ltd., developing solvent: methanol/chloroform = 1/1) to obtain 0.43 parts of the salt represented by formula (IX-7).
MASS (ESI (+) Spectrum): M ⁺ 776.8
MASS (ESI(-)Spectrum): M ^- 193.1

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

Synthesis Example 3: Synthesis of Resin A1 Monomers (a1-1-3), (a1-2-6), (a2-1-1), and (a3-4-2) were used as monomers, and they were mixed in a molar ratio [monomer (a1-1-3): monomer (a1-2-6): monomer (a2-1-1): monomer (a3-4-2)] of 45:14:2.5:38.5. Propylene glycol monomethyl ether acetate was added in an amount 1.5 times the mass of the total monomer to make a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1 mol% and 3 mol% relative to the total monomer, respectively, and these were heated at 73°C for about 5 hours. The resulting reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol/water mixed solvent to precipitate the resin. This reprecipitation operation was performed twice, and resin A1 with a weight-average molecular weight of 7.8 × ^10³ was obtained in a yield of 69%. This resin A1 has the following structural units.

Synthesis Example 4: Synthesis of Resin X1 Monomer (a5-1-1) and monomer (a4-0-12) were used as monomers, and they were mixed in a molar ratio [monomer (a5-1-1):monomer (a4-0-12)] of 50:50. Methyl isobutyl ketone was added in an amount equal to 1.2 times the total amount of monomer to form a solution. To this solution, azobis(2,4-dimethylvaleronitrile) was added as an initiator at a concentration of 3 mol% relative to the total amount of monomer, and the mixture was heated at 70°C for approximately 5 hours. The resulting reaction mixture was poured into a large amount of methanol/water mixed solvent to precipitate the resin, and this resin was filtered to obtain resin X1 with a weight-average molecular weight of 1.0 × ^10⁴ in yield at 91%. This resin X1 has the following structural units.

<Preparation of the resist composition>
As shown in Table 2, the following components were mixed, and the resulting mixture was filtered through a fluororesin filter with a pore size of 0.2 μm to prepare a resist composition.

<Resin>
A1, X1: Resin A1, Resin X1
<Acid Generator (B)>
B1-21: Salt represented by formula (B1-21) B1-22: Salt represented by formula (B1-22)
<Carboxylate salt (I)>
I-2: Salt represented by formula (I-2) I-4: Salt represented by formula (I-4) I-384: Salt represented by formula (I-384) I-669: Salt represented by formula (I-669) I-3234: Salt represented by formula (I-3234) I-4469: Salt represented by formula (I-4469) I-5324: Salt represented by formula (I-5324) <Salt (IX)>
IX-1
IX-2
IX-3
IX-4
IX-5
IX-6: Salt represented by formula (IX-6) IX-7: Salt represented by formula (IX-7) <Solvent>
Propylene glycol monomethyl ether acetate 265 parts Propylene glycol monomethyl ether 20 parts 2-heptanone 20 parts γ-butyrolactone 3.5 parts

<Manufacturing and evaluation of resist patterns>
An organic anti-reflective coating composition [ARC-29; manufactured by Nissan Chemical Corporation] was applied to a 12-inch silicon wafer and baked at 205°C for 60 seconds to form an organic anti-reflective coating with a thickness of 78 nm. Next, the above-mentioned resist composition was spin-coated onto the organic anti-reflective coating so that the thickness of the composition layer after drying (pre-baking) was 100 nm. After coating, this silicon wafer was pre-baked on a direct hot plate for 60 seconds at the temperature indicated in the "PB" column of Table 2 to form the composition layer on the silicon wafer.
A composition layer formed on a silicon wafer was exposed using an ArF excimer laser stepper for immersion lithography [XT: 1900 Gi; manufactured by ASML, NA = 1.35, Annular σ _out = 0.85 σ _in = 0.65 XY-pol. illumination], with a mask used to form a trench pattern (pitch 120 nm / trench width 40 nm), by gradually changing the exposure amount. Ultrapure water was used as the immersion medium.
After exposure, post-exposure baking was performed on a hot plate at the temperature indicated in the "PEB" column of Table 2 for 60 seconds. Next, the composition layer on the silicon wafer was developed using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as the developer by dynamic dispensing at 23°C for 20 seconds to produce a negative resist pattern.

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

<Line Edge Roughness Evaluation (LER)>
The amplitude of the surface irregularities of the obtained resist patterns was observed and measured using a scanning electron microscope. The results are shown in Table 3. The values in the table indicate the amplitude (nm).

The carboxylate salt and the resist composition containing the carboxylate salt of the present invention are suitable for semiconductor microfabrication and are extremely useful in industry because they produce resist patterns with good line edge roughness (LER).

Claims (18)

A carboxylic acid generator containing a carboxylic acid salt represented by formula (I).
[In formula (I),
^R1 , ^R2 , and ^R3 each independently represent *-O-R ¹⁰ , *-O-CO-R ¹⁰ , *-O-CO-O-R ¹⁰ , or *-O-L ¹⁰ -CO-O-R ¹⁰ , where * represents the bonding site with the benzene ring.
^L10 represents an alkanediyl group with 1 to 6 carbon atoms.
R ¹⁰ represents an alicyclic hydrocarbon group having 3 to 16 carbon atoms, which may have substituents, and one of the _-CH2- groups in the alicyclic hydrocarbon group is replaced by -CO- or a group represented by formula (R ^10-1 ).
[In formula (R ¹⁰ -1),
R ^f1 and R ^f2 each independently represent a hydrogen atom, a fluorine atom, or a C1-C6 alkyl fluoride.
s represents an integer between 0 and 10, and when s is 2 or greater, multiple R ^f1 and R ^f2 are either identical or distinct.
^R4 , ^R5 , ^R6 , ^R7 , ^R8 , and ^R9 each independently represent a halogen atom, a C1-C12 haloalkyl group, or a C1-C18 hydrocarbon group, the hydrocarbon group may have substituents, and the _-CH2- contained in the haloalkyl group and the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
^A1 , ^A2 , and ^A3 each independently represent a hydrocarbon group having 2 to 20 carbon atoms, and the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- .
m1 represents an integer from 1 to 5, and when m1 is 2 or greater, the bases within the parentheses may be the same or different.
m² represents an integer between 0 and 5, and when m² is 2 or greater, the bases within the parentheses may be the same or different.
m3 represents an integer between 0 and 5, and when m3 is 2 or greater, the bases within the parentheses may be the same or different.
m4 represents an integer between 0 and 4, and when m4 is 2 or greater, multiple ^R4s may be the same or different from each other.
m5 represents an integer between 0 and 4, and when m5 is 2 or greater, multiple ^R5s may be the same or different from each other.
m6 represents an integer between 0 and 4, and when m6 is 2 or greater, multiple ^R6s may be the same or different from each other.
m7 represents an integer between 0 and 4, and when m7 is 2 or greater, multiple ^R7s may be the same or different from each other.
m8 represents an integer between 0 and 5, and when m8 is 2 or greater, multiple ^R8s may be the same or different from each other.
m9 represents an integer between 0 and 5, and when m9 is 2 or greater, multiple ^R9s may be the same or different from each other.
However, 1 ≤ m1 + m7 ≤ 5, 0 ≤ m2 + m8 ≤ 5, and 0 ≤ m3 + m9 ≤ 5.
^X0 represents an alicyclic hydrocarbon group having 3 to 24 carbon atoms, a group combining an alicyclic hydrocarbon group having 3 to 24 carbon atoms and a chain hydrocarbon group having 1 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 24 carbon atoms, or a group combining an aromatic hydrocarbon group having 6 to 24 carbon atoms and a chain hydrocarbon group having 1 to 18 carbon atoms. The alicyclic hydrocarbon group, the chain hydrocarbon group, and the aromatic hydrocarbon group may have substituents, and the _-CH2- contained in the alicyclic hydrocarbon group and the chain hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- . ^A1 is *-X01- ^L01- or *-L01- ^X01- , ^A2 is * ^{-X02-L02- or} *-L02- ^X02- , and ^A3 is * ^-X03 - ^L03- or * ^{-L03 - X03-} ( ^X01 , ^X02 and ^X03 each independently represent -O-, -CO-, _-S- or ^-SO2- . ^L01 , ^{L02 and L03} each independently represent a hydrocarbon group having 1 to 19 carbon atoms, the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S- or _-SO2- . * is ^R1 , ^R2 or R ³ represents the bonding site with the benzene ring to which it is bonded.) The carboxylic acid generator according to claim 1. The carboxylic acid generator according to claim 2, wherein ^X01 , ^X02 , and ^X03 are each independently -O- or -S-. The carboxylic acid generator according to claim 2, wherein ^L01 , ^L02 , and ^L03 are each independently an alkanediyl group having 1 to 6 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-). The carboxylic acid generator according to claim 1, wherein R ¹⁰ represents an alicyclic hydrocarbon group having 3 to 16 carbon atoms which may have substituents, one of the _-CH2- contained in the alicyclic hydrocarbon group is replaced by a group represented by formula (R ¹⁰ - 1), and R ^f1 and R ^f2 are fluorine atoms. A carboxylic acid generator according to claim 1, wherein ^X0 is a C3- to C24 alicyclic hydrocarbon group which may have substituents (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- ), a group which is a combination of a C3- to C24 alicyclic hydrocarbon group and a C1- to C12 chain hydrocarbon group (the alicyclic hydrocarbon group and the chain hydrocarbon group may have substituents, and the -CH2- contained in the alicyclic hydrocarbon group and the chain hydrocarbon group may be _replaced with -O- , -S-, -CO- or -SO2- ₎ , an aromatic hydrocarbon group which may have substituents, a group which is represented by formula (aa) or a group which is represented by formula (bb).
[In formula (aa),
X ^a and X ^b each independently represent -O- or -S-.
^X1a represents an alicyclic hydrocarbon group having 3 to 24 carbon atoms or a chain hydrocarbon group having 1 to 12 carbon atoms , and the alicyclic hydrocarbon group and the chain hydrocarbon group may have substituents, and the -CH2- contained in the alicyclic hydrocarbon group and the chain hydrocarbon group _may be replaced with -O-, -S-, -CO-, or _-SO2- .
^X2a represents an alicyclic hydrocarbon group having 3 to 24 carbon atoms, a chain hydrocarbon group having 1 to 12 carbon atoms, or a group formed by combining an alicyclic hydrocarbon group having 3 to 24 carbon atoms and a chain hydrocarbon group having 1 to 12 carbon atoms . The alicyclic hydrocarbon group and the chain hydrocarbon group may have substituents, and the _-CH2- contained in the alicyclic hydrocarbon group and the chain hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
* indicates the bond site with the carbon atom in ^-COO- .
[In formula (bb),
L ^A represents a C1-C6 alkanediyl group which may have a fluorine atom, or a C6-C14 aromatic hydrocarbon group which may have a halogen atom or a C1-C4 perfluoroalkyl group.
L ^B represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the _-CH2- contained in the alkanediyl group may be replaced with -O-, -S-, -CO-, or _-SO2- .
R ^A represents an alicyclic hydrocarbon group having 3 to 24 carbon atoms or an aromatic hydrocarbon group having 6 to 24 carbon atoms , and the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have substituents, and the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- .
* indicates the bond site with the carbon atom in ^-COO- . ^X0 may be a 3-24 carbon alicyclic hydrocarbon group (where the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- ), a group combining a 3-24 carbon alicyclic hydrocarbon group and a 1-12 carbon chain hydrocarbon group (where the -CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- , and where the _-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-, and where the alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, a _1-4 carbon perfluoroalkyl group, or a hydroxyl group), or a 6- carbon group (where the fluorine atom, a 1-4 carbon perfluoroalkyl group, or a hydroxyl group) The carboxylic acid generator according to claim 6, wherein the group is 24 aromatic hydrocarbon groups, a group represented by formula (aa), or a group represented by formula (bb). A resist composition comprising a carboxylic acid generator according to any one of claims 1 to 7, an acid generator other than the carboxylic acid generator, and a resin having an acid-unstable group which is a group represented by formula (1) or a group represented by formula (2) .
[In formula (1), Ra1 ^, Ra2 ^, and Ra3 ^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 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group having a combination thereof. Alternatively, Ra1 ^and Ra2 ^are bonded to each other to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.
ma and na each independently represent either 0 or 1, and at least one of ma and na represents 1.
* indicates a connection 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, R ^a3' represents a hydrocarbon group having 1 to 20 carbon atoms, or R ^a2' and R ^a3' are bonded to each other to form a heterocyclic group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded and X, and the _-CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced with -O- or -S-.
X represents either an oxygen atom or a sulfur atom.
na' represents 0 or 1.
* indicates a connection site. The resist composition according to claim 8, wherein the resin having an acid-unstable group comprises at least one 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).
[In formulas (a1-0), (a1-1), and (a1-2),
L ^a01 , L ^a1 , and L ^a2 each independently represent -O- or *-O-(CH ₂ ) _k1 -CO-O-, where k1 is an integer from 1 to 7, and * represents the bond site with -CO-.
^Ra01 , ^Ra4 , and ^Ra5 each independently represent a hydrogen atom, a halogen atom, or a C1-C6 alkyl group which may contain a halogen atom.
^Ra02 , ^Ra03 , and ^Ra04 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 a combination thereof.
^Ra6 and ^Ra7 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, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by a combination of these.
m1 represents an integer between 0 and 14.
n1 represents an integer between 0 and 10.
n1' represents an integer between 0 and 3. The resist composition according to claim 8, further comprising a resin containing structural units having fluorine atoms. (1) A step of applying the resist composition according to claim 8 onto a substrate,
(2) A step of drying the coated composition to form a composition layer,
(3) Exposure step of the composition layer,
(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 that includes [the specified element]. A carboxylate salt represented by formula (I).
[In formula (I),
^R1 , ^R2 , and ^R3 each independently represent *-O-R ¹⁰ , *-O-CO-R ¹⁰ , *-O-CO-O-R ¹⁰ , or *-O-L ¹⁰ -CO-O-R ¹⁰ , where * represents the bonding site with the benzene ring.
^L10 represents an alkanediyl group with 1 to 6 carbon atoms.
R ¹⁰ represents an alicyclic hydrocarbon group having 3 to 16 carbon atoms, which may have substituents, and one of the _-CH2- groups in the alicyclic hydrocarbon group is replaced by -CO- or a group represented by formula (R ^10-1 ).
[In formula (R ¹⁰ -1),
R ^f1 and R ^f2 each independently represent a hydrogen atom, a fluorine atom, or a C1-C6 alkyl fluoride.
s represents an integer between 0 and 10, and when s is 2 or greater, multiple R ^f1 and R ^f2 are either identical or distinct.
^R4 , ^R5 , ^R6 , ^R7 , ^R8 , and ^R9 each independently represent a halogen atom, a C1-C12 haloalkyl group, or a C1-C18 hydrocarbon group, the hydrocarbon group may have substituents, and the _-CH2- contained in the haloalkyl group and the hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
^A1 , ^A2 , and ^A3 each independently represent a hydrocarbon group having 2 to 20 carbon atoms, and the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S-, or _-SO2- .
m1 represents an integer from 1 to 5, and when m1 is 2 or greater, the bases within the parentheses may be the same or different.
m² represents an integer between 0 and 5, and when m² is 2 or greater, the bases within the parentheses may be the same or different.
m3 represents an integer between 0 and 5, and when m3 is 2 or greater, the bases within the parentheses may be the same or different.
m4 represents an integer between 0 and 4, and when m4 is 2 or greater, multiple ^R4s may be the same or different from each other.
m5 represents an integer between 0 and 4, and when m5 is 2 or greater, multiple ^R5s may be the same or different from each other.
m6 represents an integer between 0 and 4, and when m6 is 2 or greater, multiple ^R6s may be the same or different from each other.
m7 represents an integer between 0 and 4, and when m7 is 2 or greater, multiple ^R7s may be the same or different from each other.
m8 represents an integer between 0 and 5, and when m8 is 2 or greater, multiple ^R8s may be the same or different from each other.
m9 represents an integer between 0 and 5, and when m9 is 2 or greater, multiple ^R9s may be the same or different from each other.
However, 1 ≤ m1 + m7 ≤ 5, 0 ≤ m2 + m8 ≤ 5, and 0 ≤ m3 + m9 ≤ 5.
^X0 represents an alicyclic hydrocarbon group having 3 to 24 carbon atoms, a group combining an alicyclic hydrocarbon group having 3 to 24 carbon atoms and a chain hydrocarbon group having 1 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 24 carbon atoms, or a group combining an aromatic hydrocarbon group having 6 to 24 carbon atoms and a chain hydrocarbon group having 1 to 18 carbon atoms. The alicyclic hydrocarbon group, the chain hydrocarbon group, and the aromatic hydrocarbon group may have substituents, and the _-CH2- contained in the alicyclic hydrocarbon group and the chain hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- . ^A1 is *-X01- ^L01- or *-L01- ^X01- , ^A2 is * ^{-X02-L02- or} *-L02- ^X02- , and ^A3 is * ^-X03 - ^L03- or * ^{-L03 - X03-} ( ^X01 , ^X02 and ^X03 each independently represent -O-, -CO-, _-S- or ^-SO2- . ^L01 , ^{L02 and L03} each independently represent a hydrocarbon group having 1 to 19 carbon atoms, the hydrocarbon group may have substituents, and the _-CH2- contained in the hydrocarbon group may be replaced with -O-, -CO-, -S- or _-SO2- . * is ^R1 , ^R2 or R ³ represents the bonding site with the benzene ring to which it is bonded.) The carboxylate salt according to claim 12. The carboxylate salt according to claim 13, wherein ^X01 , ^X02 , and ^X03 are each independently -O- or -S-. The carboxylate salt according to claim 13 or 14, wherein ^L01 , ^L02 , and ^L03 are each independently an alkanediyl group having 1 to 6 carbon atoms (the _-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-). The carboxylate salt according to claim 12 or 13 , wherein R ¹⁰ represents an alicyclic hydrocarbon group having 3 to 16 carbon atoms which may have substituents, one of the _-CH2- contained in the alicyclic hydrocarbon group is replaced by a group represented by formula (R ¹⁰ - 1), and R ^f1 and R ^f2 are fluorine atoms. A carboxylate salt according to claim 12 or 13, wherein ^X0 is a C3- to C24 alicyclic hydrocarbon group which may have substituents (the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2- ₎ , a group formed by combining a C3- to C24 alicyclic hydrocarbon group and a C1- to C12 chain hydrocarbon group (the alicyclic hydrocarbon group and the chain hydrocarbon group may have substituents, and the -CH2- contained in the alicyclic hydrocarbon group and the chain hydrocarbon group _may be replaced with -O-, -S-, -CO- or -SO2- ₎ , an aromatic hydrocarbon group which may have substituents, a group represented by formula (aa), or a group represented by formula (bb).
[In formula (aa),
X ^a and X ^b each independently represent -O- or -S-.
^X1a represents an alicyclic hydrocarbon group having 3 to 24 carbon atoms or a chain hydrocarbon group having 1 to 12 carbon atoms , and the alicyclic hydrocarbon group and the chain hydrocarbon group may have substituents, and the -CH2- contained in the alicyclic hydrocarbon group and the chain hydrocarbon group _may be replaced with -O-, -S-, -CO-, or _-SO2- .
^X2a represents an alicyclic hydrocarbon group having 3 to 24 carbon atoms, a chain hydrocarbon group having 1 to 12 carbon atoms, or a group formed by combining an alicyclic hydrocarbon group having 3 to 24 carbon atoms and a chain hydrocarbon group having 1 to 12 carbon atoms . The alicyclic hydrocarbon group and the chain hydrocarbon group may have substituents, and the _-CH2- contained in the alicyclic hydrocarbon group and the chain hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- .
* indicates the bond site with the carbon atom in ^-COO- .
[In formula (bb),
L ^A represents a C1-C6 alkanediyl group which may have a fluorine atom, or a C6-C14 aromatic hydrocarbon group which may have a halogen atom or a C1-C4 perfluoroalkyl group.
L ^B represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the _-CH2- contained in the alkanediyl group may be replaced with -O-, -S-, -CO-, or _-SO2- .
R ^A represents an alicyclic hydrocarbon group having 3 to 24 carbon atoms or an aromatic hydrocarbon group having 6 to 24 carbon atoms , and the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have substituents, and the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or _-SO2- .
* indicates the bond site with the carbon atom in ^-COO- . ^X0 may be a 3-24 carbon alicyclic hydrocarbon group (where the _-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- ), a group combining a 3-24 carbon alicyclic hydrocarbon group and a 1-12 carbon chain hydrocarbon group (where the -CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO-, or _-SO2- , and where the _-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-, and where the alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, a _1-4 carbon perfluoroalkyl group, or a hydroxyl group), or a 6- carbon group (where the fluorine atom, a 1-4 carbon perfluoroalkyl group, or a hydroxyl group) The carboxylate salt according to claim 17, wherein the group is 24 aromatic hydrocarbon groups, a group represented by formula (aa), or a group represented by formula (bb).