Carboxylic acid generator, resist composition, method for producing resist pattern, and carboxylate

Abstract

To provide a carboxylate, a resist composition, and the like which allow a resist pattern having good CD uniformity to be produced.SOLUTION: There are provided a carboxylic acid generator containing a carboxylate represented by a formula (I), a resist composition, and the like. [In the formula (I), R1 represents a hydrogen atom or an optionally substituted hydrocarbon group, and -CH2- contained in the group may be substituted with -O-, -S-, -CO-, -NR2- or -SO2-; R2 represents a hydrogen atom or an alkyl group; ring W represents an optionally substituted alicyclic hydrocarbon ring, and -CH2- contained in the alicyclic hydrocarbon ring may be substituted with -O-, -S-, -CO- or -SO2-; X0 represents a single bond or an optionally substituted hydrocarbon group, and -CH2- contained in the group may be substituted with -O-, -S-, -CO- or -SO2-; and Z+ represents an organic cation.]SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a carboxylic acid generator, a resist composition, a method for producing a resist pattern, and a carboxylate salt.

Background Art

[0002] Patent Document 1 describes a resist composition containing a carboxylate salt represented by the following formula. TIFF2025091367000001.tif2640 Patent Document 2 describes resist compositions containing salts represented by the following formulas, respectively. TIFF2025091367000002.tif2654

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention provides a carboxylate salt that forms a resist pattern with better CD uniformity (CDU) than a resist pattern formed by a resist composition containing the above carboxylate salt.

Means for Solving the Problems

[0005] The present invention includes the following inventions. [1] A carboxylic acid generator containing a carboxylate salt represented by formula (I). TIFF2025091367000003.tif17106 [In formula (I), R 1represents a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO-, -NR 2 - or -SO2-. R 2 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms which may have a substituent, and -CH2- contained in the alicyclic hydrocarbon ring may be replaced by -O-, -S-, -CO- or -SO2-. X 0 represents a single bond or a hydrocarbon group having 1 to 72 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. Z + represents an organic cation. [2]X 0 is a single bond or a group formed by combining a chain hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, an aromatic hydrocarbon group having 6 to 36 carbon atoms or these groups (the alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, a fluoroalkyl group having 1 to 4 carbon atoms, or a hydroxy group, the aromatic hydrocarbon group may have a fluorine atom, an iodine atom, a fluoroalkyl group having 1 to 4 carbon atoms, or a hydroxy group, and -CH2- contained in the alicyclic hydrocarbon group and the chain hydrocarbon group may be replaced by -O- or -CO-). The carboxylic acid generator according to [1]. [3]A resist composition containing the carboxylic acid generator according to [1] or [2] and an acid generator other than the carboxylic acid generator. [4]Further containing a resin, the resist composition according to [3], wherein the resin contains a structural unit represented by formula (a2-A). TIFF2025091367000004.tif30128[In formula (a2-A), R a2 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a27represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group. A a21 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O-, -CO- or -NR a28 -. R a28 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a2 represents a single bond or a carbonyl group. nA2 represents any integer from 1 to 5, and when nA2 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. na21 represents any integer from 0 to 4, and when na21 is 2 or more, the plurality of R a27 may be the same as or different from each other. mc represents any integer from 0 to 2. [5] The resin further contains a structural unit having an acid-labile group, The resist composition according to [4], wherein the structural unit having an acid-labile group contains 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), a structural unit represented by formula (a1-2), a structural unit represented by formula (a1-4), a structural unit represented by formula (a1-5) and a structural unit represented by formula (a1-6). TIFF2025091367000005.tif43145 [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 L a1 and L a2 each independently represents -O- or *-O-(CH2) k1 -CO-O-, k1 represents any integer from 1 to 7, and * represents the bonding site with -CO-. R a01, R a4 and R a5 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a02 , R a03 and R a04 each independently represents 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 group formed by combining these, and the alkyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. R a6 and R a7 each independently represents 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 combining these, and the alkyl group, the alkenyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. m1’ represents any integer from 0 to 14. n1 represents any integer from 0 to 10. n1’ represents any integer from 0 to 3. TIFF2025091367000006.tif31118[In formula (a1-4), R a1 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a17 represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a11 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O-, -CO-, or -NR a18 -. Ra18 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a1 represents a single bond or a carbonyl group. R a34 and R a35 each independently represents 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 by -O- or -S-. na1 represents any integer from 1 to 5. When na1 is 2 or more, the groups within the plurality of parentheses may be the same as or different from each other. na11 represents any integer from 0 to 4. When na11 is 2 or more, the plurality of R a17 may be the same as or different from each other. mc represents any integer from 0 to 2.] TIFF2025091367000007.tif4558[In formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. Z a1 represents a single bond or *-(CH2) h3 -CO-L 54 -, h3 represents any integer from 1 to 4, and * represents the bonding site with L 51 L 51 L 52 L 53 and L 54 each independently represents -O- or -S-. s1 represents any integer from 1 to 3. s1’ represents any integer from 0 to 3.] TIFF2025091367000008.tif3681[In formula (a1-6), R a61 ​represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a62 , R a63 and R a64 each independently represent an alkyl group having 1 to 6 carbon atoms or a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, or R a62 and R a63 are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. X a61 represents a single bond, -CO-O-*, or -CO-NR a65 -*, where * represents the bonding site to Ar, and R a65 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a62 represents a single bond, *-O-L a61 -, or *-CO-O-L a62 -, where * represents the bonding site to Ar, and L a61 and L a62 each independently represent an alkanediyl group having 1 to 4 carbon atoms. Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent. A step of applying the resist composition according to any one of [6] to [5] onto a substrate, (2) A step of drying the applied composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer, A method for producing a resist pattern including the above steps. [7] The carboxylate represented by the above-described formula (I). [8] X 0is a single bond, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, an aromatic hydrocarbon group having 6 to 36 carbon atoms, or a group formed by combining these groups (the alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, an alkyl fluoride group having 1 to 4 carbon atoms, or a hydroxy group, and the aromatic hydrocarbon group may have a fluorine atom, an iodine atom, an alkyl fluoride group having 1 to 4 carbon atoms, or a hydroxy group. -CH2- contained in the alicyclic hydrocarbon group and the chain hydrocarbon group may be replaced by -O- or -CO-), the carboxylate salt according to [7].

Effect of the Invention

[0006] By using the resist composition containing the carboxylate salt of the present invention, a resist pattern can be manufactured with good CD uniformity (CDU).

Mode for Carrying Out the Invention

[0007] In the present specification, the “(meth)acrylic monomer” means “at least one of an acrylic monomer and a methacrylic monomer”. Descriptions such as “(meth)acrylate” and “(meth)acrylic acid” also represent the same meaning. Among the groups described in the present specification, those that can take both a linear structure and a branched structure may be either. -CH2- contained in a hydrocarbon group or the like is -O-, -S-, -CO-, -SO-, -NR X-When replaced by - or -SO2-, the same examples apply to each group, and the number of carbon atoms before replacement is defined as the number of carbon atoms of the hydrocarbon group or the like. The "combined group" means a group formed by bonding two or more of the exemplified groups, and the valence of these groups may be appropriately changed depending on the bonding form. "Derived from" or "derived" means that the polymerizable C=C bond contained in the molecule becomes a -C-C- group (single bond) by polymerization. When stereoisomers exist, all stereoisomers are included. Depending on the number of substituents and the like, any position and number of hydrogen atoms contained in the group may be replaced by a bonding site. The number of carbon atoms in the substituent is not included in the number of carbon atoms of the group to be substituted. An acid-labile group means a group that, when contacted with an acid (e.g., trifluoromethanesulfonic acid, etc.), the leaving group is eliminated to form a hydrophilic group (e.g., a hydroxy group or a carboxy group, etc.). A base-labile group means a group that, when contacted with a base (e.g., trimethylamine, tetramethylammonium hydroxide, etc.), the leaving group is eliminated to form a hydrophilic group (e.g., a carboxy group or a hydroxy group, etc.). In the present specification, the "solid content of the resist composition" means the total of the components excluding the solvent (E) described later from the total amount of the resist composition.

[0008] [Carboxylate represented by formula (I)] The present invention relates to a carboxylate represented by formula (I) (hereinafter sometimes referred to as "carboxylate (I)" or "salt (I)"). Among salts (I), the side having a negative charge may be referred to as "anion (I)", and the side having a positive charge may be referred to as "cation (I)". TIFF2025091367000009.tif17106[In the formula, all symbols have the same meanings as described above.]

[0009] [Anion (I)] In formula (I), R 1 Examples of the hydrocarbon group include an alkyl group, an alicyclic hydrocarbon group (monocyclic or polycyclic such as a spiro ring, a condensed ring or a bridged ring), an aromatic hydrocarbon group, and a group formed by combining these groups. The number of carbon atoms in the hydrocarbon group is preferably from 1 to 20, more preferably from 1 to 18, still more preferably from 1 to 16, yet more preferably from 1 to 12, and even more preferably from 1 to 10. Examples of the alkyl group 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. Preferably, it may be an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 12 carbon atoms, and still more preferably an alkyl group having 1 to 6 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, cyclooctyl group, cycloheptyl group, cyclodecyl group, etc. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1-(adamantan-1-yl)alkane-1-yl group, norbornyl group, methylnorbornyl group, and isobornyl group, etc. It may be an alicyclic hydrocarbon group having 1 to 20 carbon atoms, preferably an alicyclic hydrocarbon group having 6 to 12 carbon atoms. Examples of the aromatic hydrocarbon group include phenyl group, tosyl group, naphthyl group, biphenyl group, xylyl group, anthracenyl group, etc. It may be an aromatic hydrocarbon group having 1 to 20 carbon atoms, preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms, and more preferably phenyl group or naphthyl group. Examples of the group formed by combination include, for example, aralkyl group, such as benzyl group, phenethyl group, etc. -CH2- contained in the hydrocarbon group is -O-, -S-, -CO-, -NR 2-Or when replaced by -SO2-, the total number of carbon atoms before replacement is defined as the total number of carbon atoms of the hydrocarbon group. Also, the number may be one or two or more. R 2 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. When -CH2- contained in the hydrocarbon group is replaced by -O-, -S-, -CO-, -NR 2 -Or -SO2-, examples of the resulting group include a hydroxy group (a group in which -CH2- contained in a methyl group is replaced by -O-), a thiol group (a group in which -CH2- contained in a methyl group is replaced by -S-), a carboxy group (a group in which -CH2-CH2- contained in an ethyl group is replaced by -O-CO-), an amino group (a group in which -CH2- contained in a methyl group is replaced by -NR 2 -, an alkoxy group (a group in which any -CH2- contained in an alkyl group is replaced by -O-), an alkylthio group (a group in which any -CH2- contained in an alkyl group is replaced by -S-), an alkoxycarbonyl group (a group in which any -CH2-CH2- contained in an alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which any -CH2- contained in an alkyl group is replaced by -CO-), an alkylsulfonyl group (a group in which any -CH2- contained in an alkyl group is replaced by -SO2-), an alkylcarbonyloxy group (a group in which any -CH2-CH2- contained in an alkyl group is replaced by -CO-O-), an alkoxycarbonyloxy group (a group in which any -CH2-CH2-CH2- contained in an alkyl group is replaced by -O-CO-O-), an oxy group (a group in which -CH2- contained in a methylene group is replaced by -O-), a carbonyl group (a group in which -CH2- contained in a methylene group is replaced by -CO-), a thio group (a group in which -CH2- contained in a methylene group is replaced by -S-), a sulfonyl group (a group in which -CH2- contained in a methylene group is replaced by -SO2-), an alkylamino group (a group in which -CH2- contained in an alkyl group is replaced by -NR 2-replaced group), an alkanediyl-oxy group (a group in which any -CH2- in the alkanediyl group is replaced by -O-), an alkanediyl-oxycarbonyl group (a group in which any -CH2-CH2- in the alkanediyl group is replaced by -O-CO-), an alkanediyl-carbonyl group (a group in which any -CH2- in the alkanediyl group is replaced by -CO-), an alkanediyl-carbonyl-oxy group (a group in which any -CH2-CH2- in the alkanediyl group is replaced by -CO-O-), an alkanediyl-thio group (a group in which any -CH2- in the alkanediyl group is replaced by -S-), an alkanediyl-sulfonyl group (a group in which any -CH2- in the alkanediyl group is replaced by -SO2-), an alkanediyl-amino group (a group in which any -CH2- at any position in the alkanediyl group is replaced by -NR 2 -replaced group), an alkanediyl-peptide group (a group in which any -CH2-CH2- in the alkanediyl group is replaced by -CO-NR 2 -replaced group), and groups formed by combining two or more of these groups, etc.

[0010] Examples of the alkoxy group include alkoxy groups having 1 to 23 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group and the like. The number of carbon atoms of the alkoxy group may be 1 to 12, preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3. Examples of the alkylthio group include alkylthio groups having 1 to 23 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, undecylthio group and the like. The number of carbon atoms of the alkylthio group may be 1 to 12, preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 23 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group and the like. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 23 carbon atoms, such as acetyl group, propionyl group and butyryl group. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 23 carbon atoms, such as acetyloxy group, propionyloxy group, butyryloxy group and the like. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 23 carbon atoms, such as butoxycarbonyloxy group. The number of carbon atoms of the alkoxycarbonyl group may be 2 to 12, preferably 2 to 6, more preferably 2 to 4, and still more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyl group may be 1 to 12, preferably 2 to 6, more preferably 2 to 4, and still more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyloxy group may be 2 to 12, preferably 2 to 6, more preferably 2 to 4, and still more preferably 2 or 3. The number of carbon atoms of the alkoxycarbonyloxy group may be 2 to 12, preferably 2 to 6, more preferably 2 to 4, and still more preferably 2 or 3. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 23 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, undecylsulfonyl group and the like. The number of carbon atoms of the alkylsulfonyl group may be 1 to 12, preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3. Examples of the alkylamino group include alkylamino groups having 1 to 23 carbon atoms, such as methylamino group, ethylamino group, propylamino group, butylamino group, pentylamino group, hexylamino group, octylamino group, 2-ethylhexylamino group, nonylamino group, decylamino group, undecylamino group and the like. The number of carbon atoms of the alkylamino group may be 1 to 12, preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3. Examples of the alkanedioxy group include alkanedioxy groups having 1 to 23 carbon atoms, such as methyleneoxy group, ethyleneoxy group, propanedioxy group, butanedioxy group, pentanedioxy group and the like. The number of carbon atoms of the alkanedioxy group may be 1 to 12, preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3.

[0011] Examples of the alkanediyl-oxycarbonyl group include alkanediyl-oxycarbonyl groups having 2 to 23 carbon atoms, such as a methylene-oxycarbonyl group, an ethylene-oxycarbonyl group, a propanediyl-oxycarbonyl group, and a butanediyl-oxycarbonyl group. Examples of the alkanediyl-carbonyl group include alkanediyl-carbonyl groups having 2 to 23 carbon atoms, such as a methylene-carbonyl group, an ethylene-carbonyl group, a propanediyl-carbonyl group, a butanediyl-carbonyl group, and a pentanediyl-carbonyl group. Examples of the alkanediyl-carbonyl-oxy group include alkanediyl-carbonyl-oxy groups having 2 to 23 carbon atoms, such as a methylene-carbonyl-oxy group, an ethylene-carbonyl-oxy group, a propanediyl-carbonyl-oxy group, and a butanediyl-carbonyl-oxy group. The number of carbon atoms in the alkanediyl-oxycarbonyl group may be 2 to 12, preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediyl-carbonyl group may be 2 to 12, preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediyl-carbonyl-oxy group may be 2 to 12, preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediyl-thio group include alkanediyl-thio groups having 1 to 23 carbon atoms, such as a methylene-thio group, an ethylene-thio group, and a propylene-thio group. The number of carbon atoms in the alkanediyl-thio group may be 1 to 12, preferably 1 to 6, more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediylsulfonyl group include alkanediylsulfonyl groups having 1 to 23 carbon atoms, such as methylenesulfonyl group, ethylenesulfonyl group, propylenesulfonyl group and the like. The number of carbon atoms of the alkanediylsulfonyl group may be 1 to 12, preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3. Examples of the alkanediylamino group include alkanediylamino groups having 1 to 23 carbon atoms, such as methyleneamino group, ethyleneamino group, propyleneamino group and the like. The number of carbon atoms of the alkanediylamino group may be 1 to 12, preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3. Examples of the alkanediylpeptide group include methylenepeptide group, ethylenepeptide group, propylpeptide group and the like. The number of carbon atoms of the alkanediylpeptide group may be 1 to 12, preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3. In addition, -CH2- contained in a group formed by combining an alicyclic hydrocarbon group or an alicyclic saturated hydrocarbon group with an aromatic hydrocarbon group is replaced by -O-, -CO-, -S-, -SO-, -SO2- or -NR 2 Examples of the group thus replaced include the following groups and the like. -O- or -CO- in the groups represented below may each be replaced by -S-, -SO-, -SO2- or -NR 2 -. The bonding site can be at any position. TIFF2025091367000010.tif73167

[0012] R 1 Examples of the substituent that the hydrocarbon group of R may optionally have include a halogen atom, a cyano group, and a nitro group. The hydrocarbon group of R 1 may substantially have substituents such as a hydroxy group, a carboxy group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a thiol group, an alkylthio group, an alkylsulfonyl group, and an alkylamino group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. A fluorine atom is preferred.

[0013] R 1 Examples of the group R include a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and a group formed by combining these groups (however, -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-). Among them, a hydrogen atom and an alkyl group having 1 to 12 carbon atoms are more preferable.

[0014] Examples of the alicyclic hydrocarbon ring having 3 to 36 carbon atoms in the ring W include rings represented by formula (a1-1) to formula (a1-11). An alicyclic hydrocarbon ring having 3 to 18 carbon atoms is preferable, and a ring represented by formula (a1-1), a ring represented by formula (a1-2) or a ring represented by formula (a1-3) is more preferable. TIFF2025091367000011.tif24163[In the rings represented by formula (a1-1) to formula (a1-11), -CH2- contained in the ring may be replaced by -O-, -S-, -CO- or -SO2-, and a hydrogen atom contained in the ring may have a substituent. * represents a bond.]

[0015] Examples of the substituent that the ring W may have include an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon ring having 3 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, a halogen atom, a cyano group, and a nitro group. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, a 2-ethylhexyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, and a dodecyl group. Examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, an n-pentyloxy group, an n-hexyloxy group, an n-octyloxy group, a 2-ethylhexyloxy group, an n-nonyloxy group, an n-decyloxy group, an n-undecyloxy group, and an n-dodecyloxy group. Examples of the alicyclic hydrocarbon group having 3 to 12 carbon atoms include the groups shown below. TIFF2025091367000012.tif15128 Examples of the aromatic hydrocarbon group having 6 to 10 carbon atoms include a phenyl group and a naphthyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0016] X 0 Examples of the hydrocarbon group of include a group formed by removing one hydrogen atom from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a group combining two or more of these groups and bonding to ring W. Examples of the chain hydrocarbon group include a group formed by removing one hydrogen atom from an alkyl group or an alkenyl group. The alkyl group may be linear or branched, and specifically includes a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decanyl group, an undecanyl group, a dodecanyl group, a tridecanyl group, a tetradecanyl group, a pentadecanyl group, a heptadecanyl group, etc. Examples of the alkenyl group include an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, an isooctenyl group, and a nonenyl group. The number of carbon atoms of the chain hydrocarbon group is preferably 1 to 36, more preferably 1 to 20, and even more preferably 1 to 10. Examples of the alicyclic hydrocarbon group include a group formed by removing one hydrogen atom from a monocyclic or polycyclic cycloalkyl group. Examples of the monocyclic cycloalkyl group include a cyclobutyl group, a cyclopentane group, a cyclohexane group, a cyclopentyl group, a cyclooctyl group, and the like. Examples of the polycyclic cycloalkyl group include a cycloalkyl group having a crosslinked structure, a cycloalkyl group in which two or more rings are condensed, or a cycloalkyl group in which two rings are spiro-bonded. Examples of the cycloalkyl group having a crosslinked structure include a norbornyl group, an adamantyl group, and the like. Examples of the cycloalkyl group in which two or more rings are condensed include a bicyclo[4,4,0]decane group, a steroid group (steroid skeleton), and the like. Examples of the ring in which two rings are spiro-bonded include a spirocyclic cycloalkyl group in which one cycloalkyl group selected from the group consisting of a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group and a cycloalkyl group having 5 to 8 carbon atoms are spiro-bonded. Further, a double bond may be formed between two carbon atoms contained in the alicyclic hydrocarbon group. More specifically, examples of the alicyclic hydrocarbon group include those represented by the following formula. TIFF2025091367000013.tif26165 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 12, more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the number of carbon atoms of the alicyclic hydrocarbon group is preferably 7 to 12. Examples of the aromatic hydrocarbon group include an aryl group from which one hydrogen atom has been removed. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, a fluorene group, and the like. The number of carbon atoms of the aromatic hydrocarbon group is preferably 5 to 14, more preferably 5 to 10. X 0 When -CH2- contained in the hydrocarbon group of X is replaced by -O-, -CO-, -S-, or -SO2-, the number of carbon atoms before replacement is defined as the number of carbon atoms of the hydrocarbon group. X 0Among the hydrocarbon groups, examples of groups in which -CH2- contained in the chain hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include a hydroxy group (a group in which -CH2- contained in the methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- contained in the ethyl group is replaced by -O-CO-), a carbonyl group (a group in which -CH2- contained in the methylene group is replaced by -CO-), an oxy group (a group in which -CH2- contained in the methylene group is replaced by -O-), an alkoxy group (a group in which -CH2- at any position contained in the alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which -CH2- at any position contained in the alkyl group is replaced by -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -CO-O-), an alkanedioxy group (a group in which -CH2- at any position contained in the alkanedioyl group is replaced by -O-), an alkanedioxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkanedioyl group is replaced by -O-CO-), an alkanedioylcarbonyl group (a group in which -CH2- at any position contained in the alkanedioyl group is replaced by -CO-), an alkanedioylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkanedioyl group is replaced by -CO-O-), and the like. These replaced groups are the same as those exemplified as replacements for the hydrocarbon group of R 1 Among the hydrocarbon groups of X X 0 Examples of groups in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include cyclic ethers, cyclic ketones, cyclic esters (lactones), cyclic thioethers, cyclic acetals, cyclic sultones, and the like. Specifically, alicyclic hydrocarbon groups represented by the following formulas are included. The bonding positions of the alicyclic hydrocarbon groups listed in the following formulas can be at any position. TIFF2025091367000014.tif51161X0 Among the hydrocarbon groups, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-. Examples of the group in which -CH2- is replaced by -O- or -S- include a furan ring and a thiophene ring, respectively. Examples of the group in which -CH2- contained in the group combining an alicyclic saturated hydrocarbon group and an aromatic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include the following groups. The bonding site can be at any position. TIFF2025091367000015.tif26164 Examples of the group combining two or more of a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group include the group combining the above chain hydrocarbon group and the above alicyclic hydrocarbon group, the group combining the above chain hydrocarbon group and the above aromatic hydrocarbon group, the group combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group, and the group combining the above chain hydrocarbon group, the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group. The group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group may be a condensed ring. X 0 Examples of the substituent that the hydrocarbon group of may have include a halogen atom, a cyano group and a nitro group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. X 0 When X is a group combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group and a chain hydrocarbon group, substantially, the chain hydrocarbon group may be regarded as a substituent that the alicyclic hydrocarbon group or the aromatic hydrocarbon group has. Also, X 0 When -CH2- of the chain hydrocarbon group contained in the hydrocarbon group of is replaced by -O-, -CO-, -S- or -SO2-, the hydrocarbon group of 0 may substantially have substituents such as a hydroxy group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group and a sulfonyl group.

[0017] X 0The hydrocarbon group represented by is preferably an aliphatic hydrocarbon group having 2 to 72 carbon atoms which may have a substituent (wherein -CH2- contained in the aliphatic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-), or a hydrocarbon group having 6 to 72 carbon atoms including an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent. More preferably, it is an alicyclic hydrocarbon group having 3 to 36 carbon atoms, an aromatic hydrocarbon group having 6 to 36 carbon atoms, or a group formed by combining two or more selected from a chain hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, and an aromatic hydrocarbon group having 6 to 36 carbon atoms (the alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, an alkyl fluoride group having 1 to 4 carbon atoms, or a hydroxy group, the aromatic hydrocarbon group may have a fluorine atom, an iodine atom, an alkyl fluoride group having 1 to 4 carbon atoms, or a hydroxy group, and -CH2- contained in the alicyclic hydrocarbon group and the chain hydrocarbon group may be replaced by -O- or -CO-). In formula (I), X 0 When it is a group formed by combining a chain hydrocarbon group with an alicyclic hydrocarbon group or an aromatic hydrocarbon group, X 0 is more preferably a group represented by formula (X 0 -1). TIFF2025091367000016.tif1491[In formula (X 0 -1), L c1 and L c2 each independently represent a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms, and -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO- and may have a substituent. W c1 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms, -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-, -CH= contained in the aromatic hydrocarbon group may be replaced by -O- or -S-, and the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have a substituent. L c1 and one or more L c2and W c1 The total carbon number of is not more than 72. * and ** represent bonding sites, and * represents a bonding site with a carboxyanion.] In formula (X 0 -1), L c1 and L c2 The chain hydrocarbon groups of can be the same groups as the chain hydrocarbon groups exemplified by X 0 as long as they have an upper limit of carbon number. In formula (X 0 -1) and, the alicyclic hydrocarbon groups and aromatic hydrocarbon groups of W c1 can be the alicyclic hydrocarbon groups and aromatic hydrocarbon groups exemplified by X 0 as long as the upper limit of carbon number permits. L c1 and L c2 The substituents that the chain hydrocarbon groups of may have and W c1 and W c2 The substituents that the alicyclic hydrocarbon groups and aromatic hydrocarbon groups of may have are the same groups as the substituents exemplified as the substituents that the hydrocarbon groups of X 0 may have. L c1 and L c2 Preferably, 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 by -O- or -CO-. The alkanediyl group may be substituted by a fluorine atom.). L c1 is preferably a group combined with a single bond, a methylene group, an ethylene group or a fluorinated alkanediyl group having 1 to 4 carbon atoms and an ester bond that binds to W c1 In formula (X 0 -1), L c2 is preferably a group combined with a single bond, a methylene group, an ethylene group, an ester bond that binds to W c1 and an alkanediyl group having 1 to 3 carbon atoms. In formula (X 0 -1), W c1 ​The alicyclic hydrocarbon group and the aromatic hydrocarbon group are each independently preferably an alicyclic hydrocarbon group and an aromatic hydrocarbon group represented below. In the alicyclic hydrocarbon group and the aromatic hydrocarbon group represented below, * and ** represent bonding sites. W c1 In the case of, * is L c1 represents the bonding site with. Also, L c2 ** not bonded to is a hydrogen atom or bonded to a substituent that W c1 may have. Further, in the alicyclic hydrocarbon group represented below, -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. When -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2-, it is preferable to form an ether ring, a lactone ring, a carbonate ester ring, a sultone ring or an acetal ring. TIFF2025091367000017.tif37167 formula (X 0 -1), W c1 is a cyclopentane ring, a cyclohexane ring (the cyclopentane ring and the cyclohexane ring may have two -CH2- contained in the cyclopentane ring and the cyclohexane ring replaced by -O- or -S- to form an acetal ring or a thioacetal ring), a norbornane ring (the norbornane ring may have -CH2- contained in the norbornane ring replaced by -O- or -S- to form an oxonorbornane ring or a thionorbornane ring), a norbornane lactone ring, an adamantane ring, an adamantane lactone ring, a benzene ring, a naphthalene ring, preferably a cyclopentane ring, a cyclohexane ring, a norbornane ring or an adamantane ring and a cyclopentane ring, a cyclohexane ring, a cycloheptane ring or a cyclooctane ring and a spiro ring-type hydrocarbon group (the spiro ring-type hydrocarbon group may have two -CH2- contained in the cyclopentane ring, the cyclohexane ring, the cycloheptane ring or the cyclooctane ring replaced by -O- or -S- respectively to form an acetal ring or a thioacetal ring), a benzene ring, a naphthalene ring are more preferable.

[0018] Examples of the carboxylate anion in the carboxylate represented by formula (I) include the carboxylate anions described below. TIFF2025091367000018.tif230148

[0019] [Cation (I)] Z in formula (I) + Examples of the organic cation include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, cations represented by any of formulas (b2-1) to (b2-5) (hereinafter may be referred to as "cation (b2-1)" etc. according to the formula number) are included. TIFF2025091367000019.tif84161[In formulas (b2-1) to (b2-5), R b4 ~R b6 each independently represents a linear 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, and the hydrogen atom contained in the linear hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R b4 and R b5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH2- contained in the ring may be replaced with -O-, -S-, or -CO-. R b7 and Rb8 Each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. m2 and n2 each independently represent any integer from 0 to 5. When m2 is 2 or more, a plurality of R b7 may be the same or different, and when n2 is 2 or more, a plurality of R b8 may be the same or different. R b9 and R b10 each independently represent a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms. R b9 and R b10 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH2- contained in the ring may be replaced by -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, and a hydrogen atom contained in the chain hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 may be bonded to each other to form a ring including -CH-CO- to which they are bonded, and -CH2- contained in the ring may be replaced by -O-, -S-, or -CO-. R b13 ~R b18 Each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R b13 and R b14They may be combined with each other to form a ring containing a sulfur atom together with the benzene ring to which they are attached, and the -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b27 ~R b29 each independently represents a hydrogen atom or a group containing an acid-labile group. L b31 and L b41 ~L b43 each independently represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent an integer from 0 to 5. q2 and r2 each independently represent an integer from 0 to 4. u2 represents 0 or 1. When o2 is 2 or more, the plurality of R b13 are the same or different, when p2 is 2 or more, the plurality of R b14 are the same or different, when q2 is 2 or more, the plurality of R b15 are the same or different, when r2 is 2 or more, the plurality of R b16 are the same or different, when s2 is 2 or more, the plurality of R b17 are the same or different, when t2 is 2 or more, the plurality of R b18 are the same or different. u3 represents an integer from 1 to 3, and satisfies 1 ≦ u3 + q23 ≦ 5. u4 and u5 each independently represent an integer from 0 to 3, and satisfy 0 ≦ u4 + o21 ≦ 5 and 0 ≦ u5 + p22 ≦ 5. o21, p22, q23, r24, t25 and s26 each independently represent an integer from 0 to 4. When u3, u4 and u5 are each 2 or more, the groups in parentheses are each the same or different. When o21, p22, q23, r24, t25 and s26 are each 2 or more, the plurality of R b21 ~R b26 are each the same or different. When u2 is 0, any one of o2, p2, q2 and r2 is 1 or more, and R b13 ~R b16At least one of them is preferably a halogen atom. When u2 is 1, any one of o2, p2, s2, t2, q2 and r2 is 1 or more, and R b13 ~R b18 At least one of them is preferably a halogen atom. Furthermore, when u2 is 0, r2 is preferably 1 or more, and more preferably 1. Also, when u2 is 0 and r2 is 1 or more, R b16 is preferably a halogen atom.

[0020] The aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. In particular, the chain hydrocarbon group of R b9 ~R b12 is preferably C1-C12. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group and the following groups. TIFF2025091367000020.tif11157 In particular, the alicyclic hydrocarbon group of R b9 ~R b12 is preferably C3-C18, more preferably C4-C12.

[0021] Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group, a 2-ethyladamantan-2-yl group, a 2-isopropyladamantan-2-yl group, a methylnorbornil group, an isobornyl group, and the like. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The alkyl fluoride group represents an alkyl group having 1 to 12 carbon atoms and having a fluorine atom, and examples thereof include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, and a perfluorobutyl group. The number of carbon atoms of the alkyl fluoride group is preferably 1 to 9, more preferably 1 to 6, and still more preferably 1 to 4.

[0022] Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a biphenyl group, a naphthyl group, and a phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples of the aromatic hydrocarbon group having a chain hydrocarbon group include a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group, and examples of the aromatic hydrocarbon group having an alicyclic hydrocarbon group include a p-cyclohexylphenyl group and a p-adamantylphenyl group. When the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms are preferred. Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group. Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.

[0023] Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, and the like. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group, and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, a 2-ethylhexylcarbonyloxy group, and the like.

[0024] R b4 and R b5 The ring formed by R and R bonding to each other together with the sulfur atom to which they are bonded may be any of a monocyclic, polycyclic, aromatic, non-aromatic, saturated, and unsaturated ring. Examples of this ring include rings having 3 to 18 carbon atoms, preferably rings having 4 to 18 carbon atoms. Further, examples of the ring containing a sulfur atom include 3-membered to 12-membered rings, preferably 3-membered to 7-membered rings. For example, the following rings can be mentioned. * represents a bonding site. TIFF2025091367000021.tif24142

[0025] R b9 and R b10 The ring formed by R and R together may be any of a monocyclic, polycyclic, aromatic, non-aromatic, saturated, and unsaturated ring. Examples of this ring include 3-membered to 12-membered rings, preferably 3-membered to 7-membered rings. For example, a thiolan-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, a 1,4-oxathian-4-ium ring, and the like can be mentioned. R b11 and R b12The ring formed together with the "and" may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring includes 3-membered rings to 12-membered rings, preferably 3-membered rings to 7-membered rings. Examples include oxocycloheptane ring, oxocyclohexane ring, oxonorbornane ring, oxoadamantane ring, etc. R b27 ~R b29 Examples of the group containing an acid-labile group of "~R" include -R c30 , -CO-O-R c30 or -L c10 -CO-O-R c30 The group represented by (where L c10 represents an alkanediyl group having 1 to 6 carbon atoms, and R c30 represents an acid-labile group.) etc. are included. R b27 ~R b29 Examples of the acid-labile group of "~R" include the group represented by formula (1) and / or the group represented by formula (2) described later.

[0026] Among cations (b2-1) to (b2-5), preferably, it is cation (b2-1). Examples of cation (b2-1) include the following cations. TIFF2025091367000022.tif158165 Examples of cation (b2-2) include the following cations. TIFF2025091367000023.tif15136 Examples of cation (b2-3) include the following cations. TIFF2025091367000024.tif21129 Examples of cation (b2-4) include the following cations. TIFF2025091367000025.tif122163 Examples of cation (b2-5) include the following cations. TIFF2025091367000026.tif115158

[0027] The carboxylate salt (I) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the salt (I), preferably, an anion represented by any of formula (I-a-1), formula (I-a-2), formula (I-a-5), formula (I-a-11) to formula (I-a-22), and a cation (b2-1), cation (b2-2), cation (b2-3), cation (b2-4) or cation (b2-5) are combined.

[0028] Specific examples of the carboxylate salt (I) include salts obtained by arbitrarily combining the above-mentioned cations and anions. Specific examples of the salt (I) are shown in the following table. In the following table, each symbol represents the symbol attached to the structure representing the above-mentioned anion or cation, and "~" indicates that each of the carboxylate salt (I) and the anion (I) corresponds. For example, the carboxylate salt (I-1) is a salt composed of an anion represented by formula (I-a-1) and a cation represented by formula (b2-c-1), the carboxylate salt (I-2) is a salt composed of an anion represented by formula (I-a-2) and a cation represented by formula (b2-c-1), and the carboxylate salt (I-26) is a salt composed of an anion represented by formula (I-a-1) and a cation represented by formula (b2-c-10). TIFF2025091367000027.tif3279

Table 1

[0029] Among them, as the carboxylate salt (I), a salt obtained by combining an anion represented by any of formula (I-a-1), formula (I-a-2), formula (I-a-5), formula (I-a-11) to formula (I-a-22) and a cation represented by any of formula (b2-c-1) to formula (b2-c-79) is preferable.

[0030] <Method for producing the carboxylate salt (I)> In the carboxylate (I), the carboxylate represented by the formula (I) can be produced, for example, by reacting a salt represented by the formula (I-a) with a compound represented by the formula (I-b) in a solvent under a base catalyst. TIFF2025091367000029.tif23151(wherein all the symbols have the same meanings as described above.) Examples of the base catalyst include pyridine. Examples of the solvent include methanol and chloroform. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0031] Examples of the salt represented by the formula (I-a) include salts represented below, and it can also be easily produced by known production methods. TIFF2025091367000030.tif97161

[0032] 〔Carboxylic acid generator〕 The carboxylic acid generator of the present invention is an acid generator containing the carboxylate (I). The carboxylate (I) of the present invention can act as an acid generator in a resist composition. When the carboxylate (I) is used as an acid generator in a resist composition, the acid generator may contain only one kind or two or more kinds of the carboxylate (I).

[0033] 〔Resist composition〕 The resist composition of the present invention may further contain an acid generator containing the carboxylate (I) of the present invention, an acid generator known in the resist field other than the acid generator containing the carboxylate (I) (hereinafter sometimes referred to as "acid generator (B)"), and / or a carboxylic acid generator known in the resist field other than the carboxylate (I). The acid generator (B) and the carboxylate other than the carboxylate (I) may be used alone or in combination of two or more. When the carboxylic acid generator of the present invention contains a carboxylate other than the acid generator (B) and / or the carboxylate (I), the content ratio (mass ratio) of the carboxylate (I) to the acid generator (B) and / or the carboxylate other than the carboxylate (I) is usually 1:99 to 100:0, preferably 1:99 to 99:1, more preferably 2:98 to 98:2, and still more preferably 5:95 to 95:5. In the resist composition of the present invention, the content rate of the carboxylate (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 still more preferably 1% by mass or more and 25% by mass or less with respect to the solid content of the resist composition. The resist composition of the present invention may further contain a resin. Examples of the resin include a resin containing a structural unit having an acid-labile group (hereinafter sometimes referred to as "resin (A)") and / or a resin other than resin (A). Here, the "acid-labile group" has a leaving group, and when in contact with an acid, the leaving group leaves to form a hydrophilic group (for example, a hydroxy group or a carboxy 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)").

[0034] <Acid generator (B)> In the resist composition of the present invention, when the acid generator (B) is contained, the total content rate of the carboxylate (I) and the acid generator (B) is preferably 0.1% by mass or more and 55% by mass or less, more preferably 1% by mass or more and 50% by mass or less, and still more preferably 3% by mass or more and 45% by mass or less with respect to the solid content of the resist composition. Further, when the resin (A) is contained, the total content rate of the carboxylate (I) and the acid generator (B) is preferably 1 part by mass or more (more preferably 3 parts by mass or more) and preferably 55 parts by mass or less (more preferably 50 parts by mass or less, still more preferably 45 parts by mass or less) with respect to 100 parts by mass of the resin (A). The content rate of the acid generator (B) is preferably 0.1 mass % or more and 55 mass % or less, more preferably 1 mass % or more and 50 mass % or less, still more preferably 3 mass % or more and 45 mass % or less, based on the solid content of the resist composition. Further, when the resin (A) is included, the content rate of the acid generator (B) is preferably 1 mass part or more (more preferably 3 mass parts or more) and preferably 55 mass parts or less (more preferably 50 mass parts or less, still more preferably 45 mass parts or less) with respect to 100 mass parts of the resin (A).

[0035] As the acid generator (B), either a nonionic compound or an ionic compound may be used. Examples of the nonionic acid compound include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxy ketone, diazonaphthoquinone 4-sulfonate), sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane), and the like. Representative examples of the ionic compound include onium salts containing an onium cation (e.g., diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of the anion of the onium salt include sulfonic acid anion, benzenesulfonyl anion, sulfonylimide anion, sulfonylmethide anion, and carboxylic acid anion, and the like. Further, the acid generator (B) may be one of the structural units constituting the resin contained in the resist composition of the present invention, such as the structural unit (a7) described later.

[0036] As the acid generator (B), compounds that generate an acid by radiation described in, for example, JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Patent No. 3,779,778, U.S. Patent No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. can be used. Further, compounds produced by known methods may also be used. The acid generator (B) may be used alone or in combination of two or more. The acid generator (B) may be an acid generator having an acid-labile group. For example, the compound or resin serving as the acid generator may contain a partial structure that becomes an acid-labile group, and the acid-labile group preferably contains the group (1) or group (2) described below. When the resist composition of the present invention has a compound having an acid-labile group, a resin containing a structural unit having an acid-labile group may not be included.

[0037] As a preferred form of the acid generator (B), a salt represented by the formula (B1) (hereinafter sometimes referred to as "acid generator (B1)") can be mentioned. TIFF2025091367000031.tif1392[In the formula (B1), L b1 represents a single bond or an (nb1 + 1)-valent hydrocarbon group which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. L b2 represents a single bond or a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. Y b1 represents a methyl group which may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. nb1 represents any integer from 1 to 6. When nb1 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. Z1 + represents an organic cation. ] L b1 Examples of the (nb1 + 1)-valent hydrocarbon group of L include a monovalent chain hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group, and a monovalent group obtained by combining two or more of these groups, from which nb1 hydrogen atoms are removed and which is bonded to one or more L b2 groups. The number of carbon atoms in the hydrocarbon group is preferably from 1 to 48, more preferably from 1 to 42, still more preferably from 1 to 36, even more preferably from 1 to 30, and even still more preferably from 1 to 24. Examples of the chain hydrocarbon group include a group formed by removing nb1 hydrogen atoms from an alkyl group or an alkenyl group. The alkyl group may be linear or branched, and specifically, examples thereof include those described as the chain hydrocarbon group of X 0 are the same as those described above. The number of carbon atoms in the chain hydrocarbon group is preferably from 1 to 36, more preferably from 1 to 24, still more preferably from 1 to 20, even more preferably from 1 to 18, even still more preferably from 1 to 12, and even still more preferably from 1 to 10. Examples of the alicyclic hydrocarbon group include a group formed by removing nb1 hydrogen atoms from a monocyclic or polycyclic cycloalkyl group. Examples of the monocyclic cycloalkyl group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic cycloalkyl group include a cycloalkyl group having a crosslinked structure, a cycloalkyl group in which two or more rings are condensed, or a cycloalkyl group in which two rings are spiro-bonded. Examples of the cycloalkyl group having a crosslinked structure include a norbornyl group and an adamantyl group. Examples of the cycloalkyl group in which two or more rings are condensed include a bicyclo[4,4,0]decane group and a steroid group (steroid skeleton). Examples of the ring in which two rings are spiro-bonded include a spirocycloalkyl group in which one cycloalkyl group selected from the group consisting of a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group is spiro-bonded to a cycloalkyl group having 5 to 8 carbon atoms. A double bond may be formed between two carbon atoms contained in the alicyclic hydrocarbon group. More specifically, examples of the alicyclic hydrocarbon group include those represented by the following formula. When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 24, more preferably 3 to 20, still more preferably 3 to 18, even more preferably 3 to 12, even still more preferably 3 to 10, and even yet more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 6 to 24, more preferably 6 to 20, still more preferably 6 to 18, even more preferably 6 to 12, and even still more preferably 7 to 12. Examples of the aromatic hydrocarbon group include a group obtained by removing nb1 hydrogen atoms from an aryl group. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, a fluorenyl group, and the like. More specifically, examples of the aromatic hydrocarbon group include those represented by the following formula. TIFF2025091367000033.tif1085 The number of carbon atoms in the aromatic hydrocarbon group is preferably 4 to 24, more preferably 4 to 20, still more preferably 4 to 18, even more preferably 5 to 14, even still more preferably 5 to 10, and even yet more preferably 6 to 10. L b1 When -CH2- contained in the hydrocarbon group of L is replaced by -O-, -CO-, -S- or -SO2-, the number of carbon atoms before replacement is taken as the number of carbon atoms of the hydrocarbon group. L b1Among the hydrocarbon groups, examples of the group in which -CH2- contained in the chain hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include a hydroxy group (a group in which -CH2- contained in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- contained in an ethyl group is replaced by -O-CO-), a carbonyl group (a group in which -CH2- contained in a methylene group is replaced by -CO-), an oxy group (a group in which -CH2- contained in a methylene group is replaced by -O-), an alkoxy group (a group in which -CH2- at any position contained in an alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in an alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which -CH2- at any position contained in an alkyl group is replaced by -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in an alkyl group is replaced by -CO-O-), an alkanedioxy group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -O-), an alkanedioxycarbonyl group (a group in which -CH2-CH2- at any position contained in an alkanediyl group is replaced by -O-CO-), an alkanediylcarbonyl group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -CO-), an alkanediylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in an alkanediyl group is replaced by -CO-O-), and the like. These replaced groups include the same ones as the groups exemplified in this specification within the range where the upper limit of the number of carbon atoms permits. L b1 Among the hydrocarbon groups, examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include a cyclic ether, a cyclic ketone, a cyclic ester (lactone), a cyclic thioether, a cyclic acetal, a cyclic sultone, and the like. Specifically, alicyclic hydrocarbon groups represented by the following formulas can be mentioned. The bonding positions of the alicyclic hydrocarbon groups listed in the following formulas can be at any position. TIFF2025091367000034.tif48165L b1Among the hydrocarbon groups, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-. Examples of the group in which -CH2- is replaced by -O- or -S- include a furan ring and a thiophene ring, respectively. Examples of the group formed by combining two or more of the chain hydrocarbon group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group include the group formed by combining the above chain hydrocarbon group and the above alicyclic hydrocarbon group, the group formed by combining the above chain hydrocarbon group and the above aromatic hydrocarbon group, the group formed by combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group, and the group formed by combining the above chain hydrocarbon group, the above alicyclic hydrocarbon group, and the above aromatic hydrocarbon group. Examples of the combined group include the above combined groups. The group formed by combining the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be a condensed ring. Examples of the group in which -CH2- contained in the group formed by combining the alicyclic saturated hydrocarbon group and the aromatic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include the same groups as those exemplified in this specification within the range where the upper limit of the number of carbon atoms permits. L b2 Examples of the divalent hydrocarbon group of L include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, and a group formed by removing one hydrogen atom from a combination of two or more of these groups, and a group that binds to Y b1 are mentioned. L b2 Examples of the divalent chain hydrocarbon group, the divalent alicyclic hydrocarbon group, the divalent aromatic hydrocarbon group, and the divalent group formed by combining two or more of these groups of L are, respectively, within the range where the number of carbon atoms permits, groups formed by removing one hydrogen atom from the chain hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the group formed by combining two or more of these exemplified by L b1 are mentioned. L b1 and L b2 Examples of the substituent that the hydrocarbon group of L and L may have include a halogen atom, a cyano group, and a nitro group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. L b1 and L b2When it is a group combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group and a chain hydrocarbon group, substantially, the chain hydrocarbon group may be regarded as a substituent possessed by the alicyclic hydrocarbon group or the aromatic hydrocarbon group. Also, L b1 and L b2 By replacing the -CH2- of the chain hydrocarbon group contained in the hydrocarbon group of with -O-, -CO-, -S- or -SO2-, L b1 and L b2 The hydrocarbon groups of can substantially have substituents such as a hydroxy group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, a sulfonyl group and the like. Y b1 Examples of the cyclic hydrocarbon group of include an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a combination of an alicyclic hydrocarbon group and an aromatic hydrocarbon group. Y b1 The alicyclic hydrogen group and the aromatic hydrocarbon group of are the same as the alicyclic hydrocarbon group and the aromatic hydrocarbon group exemplified by L b1 respectively, and when they have no substituent, they may be a monovalent alicyclic hydrocarbon group and an aromatic hydrocarbon group. Y b1 Examples of the substituent that the methyl group of may have include a halogen atom, a cyano group, a hydroxy group, and a nitro group. Y b1 Examples of the substituent that the cyclic hydrocarbon group of may have include a halogen atom, a cyano group, a nitro group, or a hydrocarbon group having 1 to 18 carbon atoms that may have a halogen atom, a cyano group, and a nitro group. The -CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-. Y b1 Examples of the hydrocarbon group having 1 to 18 carbon atoms that the cyclic hydrocarbon group of may have as a substituent include a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining these groups. Examples of a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining two or more of these groups include, within the range permitted by the upper limit of the number of carbon atoms, L b1Examples of groups similar to the chain hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and groups formed by combining two or more of these groups exemplified above include groups similar to those exemplified above. Y b1 Examples of groups in which -CH2- in the hydrocarbon group having 1 to 18 carbon atoms, which may have a methyl group and a cyclic hydrocarbon group as substituents, is replaced by -O-, -S-, -CO-, or -SO2- include, within the range allowed by the upper limit of the number of carbon atoms, groups in which -CH2- in the hydrocarbon group of L b1 is replaced by -O-, -S-, -CO-, or -SO2- and are similar to the groups exemplified above. Also, Y b1 Examples of the hydrocarbon group having 1 to 18 carbon atoms, which may have a cyclic hydrocarbon group as a substituent, may include protecting groups or leaving groups (acid-labile groups or base-labile groups) commonly used in the art.

[0038] Examples of the anion of the salt represented by formula (B1) include, for example, an anion represented by the following formula (B1-A1) (hereinafter sometimes referred to as "anion (B1-A1)") or an anion represented by formula (B1-A2) (hereinafter sometimes referred to as "anion (B1-A2)"). TIFF2025091367000035.tif31125[In formula (B1-A1), L b2 and Y b1 have the same meanings as in formula (B1). Q b1 Q b2 Q b3 and Q b4 each independently represent a hydrogen atom, a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 6 carbon atoms. z1 represents any integer from 0 to 6. X 1 represents -O-CO-, -CO-O-, -O-CO-O-, or -O-. L b3 represents a hydrocarbon group having (nb2 + 1) carbon atoms which may have substituents, and -CH2- in the hydrocarbon group may be replaced by -O-, -S-, -CO-, or -SO2-. nb2 represents an integer of any one of 1 to 3. When nb2 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. Q b1 , Q b2 , Q b3 and Q b4 Examples of the alkyl group of Q b4 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, and the like. Q b1 , Q b2 , Q b3 and Q b4 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms of Q b4 include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, and the like. Q b1 and Q b2 are preferably included in at least one of Q b1 and Q b2 , more preferably a fluorine atom or a perfluoroalkyl group, still more preferably a fluorine atom or a trifluoromethyl group, and even more preferably both are fluorine atoms. b1 and Q b2 are preferably each independently a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms, Q b3 is preferably a hydrogen atom, a fluorine atom, a perfluoroalkyl group having 1 to 3 carbon atoms, and Q b4 is preferably a hydrogen atom or a fluorine atom. Q b3 and Q b4 are preferably each independently a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms, Q b3 is preferably a hydrogen atom, a fluorine atom, a perfluoroalkyl group having 1 to 3 carbon atoms, and Q b4 is preferably a hydrogen atom or a fluorine atom. b3 is preferably a hydrogen atom, a fluorine atom, a perfluoroalkyl group having 1 to 3 carbon atoms, Q b4 b4 is preferably a hydrogen atom or a fluorine atom. z1 is preferably an integer of any one of 0 to 3, and preferably 0, 1 or 2. X 1 is preferably -O-CO- or -CO-O-.

[0039] L b3As the hydrocarbon group in [it], within the range allowed by the upper limit of the number of carbon atoms, L of formula (B1) b1 includes the same hydrocarbon groups as those exemplified in [it]. In formula (B1-A1), L b3 is a single bond, a chain hydrocarbon group having 1 to 12 carbon atoms which may have a substituent (in the chain hydrocarbon group, -CH2- contained therein may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (in the alicyclic hydrocarbon group, -CH2- contained therein may be replaced by -O-, -S-, -CO- or -SO2-), an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent (in the alicyclic hydrocarbon group, -CH2- contained therein may be replaced by -O- or -S-), and a group formed by combining two or more of these groups are preferable, and a chain hydrocarbon group having 1 to 6 carbon atoms or a group represented by the following formula (Lb3-1) is more preferable. When the chain hydrocarbon group is replaced by -O- or -CO-, the number of -CH2- contained in the chain hydrocarbon group replaced by -O- or -CO- is preferably 1 to 4, and it is preferable that one -CH2-CH2- contained in the chain hydrocarbon group is replaced by -O-CO- or -CO-O-, or -CH2-CH2-CH2- contained in the chain hydrocarbon group is replaced by -O-CO-O-. TIFF2025091367000036.tif1581 [In formula (Lb3-1), nb2 represents the same meaning as in formula (B1-A1). L b31 is a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms, -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and it may have a substituent. W b3 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms, -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-, and the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have a substituent. * and ** represent bonding sites, * is X 1represents a binding site with... In formula (Lb3-1), L b31 As long as the chain hydrocarbon group of has an upper limit on the number of carbon atoms, L b1 Examples of the chain hydrocarbon group exemplified by include groups similar to the groups exemplified by. In formula (Lb3-1), W b3 Examples of the alicyclic hydrocarbon group and aromatic hydrocarbon group of include alicyclic hydrocarbon groups and aromatic hydrocarbon groups exemplified by L b1 as long as the upper limit on the number of carbon atoms permits. In formula (Lb3-1), L b31 Substituents that the chain hydrocarbon group of may have and W b1 Substituents that the alicyclic hydrocarbon group and aromatic hydrocarbon group of may have are groups similar to the substituents exemplified as substituents that the hydrocarbon group of L b1 may have. L b31 is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms (the -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-). Among them, W b1 Examples of the alicyclic hydrocarbon group and aromatic hydrocarbon group of include alicyclic hydrocarbon groups and aromatic hydrocarbon groups represented below. In the alicyclic hydrocarbon groups and aromatic hydrocarbon groups represented below, * and ** represent binding sites, * represents the binding site with X 1 or L b31 and ** represents a hydrogen atom, a substituent or the binding site with L b2 and at least one ** represents the binding site with L b2 In addition, in the alicyclic hydrocarbon groups represented below, the -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. When the -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2-, it is preferably forming an ether ring, an ester ring (lactone), a carbonate ester ring, a sultone ring or an acetal ring. In formula (B1-A1), L b2is preferably a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms (wherein -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), and is a single bond, -O-, -O-CO-, -CO-O-, -O-CO-O- or *-L b21 -X 2 -L b22 -**(L b21 and L b22 either represents a chain hydrocarbon group having 1 to 6 carbon atoms, and the other represents a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms. X 2 represents -O-, -CO-O-, -O-CO- or -O-CO-O-. * and ** represent bonding sites, and ** represents the bonding site with Y b1 However, the total carbon number of L b21 X 2 and L b22 is 12 or less.) is more preferable. In formula (B1-A1), Y b1 is preferably a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (wherein -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO2-), more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (wherein -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO2-) or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, and even more preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms which may have a substituent (wherein -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO2-) or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent. Specifically, it is preferably a group represented by the following formula (Y1) to formula (Y36). In formula (Y1) to formula (Y36), R Yb represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms among the substituents which the cyclic hydrocarbon group of Y b1 may have, R Yc represents a hydrogen atom or a substituent which the cyclic hydrocarbon group of Y b1 may have, * represents L b2represents the binding site to. The alicyclic hydrocarbon group and aromatic hydrocarbon group represented by the following formula are not particularly shown in the following formula, but other Y b1 may have a substituent that the cyclic hydrocarbon group of may have. TIFF2025091367000038.tif83158

[0040] As the anion in the salt represented by the formula (B1), anions represented by the formulas (B1-A1-1) to (B1-A1-85) [hereinafter, may be referred to as "anion (B1-A1-1)" etc. according to the formula number] are preferable, and anions represented by any of the formulas (B1-A1-1) to (B1-A1-4), formula (B1-A1-9), formula (B1-A1-10), formulas (B1-A1-24) to (B1-A1-33), formulas (B1-A1-36) to (B1-A1-40), and formulas (B1-A1-47) to (B1-A1-85) are more preferable. TIFF2025091367000039.tif216160

[0041] TIFF2025091367000040.tif249150

[0042] TIFF2025091367000041.tif254163

[0043] Here, R i2 ~R i7 are, independently of each other, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R i8 is, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these, more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group. L A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q b1 and Q b2 represent the same meaning as described above. Examples of the anion represented by formula (B1-A1) include the anions described in JP-A-2010-204646.

[0044] Preferred anions in the salt represented by formula (B1) include the anions represented by formula (B1a-1) to formula (B1a-70), respectively. TIFF2025091367000042.tif185163

[0045] TIFF2025091367000043.tif252166

[0046] TIFF2025091367000044.tif70166

[0047] Among them, anions represented by any of formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-19), and formula (B1a-22) to formula (B1a-70) are preferred.

[0048] The anion represented by formula (B1-A2) is represented by the following formula. TIFF2025091367000045.tif23100[In formula (B1-A2), L b2 and Y b1 have the same meanings as in formula (B1). R b1 represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkyl group may be replaced by -O- or -CO-. nb4 represents an integer of any one of 1 to 5. When nb4 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. nb3 represents an integer of any one of 0 to 4. When nb3 is 2 or more, the plurality of R b1 may be the same as or different from each other. However, 1 ≦ nb4 + nb3 ≦ 5 is satisfied.]

[0049] In formula (B1-A2), L b2The hydrocarbon group and Y b1 Examples of the cyclic hydrocarbon group of are, within the range permitted by the upper limit of the number of carbon atoms, L in formula (B1) b2 Examples of the hydrocarbon group of and Y b1 Examples of the cyclic hydrocarbon group of are the same as those of the hydrocarbon group of L and Y b2 The hydrocarbon group of, Y b1 Regarding the methyl group of and the substituents that the cyclic hydrocarbon group may have, the same examples as those of the hydrocarbon group of L in formula (B1) b2 The hydrocarbon group of, Y b1 Examples of the substituents that the methyl group of and the cyclic hydrocarbon group may have are the same as those of the hydrocarbon group of L and Y L b2 preferably represents an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. More preferably, *-CO-O-L b41 -(L b41 is a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms, and -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-. * represents the bonding site with the phenyl group to which SO3 - is bonded. L b41 is preferably a single bond or a chain hydrocarbon group having 1 to 3 carbon atoms. Y b1 is preferably a cyclic hydrocarbon group having 3 to 18 carbon atoms (where -CH2- contained in the cyclic hydrocarbon group may be replaced by -O- or -CO-), more preferably Y in formula (B1-A1) b1 , and further L b1 is the cyclic hydrocarbon group exemplified by, and more preferably the following groups. R Yb and R Yc have the same meaning as above. TIFF2025091367000046.tif83158

[0050] In formula (B1-A2), nb4 is preferably any integer from 1 to 4, more preferably any integer from 1 to 3, even more preferably 1 or 2, and even more preferably 2. When nb4 is 1 or 2, -L b2 -Y b1 The bonding position of is SO3- It is preferable that it has the following structure which is m-position substitution of the benzene ring with respect to the bonding position. TIFF2025091367000047.tif26106[In the above formula, L b2 , Y b1 , R b1 , and nb3 represent the same meaning as in formula (B1-A2).] In formula (B1-A2), when nb4 is 2 or more, it is preferable that the plurality of L b2 and Y b1 represent the same group as each other.

[0051] Examples of the alkyl group having 1 to 6 carbon atoms for R b1 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, and hexyl group. The number of carbon atoms of the alkyl group is preferably 1 to 4, more preferably 1 to 3. Examples of the halogen atom for R b1 include fluorine atom, chlorine atom, bromine atom, and iodine atom. Examples of the group in which -CH2- contained in the alkyl group is replaced by -O- or -CO- include hydroxy group, carboxy group, alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, alkylcarbonyloxy group, oxy group, and carbonyl group. Specific examples thereof are the same as those described above. R b1 is each independently preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), more preferably a fluorine atom, an iodine atom or an alkyl group having 1 to 3 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methoxy group or a methyl group. nb3 is an integer from 0 to 4 (that is, nb3 - 1 represents an integer from 0 to 3), preferably an integer from 0 to 3, and more preferably an integer from 0 to 2. In one embodiment, nb3 is preferably 0. In another embodiment, nb3 is preferably 1 or 2. When nb3 is 1, R b1 is preferably a halogen atom, and R b1 is more preferably a fluorine atom or an iodine atom. When nb3 is 2, one of R b1 is preferably a halogen atom and the other is preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms, and one of R b1 is more preferably a fluorine atom or an iodine atom and the other is more preferably a fluorine atom, an iodine atom or an alkyl group having 1 to 3 carbon atoms.

[0052] Examples of the anion (B1 - A2) include the following anions. Among them, the anions represented by formula (B2a - 1) to formula (B2a - 20) are preferred, and the anions represented by formula (B2a - 1) to formula (B2a - 11), formula (B2a - 16) to formula (B2a - 20) are more preferred. Some of the following anions omit some R b1 and may contain substituents not shown. TIFF2025091367000048.tif102153

[0053] In another form of the acid generator (B), an anion in which the anion represented by formula (B1) is replaced with a sulfonamide anion, a sulfonylmethide anion or a carboxylic acid anion is also preferably used as the acid generator (B). Examples of the sulfonamide anion and the sulfonylmethide anion include those represented by the following formulas. TIFF2025091367000049.tif1289[In formula (B1 - A3), A 1 represents a nitrogen atom or a carbon atom. L b2' represents a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a single bond or a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. Y b1 ' represents a methyl group which may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-, and two -L b2’ -Y b1’ may combine together to form a ring containing A 1 is acceptable. nb5 represents 2 or 3. When nb5 is 2, A 1 represents a nitrogen atom, and when nb5 is 3, A 1 represents a carbon atom. The groups within multiple parentheses may be the same as or different from each other. In formula (B1 - A3), L b2 ' and Y b1 ' are exemplified by the same groups as L b2 and Y b1 in formula (B1 - A1). In formula (B1 - A3), L b2’ is a single bond, *-L b23 -X 2 -, or *-L b23 -X 2 -W 2 -X 3 -(L b23 represents an alkanediyl group having 1 to 6 carbon atoms which may have a fluorine atom, X 2 and X 3 each independently represent -O-, -CO - O-, -O - CO-, -O - CO - O- or -O-, and W 2 represents an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-, and * represents the bonding site with SO2. It is preferably). In formula (B1 - A3), Y b1’is preferably a trifluoromethyl group, an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, or a phenyl group which may have a substituent, and more preferably a trifluoromethyl group or a group represented by Formula (Y1) to Formula (Y36) in Formula (B1-A1). nb5 is preferably 2 or 3. In Formula (B1-A3), two L b2’ -Y b1’ together form a ring containing A 1 For example, an anion represented by Formula (B1-A3’) can be mentioned. TIFF2025091367000050.tif21123 [In Formula (B1-A3’), A 1 、Y b1 ’、L b2 ’nb5 represents the same meaning as in Formula (B1-A3). W b4 represents a disulfonylimide ring or a disulfonylmethide ring having 3 to 12 carbon atoms which may have a fluorine atom.] W b4 The disulfonylimide ring or disulfonylmethide ring of W is preferably having 3 to 6 carbon atoms, and the hydrogen atom of the methylene group contained in the ring is preferably replaced by a fluorine atom.

[0054] Examples of the anion represented by Formula (B1-A3) include the following. Among them, anions represented by Formula (B3a-1) and Formula (B3a-2) are preferred. TIFF2025091367000051.tif171163

[0055] Examples of the carboxylic acid anion include the following. However, the acid generator (B) having a carboxylic acid anion excludes the salt of Formula (I). TIFF2025091367000052.tif41155

[0056] Z1 + The organic cation of is the Z of Formula (I) + The organic cation Z +The same cations can be mentioned. Specifically, organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, organic phosphonium cations and the like can be mentioned. Among these, organic sulfonium cations and organic iodonium cations are preferable, arylsulfonium cations or aryliodonium cations are more preferable, and cations represented by any of formula (b2-1) to formula (b2-5) are even more preferable.

[0057] The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the acid generator (B), preferably, any of anions represented by any of formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-19), formula (B1a-22) to formula (B1a-70) or formula (B2a-1) to formula (B2a-11), formula (B2a-16) to formula (B2a-20), formula (B1-3a-1) to formula (B1-3a-3) or formula (B1-3a-11) to formula (B1-3a-14) and a combination with cation (b2-1), cation (b2-2), cation (b2-3), cation (b2-4) or cation (b2-5) can be mentioned.

[0058] As the acid generator (B), preferably, those represented by formula (B1-1) to formula (B1-105), formula (B2-1) to formula (B2-20) and formula (B3-1) to (B3-28) can be mentioned. Among them, those containing an arylsulfonium cation are preferable, and those represented by formula (B1-1) to formula (B1-3), formula (B1-5) to formula (B1-7), formula (B1-11) to formula (B1-14), formula (B1-20) to formula (B1-26), formula (B1-29), formula (B1-31) to formula (B1-105), formula (B2-1) to formula (B2-20) and formula (B3-1) to formula (B3-28) are particularly preferable. TIFF2025091367000053.tif176161

[0059] TIFF2025091367000054.tif254159

[0060] TIFF2025091367000055.tif254165

[0061] TIFF2025091367000056.tif252160

[0062] TIFF2025091367000057.tif249163

[0063] TIFF2025091367000058.tif250150

[0064] TIFF2025091367000059.tif187159

[0065] <Resin (A)> Resin (A) contains a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"). Resin (A) preferably further contains a structural unit other than structural unit (a1). Examples of the structural unit other than structural unit (a1) include a structural unit having no acid-labile group (hereinafter sometimes referred to as "structural unit (s)"), a structural unit other than structural unit (a1) and structural unit (s) (for example, a structural unit having a halogen atom described later (hereinafter sometimes referred to as "structural unit (a4)"), a structural unit having a non-leaving hydrocarbon group described later (hereinafter sometimes referred to as "structural unit (a5)"), and structural units derived from other monomers known in the art, etc.).

[0066] 〈Structural unit (a1)〉 Structural unit (a1) is derived from a monomer having an acid-labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid-labile group contained in Resin (A) is preferably a group represented by formula (1) (hereinafter also referred to as group (1)) and / or a group represented by formula (2) (hereinafter also referred to as group (2)). TIFF2025091367000060.tif2298[In formula (1), R a1 , R a2 and R a3each independently represents 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 combining these, or R a1 and R a2 are bonded to each other to form, together with the carbon atom to which they are bonded, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, and the alkyl group, the alkenyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * represents a bonding site.] TIFF2025091367000061.tif2278[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, together with the carbon atom to which they are bonded and X, a heterocyclic group having 3 to 20 carbon atoms, and -CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced by -O- or -S-, and the hydrocarbon group and the heterocyclic group may have a halogen atom. X represents an oxygen atom or a sulfur atom. na’ represents 0 or 1. * represents a bonding site.]

[0067] R a1 、R a2 and R a3 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, etc. R a1 、R a2 and R a3 Examples of the alkenyl group in include an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, an isooctenyl group, a nonenyl group. Ra1 , R a2 and R a3 The alicyclic hydrocarbon groups in R, R, and R may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, etc. Examples of the polycyclic alicyclic hydrocarbon groups include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups (* represents the bonding site). R a1 , R a2 and R a3 The number of carbon atoms of the alicyclic hydrocarbon groups in R, R, and R is preferably 3 to 16. TIFF2025091367000062.tif10159R a1 , R a2 and R a3 Examples of the aromatic hydrocarbon groups in R, R, and R include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, phenanthryl group, etc. Examples of the combined groups include groups combining the above-mentioned alkyl group and alicyclic hydrocarbon group (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 an alkyl group (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 an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, etc. Preferably, ma is 0 and na is 1. R a1 and R a2 When R and R are bonded to each other to form an alicyclic hydrocarbon group, -C(R a1 )(R a2 )(R a3) includes the following groups. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * represents a bond to -O-. TIFF2025091367000063.tif27138

[0068] R a1’ , R a2’ and R a3’ Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups combining these groups are R a1 , R a2 and R a3 Examples of the groups include the same groups as those listed in the above. R a2’ and R a3’ When they are bonded to each other to form a heterocycle together with the carbon atom to which they are attached and X, -C(R a1’ )(R a2’ )-XR a3’ Examples of the group include the following: * represents a bond. TIFF2025091367000064.tif19124R a1’ and R a2’ At least one of these is preferably a hydrogen atom. na' is preferably 0. R a1 , R a2 , R a3 , R a1 , R a2’ and R a3’ The halogen atom which may be contained includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0069] Examples of the group (1) include the following groups. In formula (1), R a1 , R a2 and R a3 is an alkyl group, ma = 0, and na = 1. As the group, a tert-butoxycarbonyl group is preferable. In formula (1), Ra1 , R a2 forms an adamantyl group together with the carbon atom to which they are attached, and R a3 is an alkyl group, ma = 0, and na = 1. In formula (1), R a1 and R a2 are each independently an alkyl group, R a3 is an adamantyl group, ma = 0, and na = 1. Specific examples of group (1) include the following groups. * represents a bond. TIFF2025091367000065.tif150162

[0070] Specific examples of group (2) include the following groups. * represents a bond. TIFF2025091367000066.tif55153

[0071] Monomer (a1) is preferably a monomer having an acid-labile group and an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer having an acid-labile group. Among the (meth)acrylic monomers having an acid-labile group, those having an alicyclic hydrocarbon group with 5 to 20 carbon atoms are preferably mentioned. If a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

[0072] Examples of the structural unit derived from the (meth)acrylic monomer having the group (1) include a structural unit represented by formula (a1-0) (hereinafter, sometimes referred to as structural unit (a1-0)), a structural unit represented by formula (a1-1) (hereinafter, sometimes referred to as structural unit (a1-1)), or a structural unit represented by formula (a1-2) (hereinafter, sometimes referred to as structural unit (a1-2)). Preferably, it is at least one structural unit selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2), more preferably at least one or two structural units selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). These may be used alone or in combination of two or more. TIFF2025091367000067.tif45148 [In formula (a1-0), formula (a1-1) and formula (a1-2), all symbols have the same meaning as defined above.]

[0073] R a01 , R a4 and R a5 The halogen atom in the formula (I) includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R a01 , R a4 and R a5 Examples of the alkyl group which may have a halogen atom in the above formula include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, a perfluorohexyl group, a chloromethyl group, a bromomethyl group, and an iodomethyl group. The number of carbon atoms in the alkyl group is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2. The alkyl group is preferably a methyl group or an ethyl group, and more preferably a methyl group. R a01, R a4 and R a5 is preferably a hydrogen atom or a methyl group, more preferably a methyl group. L a01 , L a1 and L a2 is preferably an oxygen atom or *-O-(CH2) k01 -CO-O- (wherein k01 is preferably any integer from 1 to 4, more preferably 1), and more preferably an oxygen atom. R a02 , R a03 , R a04 , R a6 and R a7 Examples of the alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and combinations thereof in R a1 , R a2 and R a3 are the same as those exemplified for the groups in R R a02 , R a03 , and R a04 The alkyl group in R is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. a6 and R a7 The alkyl group in R is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, or a t-butyl group, and even more preferably an ethyl group, an isopropyl group, or a t-butyl group. a6 and R a7 The alkenyl group in R is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably an ethenyl group, a propenyl group, an isopropenyl group, or a butenyl group. a02 , R a03 , R a04 , R a6 and R a7 The alicyclic hydrocarbon group of R R a02 , R a03 , Ra04 , R a6 and R a7 The number of carbon atoms of the aromatic hydrocarbon group of R and R is preferably 6 to 12, more preferably 6 to 10. For the group combining an alkyl group and an alicyclic hydrocarbon group, it is preferable that the total number of carbon atoms of these alkyl group and alicyclic hydrocarbon group is 18 or less. For the group combining an alkyl group and an aromatic hydrocarbon group, it is preferable that the total number of carbon atoms of these alkyl group and aromatic hydrocarbon group is 18 or less. R a02 and R a03 R and R are preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom or an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a halogen atom, more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group which may have a halogen atom. R a04 R is preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom or an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a halogen atom, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group which may have a halogen atom. R a6 and R a7 R and R are preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkenyl group having 2 to 6 carbon atoms which may have a halogen atom or an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a halogen atom, more preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, a phenyl group or a naphthyl group which may have a halogen atom, still more preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group or a phenyl group which may have a halogen atom. m1' is preferably any integer from 0 to 3, more preferably 0 or 1. n1 is preferably any integer from 0 to 3, more preferably 0 or 1. n1' is preferably 0 or 1.

[0074] As the structural unit (a1-0), for example, there are structural units represented by any of the formulas (a1-0-1) to (a1-0-24) and R in the structural unit (a1-0). a01 Examples of the structural unit corresponding to the methyl group replaced by a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group include structural units represented by any of the formulas (a1-0-1) to (a1-0-10), formula (a1-0-13), formula (a1-0-14), and formulas (a1-0-19) to (a1-0-24), and the structural units represented by any of these are preferred. TIFF2025091367000068.tif119160

[0075] As the structural unit (a1-1), for example, there are structural units derived from the monomers described in JP-A-2010-204646. Among them, structural units represented by any of the formulas (a1-1-1) to (a1-1-7) and R in the structural unit (a1-1). a4 Examples of the structural unit corresponding to the methyl group replaced by a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group are preferred, and structural units represented by any of the formulas (a1-1-1) to (a1-1-4) are more preferred. TIFF2025091367000069.tif34170

[0076] As the structural unit (a1-2), there are structural units represented by any of the formulas (a1-2-1) to (a1-2-20) and R in the structural unit (a1-2). a5 Examples of the structural unit corresponding to the methyl group replaced by a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group include structural units represented by any of the formulas (a1-2-2), (a1-2-5), (a1-2-6) and formulas (a1-2-10) to (a1-2-20), and the structural units represented by any of these are preferred. TIFF2025091367000070.tif92164

[0077] When the resin (A) contains the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, still even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on all the structural units of the resin (A). Also, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, it is 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, still more preferably 25 to 70 mol%, and even more preferably 30 to 70 mol%. When the resin (A) contains the structural unit (a1-0), the content thereof is 5 mol% or more, preferably 10 mol% or more, more preferably 15 mol% or more, still more preferably 20 mol% or more, even more preferably 25 mol% or more, still even more preferably 30 mol% or more, and even more preferably 35 mol% or more, based on all the structural units of the resin (A). Also, it is 80 mol% or less, preferably 75 mol% or less, and more preferably 70 mol% or less. Specifically, it is 5 to 80 mol%, preferably 5 to 75 mol%, and more preferably 10 to 70 mol%. When the resin (A) contains the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, still even more preferably 40 mol% or more, and even more preferably 50 mol% or more with respect to all the structural units of the resin (A). Further, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, still even more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, it is 10 to 90 mol%, preferably 15 to 85 mol%, more preferably 15 to 80 mol%, still more preferably 20 to 80 mol%, even more preferably 20 to 75 mol%, and still even more preferably 20 to 70 mol%.

[0078] Examples of the structural unit having the group (2) in the structural unit (a1) include a structural unit represented by the formula (a1-4) (hereinafter, may be referred to as "structural unit (a1-4)"). TIFF2025091367000071.tif31118[In the formula (a1-4), all the symbols have the same meanings as described above.]

[0079] R a1 and R a17 Examples of the halogen atom and the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R a01 are the same as those exemplified by R of the formula (a1-0). R a1 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group. R a17Examples of the alkoxy group in [compound name] include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group, and hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably an alkoxy group having 1 to 3 carbon atoms, still more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a17 Examples of the alkoxyalkyl group in [compound name] include methoxymethyl group, ethoxyethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, sec-butoxymethyl group, and tert-butoxymethyl group. The alkoxyalkyl group may be an alkoxyalkyl group having 2 to 8 carbon atoms, preferably an alkoxyalkyl group having 2 to 4 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and still more preferably a methoxymethyl group. R a17 Examples of the alkoxyalkoxy group in [compound name] 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, more preferably an alkoxyalkoxy group having 2 to 4 carbon atoms, still more preferably a methoxyethoxy group or an ethoxyethoxy group. R a17 Examples of the alkylcarbonyl group in [compound name] include acetyl group, propionyl group, and butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 4 carbon atoms, more preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and still more preferably an acetyl group. R a17 Examples of the alkylcarbonyloxy group in [compound name] include acetyloxy group, propionyloxy group, and butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 4 carbon atoms, more preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and still more preferably an acetyloxy group. R a17is preferably a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 4 carbon atoms or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group or an ethoxy methoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group.

[0080] A a11 Examples of the alkanediyl group of include linear alkanediyl 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., and 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, 2-methylbutane-1,4-diyl group, heptane-1,6-diyl group, octane-1,7-diyl group, nonane-1,8-diyl group, decane-1,9-diyl group, undecane-1,10-diyl group, etc. The number of carbon atoms of the alkanediyl group is preferably 1 to 10, more preferably 1 to 8, even more preferably 1 to 6, still more preferably 1 to 4, even still more preferably 1 to 3, and even more preferably 1 or 2. R a18 Examples of the alkyl group of include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group and tert-butyl group. A a11 When -CH2- contained in the alkanediyl group of is replaced by -O-, -CO- or -NR a18 -, the number of carbon atoms before replacement is taken as the number of carbon atoms of the alkanediyl group. A a11 When -CH2- contained in the alkanediyl group of is replaced by -O-, -CO- or -NRa18 - The groups replacing the - include a hydroxy group, a carboxy group, a carbonyl group, an oxy group, an amino group (where -CH2- contained in the methyl group is replaced by -NR a18 -), an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylamino group (where any -CH2- at an arbitrary position contained in the alkyl group is replaced by -NR a18 -), a peptide group (where -CH2-CH2- contained in the ethylene group is replaced by -CO-NR a18 -), an alkanediyl-oxy group, an alkanediyl-oxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyl-oxy group, an alkanediylsulfonyl group, an alkanediylthio group, an alkanediylamino group (where any -CH2- at an arbitrary position contained in the alkanediyl group is replaced by -NR a18 -), etc. These replaced groups include those similar to those exemplified in this specification within the range where the upper limit of the number of carbon atoms permits. For example, when -CH2- contained in the alkanediyl group of A a11 is replaced by -O-, -CO- or -NR a18 -, the groups replacing it include *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a12 -CO-O-, *-O-CO-A a12 -O-, *-O-A a12 -CO-O-, *-CO-O-A a12 -O-CO-, *-O-CO-A a12 -O-CO-, *-CO-NR a18 -. Among them, *-CO-O-, *-CO-O-A a12 -CO-O-, *-O-A a12 -CO-O-, *-CO-NR a18 - are preferred. Here, A a12 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents the bonding site with the carbon atom to which R a1 is bonded. The alkanediyl group of A a12 includes alkanediyl groups similar to A a11 within the range where the upper limit of the number of carbon atoms permits. A a11is a single bond, *-CO-O- or *-CO-O-A a12 -CO-O- is preferred, more preferably a single bond, *-CO-O- or *-CO-O-CH2-CO-O-, and even more preferably a single bond or *-CO-O-. na1 is preferably 1, 2, 3 or 4, more preferably 1, 2 or 3, and even more preferably 1 or 2. na11 is preferably 0, 1, 2 or 3, more preferably 0, 1 or 2, and even more preferably 0 or 1. mc is preferably 0 or 1.

[0081] R a34 、R a35 and R a36 Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining these. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group and the like. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and the like. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following groups (* represents the bonding site). TIFF2025091367000072.tif10151 Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, a phenanthryl group and the like. Examples of the combined group include a group formed by combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., an alkylcycloalkyl group or cycloalkylalkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), an aralkyl group such as benzyl group, an aromatic hydrocarbon group having an alkyl group (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.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), an aryl-cycloalkyl group such as phenylcyclohexyl group, etc. In particular, R a36 Examples of R include 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 combining these. R a35 and R a36 Examples of the divalent hydrocarbon group having 2 to 20 carbon atoms formed by R and R bonding to each other together with the -C-O- to which they are bonded include the following groups. * represents the bonding site, and one side is the bonding site with R a34 and the other side is the bonding site with R. TIFF2025091367000073.tif15105

[0082] R a34 is preferably a hydrogen atom. R a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, more preferably a methyl group or an ethyl group. R a36 The hydrocarbon group of R 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 combining these, 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. R a36The alkyl group and alicyclic hydrocarbon group in [it] are preferably unsubstituted. R a36 The aromatic hydrocarbon group in [it] preferably has an aromatic ring having an aryloxy group with 6 to 10 carbon atoms.

[0083] -O-C(R a34 )(R a35 )-O-R a36 in the structural unit (a1-4) eliminates upon contact with an acid (for example, p-toluenesulfonic acid) to form a hydroxy group or a carboxy group. -X a1 -O-C(R a34 )(R a35 )-O-R a36 in the case of a benzene ring, may be bonded to any of the o-position, m-position or p-position with respect to the bonding position of A a11 . Among them, it is preferable that at least one is bonded to the o-position or p-position, and more preferably bonded to the p-position. In the case of a naphthalene ring, when the bonding position of A a11 is the 1-position, it may be bonded to any of the 2nd to 8th positions, and when the bonding position of A a11 is the 2nd position, it may be bonded to any of the 1st and 3rd to 8th positions. Among them, when the bonding position of A a11 is the 1st position, it is preferable that at least one is bonded to the 3rd to 6th positions, and more preferably bonded to the 3rd or 4th position. When the bonding position of A a11 is the 2nd position, it is preferable that it is bonded to the 4th to 7th positions, and more preferably bonded to the 5th or 6th position.

[0084] Examples of the structural unit (a1-4) include structural units derived from the monomers described in JP-A-2010-204646. Preferably, the structural units represented by formula (a1-4-1) to formula (a1-4-42) and R in the structural unit (a1-4) a1Examples of the structural unit in which the hydrogen atom corresponding thereto is replaced with a halogen atom, a haloalkyl group, or an alkyl group include, more preferably, the structural units represented by Formula (a1-4-1) to Formula (a1-4-5), Formula (a1-4-10), Formula (a1-4-13), Formula (a1-4-14), Formula (a1-4-19), and Formula (a1-4-20). TIFF2025091367000074.tif228165When the resin (A) contains the structural unit (a1-4), the content thereof is 5 to 95 mol%, 5 to 60 mol%, 5 to 50 mol% based on the total of all the structural units of the resin (A), preferably 10 to 40 mol%, 10 to 95 mol%, more preferably 15 to 90 mol%, still more preferably 20 to 85 mol%, still more preferably 20 to 70 mol%, and particularly preferably 20 to 60 mol%.

[0085] Examples of the structural unit derived from the (meth)acrylic monomer having the group (2) also include the structural unit represented by Formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)"). TIFF2025091367000075.tif4659[In Formula (a1-5), all the symbols have the same meanings as described above.]

[0086] R a8 Examples of the halogen atom and the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R a01 are the same as those exemplified above for R of Formula (a1-0). In Formula (a1-5), R a8 is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group. L 51 is preferably an oxygen atom. L 52 and L 53 Among them, it is preferable that one is -O- and the other is -S-. s1 is preferably 1. s1' is preferably any integer from 0 to 2. Z a1A single bond or *-CH2-CO-O- is preferred.

[0087] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP-A-2010-61117. Among them, the structural units represented by formula (a1-5-1) to formula (a1-5-4) are preferred, and the structural unit represented by formula (a1-5-1) or formula (a1-5-2) is more preferred. When the resin (A) contains the structural unit (a1-5), the content thereof is 1 mol% or more, preferably 2 mol% or more, more preferably 3 mol% or more, still more preferably 5 mol% or more, even more preferably 10 mol% or more, still even more preferably 20 mol% or more, and even more preferably 25 mol% or more, based on all the structural units of the resin (A). Also, it is 80 mol% or less, preferably 70 mol% or less, more preferably 60 mol% or less, still more preferably 50 mol% or less, even more preferably 45 mol% or less, still even more preferably 40 mol% or less, and even more preferably 30 mol% or less. Specifically, 1 to 50 mol% is preferred, 3 to 45 mol% is more preferred, 5 to 40 mol% is still more preferred, and 5 to 30 mol% is even more preferred.

[0088] Examples of the structural unit having the group (1) in the structural unit (a1) include a structural unit represented by formula (a1-6) (hereinafter sometimes referred to as "structural unit (a1-6)"). TIFF2025091367000077.tif3481[In formula (a1-6), all the symbols have the same meanings as described above.]

[0089] R a61 Examples of the halogen atom and the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R a01 are the same as those exemplified by the like of R in formula (a1-0). R a61 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group. R a62 , R a63 , R a64 and R a65 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, etc. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group or an ethyl group. R a62 , R a63 and R a64 The cyclic hydrocarbon group in the formula (I) includes an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, and a norbornyl group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 16, and more preferably 3 to 12. Examples of the aromatic hydrocarbon group include a phenylene group and a naphthylene group. Examples of the substituent that the cyclic hydrocarbon group may have include a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. R a62 and R a63 Examples of the ring formed by bonding with each other include an adamantane ring, a cyclopentane ring, and a cyclohexane ring. a62 and R a63 When they are bonded to each other to form a ring, -C(R a62 )(R a63 )(R a64 ) includes the following groups. * represents a bonding site with an oxygen atom. The number of carbon atoms in the ring is preferably 3 to 16, and more preferably 3 to 12. TIFF2025091367000078.tif33110

[0090] L a61 and L a62 Examples of the C1-C4 alkanediyl group in and L include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, and the like. L a61 and L a62 are each independently preferably a methylene group or an ethylene group. X a61 is preferably a single bond or -CO-O-*, more preferably a single bond. X a62 is preferably a single bond or *-O-L a61 -, more preferably a single bond.

[0091] Examples of the C6-C20 aromatic hydrocarbon group of Ar include a phenylene group, a 1-naphthylene group, a 2-naphthylene group, a 1-anthrylene group, a 9-anthrylene group, a biphenylene group, a 1-phenanthrylene group, and a 2-phenanthrylene group. Examples of the substituent that the aromatic hydrocarbon group may have include a halogen atom, a hydroxy 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. Examples of the halogen atom include a fluorine atom, an iodine atom, a chlorine atom, and a bromine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably a C1-C4 alkyl group, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. Examples of the alkoxyalkyl group include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. Examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. Examples of the substituent include a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms. More preferred examples include a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group. Even more preferred examples include a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group. Ar is preferably a phenylene group which may have a substituent, more preferably a phenylene group which may have a hydroxy group.

[0092] Examples of the structural unit (a1-6) include structural units represented by Formula (a1-6-1) to Formula (a1-6-44), etc. Structural units represented by Formula (a1-6-1) to Formula (a1-6-9) are preferred, structural units represented by Formula (a1-6-1), Formula (a1-6-2), Formula (a1-6-4), Formula (a1-6-5), Formula (a1-6-7) or Formula (a1-6-8) are more preferred, and structural units represented by Formula (a1-6-1) or Formula (a1-6-2) are even more preferred. In the following structural units, R a61 Structural units in which the hydrogen atom corresponding to is replaced with a methyl group or the like, and structural units in which the methyl group corresponding to R a61 in the following structural units is replaced with a hydrogen atom or the like are also included as the structural unit (a1-6). TIFF2025091367000079.tif227164

[0093] When the resin (A) contains the structural unit (a1-6), its content is 3 mol% or more, preferably 5 mol% or more, more preferably 7 mol% or more, even more preferably 10 mol% or more, still more preferably 20 mol% or more, still even more preferably 30 mol% or more, and even more preferably 40 mol% or more with respect to all the structural units of the resin (A). Also, 80 mol% or less is included, preferably 75 mol% or less, more preferably 70 mol% or less, even more preferably 65 mol% or less. Specifically, it is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, even more preferably 7 to 70 mol%, still even more preferably 7 to 65 mol%, and particularly preferably 10 to 65 mol%.

[0094] Examples of the structural unit (a1) also include the following structural units. TIFF2025091367000080.tif33167

[0095] When the resin (A) contains structural units represented by formulas (a1-7-1) to (a1-7-7), the content thereof is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, still even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on all the structural units of the resin (A). Also, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, still even more preferably 70 mol% or less, and even more preferably 60 mol% or less. Specifically, 10 to 95 mol% is preferable, 15 to 90 mol% is more preferable, 20 to 85 mol% is still more preferable, 20 to 70 mol% is even more preferable, and 20 to 60 mol% is particularly preferable.

[0096] Also, as the structural unit (a1), the following structural units are also included. TIFF2025091367000081.tif51120 When the resin (A) contains structural units represented by formulas (a1-8-1) to (a1-8-3), the content thereof is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, still even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on all the structural units of the resin (A). Also, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, still even more preferably 70 mol% or less, and even more preferably 60 mol% or less. Specifically, 10 to 60 mol% is preferable, 15 to 55 mol% is more preferable, 20 to 50 mol% is still more preferable, 20 to 45 mol% is even more preferable, and 20 to 40 mol% is particularly preferable.

[0097] 〈Structural unit(s)〉 The structural unit(s) is / are derived from a monomer having no acid-labile group (hereinafter sometimes referred to as “monomer(s)”). As the monomer from which the structural unit(s) is / are derived, a monomer having no acid-labile group known in the resist field can be used. The structural unit(s) preferably has a hydroxy group, a carboxy group or a lactone ring. If a resin containing a structural unit having a hydroxy group or a carboxy group and having no acid-labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a structural unit having a lactone ring and having no acid-labile 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.

[0098] 〈Structural unit (a2)〉 The structural unit (a2) is a structural unit represented by formula (a2) and has an alcoholic hydroxy group, a phenolic hydroxy group or a carboxy group. TIFF2025091367000082.tif4095[In formula (a2), R a2 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A a21 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O-, -CO- or -NR a28 -. R a28 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. L a21 represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms, the hydrocarbon group may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO2-. L a22 represents a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms which may have a fluorine atom, and -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-. na2 represents any integer from 1 to 5. When na2 is 2 or more, a plurality of Ls a22 may be the same as or different from each other.] R a2 Examples of the halogen atom in R include a fluorine atom, an iodine atom, a chlorine atom, a bromine atom, etc. R a2 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, a perfluorohexyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, etc. The number of carbon atoms of the alkyl group is preferably 1 to 4, more preferably 1 to 3, and still more preferably 1 or 2. R a2 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

[0099] A a21Examples of the alkandiyl group include linear alkandiyl 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., and branched alkandiyl 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, 2-methylbutane-1,4-diyl group, heptane-1,6-diyl group, octane-1,7-diyl group, nonane-1,8-diyl group, decane-1,9-diyl group, undecane-1,10-diyl group, etc. The number of carbon atoms in the alkandiyl group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, even more preferably 1 to 4, still even more preferably 1 to 3, and even more preferably 1 or 2. R a28 Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, and tert-butyl group. A a21 When -CH2- contained in the alkandiyl group of A is replaced by -O-, -CO- or -NR a28 -, the number of carbon atoms before replacement is defined as the number of carbon atoms of the alkandiyl group. A a21 When -CH2- contained in the alkandiyl group of A is replaced by -O-, -CO- or -NR a28-As the group replaced, as described above, there may be mentioned a hydroxy group, a carboxy group, a carbonyl group, an oxy group, an amino group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylamino group, a peptide group, an alkanediyl-oxy group, an alkanediyl-oxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyl-oxy group, an alkanediylsulfonyl group, an alkanediylthio group, an alkanediylamino group and the like. These replaced groups may be the same as those exemplified herein, within the range allowed by the upper limit of the number of carbon atoms. Among them, A a21 The -CH2- contained in the alkanediyl group of, is replaced by -O-, -CO- or -NR a28 -As the group replaced, there may be mentioned *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a22 -CO-O-, *-O-CO-A a22 -O-, *-O-A a22 -CO-O-, *-CO-O-A a22 -O-CO-, *-O-CO-A a22 -O-CO-, *-CO-NR a28 - are mentioned. Among them, *-CO-O-, *-CO-O-A a22 -CO-O-, *-O-A a22 -CO-O-, *-CO-NR a28 - are preferred. Here, A a22 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents the bonding site with the carbon atom to which R a2 is bonded. The alkanediyl group of A a22 may be the same alkanediyl group as A a21 within the range allowed by the upper limit of the number of carbon atoms. A a21 is preferably a single bond, *-CO-O- or *-CO-O-A a22 -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-.

[0100] L a21The hydrocarbon group in [description] is a (na2+1)-valent hydrocarbon group, and examples thereof include linear or branched chain hydrocarbon groups, monocyclic or polycyclic (including spiro rings, condensed rings, bridged rings, etc.) alicyclic hydrocarbon groups, and cyclic hydrocarbon groups such as aromatic hydrocarbon groups. A group formed by combining two or more of these groups (for example, a hydrocarbon group formed from an alicyclic hydrocarbon group or an aromatic hydrocarbon group and a chain hydrocarbon group) may also be used. L a21 Examples of the chain hydrocarbon group of [description] include divalent to hexavalent chain hydrocarbon groups such as alkanediyl groups, alkanetriyl groups, alkanetetrayl groups, alkanepentayl groups, and alkanexayl groups. Examples of the alkanediyl group include, for example, an alkanediyl group similar to A a21 The same alkanediyl group as [description] may be mentioned. Examples of the alkanetriyl group include methanetriyl group, ethanetriyl group, propanetriyl group, butanetriyl group, pentanetriyl group, hexanetriyl group, heptanetriyl group, octanetriyl group, nonanetriyl group, decanetriyl group, undecanetriyl group, dodecanetriyl group, tridecanetriyl group, tetradecanetriyl group, pentadecanetriyl group, hexadecanetriyl group, and heptadecanetriyl group. Examples of the alkanetetrayl group include methanetetrayl group, ethanetetrayl group, propanetetrayl group, butanetetrayl group, pentanetetrayl group, hexanetetrayl group, heptanetetrayl group, octanetetrayl group, nonanetetrayl group, decanetetrayl group, undecanetetrayl group, dodecanetetrayl group, tridecanetetrayl group, tetradecanetetrayl group, pentadecanetetrayl group, hexadecanetetrayl group, and heptadecanetetrayl group. Examples of the alkanepentayl group include methanepentayl group, ethanepentayl group, propanepentayl group, butanepentayl group, pentanepentayl group, and hexanepentayl group. Examples also include a group in which one or more hydrogen atoms of the above-described group are replaced with a bonding site. The number of carbon atoms in the chained hydrocarbon group is preferably from 1 to 18, more preferably from 1 to 12, still more preferably from 1 to 10, even more preferably from 1 to 9, yet even more preferably from 1 to 8, still even more preferably from 1 to 6, yet still even more preferably from 1 to 5, and particularly preferably from 1 to 4. L a21 Examples of the monocyclic and polycyclic alicyclic hydrocarbon groups in a21 include the following alicyclic hydrocarbon groups and the like. The bonding site can be at any position. TIFF2025091367000083.tif46168For example, divalent to hexavalent alicyclic hydrocarbon groups such as cycloalkanediyl groups, cycloalkanetriyl groups, cycloalkanetetrayl groups, cycloalkanepentayl groups, cycloalkanehexayl groups and the like can be mentioned. Specifically, monocyclic alicyclic hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, cyclopropanetriyl group, cyclobutanetriyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclodecanetriyl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, cyclodecanetetrayl group and polycyclic alicyclic hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, decahydronaphthalenediyl group, bicyclo[3.3.0]octanediy group, norbornanetriyl group, adamantanetriyl group, decahydronaphthalenetriyl group, bicyclo[3.3.0]octanetriyl group, norbornanetetrayl group, adamantanetetrayl group, decahydronaphthalenetetrayl group, bicyclo[3.3.0]octanetetrayl group and the like can be mentioned. Moreover, groups in which one or more hydrogen atoms of the above-mentioned groups are replaced by a bonding site and the like can also be mentioned. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 20, more preferably 3 to 18, still more preferably 3 to 16, even more preferably 3 to 12, yet even more preferably 6 to 12, and still even more preferably 6 to 10. L a21 Examples of the aromatic hydrocarbon group in a21 include divalent to hexavalent aromatic hydrocarbon groups such as an arylene group, an arenetriyl group, an arenetetrayl group, an arenepentayl group, and an arenexayl group. Specifically, a phenylene group, a naphthylene group, an anthrylene group, a biphenylene group, a phenanthrylene group, a benzenetriyl group, a naphthalenetriyl group, an anthracenetriyl group, a biphenylenetriyl group, a phenanthrenetriyl group, a benzenetetrayl group, a naphthalenetetrayl group, an anthracenetetrayl group, a biphenylenetetrayl group, a phenanthrenetetrayl group, etc. can be mentioned. Moreover, groups in which one or more hydrogen atoms of the above-described groups are replaced with bonding sites, etc. can also be mentioned. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 20, more preferably 6 to 18, still more preferably 6 to 14, even more preferably 6 to 12, and yet even more preferably 6 to 10. Examples of the group formed by combining two or more types include a group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group, a group formed by combining an aromatic hydrocarbon group and a chain hydrocarbon group, a group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group, a group formed by combining an alicyclic hydrocarbon group, a chain hydrocarbon group, and an aromatic hydrocarbon group, etc. In the combination, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the chain hydrocarbon group may each be combined with two or more types. Also, any group may be bonded to A a21 and L a22 and may be bonded. Examples of the group in which -CH2- contained in the hydrocarbon group is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group, a carboxy group, a thiol group, an alkoxy group, an alkylthio group, an alkoxycarbonyl group, an alkoxycarbonyloxy group, an alkylsulfonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an oxy group, a carbonyl group, a thio group, a sulfonyl group, an alkanedioxy group, an alkanedioxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyloxy group, an alkanediylsulfonyl group, an alkanediylthio group, a cycloalkoxy group, a cycloalkylalkoxy group, an aromatic hydrocarbon group-carbonyl-oxy group, an aromatic hydrocarbon group-carbonyl group, an aromatic hydrocarbon group-oxy group, a group formed by combining two or more of these groups, and the like. Also included are groups in which one or more hydrogen atoms of these groups are replaced by a bonding site, and the like. These replaced groups include those similar to the groups exemplified in this specification within the range allowed by the upper limit of the number of carbon atoms.

[0101] Examples of the group in which -CH2- contained in the group formed by combining an alicyclic hydrocarbon group and an alicyclic saturated hydrocarbon group with an aromatic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include those similar to the groups exemplified in this specification within the range allowed by the upper limit of the number of carbon atoms. L a21 The hydrocarbon group in L may have one or more substituents. Examples of the substituent include a halogen atom, a haloalkyl group having 1 to 12 carbon atoms, an alkyl group having 1 to 16 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), an acryloyloxy group, a methacryloyloxy group, and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. L a21The hydrocarbon group in [compound name] can have substituents such as haloalkyl groups by having a halogen atom as a substituent. Examples of haloalkyl groups include alkyl fluoride groups, alkyl chloride groups, alkyl bromide groups, alkyl iodide groups, etc. For example, chloromethyl group, bromomethyl group, iodomethyl group, fluoromethyl group, difluoromethyl group, trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group, etc. can be mentioned. The number of carbon atoms in the haloalkyl group is preferably 1 to 8, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. L a21 The hydrocarbon group of a21 can have substituents such as alkyl groups by including a branched structure, so that L a21 can have substituents such as alkyl groups substantially. 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, dodecyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 10, still more preferably 1 to 8, even more preferably 1 to 6, still even more preferably 1 to 4, and even more preferably 1 to 3. L a21 When the -CH2- contained in the hydrocarbon group of a21 is replaced by a group such as -O- or -CO-, L a21can substantially have substituents such as a hydroxy group, a carboxy group, an alkoxy group, a thiol group, a sulfonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkoxyalkyl group, an alkoxyalkoxy group, an acryloyloxy group, a methacryloyloxy group, etc. The number of carbon atoms of the alkoxy group is preferably 1 to 12, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. The number of carbon atoms of the alkoxycarbonyl group, the alkylcarbonyl group, and the alkylcarbonyloxy group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 to 3. The number of carbon atoms of the alkoxyalkyl group and the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 8, still more preferably 2 to 6, and even more preferably 2 to 4. Examples of the above groups include the same ones as those exemplified in the present specification. L a21 Examples of the substituent that the hydrocarbon group in L may have include a halogen atom, a haloalkyl group having 1 to 8 carbon atoms, or an alkyl group having 1 to 12 carbon atoms (the -CH2- contained in the alkyl group may be replaced by -O- or -CO-). A halogen atom, a haloalkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 10 carbon atoms (the -CH2- contained in the alkyl group may be replaced by -O- or -CO-) is more preferable. A halogen atom, a haloalkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms is still more preferable. A fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group is even more preferable. A fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, a methoxy group, or an ethoxyethoxy group is still even more preferable. Also, when the alkanediyl group of L is replaced by -O-, -CO-, etc., for example, *-L a21 -X a23 -X a21 -(La23 represents an alkanediyl group having 1 to 8 carbon atoms, and X a21 represents -O-, -O-CO-, -CO-O- or -O-CO-O-, and * represents the bonding site with A a21 It is also preferable that it is (). L a21 is a single bond, an optionally substituted chain hydrocarbon group having 1 to 12 carbon atoms (however, -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), an optionally substituted cyclic hydrocarbon group having 3 to 20 carbon atoms (however, -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2), or a group formed by combining an optionally substituted chain hydrocarbon group having 1 to 8 carbon atoms and an optionally substituted cyclic hydrocarbon group having 3 to 20 carbon atoms (however, -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2 or -CO). It is preferably a single bond, an optionally substituted chain hydrocarbon group having 1 to 10 carbon atoms (however, -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms (however, -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2), or a group formed by combining an optionally substituted chain hydrocarbon group having 1 to 6 carbon atoms and an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms (however, -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2 or -CO). It is more preferably so.

[0102] L a22Examples of the chain hydrocarbon group having 1 to 12 carbon atoms include linear alkanediyl 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., 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, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-dimethylpropane-1,3-diyl group, pentane-2,4-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. The number of carbon atoms of the chain hydrocarbon group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, and even more preferably 1 to 4. Examples of the group in which -CH2- contained in the chain hydrocarbon group is replaced by -O- or -CO- include the same ones as those exemplified in the present specification. L a22 The fluorine atom that L has may be one or two or more. na2 is preferably any integer from 1 to 4, and more preferably any integer from 1 to 3. L a21 Examples of the structural unit (a2) when L is a single bond or a chain hydrocarbon group include, for example, the following structural units. Among the following structural units, the structural unit in which the methyl group corresponding to R a2 is replaced by a hydrogen atom or the like is also a preferred structural unit of the structural unit (a2) in the same manner as the following structural units. TIFF2025091367000084.tif67168

[0103] When producing a resist pattern from the resist composition of the present invention, when using a high-energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) as the exposure light source, as the structural unit (a2), a structural unit (a2) having a phenolic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-A) described later. Further, when using an ArF excimer laser (193 nm) or the like, as the structural unit (a2), a structural unit (a2) having an alcoholic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-C) described later. The structural unit (a2) may contain one kind alone or two or more kinds.

[0104] In the structural unit (a2), L a21 When it is a cyclic hydrocarbon group, examples of the structural unit having a phenolic hydroxy group or a carboxy group include a structural unit represented by the formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)"). TIFF2025091367000085.tif30128[In the formula (a2-A), all the symbols have the same meanings as described above.]

[0105] R a2 and A a21 are the same groups as those exemplified in the formula (a2), respectively. R a27 Examples of the halogen atom of R include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom. R a27Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, chloromethyl group, bromomethyl group, iodomethyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, still more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a27 Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, tert-butoxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably an alkoxy group having 1 to 3 carbon atoms, still more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a27 Examples of the alkoxyalkyl group include methoxymethyl group, ethoxyethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, sec-butoxymethyl group, 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 still more preferably a methoxymethyl group. R a27Examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group. R a27 Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group. R a27 Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably an acetyloxy group. R a27 is preferably a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, still more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group. nA2 is preferably 1, 2, 3, or 4, more preferably 1, 2, or 3, still more preferably 1 or 2. na21 is preferably 0, 1, 2, or 3, more preferably 0, 1, or 2, still more preferably 0 or 1. mc is preferably 0 or 1. -X a2 -OH, in the case of a benzene ring, may be bonded to any of the o-position, m-position, or p-position with respect to the bonding position of A a21 . Among them, at least one is preferably bonded to the m-position or p-position, more preferably bonded to the m-position. In the case of a naphthalene ring, A a21When the bonding position of is the 1st position, it may be bonded to any of the 2nd to 8th positions, A a21 When the bonding position of is the 2nd position, it may be bonded to the 1st position and any of the 3rd to 8th positions. Among them, A a21 When the bonding position of is the 1st position, at least one is preferably bonded to the 3rd to 6th positions, and more preferably bonded to the 3rd or 4th position. A a21 When the bonding position of is the 2nd position, it is preferably bonded to the 4th to 7th positions, and more preferably bonded to the 5th or 6th position.

[0106] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577. Examples of the structural unit (a2-A) include structural units represented by formula (a2-2-1) to formula (a2-2-32), formula (a2-3-1) to formula (a2-3-24), and in the structural units represented by formula (a2-2-1) to formula (a2-2-32), formula (a2-3-1) to formula (a2-3-24), R in the structural unit (a2-A) a2 Examples include structural units in which the methyl group corresponding to is replaced by a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. TIFF2025091367000086.tif107170

[0107] When the structural unit (a2-A) is contained in the resin (A), the content of the structural unit (a2-A) is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 15 mol% or more, and even more preferably 20 mol% or more with respect to all the structural units. Further, it is preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 65 mol% or less, even more preferably 60 mol% or less, still even more preferably 50 mol% or less, still more preferably 45 mol% or less, and even more preferably 40 mol% or less. Specifically, it is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, still more preferably 15 to 65 mol%, and even more preferably 20 to 65 mol%. The structural unit (a2-A) can be incorporated into the resin (A) by polymerizing a compound that induces the structural unit (a2-A) (for example, a compound (a2-A') in which the -CH2-C(-R a2 )- of the structural unit (a2-A) is in the state of CH2=C(-R a2 ) before cleavage). Further, for example, after polymerization using the structural unit (a1-4), it can be incorporated into the resin (A) by treatment with an acid such as p-toluenesulfonic acid. Further, after polymerization using acetoxystyrene or the like, the structural unit (a2-A) can be incorporated into the resin (A) by treatment with an alkali such as tetramethylammonium hydroxide.

[0108] In the structural unit (a2), when L a21 is a cyclic hydrocarbon group, examples of the structural unit having an alcoholic hydroxy group or a carboxy group include a structural unit represented by the formula (a2-B) (hereinafter sometimes referred to as "structural unit (a2-B)"), a structural unit represented by the formula (a2-C) (hereinafter sometimes referred to as "structural unit (a2-C)"), and a structural unit represented by the formula (a2-D) (hereinafter sometimes referred to as "structural unit (a2-D)"). TIFF2025091367000088.tif46100In formulas (a2-B) and (a2-C), R a2 represents the same meaning as in formula (a2). R a27 represents the same meaning as in formula (a2-A). L a25 represents -O- or *-O-(CH2) k2 -CO-O-, and k2 represents an integer from 1 to 7. * represents the bonding site with -CO-. X a2 represents a single bond or -CO-. R a25 and R a26 each independently represents a hydrogen atom, a methyl group, or a hydroxy group. nB2 represents an integer from 1 to 5. When nB2 is 2 or more, the plurality of X a2 may be the same as or different from each other. nB22 represents an integer from 0 to 8. When nB22 is 2 or more, the plurality of R a27 may be the same as or different from each other. nC22 represents an integer from 0 to 10. When nC22 is 2 or more, the plurality of R a27 may be the same as or different from each other.] L a25 is preferably -O-, -O-(CH2) f1 -CO-O- (where f1 represents an integer from 1 to 4), and more preferably -O-. R a2 is preferably a methyl group. X a2 is preferably a single bond. R a25 is preferably a hydrogen atom. R a26 is preferably a hydrogen atom or a hydroxy group. R a27is preferably a halogen atom, a hydroxy group, a carboxy group, an optionally halogenated alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy 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 hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group. nB2 is preferably 1, 2, 3 or 4, more preferably 1, 2 or 3, and even more preferably 1 or 2. nB22 is preferably any integer from 0 to 3, more preferably 0, 1 or 2, and even more preferably 0 or 1. nC22 is preferably any integer from 0 to 6, more preferably any integer from 0 to 3, and even more preferably 0 or 1.

[0109] Examples of the structural unit (a2-B) and the structural unit (a2-C) include structural units derived from the monomers described in JP-A-2010-204646, the following structural units, and methyl groups or hydrogen atoms corresponding to R in the following structural units a2 which are replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. Among them, the structural units represented by any of formula (a2-B-1) to formula (a2-B-5) and formula (a2-C-1) to formula (a2-C-9) are preferable. When the resin (A) contains the structural unit (a2-B) or the structural unit (a2-C), the content thereof is 1 mol% or more, preferably 2 mol% or more, based on all the structural units of the resin (A). Further, it is 45 mol% or less, preferably 40 mol% or less, more preferably 35 mol% or less, even more preferably 20 mol% or less, and still more preferably 10 mol% or less. Specifically, it is 1 to 45 mol%, preferably 1 to 40 mol%, more preferably 1 to 35 mol%, even more preferably 1 to 20 mol%, and still more preferably 1 to 10 mol%.

[0110] TIFF2025091367000090.tif51106[In formula (a2-D), R a2 and A a21 each represent the same meaning as in formula (a2). R a27 represents the same meaning as in formula (a2-A). R a21 and R a22 each independently represent an alkyl fluoride group having 1 to 4 carbon atoms. L a24 represents a single bond or an alkanediyl group having 1 to 3 carbon atoms, and the alkanediyl group may be substituted with a fluorine atom. nD2 represents any integer from 1 to 5. When nD2 is 2 or more, the groups in multiple parentheses may be the same or different from each other. nD22 represents any integer from 0 to 4. When nD22 is 2 or more, the plurality of a27 R's may be the same or different from each other. However, 1 ≦ nD2 + nD22 ≦ 5.] R a21 and R a22 As the alkyl fluoride groups of, each independently, a trifluoromethyl group, 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, etc. may be mentioned. R a21 and R a22 are preferably a trifluoromethyl group. L a24 As the alkanediyl groups of, a methylene group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group, etc. may be mentioned. L a24 is preferably a single bond or a methylene group. R a27is preferably a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 4 carbon atoms or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy 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 hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group. nD2 is preferably 1, 2, 3 or 4, more preferably 1, 2 or 3, even more preferably 1 or 2, and still more preferably 1. Further, preferably, nD2 is 1 and the group in parentheses is bonded to the para position. nD22 is preferably any integer from 0 to 3, more preferably any integer from 0 to 2, even more preferably 0 or 1, and still more preferably 0.

[0111] As the structural unit (a2-D), a structural unit represented by the following formula (a2-D1) (hereinafter sometimes referred to as "structural unit (a2-D1)") is more preferable. TIFF2025091367000091.tif51108[In formula (a2-D1), R a2 、A a21 、R a27 、nD2 and nD22 represent the same meanings as in formula (a2-D).] In formula (a2-D1), R a2 is preferably a hydrogen atom or a methyl group. A a21 is preferably a single bond.

[0112] Examples of the structural unit (a2-D) include the structural units described below. TIFF2025091367000092.tif62167

[0113] In the structural units represented by formula (a2-D-1) to formula (a2-D-8), R a2A structural unit in which a hydrogen atom corresponding to is replaced by a methyl group or the like, and in the structural units represented by formula (a2-D-9) to formula (a2-D-16), R a2 Structural units in which the methyl group corresponding to is replaced by a hydrogen atom or the like can also be cited as specific examples of the structural unit (a2-D). Among them, the structural units represented by formula (a2-D-1) to formula (a2-D-8) are preferable, the structural units represented by formula (a2-D-1) to formula (a2-D-4) are more preferable, and the structural unit represented by formula (a2-D-1) is even more preferable.

[0114] When the resin (A) contains the structural unit (a2-D), its content is preferably 3 mol% or more, more preferably 5 mol% or more, still more preferably 10 mol% or more, based on all the structural units of the resin (A). Also, it is preferably 80 mol% or less, more preferably 75 mol% or less, still more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, it is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, still more preferably 10 to 70 mol%, and even more preferably 10 to 65 mol%.

[0115] 〈Structural unit (a3)〉 The lactone ring contained in the structural unit (a3) may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or may be a condensed ring of a monocyclic lactone ring and another ring. Preferably, a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, the structural unit represented by the following formula (a3-2)) can be mentioned.

[0116] The structural unit (a3) is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3), or formula (a3-4). These may be contained alone or in combination of two or more. TIFF2025091367000093.tif48155[In formula (a3-1), formula (a3-2), formula (a3-3), and formula (a3-4), L a4 、La5 and L a6 each independently represents a group represented by -O- or *-O-(CH2) k3 -CO-O- (where k3 represents an integer from 1 to 7). L a7 represents -O-, *-O-L a8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O- or *-O-L a8 -O-CO-L a9 represents -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * represents the bonding site with the carbonyl group. R a18 R a19 R a20 and R a24 each independently represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. X a3 represents -CH2- or an oxygen atom. R a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms. R a22 R a23 and R a25 each independently represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. p1 represents an integer from 0 to 5. q1 represents an integer from 0 to 3. r1 represents an integer from 0 to 3. w1 represents an integer from 0 to 8. When p1, q1, r1, and / or w1 is 2 or more, the plurality of Rs a21 R a22 R a23 and / or R a25 may be the same as or different from each other.]

[0117] R a21 Ra22 and R a23 and R a25 Examples of the aliphatic hydrocarbon group in R R a18 and R a19 and R a20 and R a24 Examples of the halogen atom and the alkyl group which may have a halogen atom in R a01 are the same as those exemplified by R L a8 and L a9 Examples of the alkanediyl group in L L a4 ~L a6 are each independently preferably -O- or, *-O-(CH2) k3 -CO-O- where k3 is an integer of 1 to 4, more preferably -O- and, *-O-CH2-CO-O-, still more preferably an oxygen atom. L a7 is preferably -O- or *-O-L a8 -CO-O-, more preferably -O-, -O-CH2-CO-O- or -O-C2H4-CO-O-. R a18 and R a19 and R a20 and R a24 are 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, still more preferably a hydrogen atom or a methyl group. R a21 is preferably a methyl group. R a22 and Ra23 and R a25 is, independently of one another, preferably a carboxy group, a cyano group or a methyl group. p1, q1 and r1 are, independently of one another, preferably any integer from 0 to 2, more preferably 0 or 1. w1 is preferably any integer from 0 to 2, more preferably 0 or 1. In particular, formula (a3-4) is preferably formula (a3-4)'. TIFF2025091367000094.tif3848 (wherein R a24 , L a7 represents the same meaning as described above.)

[0118] Examples of the structural unit (a3) include structural units derived from the monomers described in JP-A-2010-204646, the monomers described in JP-A-2000-122294, and the monomers described in JP-A-2012-41274. Examples of the structural unit (a3) include structural units represented by any of formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3-1), formula (a3-3-2), and formula (a3-4-1) to formula (a3-4-12), and, in the above structural units, structural units in which the methyl groups corresponding to R a18 , R a19 , R a20 and R a24 in formula (a3-1) to formula (a3-4) are replaced with hydrogen atoms are preferred. TIFF2025091367000095.tif107164

[0119] When the resin (A) contains the structural unit (a3), the total content rate is 1 mol% or more, preferably 3 mol% or more, more preferably 5 mol% or more, still more preferably 10 mol% or more, based on all the structural units of the resin (A). Further, 70 mol% or less is mentioned, preferably 65 mol% or less, more preferably 60 mol% or less, still more preferably 50 mol% or less, even more preferably 40 mol% or less, still even more preferably 30 mol% or less, still more preferably 25 mol% or less, and still even more preferably 20 mol% or less. Specifically, 1 to 70 mol% is mentioned, preferably 3 to 70 mol%, more preferably 3 to 65 mol%, still more preferably 5 to 65 mol%, even more preferably 5 to 60 mol%, and still even more preferably 10 to 60 mol%. Further, the content rate of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3), or the structural unit (a3-4) is preferably 1 mol% or more, more preferably 3 mol% or more, still more preferably 5 mol% or more, and still more preferably 10 mol% or more, based on all the structural units of the resin (A). Further, it is preferably 60 mol% or less, more preferably 55 mol% or less, still more preferably 50 mol% or less, even more preferably 40 mol% or less, still even more preferably 30 mol% or less, still more preferably 25 mol% or less, and still even more preferably 20 mol% or less. Specifically, 1 to 60 mol% is preferable, 3 to 60 mol% is more preferable, 3 to 55 mol% is still more preferable, 5 to 55 mol% is still more preferably, 5 to 50 mol% is even more preferably, and 10 to 50 mol% is still even more preferably.

[0120] 〈Structural unit (a4)〉 The structural unit represented by the formula (a4) is shown below. TIFF2025091367000096.tif3255[In the formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42represents a saturated hydrocarbon group having a halogen atom with 1 to 24 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-.

[0121] R 42 The saturated hydrocarbon group represented by 42 includes a linear or branched chain saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and a group formed by combining these, etc. Examples of the chain saturated hydrocarbon group include linear alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and octadecyl group; and branched alkyl groups such as isopropyl group and isobutyl group. Examples of the monocyclic or polycyclic alicyclic saturated hydrocarbon group include monocyclic alicyclic saturated hydrocarbon groups which are monocyclic cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group; and polycyclic alicyclic saturated hydrocarbon groups which are polycyclic cycloalkyl groups such as decahydronaphthyl group, adamantyl group, norbornyl group, and the following group (* represents the bonding site). Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group - alicyclic saturated hydrocarbon group, - alicyclic saturated hydrocarbon group - alkyl group, - alkanediyl group - alicyclic saturated hydrocarbon group - alkyl group, etc. Examples of the alkanediyl group 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. The terminal of the branched alkanediyl group may be a methyl group. R42 Examples of the halogen atom included in the saturated hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. R 42 Examples of the group in which -CH2- of the saturated hydrocarbon group included in is replaced by -O- or -CO- include a hydroxy group, a carboxy group, a carbonyl group, an oxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkanedioxy group, an alkanedioxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyloxy group, a cycloalkoxy group, a cycloalkylalkoxy group, a group formed by combining two or more of these groups, and the like. These replaced groups include those similar to the groups exemplified in this specification within the range where the upper limit of the number of carbon atoms permits.

[0122] As the structural unit (a4), R 42 is preferably a saturated hydrocarbon group having a fluorine atom, and an example of the structural unit (a4) in which R 42 is a saturated hydrocarbon group having a fluorine atom includes a structural unit represented by the formula (a4-1) (hereinafter, may be referred to as "structural unit (a4-1)"), a structural unit represented by the formula (a4-2) (hereinafter, may be referred to as "structural unit (a4-2)"), a structural unit represented by the formula (a4-3) (hereinafter, may be referred to as "structural unit (a4-3)"), and a structural unit represented by the formula (a4-A) (hereinafter, may be referred to as "structural unit (a4-A)"). The structural unit represented by the formula (a4-1) is the structural unit shown below. TIFF2025091367000098.tif4864[In the formula (a4-1), R 41 represents a hydrogen atom or a methyl group. L 41 represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. L 42f represents an alkanediyl group having 1 to 8 carbon atoms and having a fluorine atom or a cycloalkanediyl group having 3 to 12 carbon atoms and having a fluorine atom. R 42frepresents a hydrogen atom or a fluorine atom.

[0123] L 41 Examples of the alkanediyl group in L include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, etc., 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. The terminal of the branched alkanediyl group may be a methyl group. L 42f Examples of the alkanediyl group having a fluorine atom in L include linear alkanediyl groups having a fluorine atom such as methylene group having a fluorine atom, ethylene group having a fluorine atom, propane-1,3-diyl group having a fluorine atom, butane-1,4-diyl group having a fluorine atom, pentane-1,5-diyl group having a fluorine atom, hexane-1,6-diyl group having a fluorine atom, heptane-1,7-diyl group having a fluorine atom, octane-1,8-diyl group having a fluorine atom; branched alkanediyl groups having a fluorine atom such as ethane-1,1-diyl group having a fluorine atom, propane-1,1-diyl group having a fluorine atom, propane-1,2-diyl group having a fluorine atom, propane-2,2-diyl group having a fluorine atom, pentane-2,4-diyl group having a fluorine atom, 2-methylpropane-1,3-diyl group having a fluorine atom, 2-methylpropane-1,2-diyl group having a fluorine atom, pentane-1,4-diyl group having a fluorine atom, 2-methylbutane-1,4-diyl group having a fluorine atom. The terminal of the branched alkanediyl group may be a methyl group which may have a fluorine atom. L 42fExamples of the cycloalkanediyl group having a fluorine atom in [compound] [L] include monocyclic cycloalkanediyl groups having a fluorine atom such as a cyclobutane-1,3-diyl group having a fluorine atom, a cyclopentane-1,3-diyl group having a fluorine atom, a cyclohexane-1,4-diyl group having a fluorine atom, a cyclohexene-3,6-diyl group having a fluorine atom, a cycloheptane-1,4-diyl group having a fluorine atom, and a cyclooctane-1,5-diyl group having a fluorine atom. Examples of the polycyclic cycloalkanediyl group having a fluorine atom include a norbornane-1,4-diyl group having a fluorine atom, a norbornane-2,5-diyl group having a fluorine atom, a 5-norbornene-2,3-diyl group having a fluorine atom, an adamantane-1,5-diyl group having a fluorine atom, and an adamantane-2,6-diyl group having a fluorine atom. L 42f The number of fluorine atoms in the alkanediyl group and the cycloalkanediyl group having a fluorine atom in [compound] [L] may be 1 or more, and is preferably 2 or more. L 42f The alkanediyl group and the cycloalkanediyl group having a fluorine atom in [compound] [L] are preferably a perfluoroalkanediyl group and a perfluorocycloalkanediyl group, respectively.

[0124] L 42fExamples of the perfluoroalkanediyl group in [specific context] include a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene 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-3,3-diyl group, a perfluorohexane-1,6-diyl group, a perfluorohexane-2,2-diyl group, a perfluorohexane-3,3-diyl group, a perfluoroheptane-1,7-diyl group, a perfluoroheptane-2,2-diyl group, a perfluoroheptane-3,4-diyl group, a perfluoroheptane-4,4-diyl group, a perfluorooctane-1,8-diyl group, a perfluorooctane-2,2-diyl group, a perfluorooctane-3,3-diyl group, a perfluorooctane-4,4-diyl group, and the like. L 42f Examples of the perfluorocycloalkanediyl group in [specific context] include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantanediyl group, and the like.

[0125] L 41 is preferably a single bond or an alkanediyl group having 1 to 3 carbon atoms, more preferably a single bond, a methylene group or an ethylene group, and even more preferably a single bond or a methylene group. L 42f is preferably a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and even more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

[0126] Examples of the structural unit (a4-1) include the structural units shown below and R in the structural unit (a4-1) in the following structural units 41Examples include structural units in which a methyl group corresponding thereto is replaced with a hydrogen atom. The structural unit represented by TIFF2025091367000099.tif98158 formula (a4-2) is the structural unit shown below. TIFF2025091367000100.tif5574[In formula (a4-2), R 41 represents a hydrogen atom or a methyl group. L 43f represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. R 43f represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. However, at least one of L 43f and R 43f has a fluorine atom, and the upper limit of the total number of carbon atoms of L 43f and R 43f is 21.]

[0127] Examples of the saturated hydrocarbon group in L 43f and R 43f include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these. Examples of the saturated hydrocarbon group in L 43f and R 43f include, as long as the upper limit of the total number of carbon atoms of L 43f and R 43f allows, groups similar to the saturated hydrocarbon groups exemplified as the saturated hydrocarbon group of R 42 in formula (a4).

[0128] As the saturated hydrocarbon group of L 43f a C1-C6 alkanediyl group or a group represented by formula (L43f-1) is preferable. TIFF2025091367000101.tif13120[In formula (L43f-1), s represents 0 or 1. L 45f and L 46f each independently represents a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a fluorine atom. L 47f represents a single bond or a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a fluorine atom. X 46f and X 47f each independently represents -O-, -CO-, -CO-O- or -O-CO-. However, the total number of carbon atoms of L 45f , L 46f , L 47f , X 46f and X 47f is 7 or less. * and ** are bonding sites, and ** is the bonding site with -O-CO-R 43f is the bonding site therewith.

[0129] In the group represented by formula (L43f-1), examples of the divalent saturated hydrocarbon group represented by L 45f , L 46f and L 47f include linear or branched alkanediyl groups, monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and divalent saturated hydrocarbon groups formed by combining an alkanediyl group and a divalent alicyclic saturated hydrocarbon group. Specifically, examples include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group and the like. s is preferably 0.

[0130] Examples of the group represented by formula (L43f-1) include the following groups. In the following examples, * and ** each represent a bonding site, and ** is the bonding site with -O-CO-R 43f is the bonding site therewith. TIFF2025091367000102.tif47140

[0131] R 43fA saturated hydrocarbon group having a fluorine atom is preferred. The structural unit represented by the formula (a4-2) in this case includes, for example, the structural units represented by the formula (a4-2A) or (formula a4-2B). TIFF2025091367000103.tif69102 [In the formula (a4-2A) and the formula (a4-2B), R 41 and L 43f represent the same as those in the formula (a4-2). R 43fA represents a saturated hydrocarbon group having 1 to 20 carbon atoms and having a fluorine atom. A 43f represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. X 43 represents **-O-CO- or **-CO-O-, and ** represents the bonding site with A 43f and represents the bonding site with A. R 43fB represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom. However, in the formula (a4-2A), the total number of carbon atoms of L 43f and R 43fA is 21 or less, and in the formula (a4-2B), the total number of carbon atoms of L 43f , A 43f , X 43 and R 43fB is 21 or less, and at least one of A 43f and R 43fB has at least one fluorine atom. R 43fA The saturated hydrocarbon group of R 42 includes the same saturated hydrocarbon groups as those exemplified by R R 43fA is preferably an alkyl group having 1 to 13 carbon atoms and having a fluorine atom, a cycloalkyl group having 3 to 12 carbon atoms and having a fluorine atom, or a group combining them, *-(CF2) n43f -R 42’(* represents the bonding site with the carbonyl group. n43f represents an integer from 1 to 6. R 42’ is more preferably a hydrogen atom, a fluorine atom, or a perfluorocycloalkyl group having 3 to 12 carbon atoms. A 43f and R 43fB The saturated hydrocarbon groups of are, as long as the upper limit of the number of carbon atoms permits, the same saturated hydrocarbon groups as those exemplified by R 42 in formula (a4). A 43f is preferably a divalent chain saturated hydrocarbon group which may have a fluorine atom, a divalent alicyclic saturated hydrocarbon group, or a group combining them, more preferably a divalent chain saturated hydrocarbon group having a fluorine atom, and even more preferably a fluoroalkanediyl group having 1 to 6 carbon atoms. R 43fB The saturated hydrocarbon group which may have a fluorine atom of is preferably a chain saturated hydrocarbon group which may have a fluorine atom, an alicyclic saturated hydrocarbon group, or a group combining them, more preferably an alkyl group having 1 to 12 carbon atoms which may have a fluorine atom, a cycloalkyl group having 3 to 12 carbon atoms, or a group combining them, and even more preferably a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, a perfluorohexyl group, a heptyl group, a perfluoroheptyl group, an octyl group, a perfluorooctyl group and other fluoroalkyl groups, a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, a perfluorocyclohexyl group, an adamantyl group, an adamantylmethyl group, an adamantyldimethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, a perfluoroadamantylmethyl group, etc.

[0132] In formula (a4-2B), *-A f43 -X 43 -R f43B An example of the structure that the group represented by can take is the following structure (* is the bonding site with the carbonyl group). TIFF2025091367000104.tif14169

[0133] Examples of the structural unit represented by formula (a4-2A) include the following structural units and the methyl group corresponding to R in the structural unit represented by formula (a4-2A) in the following structural units 41 in which the methyl group is replaced by a hydrogen atom. TIFF2025091367000105.tif99167

[0134] Examples of the structural unit represented by formula (a4-2B) include the following structural units and the methyl group corresponding to R in the structural unit represented by formula (a4-2B) in the following structural units 41 in which the methyl group is replaced by a hydrogen atom. TIFF2025091367000106.tif111164

[0135] Examples of the structural unit (a4) also include the structural unit represented by formula (a4-3). TIFF2025091367000107.tif5576[In formula (a4-3), R 41 represents a hydrogen atom or a methyl group. L 44f represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. R 44f represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. However, at least one of 44f L 44f and 44f R44f The upper limit of the total number of carbon atoms is 21.

[0136] L 44f and R 44f Examples of the saturated hydrocarbon group in L 44f and R 44f include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these, etc. 44f and R 44f As long as the upper limit of the total number of carbon atoms in L 42 and R permits, groups similar to the saturated hydrocarbon groups exemplified as the saturated hydrocarbon group of R in formula (a4) are included. L 44f is preferably an alkanediyl group having 1 to 14 carbon atoms (wherein -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), and -(CH2) j1 -, -(CH2) j2 -O-(CH2) j3 - or -(CH2) j4 -CO-O-(CH2) j5 - (where j1 to j5 each independently represent an integer of 1 to 6). More preferably, it is an alkanediyl group having 1 to 4 carbon atoms (wherein one -CH2- contained in the alkanediyl group may be replaced by -O-, and one -CH2-CH2- contained in the alkanediyl group may be replaced by -CO-O- or -O-CO-). R 44f is preferably a saturated hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom, an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms having a fluorine atom, or a group combining them, still more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom, and even more preferably an alkyl group having 1 to 6 carbon atoms having a fluorine atom.

[0137] Examples of the structural unit represented by formula (a4-3) include structural units represented by the following structural units and the following formulas, in which the methyl group corresponding to R in structural unit (a4-3) is replaced by a hydrogen atom. 41 Examples thereof include a structural unit in which the methyl group corresponding to R is replaced by a hydrogen atom. TIFF2025091367000108.tif85165

[0138] TIFF2025091367000109.tif3686[In formula (a4-A), R 1 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X 11 represents a single bond or *-CO-O-. * represents the bonding site with the carbon atom to which R 1 is bonded. L 1 represents an aliphatic hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH2- contained in the aliphatic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. R 2 represents a fluorinated alkyl group having 1 to 8 carbon atoms. R 3 represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms, and the fluorinated alkyl group may be bonded to L 1 to form an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-. mi represents any integer from 1 to 4. When mi is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other.]

[0139] R 1 Examples of the halogen atom and the alkyl group which may have a halogen atom in R are the same as those exemplified by R a01 、R a4 and R a5 in formulas (a1-0) to (a1-2). R 1is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, still more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.

[0140] L 1 Examples of the aliphatic hydrocarbon group in L include a chain hydrocarbon group, an alicyclic hydrocarbon group which is monocyclic or polycyclic (including a spiro ring, a condensed ring, a bridged ring, etc.), and a group formed by combining two or more of these groups (for example, a hydrocarbon group formed from an alicyclic hydrocarbon group and a chain hydrocarbon group) may also be used. Examples of the chain hydrocarbon group include divalent to pentavalent chain hydrocarbon groups such as an alkanediyl group, an alkanetriyl group, an alkanetetrayl group, and an alkanepentayl group. Examples of the alkanediyl group include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, and a heptadecane-1,17-diyl group, and branched alkanediyl groups such as an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-2,2-diyl group, a pentane-2,4-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. Examples also include a group in which one or more hydrogen atoms of the above-described groups are replaced by a bonding site. The number of carbon atoms in the chain hydrocarbon group is preferably from 1 to 18, more preferably from 1 to 12, still more preferably from 1 to 10, even more preferably from 1 to 9, still even more preferably from 1 to 8, still more preferably from 1 to 6, still even more preferably from 1 to 5, and particularly preferably from 1 to 4.

[0141] Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include the following alicyclic hydrocarbon groups, etc. The bonding site can be at any position. TIFF2025091367000110.tif46163For example, divalent to pentavalent alicyclic hydrocarbon groups such as cycloalkanediyl group, cycloalkanetriyl group, cycloalkanetetrayl group, cycloalkanepentayl group, etc. Specifically, monocyclic alicyclic hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, etc. and Polycyclic alicyclic hydrocarbon groups such as spiro rings having a cycloalkanediyl group, norbornanediyl group or adamantanediyl group and a cycloalkanediyl group spiro-bonded thereto, respectively, such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, decahydronaphthalenediyl group, bicyclo[3.3.0]octanediy group, spirocyclohexane-1,2'-cyclopentane-diyl group, spiroadamantane-2,3'-cyclopentane-diyl group, etc. Also included are groups in which one or more hydrogen atoms of the above-described groups are replaced at the bonding site, etc. The number of carbon atoms in the alicyclic hydrocarbon group is preferably from 3 to 20, more preferably from 3 to 18, still more preferably from 3 to 16, and even more preferably from 3 to 12.

[0142] Examples of the group formed by combining two or more groups include a group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group. In the combination, two or more alicyclic hydrocarbon groups and two or more chain hydrocarbon groups may be combined respectively. Also, any group may be bonded to X 11 . Examples of the group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group include a group in which an alicyclic hydrocarbon group is bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which a chain hydrocarbon group is bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-chain hydrocarbon group-), a group in which an alicyclic hydrocarbon group and a chain hydrocarbon group are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-), a group in which a chain hydrocarbon group and an alicyclic hydrocarbon group are bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which an alicyclic hydrocarbon group, a chain hydrocarbon group, and an alicyclic hydrocarbon group are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which a chain hydrocarbon group, an alicyclic hydrocarbon group, and a chain hydrocarbon group are bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-), etc. * represents the bonding site with X 11 . Examples also include a group in which one or more hydrogen atoms of the above-described group are replaced with a bonding site, etc.

[0143] L 1 The -CH2- contained in the aliphatic hydrocarbon group having 1 to 28 carbon atoms of may be replaced by -O-, -S-, -SO2- or -CO- L 1 When the -CH2- contained in the aliphatic hydrocarbon group having 1 to 28 carbon atoms of is replaced by -O-, -S-, -SO2- or -CO-, the carbon number before replacement is regarded as the carbon number of the aliphatic hydrocarbon group. Examples of groups in which -CH2- in the aliphatic hydrocarbon group is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group, a carboxy group, a thiol group, an alkoxy group, an alkylthio group, an alkoxycarbonyl group, an alkylsulfonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an oxy group, a carbonyl group, a thio group, a sulfonyl group, an alkanedioxy group, an alkanedioxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyloxy group, an alkanediylsulfonyl group, an alkanediylthio group, a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, a group formed by combining two or more of these groups, and the like. These replaced groups include those similar to the groups exemplified herein within the range allowed by the upper limit of the number of carbon atoms. Examples also include a group in which one or more hydrogen atoms of the above-described group are replaced by a bonding site. Examples of groups in which -CH2- in the alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include those similar to the groups exemplified herein within the range allowed by the upper limit of the number of carbon atoms.

[0144] L 1 The aliphatic hydrocarbon group in L may have one or more substituents. Examples of the substituent include a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, an alkyl 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 (wherein -CH2- contained in the alkyl group or the alicyclic hydrocarbon group may be replaced by -O- or -CO-). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. The haloalkyl groups having 1 to 4 carbon atoms include fluoroalkyl groups having 1 to 4 carbon atoms, chloroalkyl groups having 1 to 4 carbon atoms, bromoalkyl groups having 1 to 4 carbon atoms, iodoalkyl groups having 1 to 4 carbon atoms, and the like. Examples of the haloalkyl group include perfluoroalkyl groups having 1 to 4 carbon atoms (such as trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, etc.), 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, chloromethyl group, bromomethyl group, iodomethyl group, and the like. The number of carbon atoms of the haloalkyl group is preferably 1 to 3, more preferably 1 or 2. Examples of the alkyl group having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, and the like. The number of carbon atoms of the alkyl group is preferably 1 to 9, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alicyclic hydrocarbon group having 3 to 18 carbon atoms include monocyclic cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, and polycyclic cycloalkyl groups such as decahydronaphthyl group, adamantyl group, norbornyl group, and the like. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 16, more preferably 3 to 12, still more preferably 3 to 10. Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms include phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, binaphthyl group, and the like. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 14, more preferably 6 to 12, still more preferably 6 to 10. When -CH2- contained in an alkyl group is replaced by -O- or -CO-, the number of carbon atoms before replacement is defined as the total number of carbon atoms of the alkyl group. Examples of the replaced group include a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, etc. These replaced groups include those similar to the groups exemplified in this specification as long as the upper limit of the number of carbon atoms permits. The number of carbon atoms of the alkoxy group is preferably 1 to 9, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 9, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 10, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 9, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. In addition, examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O- or -CO- include those similar to the groups exemplified in this specification as long as the upper limit of the number of carbon atoms permits. L 1 Examples of the substituent that the aliphatic hydrocarbon group in L may have include a halogen atom, a haloalkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms (wherein -CH2- contained in the alkyl group or the alicyclic hydrocarbon group may be replaced by -O- or -CO-). A fluorine atom, an iodine atom, a perfluoroalkyl group having 1 to 3 carbon atoms, or an alkyl group having 1 to 4 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-) is more preferable, and a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, or a methoxy group is still more preferable. L 1 is R 3When not forming an alkyl fluoride group and an alicyclic hydrocarbon group, it is preferably a linear hydrocarbon group having 1 to 12 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (wherein -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-), or a group formed by combining a linear hydrocarbon group having 1 to 6 carbon atoms which may have a substituent and an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-). More preferably, it is a linear hydrocarbon group having 1 to 8 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a substituent, or a group formed by combining a linear hydrocarbon group having 1 to 6 carbon atoms which may have a substituent and an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-). Even more preferably, it is a linear hydrocarbon group having 1 to 8 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent, a group formed by combining a linear hydrocarbon group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-), or a group formed by combining an alicyclic hydrocarbon group having 5 to 12 carbon atoms, a linear hydrocarbon group having 1 to 6 carbon atoms, and an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-).

[0145] R 2Examples of the C1-C8 fluoroalkyl group 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(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, perfluorohexyl group, perfluoroheptyl group, and perfluorooctyl group. The number of carbon atoms of the fluoroalkyl group is preferably 1-6, more preferably 1-5, still more preferably 1-4, and even more preferably 1-3. R 3 When the C1-C6 fluoroalkyl group in 3 is within the limit allowed by the upper limit of the number of carbon atoms, the C1-C6 fluoroalkyl groups exemplified in the examples of the fluoroalkyl group of R 2 are similarly exemplified. R 2 is preferably a C1-C6 fluoroalkyl group, more preferably a C1-C3 fluoroalkyl group, still more preferably a trifluoromethyl group, a perfluoroethyl group or a perfluoropropyl group, and even more preferably a trifluoromethyl group when R 3 is a C1-C6 fluoroalkyl group. R2 is, when R 3 is a hydrogen atom, preferably an alkyl fluoride group having 1 to 6 carbon atoms, more preferably an alkyl fluoride group having 1 to 5 carbon atoms, and still more preferably an alkyl fluoride group having 3 to 5 carbon atoms. R 3 is L 1 and combines to form an alicyclic hydrocarbon group having 3 to 12 carbon atoms, R 3 is L 1 Examples of the group formed by combining with L 2 include, for example, groups represented by the following formulas. In the following formulas, * and ** represent bonding sites, and two ** represent, one represents the bonding site with a hydroxy group, and the other represents the bonding site with R 1A is, L 1 is a part of the hydrocarbon group of L 3 is L 1 and the alicyclic hydrocarbon group formed by combining has preferably 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, and still more preferably 3 to 6 carbon atoms. TIFF2025091367000111.tif25130R 3 is preferably a hydrogen atom or an alkyl fluoride group having 1 to 3 carbon atoms. mi is preferably any integer from 1 to 3, more preferably 1 or 2, and still more preferably 1.

[0146] Examples of the structural unit (a4-A) include the following structural units and the like. In these structural units, the methyl group corresponding to R 1 replaced by a hydrogen atom, a halogen atom, a haloalkyl group or an alkyl group other than a methyl group and the structural unit in which the hydrogen atom corresponding to R 1 is replaced by a halogen atom, a haloalkyl group or an alkyl group can also be cited as specific examples of the structural unit (a4-A). TIFF2025091367000112.tif192167

[0147] When the resin (A) contains the structural unit (a4), its content is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and still more preferably 3 to 10 mol% based on all the structural units of the resin (A).

[0148] 〈Structural unit (a5)〉 Examples of the non-detachable hydrocarbon group possessed by the structural unit (a5) include groups having a linear, branched or cyclic hydrocarbon group. Among them, the structural unit (a5) preferably has a group having an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1). TIFF2025091367000113.tif3971[In the formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atoms contained in the alicyclic hydrocarbon group may be substituted with aliphatic hydrocarbon groups 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 -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-.]

[0149] R 52 The alicyclic hydrocarbon group in R may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group, etc. Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group and a 2-ethylhexyl group. Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group, etc. R 52is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group or a cyclohexyl group. L 55 Examples of the divalent saturated hydrocarbon group in include divalent chain saturated hydrocarbon groups and divalent alicyclic saturated hydrocarbon groups, preferably divalent chain saturated hydrocarbon groups. Examples of the divalent chain saturated hydrocarbon group include alkane diyl groups such as a methylene group, an ethylene group, a propane diyl group, a butane diyl group and a pentane diyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkane diyl groups such as a cyclopentane diyl group and a cyclohexane diyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantane diyl group and a norbornane diyl group.

[0150] L 55 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by is replaced by -O- or -CO- include groups represented by formula (L1-1) to formula (L1-4). In the following formulas, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom. TIFF2025091367000114.tif18165[In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents a bonding site with L x1 .). L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, x1 and x2 the total number of carbon atoms of is 16 or less. In formula (L1-2), L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4represents 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 is 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, the total number of carbon atoms in L x5 , L x6 and L x7 is 15 or less. In formula (L1-4), L x8 and L x9 represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, the total 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 x6is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. L x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. W x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group. Examples of the group represented by the formula (L1-1) include the following divalent groups. TIFF2025091367000115.tif37147 Examples of the group represented by the formula (L1-2) include the following divalent groups. TIFF2025091367000116.tif23130 Examples of the group represented by the formula (L1-3) include the following divalent groups. TIFF2025091367000117.tif15147 Examples of the group represented by the formula (L1-4) include the following divalent groups. TIFF2025091367000118.tif13168L 55 is preferably a single bond or a group represented by the formula (L1-1).

[0151] Examples of the structural unit (a5-1) include the following structural units and the structural units in which the methyl group corresponding to R in the following structural units of the structural unit (a5-1) is replaced by a hydrogen atom. 51 When the resin (A) contains the structural unit (a5), its content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and even more preferably 3 to 15 mol% based on all the structural units of the resin (A).

[0152] 〈Structural unit (a6)〉 The structural unit (a6) is a structural unit having a -SO2- group, and preferably has a -SO2- group in the side chain. The structural unit having a -SO2- group may have a linear structure having a -SO2- group, a branched structure having a -SO2- group, or a cyclic structure (monocyclic and polycyclic structures) having a -SO2- group. Preferably, it is a structural unit having a cyclic structure having a -SO2- group, and more preferably, it is a structural unit having a cyclic structure (sultone ring) containing -SO2-O-.

[0153] Examples of the sultone ring include the rings represented by the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and formula (T 1 -4). The bonding site can be at any position. The sultone ring may be monocyclic, but is preferably polycyclic. The polycyclic sultone ring means a bridged ring containing -SO2-O- as an atomic group constituting the ring, and examples include the rings represented by formula (T 1 -1) and formula (T 1 -2). The sultone ring may further contain a heteroatom in addition to -SO2-O- as an atomic group constituting the ring, like the ring represented by formula (T 1 -2). Examples of the heteroatom include an oxygen atom, a sulfur atom or a nitrogen atom, and preferably an oxygen atom. TIFF2025091367000120.tif2977

[0154] The sultone ring may have a substituent, and examples of the substituent include an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, and an alkylcarbonyl group having 2 to 4 carbon atoms, etc.

[0155] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group, preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group. Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, and preferably a trifluoromethyl group. Examples of the alkyl group having a hydroxy group include a hydroxymethyl group and a hydroxyalkyl group such as a 2-hydroxyethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the alkoxycarbonyl group 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, more preferably a methoxycarbonyl group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. From the viewpoint of easy production of the monomer leading to the structural unit (a6), a sultone ring having no substituent is preferred.

[0156] As the sultone ring, a ring represented by the following formula (T1') is preferred. TIFF2025091367000121.tif2665[In the formula (T1'), X 11 represents an oxygen atom, a sulfur atom, or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. The bonding site is at an arbitrary position.] X 11 is preferably an oxygen atom or a methylene group, more preferably a methylene group. R 41 includes the same groups as the substituents of the sultone ring, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group is preferred. ma is preferably 0 or 1, more preferably 0.

[0157] Examples of the ring represented by the formula (T1’) include the following rings. The bonding site can be at any position. Among them, the bonding site is preferably at the 1-position or the 3-position. TIFF2025091367000122.tif44147

[0158] The structural unit having a -SO2- group preferably further has a group derived from a polymerizable group. Examples of the polymerizable group include a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, a methacryloylthio group, and the like. Among them, 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.

[0159] The structural unit (a6) is preferably a structural unit represented by the formula (a6-0). TIFF2025091367000123.tif4077[In the formula (a6-0), R x represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. A xx represents an oxygen atom, -N(R c )-, or a sulfur atom. A x represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -CO-, or -N(R d )-. X 11 represents an oxygen atom, a sulfur atom, or a methylene group. R 41 represents the same meaning as described above. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. R c and R d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R x Examples of the halogen atom of R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R x Examples of the alkyl group of R include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group, etc. Preferably, it is an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group. R x Examples of the alkyl group having a halogen atom of R include, for example, a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, etc. R x R is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group. A x Examples of the divalent saturated hydrocarbon group of A include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and those obtained by combining two or more of these groups may also be used. Specifically, linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, a heptadecane-1,17-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, and a 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, 2-methylbutane-1,4-diyl group; Monocyclic divalent alicyclic saturated hydrocarbon groups that are cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; Polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. can be mentioned. A x The bonding position to the sultone ring of can be any position, but the one at the 1-position is preferred.

[0160] Examples of the structural unit (a6-0) include the following structural units. TIFF2025091367000124.tif93150Among them, the structural units represented by formula (a6-1), formula (a6-2), formula (a6-6), formula (a6-7), formula (a6-8) and formula (a6-12) are preferred, and the structural units represented by formula (a6-1), formula (a6-2), formula (a6-7) and (a6-8) are more preferred. When the resin (A) contains the structural unit (a6), its content is preferably 1 to 50 mol%, more preferably 2 to 40 mol%, and even more preferably 3 to 30 mol% based on all the structural units of the resin (A).

[0161] 〈Structural unit (a7)〉 The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as "structural unit (a7)"). Specific examples of the structural unit (a7) include the structural units described in JP-A-2016-79235, and it is preferably a structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain or a structural unit having a sulfonio group and an organic anion in the side chain.

[0162] The structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain is preferably a structural unit represented by the formula (a7-A). TIFF2025091367000125.tif26123[In the formula (a7-A), R a7 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X a71 represents a single bond, *-O-**, *-CO-O-**, *-O-CO-O-**, *-CO-NR a71 -**, *-NR a71 -CO-O-**, *-O-CO-NR a71 -** or *-Ax-Ph-Ay-**. R a71 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Ph represents a phenylene group which may have a substituent. Ax and Ay each independently represent one or more bond types selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, an amide bond, and a carbonate ester bond. * and ** represent bonding sites, and * represents the bonding site with the carbon atom to which R a7 is bonded. L a71 and L a72 each independently represent a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO-, or -SO2-. X a72 represents ***-CO-O-, ***-O-CO-, ***-O-CO-O-, ***-O-, and *** represents the bonding site with L a71 . na7 represents any integer from 0 to 2. When na7 is 2, the groups in the plurality of parentheses may be the same as or different from each other. RA - represents a sulfonate anion or a carboxyl anion. ZA + represents an organic cation.]

[0163] R a7 and R a71 The alkyl group having 1 to 6 carbon atoms in R includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. R a7 Examples of the halogen atom in R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R a7 Examples of the alkyl group having 1 to 6 carbon atoms and having a halogen atom in R include a trifluoromethyl group, a difluoromethyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a dichloromethyl group, a triiodomethyl group, a diiodomethyl group, a tribromomethyl group, a dibromomethyl group, etc. R a7 R is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, still more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

[0164] X a71 When X is a group represented by *-Ax-Ph-Ay-**, it is preferably a linking group represented by the following formula (X10). TIFF2025091367000126.tif3251[In the formula (X10), Ax represents the type of bond that binds to the carbon atom to which R a7 is bonded, and represents one or more types of bonds selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, a carbonate ester bond, and an amide bond. Ay is L a71Represents a bonding type that binds to, and represents one or more bonding types selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, a carbonate bond, and an amide bond. Rx represents a halogen atom, a hydroxy group, a C1-C6 fluoroalkyl group, a C1-C18 alkyl group, or a C1-C6 alkoxy group. mx represents any integer from 0 to 4, and when mx is an integer of 2 or more, the plurality of Rx may be the same as or different from each other. When either Ax or Ay is a single bond, it is preferable that the other is one or more selected from the group consisting of an ether bond, a thioether bond, an ester bond, a carbonate bond, and an amide bond. When either Ax or Ay is an amide bond, it is preferably a bond represented by -CO-NR a71 -. The bonding position of Ay in the phenylene group is preferably the m-position or the p-position with respect to the bonding position of Ax, and more preferably the p-position. Among them, Rx is preferably a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, or an ethyl group. mx is preferably 0, 1, or 2. X a71 Examples of X 10 -1) to the group represented by the formula (X 10 -10). * represents the bonding site with the carbon atom to which -R a7 is bonded. ** represents the bonding site with L a71 . X 20 represents -O- or -NR a71 -. TIFF2025091367000127.tif43161 The specific examples of the group represented by the formula (X 10 -1) to the formula (X 10 -10) include the following groups. TIFF2025091367000128.tif87162 Among them, X a71 is a single bond and the formula (X 10 -1’), the formula (X 10 -3’) to the formula (X10 It is preferably a group represented by any one of -9’), and is a single bond or formula (X 10 -1’), formula (X 10 -4’), formula (X 10 -5’), formula (X 10 -6’) and formula (X 10 -9’), more preferably a single bond, a group represented by formula (X 10 -1’), a group represented by formula (X 10 -5’), a group represented by formula (X 10 -6’) or a group represented by formula (X 10 -9’).

[0165] L a71 Examples of the hydrocarbon group of include a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining two or more of these groups, from which one hydrogen atom is removed, and a group that binds to X a71 and X a72 . Further, examples of the hydrocarbon group of L a72 include a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining two or more of these groups, from which one hydrogen atom is removed, and a group that binds to X a72 and RA - . L a71 and L a72 Examples of the chain hydrocarbon group of include a group obtained by removing one hydrogen atom from an alkyl group or an alkenyl group. The alkyl group may be linear or branched, and specifically includes a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a heptadecyl group, etc. Examples of the alkenyl group include an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, an isooctenyl group, a nonenyl group, etc. The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 20, more preferably 1 to 18, and even more preferably 1 to 10. L a71 and L a72 Examples of the alicyclic hydrocarbon group of L and L include a group obtained by removing one hydrogen atom from a monocyclic or polycyclic cycloalkyl group. Examples of the monocyclic cycloalkyl group include a cyclobutyl group, a cycloheptyl group, a cyclohexyl group, a cyclopentyl group, a cyclooctyl group, and the like. L a71 and L a72 Examples of the polycyclic cycloalkyl group of L and L include a cycloalkyl group having a crosslinked structure, a cycloalkyl group in which two or more rings are condensed, or a cycloalkyl group in which two rings are spiro-bonded. Examples of the cycloalkyl group having a crosslinked structure include a norbornyl group, an adamantyl group, and the like. Examples of the cycloalkyl group in which two or more rings are condensed include a bicyclo[4,4,0]decane group, a steroid group (steroid skeleton), and the like. Examples of the cycloalkyl group in which two rings are spiro-bonded include a spirocyclic cycloalkyl group in which one or more cycloalkyl groups selected from the group consisting of a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group and a cycloalkyl group having 5 to 8 carbon atoms are spiro-bonded. Further, a double bond may be formed between two carbon atoms contained in the alicyclic hydrocarbon group. More specifically, the alicyclic hydrocarbon group represented by the following formula can be mentioned. TIFF2025091367000129.tif28158 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 12, and even more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 6 to 18, more preferably 7 to 12. L a71 and L a72Examples of the aromatic hydrocarbon group include a group obtained by removing one hydrogen atom from an aryl group. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, a fluorenyl group, and the like. The number of carbon atoms of the aromatic hydrocarbon group is preferably 5 to 14, more preferably 6 to 14, and even more preferably 6 to 10. L a71 and L a72 When -CH2- contained in the hydrocarbon group of and L is replaced by -O-, -CO-, -S- or -SO2-, the number of carbon atoms before replacement is defined as the number of carbon atoms of the hydrocarbon group. L a71 and L a72 Examples of the group in which -CH2- contained in the chain hydrocarbon group among the hydrocarbon groups of and L is replaced by -O-, -CO-, -S- or -SO2- include a hydroxy group, a carboxy group, a thiol group, a carbonyl group, an oxy group, a thio group, a sulfonyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkanedioxy group, an alkanedioxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyloxy group, and the like. These replaced groups include those similar to the groups exemplified in this specification within the range allowed by the upper limit of the number of carbon atoms. L a71 and L a72 Examples of the group in which -CH2- contained in the group combining an alicyclic hydrocarbon group or an alicyclic saturated hydrocarbon group and an aromatic hydrocarbon group among the hydrocarbon groups of and L is replaced by -O-, -CO-, -S- or -SO2- include those similar to the groups exemplified in this specification within the range allowed by the upper limit of the number of carbon atoms. L a71 and L a72 Among the hydrocarbon groups of and L, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-. Examples of the group in which -CH2- is replaced by -O- or -S- include groups derived from a furan ring or a thiophene ring, respectively. L a71 and L a72Examples of a group formed by combining two or more of an alicyclic hydrocarbon group, an aliphatic hydrocarbon group, and an aromatic hydrocarbon group include a group formed by combining the above aliphatic hydrocarbon group and the above alicyclic hydrocarbon group, a group formed by combining the above aliphatic hydrocarbon group and the above aromatic hydrocarbon group, a group formed by combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group, and a group formed by combining the above aliphatic hydrocarbon group, the above alicyclic hydrocarbon group, and the above aromatic hydrocarbon group. The group formed by combining the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be a condensed ring. L a71 and L a72 Examples of the substituent that the hydrocarbon group of may have include a halogen atom, a cyano group, and a nitro group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. L a71 and L a72 When and are a group formed by combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group with an aliphatic hydrocarbon group, the aliphatic hydrocarbon group may be substantially regarded as a substituent that the alicyclic hydrocarbon group or the aromatic hydrocarbon group has. Also, when the -CH2- of the aliphatic hydrocarbon group contained in the hydrocarbon group of and is replaced by -O-, -CO-, -S-, or -SO2-, the hydrocarbon group of and may substantially have substituents such as a hydroxy group, a carboxy group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a thiol group, and a sulfonyl group. a71 and L a72 When the -CH2- of the aliphatic hydrocarbon group contained in the hydrocarbon group of and is replaced by -O-, -CO-, -S-, or -SO2-, the hydrocarbon group of and may substantially have substituents such as a hydroxy group, a carboxy group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a thiol group, and a sulfonyl group. a71 and L a72 When the -CH2- of the aliphatic hydrocarbon group contained in the hydrocarbon group of and is replaced by -O-, -CO-, -S-, or -SO2-, the hydrocarbon group of and may substantially have substituents such as a hydroxy group, a carboxy group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a thiol group, and a sulfonyl group. na7 is preferably 0 or 1. ZA in formula (a7-A) + is the same as the cation in the salt represented by formula (B1) and the like.

[0166] In formula (a7-A), when the hydrocarbon groups of and are saturated hydrocarbon groups, in formula (a7-B) described later, may contain the same groups as the groups exemplified as the divalent linking group of A. a71 and L a72 In formula (a7-A), when the hydrocarbon groups of and are saturated hydrocarbon groups, in formula (a7-B) described later, may contain the same groups as the groups exemplified as the divalent linking group of A. b7 In formula (a7-A), when the hydrocarbon groups of and are saturated hydrocarbon groups, in formula (a7-B) described later, may contain the same groups as the groups exemplified as the divalent linking group of A. Examples of the structural unit represented by the formula (a7-A) include the structural unit represented by the formula (a7-A1). TIFF2025091367000130.tif30138[In the formula (a7-A1), R a7 、X a71 、L a71 、X a72 、na7、RA - and ZA + have the same meanings as described above. z7 represents any integer from 0 to 6. Q a7 、Q b7 、R z71 and R z72 each independently represent a hydrogen atom, a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 6 carbon atoms. When z7 is 2 or more, a plurality of R z71 and R z72 may be the same as or different from each other.] Q a7 、Q b7 、R z71 and R z72 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms or the alkyl group having 1 to 6 carbon atoms in Q a7 include the same groups as those exemplified for R

[0167] Examples of the structural unit represented by the formula (a7-A) include, for example, the following structural units, a group corresponding to the methyl group of R a7 being replaced with a hydrogen atom, a halogen atom (for example, a fluorine atom), or an alkyl group having 1 to 6 carbon atoms that may have a halogen atom (for example, a trifluoromethyl group, etc.), and the structural units described in WO 2012 / 050015. ZA + represents an organic cation. TIFF2025091367000131.tif244163

[0168] TIFF2025091367000132.tif131157

[0169] The structural unit having a sulfonio group and an organic anion in the side chain is preferably a structural unit represented by the formula (a7-B). TIFF2025091367000133.tif28104[In the formula (a7-B), R a7 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A b7 represents a single bond or a divalent linking group. R b71 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. R b72 and R b73 each independently represent a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and R b72 and R b73 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. A - represents an organic anion.] R a7 Examples of the halogen atom and the alkyl group which may have a halogen atom of R include the same halogen atoms and alkyl groups which may have a halogen atom as those in the formula (a7-A). R b71 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by include a phenylene group and a naphthylene group. R b72 and R b73 Examples of the hydrocarbon group represented by include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. Examples of the alkyl group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the group formed by combining these are the same as those described above. A b7 Examples of the divalent linking group represented by include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S-, or -CO-. Examples of the divalent saturated hydrocarbon group include a divalent chain saturated hydrocarbon group such as a linear or branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and combinations thereof may also be used. Specific examples thereof include linear alkanediyl 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; 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, 2-methylbutane-1,4-diyl group; divalent monocyclic alicyclic saturated hydrocarbon groups which are monocyclic cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; and divalent polycyclic alicyclic saturated hydrocarbon groups which are polycyclic cycloalkanediyl groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group. Examples of the group in which -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- include the following divalent groups. However, the number of carbon atoms before -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- is 17 or less, respectively. In the following formulae, * and ** represent bonding sites, and * represents the bonding site with R b71 and represents the bonding site with R. TIFF2025091367000134.tif123161[wherein, X 3 represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms. X 4 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. X 5 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. X 6represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 7 represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 8 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

[0170] Examples of the structural unit containing the cation in formula (a7-B) include the structural unit represented below and a group corresponding to the methyl group of R a7 in which the hydrogen atom, halogen atom (e.g., fluorine atom) or alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., trifluoromethyl group, etc.) is substituted, and the like. TIFF2025091367000135.tif75164

[0171] A - Examples of the organic anion represented by A include sulfonate anion, sulfonylimide anion, sulfonylmethide anion, and carboxylate anion. - The organic anion represented by A is preferably a sulfonate anion, and more preferably the same as the anion exemplified by the acid generator (B). Examples of the sulfonylimide anion, sulfonylmethide anion, and carboxylate anion include the same anions as those exemplified by the acid generator (B).

[0172] Examples of the structural unit represented by formula (a7-B) include the structural unit represented below. TIFF2025091367000136.tif95157

[0173] When the resin (A) contains the structural unit (a7), the structural unit (a7) may be contained alone or in two or more kinds. The content of the total structural unit (a7) is preferably 1 to 30 mol% with respect to all the structural units of the resin (A), more preferably 2 to 25 mol%, and still more preferably 3 to 20 mol%.

[0174] Resin (A) may contain structural units other than the above-mentioned structural units, and examples of such structural units include structural units well-known in the art.

[0175] Resin (A) is preferably a resin composed of structural unit (a1) and structural unit (s). 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 the structural unit having a cyclohexyl group or a cyclopentyl group), the structural unit represented by formula (a1-4), the structural unit represented by formula (a1-5), and the structural unit represented by formula (a1-6); more preferably at least two; still more preferably, structural unit (a1-1) and / or structural unit (a1-2). Structural unit (s) is preferably at least one selected from the group consisting of structural unit (a2) and structural unit (a3). Structural unit (a2) is preferably the structural unit represented by formula (a2-A) or the structural unit represented by formula (a2-C). Structural unit (a3) is preferably at least one selected from the group consisting of the structural unit represented by formula (a3-1), the structural unit represented by formula (a3-2), and the structural unit represented by formula (a3-4).

[0176] Each structural unit constituting resin (A) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, radical polymerization method) using the monomers that lead to these structural units. The content of each structural unit of resin (A) can be adjusted by the amount of monomers used in the polymerization. The weight average molecular weight of resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more), and 50,000 or less (more preferably 30,000 or less, still more preferably 15,000 or less). In this specification, the weight average molecular weight is the value determined by gel permeation chromatography under the conditions described in the examples.

[0177] <Resins other than resin (A)> The resist composition of the present invention may be used in combination with a resin other than resin (A). Examples of the resin other than resin (A) include resins containing structural unit (a2), structural unit (a4), or structural unit (a5) (hereinafter sometimes referred to as resin (X)). Among them, examples of resin (X) include a resin composed only of structural unit (a2), a resin composed only of structural unit (a4), and a resin composed of structural unit (a4) and structural unit (a5). Examples of the structural unit that resin (X) may further have include structural unit (a3) and structural units derived from other known monomers. When resin (X) contains structural unit (a2), structural unit (a2) is preferably structural unit (a2-A) or structural unit (a2-B). When the resin (X) contains the structural unit (a4), in the resin (X), the content of the structural unit (a4) is 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 45 mol% or more, based on the total of all the structural units of the resin (X). Also, it is 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, it is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, still more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. When the resin (X) contains the structural unit (a5), the content of the structural unit (a5) is 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 45 mol% or more, based on the total of all the structural units of the resin (X). Also, it is 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, it is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, still more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. Further, when the resin (X) contains the structural unit (a4) and the structural unit (a5), the total content of the structural unit (a4) and the structural unit (a5) is 40 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and still more preferably 80 mol% or more, based on the total of all the structural units of the resin (X). Also, it is 100 mol% or less. Specifically, it is 40 to 100 mol%, preferably 60 to 100 mol%, more preferably 70 to 100 mol%, and still more preferably 80 to 100 mol%. Among them, the resin (X) is preferably a resin composed of only the structural unit (a4) and / or the structural unit (a5). In this case, the ratio of the structural unit (a4): the structural unit (a5) is 0:100 to 100:0, preferably 10:90 to 90:10, and more preferably 30:70 to 70:30 or 40:60 to 60:40. Each structural unit constituting the resin (X) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, radical polymerization method) using monomers that induce these structural units. The content of each structural unit of the resin (X) can be adjusted by the amount of monomers used in the polymerization. The weight average molecular weight of the resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less), but may contain oligomers having a weight average molecular weight smaller than this. The measuring means for the weight average molecular weight of the resin (X) is the same as that of the resin (A).

[0178] When the resist composition of the present invention contains the resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, still more preferably 1 to 40 parts by mass, still more preferably 1 to 30 parts by mass, and particularly preferably 1 to 8 parts by mass with respect to 100 parts by mass of the resin (A).

[0179] The content of the resin (A) in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. When the resist composition contains a resin other than the resin (A), the total content of the resin (A) and the resin other than the resin (A) is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. The solid content of the resist composition and the content of the resin relative thereto can be measured by known analytical means such as liquid chromatography or gas chromatography.

[0180] <Solvent (E)> The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, more preferably 94% by mass or more and 99% by mass or less. The content of the solvent (E) can be measured by known analytical means such as liquid chromatography or gas chromatography. Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate, and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. One type of the solvent (E) may be used alone, or two or more types may be used.

[0181] <Quencher (C)> The quencher (C) includes a basic nitrogen-containing organic compound or a salt that generates an acid having a lower acidity than the acid generated from the acid generator (B) (however, excluding the carboxylate represented by the formula (I)). When the resist composition contains the quencher (C), the content of the quencher (C) is preferably about 0.01 to 15% by mass, more preferably about 0.01 to 10% by mass, still more preferably about 0.1 to 8% by mass, and still more preferably about 0.1 to 7% by mass based on the solid content of the resist composition. Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Examples of the amines include aliphatic amines and aromatic amines. Examples of the aliphatic amines include primary amines, secondary amines, and tertiary amines. Examples of the amine include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, 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)ethane, 1,2-di(4-pyridyl)ethane, 1,2-di(2-pyridyl)ethene, 1,2-di(4-pyridyl)ethene, 1,3-di(4-pyridyl)propane, 1,2-di(4-pyridyloxy)ethane, di(2-pyridyl)ketone, 4,4'-dipyridylsulfide, 4,4'-dipyridyldisulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, bipyridine, etc. Aromatic amines such as diisopropylaniline are preferable, and 2,6-diisopropylaniline is more preferable. Examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate, choline, and the like.

[0182] The acidity of a salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is indicated by the acid dissociation constant (pKa). A salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is a salt having an acid dissociation constant of the acid generated from the salt usually of -3 < pKa, preferably -1 < pKa < 7, and more preferably 0 < pKa < 5. Examples of the salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) include salts represented by the following formula, salts represented by formula (D) described in JP-A-2015-147926 (hereinafter sometimes referred to as "weak acid inner salt (D)"), and salts described in JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502, and JP-A-2011-191745. The salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is preferably a salt that generates a carboxylic acid with a lower acidity than the acid generated from the acid generator (B) (a salt having a carboxylic acid anion), more preferably the weak acid inner salt (D), and still more preferably a diphenyliodonium salt containing a phenyl group substituted with a carboxylic acid anion among the weak acid inner salts (D). JPEG2025091367000137.jpg97153

[0183] As the weak acid inner salt (D), a diphenyliodonium salt having an iodonium cation to which two phenyl groups are bonded and a carboxylic acid anion substituted for at least one of the two phenyl groups bonded to the iodonium cation is preferable. Specifically, salts represented by the following formulae may be mentioned.

[0184] TIFF2025091367000138.tif1695[In formula (D), R D1 and R D2 each independently represents 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 of any one of 0 to 4. When m’ is 2 or more, a plurality of R D1 may be the same or different, and when n’ is 2 or more, a plurality of R D2 may be the same or different.] R D1 and R D2 Examples of the hydrocarbon group include a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. Examples of the chain hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, nonyl group and the like. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and may be either saturated or unsaturated. Examples thereof include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group, cyclododecyl group, norbornyl group, adamantyl group and the like. Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, etc. Examples of the group formed by combining these include alkyl-cycloalkyl group, cycloalkyl-alkyl group, aralkyl group (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 the alkoxy group include methoxy group, ethoxy group, etc. Examples of the acyl group include acetyl group, propanoyl group, benzoyl group, cyclohexanecarbonyl group, etc. Examples of the acyloxy group include a group in which an oxy group (-O-) is bonded to the above acyl group, etc. Examples of the alkoxycarbonyl group include a group in which a carbonyl group (-CO-) is bonded to the above alkoxy group, etc. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, etc. R D1 and R D2 are each independently 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 any integer from 0 to 2, and more preferably 0. When m' is 2 or more, a plurality of RD1 may be the same or different, and when n’ is 2 or more, a plurality of R D2 may be the same or different.

[0185] More specifically, the following salts can be mentioned. TIFF2025091367000139.tif72165

[0186] <Other components> The resist composition of the present invention may contain, if necessary, components other than the above-mentioned components (hereinafter sometimes referred to as "other components (F)"). There is no particular limitation on the other components (F), and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, etc. can be used.

[0187] <Preparation of resist composition> The resist composition of the present invention can be prepared by mixing the carboxylate (I), the acid generator (B), and, if necessary, the resin (A), a resin other than the resin (A), the solvent (E), the quencher (C), and the other components (F). The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can be appropriately selected from 10 to 40°C according to the type of resin, etc. and the solubility of the resin, etc. in the solvent (E). The mixing time can be appropriately selected from 0.5 to 24 hours according to the mixing temperature. Note that the mixing means is also not particularly limited, and stirring and mixing, etc. can be used. After mixing the respective components, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

[0188] <Method for manufacturing resist pattern> 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 applied composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) includes a step of developing the composition layer after heating. To apply the resist composition onto a substrate, it can usually be done by a commonly used apparatus such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers and organic substrates with a resist film or the like formed on the surface. Before applying the resist composition, the substrate may be cleaned, or an antireflection film or the like may be formed on the substrate. By drying the applied composition, the solvent is removed to form a composition layer. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-bake), or by using a decompression device. The heating temperature is preferably 50 to 200 °C, and the heating time is preferably 10 to 180 seconds. Also, the pressure during decompression drying is preferably about 1 to 1.0×10 5 Pa. The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. As the exposure light source, those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F2 excimer laser (wavelength 157 nm), those that convert laser light from a solid laser light source (YAG or semiconductor laser, etc.) into harmonic laser light in the far ultraviolet region or vacuum ultraviolet region and emit it, those that irradiate electron beams, extreme ultraviolet light (EUV), etc., various types can be used. In this specification, irradiating these radiations may be collectively referred to as "exposure" in some cases. During exposure, usually, exposure is performed through a mask corresponding to the required pattern. When 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 heat-treated (so-called post-exposure bake) to promote the deprotection reaction in the acid-labile group. The heating temperature is usually about 50 to 200 °C, preferably about 70 to 150 °C. Chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the composition after heating. Also, before development, the steps of applying, drying, exposing, and heating the resist composition may be repeated on the composition layer after exposure. The heated composition layer is usually developed using a developer with a developing apparatus. Examples of the developing method include dip method, paddle method, spray method, dynamic dispense method, etc. The developing temperature is preferably, for example, 5 to 60 °C, and the developing time is preferably, for example, 5 to 300 seconds. By selecting the type of developer as follows, a positive resist pattern or a negative resist pattern can be manufactured. When manufacturing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be various alkaline aqueous solutions used in this field. For example, aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline) etc. may be mentioned. The alkaline developer may contain a surfactant. It is preferable to wash the resist pattern with ultrapure water after development, and then remove the water remaining on the substrate and the pattern. When manufacturing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as an "organic-based developer") is used as the developer. Examples of the organic solvent contained in the organic-based developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole, etc. In the organic-based 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 only the organic solvent. Among them, as the organic-based developer, a developer containing butyl acetate and / or 2-heptanone is preferable. In the organic-based developer, the total content of butyl acetate and 2-heptanone 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. The organic developing solution may contain a surfactant. Further, the organic developing solution may contain a trace amount of water. During development, development may be stopped by replacing with a solvent of a type different from the organic developing solution. It is preferable to wash the resist pattern after development 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 washing, it is preferable to remove the rinsing solution remaining on the substrate and the pattern.

[0189] <Usage> The resist composition of the present invention is a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, and is particularly suitable as a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for semiconductor microfabrication.

Examples

[0190] The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing content or usage amount are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows. Column: TSKgel Multipore HXL-M x 3 + guard column (manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Detector: RI detector Column temperature: 40 °C Injection volume: 100 μl Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent 1100 type, MASS: Agilent LC / MSD type). In the following examples, the value of this molecular ion peak is indicated as "MASS".

[0191] Example 1: Synthesis of the salt represented by formula (I-1) 15.57 parts of the salt represented by formula (I-1-a), 3.42 parts of the compound represented by formula (I-1-b), and 100 parts of methanol were charged and stirred at 23°C for 30 minutes. Then, 2.70 parts of pyridine was added and stirred at 23°C for 1 hour. To the obtained reaction product, 300 parts of chloroform was added and stirred, then 60 parts of 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes. Then, it was allowed to stand and separated. 150 parts of ion-exchanged water was charged into the recovered organic layer, stirred at 23°C for 30 minutes, and the organic layer was recovered by liquid separation. This washing operation with water was performed 5 times. 5 parts of acetonitrile and 95 parts of tert-butyl methyl ether were added to the obtained organic layer and stirred, and then the supernatant was removed. The obtained residue was concentrated to obtain 13.22 parts of the salt represented by formula (I-1). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 222.1

[0192] Example 2: Synthesis of the salt represented by formula (I-2) 15.57 parts of the salt represented by formula (I-1-a), 2.84 parts of the compound represented by formula (I-2-b), and 100 parts of methanol were charged and stirred at 23°C for 30 minutes. Then, magnesium sulfate was added, and the mixture was refluxed and dehydrated at 65°C for 6 hours, and then cooled to 23°C. To the obtained reaction product, 300 parts of chloroform was added and stirred, then 60 parts of 5% aqueous oxalic acid solution was added, and the mixture was stirred at 23°C for 30 minutes. Then, it was allowed to stand and separated. 150 parts of ion-exchanged water was charged into the recovered organic layer, stirred at 23°C for 30 minutes, and the organic layer was recovered by liquid separation. This washing operation was performed 5 times. 30 parts of tert-butyl methyl ether was added to the obtained organic layer and stirred, and then the supernatant was removed. The obtained residue was concentrated to obtain 6.12 parts of the salt represented by formula (I-2). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 208.1

[0193] Example 3: Synthesis of the salt represented by formula (I-12) 19.67 parts of the salt represented by formula (I-12-a), 3.42 parts of the compound represented by formula (I-1-b), and 100 parts of methanol were charged and stirred at 23°C for 30 minutes. Then, 2.70 parts of pyridine was added, and the mixture was stirred at 23°C for 1 hour. To the obtained reaction product, 300 parts of chloroform was added and stirred, then 60 parts of 5% aqueous oxalic acid solution was added, and the mixture was stirred at 23°C for 30 minutes. Then, it was allowed to stand and separated. 150 parts of ion-exchanged water was charged into the recovered organic layer, stirred at 23°C for 30 minutes, and the organic layer was recovered by liquid separation. This washing operation was performed 5 times. 5 parts of acetonitrile and 95 parts of tert-butyl methyl ether were added to the obtained organic layer and stirred, and then the supernatant was removed. The obtained residue was concentrated to obtain 14.88 parts of the salt represented by formula (I-12). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M -342.1

[0194] Example 4: Synthesis of the salt represented by formula (I-5) 13.79 parts of the salt represented by formula (I-5-a), 3.42 parts of the compound represented by formula (I-1-b), and 100 parts of methanol were charged and stirred at 23°C for 30 minutes. Then, 2.70 parts of pyridine was added and stirred at 23°C for 1 hour. To the resulting reaction product, 300 parts of chloroform was added and stirred, then 60 parts of 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes. Then, it was allowed to stand and separated. 150 parts of ion-exchanged water was charged into the recovered organic layer, stirred at 23°C for 30 minutes, and the organic layer was recovered by separation. This water washing operation was performed 5 times. 2 parts of acetonitrile and 40 parts of tert-butyl methyl ether were added to the obtained organic layer and stirred, and then the supernatant was removed. The obtained residue was concentrated to obtain 12.19 parts of the salt represented by formula (I-5). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 170.1

[0195] Example 5: Synthesis of the salt represented by formula (I-15) 11.03 parts of the salt represented by formula (I-15-a), 1.71 parts of the compound represented by formula (I-1-b), and 50 parts of methanol were charged and stirred at 23°C for 30 minutes. Then, 1.35 parts of pyridine was added and stirred at 23°C for 1 hour. To the resulting reaction product, 150 parts of chloroform was added and stirred, then 30 parts of 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes. Then, it was allowed to stand and separated. 75 parts of ion-exchanged water was charged into the recovered organic layer, stirred at 23°C for 30 minutes, and the organic layer was recovered by separation. This water washing operation was performed 5 times. 2 parts of acetonitrile and 40 parts of tert-butyl methyl ether were added to the obtained organic layer and stirred, and then the supernatant was removed. The obtained residue was concentrated to obtain 10.67 parts of the salt represented by formula (I-15). MS(ESI(+)Spectrum): M + 263.1 MS(ESI(-)Spectrum): M - 414.1

[0196] Example 6: Synthesis of the salt represented by formula (I-290) 15.48 parts of the salt represented by formula (I-290-a), 1.71 parts of the compound represented by formula (I-1-b), and 50 parts of methanol were charged and stirred at 23°C for 30 minutes. Then, 1.35 parts of pyridine was added and stirred at 23°C for 1 hour. To the resulting reaction mixture, 150 parts of chloroform was added and stirred, then 30 parts of 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes. Then, it was allowed to stand and separated. 75 parts of ion-exchanged water was charged into the recovered organic layer, stirred at 23°C for 30 minutes, and the organic layer was recovered by separation. This water washing operation was carried out 5 times. 2 parts of acetonitrile and 40 parts of tert-butyl methyl ether were added to the obtained organic layer and stirred, and then the supernatant was removed. The obtained residue was concentrated to obtain 14.18 parts of the salt represented by formula (I-290). MS(ESI(+)Spectrum): M + 525.0 MS(ESI(-)Spectrum): M - 414.1

[0197] Example 7: Synthesis of the salt represented by formula (I-965) 13.78 parts of the salt represented by TIFF2025091367000146.tif48167 formula (I-965-a), 1.71 parts of the compound represented by formula (I-1-b), and 50 parts of methanol were charged and stirred at 23 °C for 30 minutes. Then, 1.35 parts of pyridine was added and stirred at 23 °C for 1 hour. To the resulting reaction product, 150 parts of chloroform was added and stirred, then 30 parts of 5% aqueous oxalic acid solution was added and stirred at 23 °C for 30 minutes. Then, it was allowed to stand and separated. 75 parts of ion-exchanged water was charged into the recovered organic layer and stirred at 23 °C for 30 minutes, and the organic layer was recovered by liquid separation. This washing operation with water was carried out 5 times. 2 parts of acetonitrile and 40 parts of tert-butyl methyl ether were added to the obtained organic layer and stirred, and then the supernatant was removed. The obtained residue was concentrated to obtain 12.74 parts of the salt represented by formula (I-965). MS(ESI(+)Spectrum):M + 425.0 MS(ESI(-)Spectrum):M - 414.1

[0198] Synthesis of resin The compounds (monomers) used in the synthesis of resin (A) are shown below. Hereinafter, these compounds are referred to as "monomer (a1-2-6)" etc. according to their formula numbers. TIFF2025091367000147.tif4051

[0199] Synthesis Example 1 [Synthesis of Resin A1] As monomers, monomer (a1-4-2) and monomer (a1-2-6) were used and mixed so that the molar ratio [monomer (a1-4-2): monomer (a1-2-6)] was 38:62. Further, 1.5 mass times of methyl isobutyl ketone was mixed with this monomer mixture based on the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% based on the total number of moles of all monomers, and polymerization was carried out by heating this at 85 °C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, and after stirring for 6 hours, liquid separation was carried out. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was obtained by filtration and recovery, and resin A1 (copolymer) having a weight average molecular weight of about 5.4×10 3 was obtained in a yield of 89%. This resin A1 has the following structural units. TIFF2025091367000148.tif2887

[0200] <Preparation of resist composition> As shown in Table 2, the following respective components were mixed, and the obtained mixture was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

Table 2

[0201] <Resin> A1: Resin A1 <Acid generator (B)> B1-25: Salt represented by formula (B1-25); synthesized by the method described in JP-A-2011-126869 TIFF2025091367000150.tif2382<Carboxylate (I)> I-1: Salt represented by formula (I-1) I-2: Salt represented by formula (I-2) I-5: Salt represented by formula (I-5) I-12: Salt represented by formula (I-12) I-15: Salt represented by formula (I-15) I-290: Salt represented by formula (I-290) I-965: Salt represented by formula (I-965) <Quencher> IX-1: Synthesized by the method described in JP-A-2011-039502 IX-2: Synthesized by the method described in JP-A-2015-196669 TIFF2025091367000151.tif35114 <Solvent> 400 parts of propylene glycol monomethyl ether acetate 100 parts of propylene glycol monomethyl ether 5 parts of γ-butyrolactone

[0202] (Electron beam exposure evaluation of resist composition) A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 °C for 60 seconds. The resist composition was spin-coated on this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, it was prebaked on a direct hot plate at the temperature shown in the "PB" column of Table 2 for 60 seconds to form a composition layer. A contact hole pattern (hole pitch 40 nm / hole diameter 17 nm) was directly drawn on the composition layer formed on the wafer using an electron beam lithography machine ["ELS-F125 125 keV" manufactured by Elionix, Inc.] while changing the exposure dose stepwise. After exposure, post-exposure baking was performed on a hot plate at the temperature shown in the "PEB" column of Table 2 for 60 seconds, and further paddle development was performed with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide for 60 seconds to obtain a resist pattern.

[0203] In the resist pattern obtained after development, the exposure dose at which the formed hole diameter became 17 nm was defined as the effective sensitivity.

[0204] <CD uniformity (CDU) evaluation> In terms of effective sensitivity, the hole diameter of the pattern formed with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was taken as the average hole diameter of one hole. The standard deviation was determined using as the population the measurement of the average hole diameter of 400 patterns formed with a hole diameter of 17 nm within the same wafer. The results are shown in Table 3. The numerical values in the table indicate the standard deviation (nm).

Table 3

Industrial Applicability

[0205] The carboxylate salt of the present invention and the resist composition containing the carboxylate salt have good CD uniformity (CDU) and are useful for semiconductor microfabrication.

Claims

1. A carboxylic acid generator comprising a carboxylate represented by formula (I): [In formula (I), R 1 represents a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and the —CH 2 - is -O-, -S-, -CO-, -NR ２ -or-SO ２ It may be replaced with -. R ２ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms which may have a substituent, and —CH 2 - is -O-, -S-, -CO- or -SO ２ It may be replaced with -. X ０ represents a single bond or a hydrocarbon group having 1 to 72 carbon atoms which may have a substituent, and —CH 2 - is -O-, -S-, -CO- or -SO ２ It may be replaced with -. Z ＋ represents an organic cation.

2. X ０ is a single bond, a chain hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, an aromatic hydrocarbon group having 6 to 36 carbon atoms, or a group formed by combining these groups (the alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, a fluorinated alkyl group having 1 to 4 carbon atoms, or a hydroxy group, and the aromatic hydrocarbon group may have a fluorine atom, an iodine atom, a fluorinated alkyl group having 1 to 4 carbon atoms, or a hydroxy group, and the -CH contained in the alicyclic hydrocarbon group and the chain hydrocarbon group ２ 2. The carboxylic acid generator according to claim 1, wherein - may be replaced by -O- or -CO-.

3. A resist composition comprising the carboxylic acid generator according to claim 1 or 2 and an acid generator other than the carboxylic acid generator.

4. The method further comprises the steps of: The resist composition according to claim 3, which contains a structural unit represented by formula (a2-A): [In formula (a2-A), R ａ２ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R ａ２７ represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A ａ２１ represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and the —CH ２ - is -O-, -CO- or -NR ａ２８ May be replaced with -. R ａ２８ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X ａ２ represents a single bond or a carbonyl group. nA2 represents an integer of 1 to 5, and when nA2 is 2 or more, the groups in the multiple parentheses may be the same or different. na21 represents an integer of 0 to 4, and when na21 is 2 or more, a plurality of R ａ２７ may be the same or different from each other. mc represents an integer of 0 to 2.

5. the resin further comprises structural units having acid labile groups; The resist composition according to claim 4, wherein the structural unit having an acid labile group includes 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), a structural unit represented by formula (a1-2), a structural unit represented by formula (a1-4), a structural unit represented by formula (a1-5), and a structural unit represented by formula (a1-6). [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 , L ａ１ and L ａ２ are each independently -O- or *-O-(CH ２ ) ｋ１ represents --CO--O--, k1 represents an integer of 1 to 7, and * represents the bonding site with --CO--. R a01 , R ａ４ and R ａ５ each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a02 , R a03 and R a04 each independently represents 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, and the alkyl group, alicyclic hydrocarbon group and aromatic hydrocarbon group may have a halogen atom. R ａ６ and R ａ７ each independently represents 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 combining these, and the alkyl group, alkenyl group, alicyclic hydrocarbon group and aromatic hydrocarbon group may have a halogen atom. m1′ represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3. [In formula (a1-4), R ａ１ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R ａ１７ represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A ａ１１ represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and the —CH ２ - is -O-, -CO- or -NR ａ１８ May be replaced with -. R ａ１８ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X ａ１ represents a single bond or a carbonyl group. R a34 and R a35 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; 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 hydrocarbon group and the -CH 2 - may be replaced by -O- or -S-. na1 represents an integer of 1 to 5, and when na1 is 2 or more, the groups in the parentheses may be the same or different. na11 represents an integer of 0 to 4, and when na11 is 2 or more, a plurality of R ａ１７ may be the same or different from each other. mc represents an integer of 0 to 2. [In formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. Z a1 is a single bond or *-(CH 2 ) h3 -CO-L 54 -, h3 represents an integer of 1 to 4, * represents L 51 represents the binding site with L 51 , L 52 , L 53 and L 54 each independently represents --O-- or --S--. s1 represents an integer of 1 to 3. s1′ represents an integer of 0 to 3.] [In formula (a1-6), R a61 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a6２ , R a63 and R a6４ each independently represents an alkyl group having 1 to 6 carbon atoms or a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, or R a6２ and R a63 are bonded to each other to form, together with the carbon atoms to which they are attached, a ring having 3 to 20 carbon atoms. X a61 is a single bond, -CO-O-* or -CO-NR a65 - represents *, * represents a bonding site with Ar, R a65 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a62 is a single bond, *-O-L a61 - or *-CO-OL a62 -, * represents a bonding site with Ar, L a61 and L a62 each independently represents an alkanediyl group having 1 to 4 carbon atoms. Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent.

6. (1) A step of applying the resist composition according to claim 3 onto a substrate; (2) A step of drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) developing the composition layer after heating; A method for producing a resist pattern comprising the steps of:

7. A carboxylate represented by formula (I): [In formula (I), R 1 represents a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and the —CH 2 - is -O-, -S-, -CO-, -NR ２ -or-SO ２ It may be replaced with -. R ２ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Ring W represents an alicyclic hydrocarbon ring having 3 to 36 carbon atoms which may have a substituent, and —CH 2 - is -O-, -S-, -CO- or -SO ２ It may be replaced with -. X ０ represents a single bond or a hydrocarbon group having 1 to 72 carbon atoms which may have a substituent, and —CH 2 - is -O-, -S-, -CO- or -SO ２ It may be replaced with -. Z ＋ represents an organic cation.

8. X ０ is a single bond, a chain hydrocarbon group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, an aromatic hydrocarbon group having 6 to 36 carbon atoms, or a group formed by combining these groups (the alicyclic hydrocarbon group and the chain hydrocarbon group may have a fluorine atom, a fluorinated alkyl group having 1 to 4 carbon atoms, or a hydroxy group, and the aromatic hydrocarbon group may have a fluorine atom, an iodine atom, a fluorinated alkyl group having 1 to 4 carbon atoms, or a hydroxy group, and the -CH contained in the alicyclic hydrocarbon group and the chain hydrocarbon group ２ The carboxylate according to claim 7, wherein - may be replaced by -O- or -CO-.

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