Salt, acid generator, resist composition, and method for producing resist pattern

Abstract

To provide an acid generator and a resist composition which allow a resist pattern having a good pattern collapse margin to be produced.SOLUTION: The acid generator contains a salt represented by formula (I). [In the formula, Q1, Q2, R11 and R12 each represent a hydrogen atom, a fluorine atom or the like; z represents an integer of 0-6; X1 represents -CO-O-, -O-CO-, -O-CO-O- or the like; L1 represents a substituted / unsubstituted chain hydrocarbon group, a substituted / unsubstituted aromatic hydrocarbon group, or a group composed of a combination thereof; L2 represents a single bond or an alkanediyl group; R3 represents a group represented by formula (IC); m3 represents an integer of 2-6; Z+ represents an organic cation; RA represents a saturated hydrocarbon group; u1 represents an integer of 0-2; and s1 represents 1 or 2 and t1 represents 0 or 1, provided that the sum of s1 and t1 is 1 or 2.]SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Patent Document 1 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator. TIFF2025074940000001.tif5663 Patent Document 2 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator. TIFF2025074940000002.tif3057 [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-095446 A [Patent Document 2] JP 2011-246439 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a salt that forms a resist pattern that has better pattern collapse resistance (PCM) than a resist pattern formed from a resist composition containing the above salt. [Means for solving the problem]

[0005] The present invention includes the following inventions. [1] An acid generator comprising a salt represented by formula (I). TIFF2025074940000003.tif22103 [In formula (I), Q 1 and Q 2each independently represents 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. R 11 and R 12 each independently represents 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. z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R 11 and R 12 may be the same or different from each other. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, and * represents C(R 11 )(R 12 ) or C(Q 1 )(Q 2 ) binding site. L 1 represents an optionally substituted chain hydrocarbon group having 1 to 36 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, in which -CH2- contained in the chain hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. L 2 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. R 3 represents a group represented by formula (IC). m3 represents an integer from 2 to 6, and a plurality of R 3 may be the same or different from each other. Z + represents an organic cation. TIFF2025074940000004.tif2562[In formula (IC), R A represents a saturated hydrocarbon group having 1 to 12 carbon atoms. u1 represents an integer of 0 to 2, and when u1 is 2, a plurality of R A are either the same or different. s1 represents 1 or 2. t1 represents 0 or 1, provided that the sum of s1 and t1 is 1 or 2. * denotes a binding site.] [2] L 1 is a chain hydrocarbon group having 1 to 10 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-). [3] L 1 but, an aromatic hydrocarbon group having 6 to 10 carbon atoms; a group combining an alkanediyl group having 1 to 10 carbon atoms with an aromatic hydrocarbon group having 6 to 10 carbon atoms, a group consisting of an alkanetriyl group having 1 to 10 carbon atoms and one or two aromatic hydrocarbon groups having 6 to 10 carbon atoms; a group consisting of an alkanetetrayl group having 2 to 10 carbon atoms and one to three aromatic hydrocarbon groups having 6 to 10 carbon atoms, The acid generator according to [1] or [2], wherein the aromatic hydrocarbon group having 6 to 10 carbon atoms may have a substituent, and -CH2- contained in the alkanediyl group, the alkanetriyl group, and the alkanetetrayl group may be replaced with -O- or -CO-. [4] The acid generator according to any one of [1] to [3], wherein m3 is 2 or 3. [5] The compound includes two or more salts represented by formula (I), and R of one of the salts represented by formula (I) 3 is a group represented by formula (IC-1), and R of one of the salts represented by two or more formulas (I) 3 is a group represented by formula (IC-2) or formula (IC-3). TIFF2025074940000005.tif31127[In formula (IC-1), formula (IC-2) and formula (IC-3), *, R A and u1 each have the same meaning as in formula (IC). u1' represents 0 or 1. * represents a binding site.] [6] A resist composition comprising the acid generator according to any one of [1] to [5]. [7] The resist composition according to [6], further comprising a compound having a phenolic hydroxyl group and / or a compound in which the hydroxyl group of a phenolic hydroxyl group is protected with an acid labile group. [8] The resist composition according to [6] or [7], further comprising a resin containing one or more structural units represented by formula (a2). TIFF2025074940000006.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 is -O-, -CO- or -NR a28 - may be replaced. 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 optionally having a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO2-. L a22 represents a chain hydrocarbon group having 1 to 12 carbon atoms which may have a single bond or a fluorine atom, and -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-. na2 represents an integer of 1 to 4. When na2 is 2 or more, a plurality of L a22 may be the same or different. [9] At least one structural unit represented by formula (a2) The resist composition according to [8], which contains one or more structural units represented by formula (a2-A): TIFF2025074940000007.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 is -O-, -CO- or -NR a28 - may be replaced. 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 4, and when nA2 is 2 or greater, 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 from 0 to 2.

[10] One or more structural units represented by formula (a2) The resist composition according to [8] or [9], which contains a structural unit represented by formula (a2-D): TIFF2025074940000008.tif51106[In formula (a2-D), 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 a21represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group is -O-, -CO- or -NR a28 - may be replaced. R a28 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R a21 and R a22 each independently represents a fluorinated alkyl 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 an integer of 1 to 4. When nD2 is 2 or more, the groups in the parentheses may be the same or different. nD22 represents an integer of 0 to 4. When nD22 is 2 or more, a plurality of R a27 may be the same or different.

[11] The resist composition according to any one of [6] to

[10] , further comprising a salt that generates an acid having a weaker acidity than the acid generated from the acid generator containing the salt represented by formula (I).

[12] (1) A step of applying the resist composition according to any one of [6] to

[11] onto a substrate; (2) A step of drying the applied resist composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) A method for producing a resist pattern, comprising the step of developing the composition layer after heating.

[13] A salt represented by the above formula (I).

[14] L 1 is a chain hydrocarbon group having 1 to 10 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-).

[15] L 1 but, an aromatic hydrocarbon group having 6 to 10 carbon atoms; a group combining an alkanediyl group having 1 to 10 carbon atoms with an aromatic hydrocarbon group having 6 to 10 carbon atoms, a group consisting of an alkanetriyl group having 1 to 10 carbon atoms and one or two aromatic hydrocarbon groups having 6 to 10 carbon atoms; a group consisting of an alkanetetrayl group having 2 to 10 carbon atoms and one to three aromatic hydrocarbon groups having 6 to 10 carbon atoms, The salt according to

[13] , wherein the aromatic hydrocarbon group having 6 to 10 carbon atoms may have a substituent, and -CH2- contained in the alkanediyl group, the alkanetriyl group, or the alkanetetrayl group may be replaced by -O- or -CO-.

[16] The salt according to any one of

[13] to

[15] , wherein m3 is 2 or 3. Effect of the Invention

[0006] By using a resist composition containing the salt of the present invention, a resist pattern with good pattern collapse resistance (PCM) can be produced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] In this specification, "(meth)acrylic monomer" means "at least one of acrylic monomer and methacrylic monomer". The terms "(meth)acrylate" and "(meth)acrylic acid" have the same meaning. In the groups described in this specification, those that can have both a linear structure and a branched structure may be either. When -CH2- contained in a hydrocarbon group or the like is replaced with -O-, -S-, -CO- or -SO2-, the same examples are applied to each group, and the number of carbon atoms before the replacement is the number of carbon atoms of the hydrocarbon group or the like. "Combined group" means a group in which two or more of the exemplified groups are bonded, and the valence of these groups may be appropriately changed depending on the bond form. "Derived from" or "derived from" refers to a polymerizable C=C bond contained in the molecule becoming a single bond (-CC- group) by polymerization. When stereoisomers exist, all stereoisomers are included. Depending on the number of substituents, etc., hydrogen atoms in any position and number contained in each group may be replaced with bonds. The number of carbon atoms in a substituent is not included in the number of carbon atoms of the substituted group. An "acid labile group" refers to a group that has a leaving group and that is eliminated by contact with an acid, converting the structural unit into a structural unit having a hydrophilic group (e.g., a hydroxyl group or a carboxyl group). A base labile group refers to a group that is eliminated by contact with a base (e.g., trimethylamine, etc.), forming a hydrophilic group (e.g., a carboxyl group or a hydroxyl group). In this specification, the term "solids content of a resist composition" refers to the sum of the components excluding the solvent (E), which will be described later, from the total amount of the resist composition.

[0008] [Salt represented by formula (I)] The present invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)"). In salt (I), the negatively charged side is sometimes called the "anion (I)" and the positively charged side is sometimes called the "cation (I)". TIFF2025074940000009.tif22103 [wherein all symbols have the same meanings as defined above.]

[0009] In formula (I), Q1 , Q 2 , R 11 and R 12 Examples of the perfluoroalkyl group include 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, etc. The number of carbon atoms in the perfluoroalkyl group is preferably 1 to 4, and more preferably 1 to 3. In formula (I), Q 1 , Q 2 , R 11 and R 12 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, a hexyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 4, and more preferably 1 to 3. Q 1 and Q 2 Preferably, at least one of is a fluorine atom or a perfluoroalkyl group, more preferably, each independently is a trifluoromethyl group or a fluorine atom, and further preferably, both are fluorine atoms. R 11 and R 12 are each independently preferably a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, more preferably a hydrogen atom, a fluorine atom or a trifluoromethyl group, and even more preferably a hydrogen atom or a trifluoromethyl group. z is preferably an integer of 0 to 4, more preferably an integer of 0 to 3, even more preferably 0 or 2, and even more preferably 0 or 1. X 1 is preferably *-CO-O-, *-O-CO-O- or *-O-CO-, more preferably *-CO-O- or *-O-CO- (* is C(R 11 )(R 12 ) or C(Q 1 )(Q 2 ) represents the binding site.

[0010] L 1 Examples of the chain hydrocarbon group in include chain hydrocarbon groups having a valence of 1 to 18, such as an alkanetriyl group, an alkanetetrayl group, an alkanpentyl group, an alkanehexyl group, an alkaneheptyl group, an alkaneoctyl group, an alkenetriyl group, an alkenetetrayl group, an alkenepentyl group, an alkenehexyl group, an alkeneheptyl group, an alkeneoctyl group, an alkynetriyl group, an alkinetetrayl group, an alkinepentyl group, an alkynehexyl group, an alkineheptyl group, and an alkyneoctyl group. Examples of the alkanetriyl group include a methanetriyl group, an ethanetriyl group, a propanetriyl group, a butanetriyl group, a pentanetriyl group, a hexanetriyl group, a heptanetriyl group, an octanetriyl group, a nonanetriyl group, a decanetriyl group, an undecanetriyl group, a dodecanetriyl group, a tridecanetriyl group, a tetradecanetriyl group, a pentadecanetriyl group, a hexadecanetriyl group, and a heptadecanetriyl group. Examples of the alkanetetrayl group include a methanetetrayl group, an ethanetetrayl group, a propanetetrayl group, a butanetetrayl group, a pentanetetrayl group, a hexanetetrayl group, a heptanetetrayl group, an octanetetrayl group, a nonanetetrayl group, a decanetetrayl group, an undecanetetrayl group, a dodecanetetrayl group, a tridecanetetrayl group, a tetradecanetetrayl group, a pentadecanetetrayl group, a hexadecanetetrayl group, and a heptadecanetetrayl group. Examples of the alkene triyl group include an ethene triyl group, a propene triyl group, an isopropene triyl group, a butene triyl group, an isobutene triyl group, a tert-butene triyl group, a pententriyl group, a hexene triyl group, a hepten triyl group, an octene triyl group, an isooctene triyl group, and a nonenyne triyl group. Examples of the alkenetetrayl group include an ethenetetrayl group, a propenetetrayl group, an isopropenetetrayl group, a butenetetrayl group, an isobutenetetrayl group, a tert-butenetetrayl group, a pentenetetrayl group, a hexenetetrayl group, a heptenetetrayl group, an octenediyl group, an isooctenetetrayl group, and a nonenynetetrayl group. Examples of the alkynetriyl group include an ethynetriyl group, a propynetriyl group, an isopropynetriyl group, a butynetriyl group, an isobutynetriyl group, a tert-butynetriyl group, a pentynetriyl group, a hexynetriyl group, an octynetriyl group, and a nonynetriyl group. Examples of the alkynetetrayl group include an ethynetetrayl group, a propynetetrayl group, an isopropynetetrayl group, a butynetetrayl group, an isobutynetetrayl group, a tert-butynetetrayl group, a pentynetetrayl group, a hexynetetrayl group, an octynetetrayl group, and a nonynetetrayl group. Further examples include groups in which one or more hydrogen atoms of the above groups are replaced with bonding sites. The chain hydrocarbon group may have 1 to 24 carbon atoms, may have 1 to 18 carbon atoms, is preferably 1 to 12 carbon atoms, is more preferably 1 to 10 carbon atoms, is further preferably 1 to 8 carbon atoms, is even further preferably 1 to 7 carbon atoms, and is further preferably 1 to 6 carbon atoms. L 1 Examples of the aromatic hydrocarbon group in include trivalent to tridecyl aromatic hydrocarbon groups such as arenetriyl, arenettetrayl, arenetpentyl, arenethexyl, arenetheptyl and arenetoctyl groups. Specific examples of aromatic hydrocarbon groups include 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, and a phenanthrenetetrayl group. Further examples include groups in which one or more hydrogen atoms of the above groups are replaced with bonding sites. The aromatic hydrocarbon group preferably has 6-14 carbon atoms, and more preferably 6-10 carbon atoms.

[0011] Examples of groups that combine two or more types include groups that combine an aromatic hydrocarbon group and a chain hydrocarbon group. In the combination, two or more types of chain hydrocarbon groups and two or more types of aromatic hydrocarbon groups may be combined. 1 may be bound to Examples of groups that combine an aromatic hydrocarbon group and a chain hydrocarbon group include groups in which one or more aromatic hydrocarbon groups are bonded to a chain hydrocarbon group (for example, *-chain hydrocarbon group-(aromatic hydrocarbon group-) m3 etc.), groups in which one or more chain hydrocarbon groups are bonded to an aromatic hydrocarbon group (for example, *-aromatic hydrocarbon group-(chain hydrocarbon group-) m3 etc.), groups in which one or more aromatic hydrocarbon groups and a chain hydrocarbon group are bonded to a chain hydrocarbon group (for example, *-chain hydrocarbon group-(aromatic hydrocarbon group-chain hydrocarbon group-) m3 , *-Linear hydrocarbon group-Aromatic hydrocarbon group-(Linear hydrocarbon group-) m3 etc.) In the case of a combination of groups or when the group has a substituent, the above groups may contain groups having different valences (such as an alkyl group, an alkanediyl group, an alkanetriyl group, etc.). Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. Examples of the alkanediyl group include a methylene group, an ethylene group, a propylene group, and a butylene group.

[0012] L 1 -CH2- contained in the chain hydrocarbon group having 1 to 36 carbon atoms may be replaced by -O-, -S-, -SO2- or -CO-. L 1 When --CH2-- contained in the chain hydrocarbon group having 1 to 36 carbon atoms is replaced with --O--, --S--, --SO2-- or --CO--, the number of carbon atoms before replacement is regarded as the number of carbon atoms of the chain hydrocarbon group. Examples of groups in which -CH2- in an open chain hydrocarbon group is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a thiol group (a group in which -CH2- in a methyl group is replaced by -S-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced by -O-), an alkylthio group (a group in which -CH2- at any position in an alkyl group is replaced by -S -), alkylsulfonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -SO2-), alkoxycarbonyl group (a group in which -CH2-CH2- at any position in the alkyl group is replaced with -O-CO-), alkylcarbonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -CO-), alkylcarbonyloxy group (a group in which -CH2-CH2- at any position in the alkyl group is replaced with -CO-O-), alkoxycarbonyloxy group (a group in which -CH2- a group in which -CH2-CH2-CH2- at any position in the alkanediyl group is replaced with -O-CO-O-), an oxy group (a group in which -CH2- in a methylene group is replaced with -O-), a carbonyl group (a group in which -CH2- in a methylene group is replaced with -CO-), an alkanediyloxy group (a group in which -CH2- at any position in an alkanediyl group is replaced with -O-), an alkanediyloxycarbonyl group (a group in which -CH2-CH2- at any position in an alkanediyl group is replaced with -O-CO-), an alkanediylcarbonyl group ( an alkanediyl group in which -CH2- at any position is replaced with -CO-), an alkanediylcarbonyloxy group (an alkanediyl group in which -CH2-CH2- at any position is replaced with -CO-O-), an alkanediylthio group (an alkanediyl group in which -CH2- at any position is replaced with -S-), an alkanediylsulfonyl group (an alkanediyl group in which -CH2- at any position is replaced with -SO2-), a thio group (a methylene group in which -CH2- is replaced with -S-),Examples of such groups include a sulfonyl group (a group in which -CH2- in a methylene group is replaced with -SO2-), a cycloalkoxy group, a cycloalkylalkoxy group, an aromatic hydrocarbon group-carbonyloxy group, an aromatic hydrocarbon group-carbonyl group, an aromatic hydrocarbon group-oxy group, and a group that combines two or more of these groups. In addition, examples of such groups include groups in which one or more hydrogen atoms of these groups are replaced with a bonding site. Examples of the alkoxy group include alkoxy groups having 1 to 35 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, etc. The number of carbon atoms in the alkoxy group may be 1 to 17, preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. The alkylthio group includes an alkylthio group having 1 to 35 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, a hexylthio group, an octylthio group, a 2-ethylhexylthio group, a nonylthio group, a decylthio group, and an undecylthio group. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 35 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, etc. The number of carbon atoms in the alkylthio group and the alkylsulfonyl group may be 1 to 17, preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. Examples of the alkoxycarbonyl group include an alkoxycarbonyl group having 2 to 35 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. Examples of the alkylcarbonyl group include an alkylcarbonyl group having 2 to 36 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group include an alkylcarbonyloxy group having 2 to 35 carbon atoms, such as an acetyloxy group, a propionyloxy group, and a butyryloxy group. Examples of the alkoxycarbonyloxy group include an alkoxycarbonyloxy group having 3 to 34 carbon atoms, such as a butoxycarbonyloxy group. The number of carbon atoms of the alkoxycarbonyl group and the alkylcarbonyloxy group may be 2 to 17, preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyl group may be 2 to 18, preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkoxycarbonyloxy group may be 3 to 17, preferably 3 to 11, more preferably 3 to 6, and even more preferably 3 to 4. Examples of the alkanediyloxy group include alkanediyloxy groups having 1 to 35 carbon atoms, such as a methyleneoxy group, an ethyleneoxy group, a propanediyloxy group, a butanediyloxy group, and a pentanediyloxy group. The number of carbon atoms of the alkanediyloxy group may be 1 to 17, preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3.

[0013] Examples of the alkanediyloxycarbonyl group include alkanediyloxycarbonyl groups having 2 to 35 carbon atoms, such as methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propanediyloxycarbonyl group, butanediyloxycarbonyl group, etc. Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 36 carbon atoms, such as methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, pentanediylcarbonyl group, etc. Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 35 carbon atoms, such as methylenecarbonyloxy group, ethylenecarbonyloxy group, propanediylcarbonyloxy group, butanediylcarbonyloxy group, etc. The number of carbon atoms in the alkanediyloxycarbonyl group and the alkanediylcarbonyloxy group may each be 2 to 17, preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyl group may be 2 to 18, preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The alkanediylthio group includes an alkanediylthio group having 1 to 35 carbon atoms, such as a methylenethio group, an ethylenethio group, and a propylenethio group. The alkanediylsulfonyl group includes an alkanediylsulfonyl group having 1 to 35 carbon atoms, such as a methylenesulfonyl group, an ethylenesulfonyl group, a propylenesulfonyl group, etc. The number of carbon atoms in the alkanediylthio group and the alkanediylsulfonyl group may be 1 to 17, preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 35 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 35 carbon atoms, such as a cyclohexylmethoxy group. Examples of the aromatic hydrocarbon group-carbonyloxy group include aromatic hydrocarbon group-carbonyloxy groups having 7 to 35 carbon atoms, such as a benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 17 carbon atoms, such as a benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include aromatic hydrocarbon group-oxy groups having 6 to 34 carbon atoms, such as a phenyloxy group.

[0014] L 1 Examples of the substituent that the chain hydrocarbon group contained in L may have include a halogen atom, a cyano group, a cycloalkyl group having 3 to 18 carbon atoms, a group formed by combining a cycloalkanediyl group having 3 to 18 carbon atoms with an alkyl group having 1 to 12 carbon atoms, or a group formed by combining these groups. 1 The -CH2- of the chain carbon group contained in is replaced by -O-, -S-, -SO2- or -CO-, and L 1 The chain carbon group contained in may substantially have a hydroxyl group, a carboxyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, or a combination thereof as a substituent. L 1 Examples of the substituent that the aromatic hydrocarbon group contained in the formula (1) may have include a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyloxy group having 2 to 13 carbon atoms, a cycloalkyl group having 3 to 18 carbon atoms, or a group combining these. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the cycloalkyl group having 3 to 18 carbon atoms include monocyclic cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group, and polycyclic cycloalkyl groups such as a norbornyl group and an adamantane group. Examples of the cycloalkanediyl group having 3 to 18 carbon atoms include groups in which a hydrogen atom has been removed from the above cycloalkyl groups. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, and a nonyl group. Examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, and a dodecyloxy group. The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group having 2 to 13 carbon atoms represent groups in which a carbonyl group or a carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. Examples of the alkylcarbonyl group having 2 to 13 carbon atoms include an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, and a butyryloxy group. L 1 The substituent of the chain hydrocarbon group contained in L is preferably an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, or a halogen atom. 1 The substituent on the aromatic hydrocarbon group contained in is preferably an alkyl group having 1 to 4 carbon atoms, a hydroxyl group or a halogen atom.

[0015] L 1is preferably a chain hydrocarbon group having 1 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a group combining these, and is preferably an alkanetriyl group having 1 to 10 carbon atoms, an alkanetetrayl group having 2 to 10 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, a group combining an alkanediyl group having 1 to 10 carbon atoms and an aromatic hydrocarbon group having 6 to 10 carbon atoms, a group combining an alkanetriyl group having 1 to 10 carbon atoms and one or two aromatic hydrocarbon groups having 6 to 10 carbon atoms, or a group combining an alkanetetrayl group having 2 to 10 carbon atoms and one to three aromatic hydrocarbon groups having 6 to 10 carbon atoms, the above-mentioned aromatic hydrocarbon group having 6 to 10 carbon atoms may have a substituent, and -CH2- contained in the alkanediyl group, the alkanetriyl group, and the alkanetetrayl group may be replaced by -O- or -CO-.

[0016] L 2 The alkanediyl group of L is as long as the upper limit of the carbon number allows. 1 Examples of the chain hydrocarbon group contained in the above formula (1) include the same groups as the alkanediyl groups given as examples of the chain hydrocarbon group contained in the above formula (1). L 2 is a single bond or -X 2 -(CH2) 0~3 (In the formula, X 2 represents -CO-O-, -O-CO-, -O-CO-O- or -O-.

[0017] The anion (I) of the salt represented by formula (I) has a group represented by formula (IC). TIFF2025074940000010.tif2562 [wherein all symbols have the same meanings as defined above.]

[0018] s1 is preferably 1, t1 is preferably 1, and the sum of s1 and t1 is preferably 2. The group represented by formula (IC) is preferably a group represented by the following formula (IC-1), formula (IC-2), or formula (IC-3). TIFF2025074940000011.tif31127 [In formula (IC-1), formula (IC-2) and formula (IC-3), *, R A and u1 have the same meaning as in formula (IC). u1′ represents 0 or 1. * denotes a binding site.]

[0019] In the group represented by formula (IC), u1 is 1, and R A L 1 The group bonded to the carbon atom adjacent to is represented by the following formula: TIFF2025074940000012.tif2641R A Examples of the saturated hydrocarbon group include chain saturated hydrocarbon groups such as alkyl groups, alicyclic saturated hydrocarbon groups, and groups in which two or more of these groups are combined. R A Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, octyl, nonyl, etc. The number of carbon atoms in the chain saturated hydrocarbon group is preferably 1 to 9, more preferably 1 to 6, and further preferably 1 to 4. The alicyclic saturated hydrocarbon group may be any of monocyclic, polycyclic and spirocyclic. Examples of the alicyclic saturated hydrocarbon group include monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclononyl, cyclodecyl and cyclododecyl, and polycyclic cycloalkyl groups such as norbornyl and adamantyl. The number of carbon atoms in the alicyclic saturated hydrocarbon group is preferably 3 to 10, more preferably 3 to 8, and even more preferably 3 to 6. The combined group may be a group in which one each of the above-mentioned alkyl groups and alicyclic saturated hydrocarbon groups is combined, or a group in which two or more of either one or two or more of both are combined.

[0020] Examples of the anion (I) include the following anions. Among them, the anions represented by formulae (Ia-1) to (Ia-12) are preferred, and the anions represented by formulae (Ia-1) to (Ia-6) are more preferred. TIFF2025074940000013.tif238168

[0021] TIFF2025074940000014.tif110161

[0022] Z + Examples of the organic cation include organic onium cation, organic sulfonium cation, organic iodonium cation, organic ammonium cation, benzothiazolium cation, and organic phosphonium cation. Among these, organic sulfonium cation and organic iodonium cation are preferred, and arylsulfonium cation is more preferred. Specific examples include cations represented by any of formulas (b2-1) to (b2-5) (hereinafter, sometimes referred to as "cation (b2-1)" depending on the formula number). TIFF2025074940000015.tif82160[Formula (b2-1) to (b2-5), R b4 ~R b6 each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, a hydrogen atom contained in the chain 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, a 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 a 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 b5may 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 R b8 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 an integer of 0 to 5. When m2 is 2 or more, multiple R b7 may be the same or different, and when n2 is 2 or more, multiple R b8 may be the same or different. R b9 and R b10 each independently represents 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 with -O-, -S- or -CO-. R b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R b12 represents an open 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, a hydrogen atom contained in the open 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 the -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 , Rb21 ~R b26 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 b14 and R b21 and R b22 may be bonded to each other to form a ring containing a sulfur atom together with the benzene ring to which they are attached, and -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 , L b41 ~L b43 represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent an integer of 0 to 5. q2 and r2 each independently represent an integer of 0 to 4. u2 represents 0 or 1. o21, p22, q23, s26, t25 and r24 each independently represent an integer of 0 to 4. u3 represents an integer of 1 to 3, and satisfies 1≦u3+q23≦5. u4 and u5 each independently represent an integer of 0 to 3, and satisfy 0≦u4+o21≦5 and 0≦u5+p22≦5. When o2 is 2 or more, multiple R b13 are the same or different, and when p2 is 2 or more, multiple R b14 are the same or different, and when q2 is 2 or more, multiple R b15 are the same or different, and when r2 is 2 or more, multiple R b16 are the same or different, and when s2 is 2 or more, multiple R b17 are the same or different, and when t2 is 2 or more, multiple R b18 are the same or different. When o21, p22, q23, s26, t25, and r24 are each 2 or more, multiple Rb21 ~R b26 are the same or different. When u2, u3, u4, and u5 are each 2 or more, the groups in the parentheses are the same or different. When u2 is 0, any one of o2, p2, q2, and r2 is 1 or more, and R b13 ~R b16 At least one of them is preferably a halogen atom, and 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 these is preferably a halogen atom. Furthermore, when u2 is 0, r2 is preferably 1 or more, and more preferably 1. When u2 is 0 and r2 is 1 or more, R b16 is preferably a halogen atom. The aliphatic hydrocarbon group refers to a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl. In particular, R b9 ~R b12 The chain hydrocarbon group preferably has 1 to 12 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups: TIFF2025074940000016.tif10158 In particular, R b9 ~R b12 The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, and more preferably has 4 to 12 carbon atoms. 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 methylnorbornyl group, an isobornyl group, etc. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms in the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The fluorinated alkyl group refers to an alkyl group having 1 to 12 carbon atoms and a fluorine atom, and examples of such groups include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group, etc. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 9, more preferably 1 to 6, and further preferably 1 to 4.

[0023] 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 thereof include aromatic hydrocarbon groups having a chain hydrocarbon group with 1 to 18 carbon atoms (tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and aromatic hydrocarbon groups having an alicyclic hydrocarbon group with 3 to 18 carbon atoms (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.). When the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group with 1 to 18 carbon atoms and an alicyclic hydrocarbon group with 3 to 18 carbon atoms are preferred. An example of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group is a p-methoxyphenyl group. Examples of the chain hydrocarbon group in which a hydrogen atom has been 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. 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 alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkylcarbonyloxy group include 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, and a 2-ethylhexylcarbonyloxy group. R b4 and R b5 The ring formed by bonding to each other together with the sulfur atom to which they are bonded may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of this ring include rings having 3 to 18 carbon atoms, and preferably rings having 4 to 18 carbon atoms. Examples of the ring containing a sulfur atom include 3-membered to 12-membered rings, and preferably 3-membered to 7-membered rings, and examples of such rings include the following rings. * represents a bond. TIFF2025074940000017.tif23143R b9 and R b10 The ring formed by these together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring may be a 3-membered to 12-membered ring, preferably a 3-membered to 7-membered ring. For example, it may be a thiolane-1-ium ring (tetrahydrothiophenium ring), a thiane-1-ium ring, a 1,4-oxathiane-4-ium ring, etc. R b11 and R b12The ring formed by combining with may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. The ring may be a 3-membered to 12-membered ring, preferably a 3-membered to 7-membered ring. Examples of the ring include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring. R b27 ~R b29 Examples of groups containing an acid labile group include -R c30 , -CO-OR c30 Or -L c10 -CO-OR c30 A group represented by (L c10 represents an alkanediyl group having 1 to 6 carbon atoms, R c30 represents an acid labile group. R b27 ~R b29 The acid labile group may be a group represented by formula (1) or (2).

[0024] Among the cations (b2-1) to (b2-5), the cation (b2-1), the cation (b2-4) or the cation (b2-5) is preferred. Examples of the cation (b2-1) include the following cations. TIFF2025074940000018.tif148165Examples of the cation (b2-2) include the following cations. TIFF2025074940000019.tif18150Examples of the cation (b2-3) include the following cations. TIFF2025074940000020.tif26140Examples of the cation (b2-4) include the following cations. TIFF2025074940000021.tif130167Examples of the cation (b2-5) include the following cations. TIFF2025074940000022.tif115158

[0025] The salt (I) is a combination of the above-mentioned anion and the above-mentioned organic cation, which can be combined arbitrarily. The salt (I) is preferably a combination of an anion represented by any one of formulas (Ia-1) to (Ia-12) and a cation (b2-1), a cation (b2-2), a cation (b2-3), a cation (b2-4), or a cation (b2-5).

[0026] Examples of the salt (I) include salts shown in Table 1. In the table below, each symbol represents the symbol attached to the structure representing the above-mentioned anion or cation. For example, salt (I-1) means a salt consisting of an anion represented by formula (Ia-1) and a cation represented by formula (b2-c-1), and represents the salt shown below. TIFF2025074940000023.tif3093 [Table 1] Among these, the salt (I) is preferably a salt obtained by combining an anion represented by any one of formulas (Ia-1) to (Ia-12) with a cation represented by any one of formulas (b2-c-1) to (b2-c-79).

[0027] <Method for producing salt (I)> In the salt (I), X 1 However, *-CO-O-(* is C(R 11 )(R 12 ) or C(Q 1 )(Q 2 ) (salt represented by formula (I1)) can be produced, for example, by reacting a salt represented by formula (I1-a) with carbonyldiimidazole in a solvent, and then reacting the salt with a compound represented by formula (I1-b). TIFF2025074940000025.tif50138 (wherein all symbols have the same meanings as above.) Solvents for this reaction include chloroform, acetonitrile, and the like. The reaction temperature is usually 5° C. to 80° C., and the reaction time is usually 0.5 hours to 24 hours.

[0028] Examples of the salt represented by formula (I1-a) include the salts represented by the following formulas, and can be produced by the method described in JP-A-2008-127367. TIFF2025074940000026.tif74162 Examples of the compound represented by formula (I1-b) include compounds represented by the following formula, which are easily available on the market and can also be easily produced by known production methods. TIFF2025074940000027.tif131147

[0029] In the salt (I), X 1 The salt in which * is --O--CO--O-- (salt represented by formula (I2)) can be produced, for example, by reacting a salt represented by formula (I2-a) with carbonyldiimidazole in a solvent, and then reacting the resulting mixture with a compound represented by formula (I1-b). In addition, the salt represented by formula (I2) can also be produced, for example, by reacting a compound represented by formula (I1-b) with carbonyldiimidazole in a solvent, and then further reacting the resulting mixture with a salt represented by formula (I2-a). TIFF2025074940000028.tif79150 (wherein all symbols have the same meanings as defined above.) Solvents for this reaction include chloroform, acetonitrile, and the like. The reaction temperature is usually 5° C. to 80° C., and the reaction time is usually 0.5 hours to 24 hours. Examples of the salt represented by formula (I2-a) include the salts represented by the following formulas, and can be produced by the method described in JP-A-2012-193170. TIFF2025074940000029.tif79160

[0030] In the salt (I), X 1The salt in which * is --O--CO- (salt represented by formula (I3)) can be produced, for example, by reacting a compound represented by formula (I3-b) with carbonyldiimidazole in a solvent, and then further reacting it with a salt represented by formula (I2-a). TIFF2025074940000030.tif34163 (wherein all symbols have the same meanings as above.) Solvents for this reaction include chloroform, acetonitrile, and the like. The reaction temperature is usually 5° C. to 80° C., and the reaction time is usually 0.5 hours to 24 hours.

[0031] Examples of the compound represented by formula (I3-b) include the compounds represented by the following formulas, which are readily available on the market or can be readily produced by known methods. TIFF2025074940000031.tif49146

[0032] In the salt (I), X 1 The salt in which is *-O- (salt represented by formula (I4)) can be obtained by reacting a salt represented by formula (I2-a) with a compound represented by formula (I1-b) in a solvent in the presence of a base. TIFF2025074940000032.tif23162 (wherein all symbols have the same meanings as above.) The base in this reaction includes potassium hydroxide and the like. The solvent for this reaction may be acetonitrile or the like. The reaction temperature is usually 5° C. to 80° C., and the reaction time is usually 0.5 hours to 24 hours.

[0033] <Acid generator> The acid generator of the present invention is an acid generator containing a salt (I). It may contain one type of salt (I) or two or more types of salt (I). When it contains two or more types of salt (I) represented by formula (I), R of one of the two or more salts (I) is 3is a group represented by formula (IC-1), and R 3 is preferably a group represented by formula (IC-2) or formula (IC-3). 3 is a group represented by formula (IC-1), and R 3 However, the ratio of the mass mol % of the salt (I) represented by formula (IC-2) or formula (IC-3) is preferably 5:1 to 3:2. The acid generator of the present invention may contain, in addition to the salt (I), a known compound that acts as an acid generator in the resist field (hereinafter, sometimes referred to as "compound (B)", except for the salt (I). The compound (B) may be used alone or in combination of two or more kinds.

[0034] The compound (B) may be either a nonionic compound or an ionic compound. Examples of the nonionic compound include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane), and the like. Examples of the ionic compound include onium salts containing onium cations (e.g., diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). Examples of the anion of the onium salt include sulfonate anion, sulfonylimide anion, sulfonylmethide anion, and carboxylate anion. The compound (B) may be a part of a structural unit that constitutes the resin contained in the resist composition, like the structural unit (a7) described below.

[0035] As the compound (B), compounds that generate an acid when exposed to radiation, such as those described in 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, and European Patent No. 126,712, can be used. Compounds produced by known methods may also be used. Compound (B) may be an acid generator having an acid labile group. For example, a compound or resin serving as an acid generator may contain a partial structure that becomes an acid labile group, and the acid labile group preferably contains a group (1) or group (2) described below. When the resist composition of the present invention contains a compound having an acid labile group, it is not necessary to contain a resin containing a structural unit having an acid labile group.

[0036] A preferred embodiment of the compound (B) is a salt represented by formula (B1) (hereinafter, sometimes referred to as "acid generator (B1)"). TIFF2025074940000033.tif1395[In 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 an integer of 1 to 6. When nb1 is 2 or more, the groups in the multiple parentheses may be the same or different. ZI+ represents an organic cation. L b1 The (nb1+1)-valent hydrocarbon group is a group obtained by removing nb1 hydrogen atoms from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a group combining two or more of these groups, to form a ring structure. b2 Examples of such groups include groups that bond to the Examples of the chain-like hydrocarbon group include a group in which nb1 hydrogen atoms have been removed from an alkyl group or an alkenyl group. The alkyl group may be linear or branched, and specific examples thereof include a methane group, an ethane group, a propane group, an isopropyl group, a n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a heptyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decane group, an undecane group, a dodecane group, a tridecane group, a tetradecane group, a pentanedecane group, and a heptadecane group. 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 in the chain hydrocarbon group is preferably 1 to 36, more preferably 1 to 24, even more preferably 1 to 20, still more preferably 1 to 18, even more preferably 1 to 12, and even more preferably 1 to 10. Examples of the alicyclic hydrocarbon group include a group in which nb1 hydrogen atoms have been removed 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, and a cyclooctyl group. Examples of polycyclic cycloalkyl groups include cycloalkyl groups having a bridged structure, cycloalkyl groups in which two or more rings are condensed, or cycloalkyl groups in which two rings are bonded by a spiro bond. Examples of cycloalkyl groups having a bridged structure include norbornane and adamantane groups. Examples of cycloalkyl groups in which two or more rings are condensed include bicyclo[4,4,0]decane groups and steroid groups (steroid skeletons). Examples of rings in which two rings are bonded by a spiro bond include spirocyclic cycloalkyl groups in which one cycloalkyl group selected from the group consisting of a cyclopentyl group, a cyclohexyl group, a norbornane group, and an adamantyl group is bonded by a spiro bond 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, alicyclic hydrocarbon groups represented by the following formulas are included. TIFF2025074940000034.tif27168When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group may be 3 to 24, and may be 3 to 18, preferably 3 to 12, and 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 may be 6 to 24, and may be 6 to 18, preferably 6 to 12, and more preferably 7 to 12. The aromatic hydrocarbon group may be an aryl group from which nb1 hydrogen atoms have been removed. The aryl group may be a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, a fluorene group, etc. The number of carbon atoms in the aromatic hydrocarbon group may be 6 to 24, may be 6 to 18, is preferably 5 to 14, and is more preferably 5 to 10. L b1 When --CH2-- in the hydrocarbon group is replaced with --O--, --CO--, --S-- or --SO2--, the number of carbon atoms before the replacement is regarded as the number of carbon atoms in the hydrocarbon group. L b1Among the hydrocarbon groups in which -CH2- in a chain hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2-, there may be mentioned a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a carbonyl group (a group in which -CH2- in a methylene group is replaced by -CO-), an oxy group (a group in which -CH2- in a methylene group is replaced by -O-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position in an alkyl group is replaced by -O-CO-), an alkylcarbonyl group (an alkyl group in which -CH2- Examples of the substituted groups include -CH- at any position in the alkyl group, which is replaced with -CO-), alkylcarbonyloxy groups (wherein -CH-CH- at any position in the alkyl group is replaced with -CO-O-), alkanediyloxy groups (wherein -CH- at any position in the alkanediyl group is replaced with -O-), alkanediyloxycarbonyl groups (wherein -CH-CH- at any position in the alkanediyl group is replaced with -O-CO-), alkanediylcarbonyl groups (wherein -CH- at any position in the alkanediyl group is replaced with -CO-), and alkanediylcarbonyloxy groups (wherein -CH-CH- at any position in the alkanediyl group is replaced with -CO-). Examples of the substituted groups include the same groups as those exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms. L b1 Among these hydrocarbon groups, examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced with -O-, -CO-, -S- or -SO2- include cyclic ethers, cyclic ketones, cyclic esters (lactones), cyclic thioethers, cyclic acetals, and cyclic sultones. Specific examples include alicyclic hydrocarbon groups represented by the following formulas. The bonding position of the alicyclic hydrocarbon groups represented by the following formulas may be any position. TIFF2025074940000035.tif48165L b1Among these hydrocarbon groups, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-, and 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 that combines two or more groups selected from the chain hydrocarbon group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group include a group that combines the above-mentioned chain hydrocarbon group with the above-mentioned alicyclic hydrocarbon group, a group that combines the above-mentioned chain hydrocarbon group with the above-mentioned aromatic hydrocarbon group, a group that combines the above-mentioned alicyclic hydrocarbon group with the above-mentioned aromatic hydrocarbon group, a group that combines the above-mentioned chain hydrocarbon group with the above-mentioned alicyclic hydrocarbon group with the above-mentioned aromatic hydrocarbon group, and ... the above-mentioned combined groups. The group that combines the alicyclic hydrocarbon group with the aromatic hydrocarbon group may be a condensed ring. L b2 The divalent hydrocarbon group is a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, or a group formed by removing one hydrogen atom from the group consisting of two or more of these groups, b1 Examples of such groups include groups that bond to the L b2 The divalent chain hydrocarbon group, the divalent alicyclic hydrocarbon group, the divalent aromatic hydrocarbon group, and the divalent group consisting of two or more of these groups are each, within the range permitted by the number of carbon atoms, L b1 Examples of the alkyl group include groups in which one hydrogen atom has been removed from the chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups exemplified above, and groups in which two or more of these groups have been combined. L b1 and L b2 The substituents which the hydrocarbon group 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 b1 and L b2 When L is a group in which an alicyclic hydrocarbon group or an aromatic hydrocarbon group is combined with a chain hydrocarbon group, the chain hydrocarbon group may be regarded as a substituent that the alicyclic hydrocarbon group or the aromatic hydrocarbon group has. b1 and L b2The -CH2- of the chain hydrocarbon group contained in the hydrocarbon group is replaced with -O-, -CO-, -S- or -SO2-, thereby forming L b1 and L b2 The hydrocarbon group may substantially have a substituent 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, or a sulfonyl group. Y b1 Examples of the cyclic hydrocarbon group 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 aromatic hydrocarbon group of b1 Examples of the alicyclic hydrocarbon groups and aromatic hydrocarbon groups are the same as those exemplified in 1. When the alicyclic hydrocarbon groups and aromatic hydrocarbon groups do not have a substituent, they may be monovalent alicyclic hydrocarbon groups and aromatic hydrocarbon groups. Y b1 The substituents that the methyl group in Y may have include a halogen atom, a cyano group, a hydroxyl group, and a nitro group. b1 Examples of the substituent that the cyclic hydrocarbon group 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, or a nitro group (-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or -SO2-). b1 The number of carbon atoms in the hydrocarbon group that may be contained in the cyclic hydrocarbon group of Y b1 The number of cyclic hydrocarbon groups is not included in the number of hydrocarbon groups. Y b1 Examples of the hydrocarbon group having 1 to 18 carbon atoms that the cyclic hydrocarbon group may have as a substituent include linear hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups combining these groups. Examples of the linear hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and groups combining two or more of these groups include, within the range permitted by the upper limit of the carbon number, b1 Examples of the linear hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the group obtained by combining two or more of these groups are given as examples of the linear hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the group obtained by combining two or more of these groups. b1Examples of the group in which -CH2- in the hydrocarbon group having 1 to 18 carbon atoms that the cyclic hydrocarbon group may have as a substituent are replaced with -O-, -S-, -CO- or -SO2-, within the range permitted by the upper limit of the number of carbon atoms, and include the same groups as those exemplified as the group in which -CH2- in the hydrocarbon group of Lb1 is replaced with -O-, -S-, -CO- or -SO2-. b1 The hydrocarbon group having 1 to 18 carbon atoms which the cyclic hydrocarbon group may have as a substituent may constitute a protecting group or leaving group (acid labile group or base labile group) generally used in the art. The anion of the salt represented by formula (B1) is preferably an anion represented by the following formula (B1-A1) or an anion represented by formula (B1-A2). TIFF2025074940000036.tif30124[In formula (B1-A1), L b2 and Y b1 has the same meaning as in formula (B1). Q b1 , Q b2 , Q b3 and Q b4 each independently represents 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 an integer of 0 to 6. When z1 is 2 or more, the groups in the multiple parentheses may be the same or different. X 1 represents -O-CO-, -CO-O-, -O-CO-O- or -O-. L b3 represents a single bond or a (nb2+1) 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-. nb2 represents an integer of 1 to 3. When nb2 is 2 or more, the groups in the parentheses may be the same or different.] Q b1 , Q b2 , Q b3 and Q b4Examples of the alkyl group represented by the formula (I) 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. Q b1 , Q b2 , Q b3 and Q b4 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms include 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, and a perfluorohexyl group. Q b1 and Q b2 Q b1 and Q b2 At least one of the groups preferably contains a fluorine atom or a perfluoroalkyl group, more preferably a fluorine atom or a perfluoroalkyl group, even more preferably a fluorine atom or a trifluoromethyl group, and even more preferably both are fluorine atoms. Q b3 and Q b4 are each preferably independently a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 3 carbon atoms, and Q b3 is preferably a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 3 carbon atoms, and Q b4 is preferably a hydrogen atom or a fluorine atom. z1 is preferably an integer of 0 to 3, and is preferably 0, 1 or 2. X 1 is preferably -O-CO- or -CO-O-.

[0037] L b3 As the hydrocarbon group in the formula (B1), within the range permitted by the upper limit of the number of carbon atoms, b1 The same hydrocarbon groups as those exemplified above are included. In formula (B1-A1), L b3is preferably a single bond, a chain hydrocarbon group having 1 to 12 carbon atoms which may have a substituent (-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-), an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-), an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O- or -S-), and a group combining two or more of these groups, and more preferably a single bond, a chain hydrocarbon group having 1 to 6 carbon atoms, or a group represented by the following formula (Lb3-1). In addition, 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 one -CH2-CH2-CH2- contained in the chain hydrocarbon group is replaced by -O-CO-O-. TIFF2025074940000037.tif1582[In formula (Lb3-1), nb2 has the same meaning as in formula (B1-A1). L b31 represents 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 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 binding sites, * represents X 1 represents the binding site for In formula (Lb3-1), L b31 As long as the chain hydrocarbon group has the upper limit of the number of carbon atoms, L b1Examples of the chain hydrocarbon groups include the same chain hydrocarbon groups as those exemplified in the chain hydrocarbon groups 1. W b3 The alicyclic and aromatic hydrocarbon groups of L are as long as the upper limit of the carbon number permits. b1 Examples of the alicyclic hydrocarbon groups and aromatic hydrocarbon groups are given below. L b31 The substituents that the chain hydrocarbon group may have and W b1 The substituents that the alicyclic hydrocarbon group and aromatic hydrocarbon group may have are b1 The substituents which the hydrocarbon group may have include the same groups as those exemplified above. L b31 is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms (-CH2- contained in the alkanediyl group may be replaced by -O- or -CO-). Among them, W b1 The alicyclic hydrocarbon group and aromatic hydrocarbon group of the formula (I) include the alicyclic hydrocarbon group and aromatic hydrocarbon group represented below. In the alicyclic hydrocarbon group and aromatic hydrocarbon group represented below, * and ** represent a bonding site, * represents X 1 Or L b31 represents a bonding site with L, and ** represents a hydrogen atom, a substituent, or L b2 At least one ** represents a binding site for L b2 represents a bonding site with the alicyclic hydrocarbon group. In the alicyclic hydrocarbon groups represented below, -CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-. When -CH2- contained in the alicyclic hydrocarbon group is replaced with -O-, -S-, -CO- or -SO2-, it is preferable that an ether ring, an ester ring (lactone), a carbonate ring, a sultone ring or an acetal ring is formed. TIFF2025074940000038.tif36168In the formula (B1-A1), L b2 is preferably a single bond or an alkanediyl group having 1 to 12 carbon atoms (-CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), andb21 -X 2 -L b22 -**(L b21 and L b22 one of X represents an alkanediyl group having at least 1 to 6 carbon atoms, and the other represents a single bond or an alkanediyl group having 1 to 6 carbon atoms; 2 represents -O-, -CO-O-, -O-CO-, or -O-CO-O-; * and ** represent binding sites; ** represents Y b1 where L b21 , X 2 and L b22 The total number of carbon atoms is 12 or less. In formula (B1-A1), Y b1 is preferably a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (-CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -CO-, -S- or -SO2-), more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -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 (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -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 formulae (Y1) to (Y36). In formulae (Y1) to (Y36), R Yb is a hydrogen atom or Y b1 Among the substituents that the cyclic hydrocarbon group may have, R represents an alkyl group having 1 to 4 carbon atoms. Yc is a hydrogen atom or Y b1 represents a substituent that the cyclic hydrocarbon group may have, and * represents L b2 The alicyclic hydrocarbon group and aromatic hydrocarbon group represented by the following formulae may have other substituents, although these are not specifically shown in the following formulae. TIFF2025074940000039.tif95165

[0038] The anion represented by formula (B1-A1) is preferably an anion represented by formula (B1-A1-1) to formula (B1-A1-85) [hereinafter, may be referred to as "anion (B1-A1-1)" depending on the formula number.], and more preferably an anion represented by any of formula (B1-A1-1) to formula (B1-A1-4), formula (B1-A1-9), formula (B1-A1-10), formula (B1-A1-24) to formula (B1-A1-33), formula (B1-A1-36) to formula (B1-A1-40), and formula (B1-A1-47) to formula (B1-A1-85). TIFF2025074940000040.tif234160

[0039] TIFF2025074940000041.tif249152

[0040] TIFF2025074940000042.tif254163

[0041] In formulae (B1-A1-1) to (B1-A1-85), R i2 ~R i7 are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. i8 L 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. A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q b1 and Q b2 has the same meaning as above. Specific examples of the anion in the salt represented by formula (B1-A1) include the anions described in JP-A-2010-204646.

[0042] Preferable anions in the salt represented by formula (B1-A1) include the anions represented by formulas (B1a-1) to (B1a-70). TIFF2025074940000043.tif185163

[0043] TIFF2025074940000044.tif252165

[0044] TIFF2025074940000045.tif69165

[0045] Of these, anions represented by any one of formulae (B1a-1) to (B1a-3), (B1a-7) to (B1a-19), and (B1a-22) to (B1a-70) are preferred.

[0046] The anion represented by formula (B1-A2) is represented by the following formula: TIFF2025074940000046.tif24100[In formula (B1-A2), L b2 and Y b1 has the same meaning as in formula (B1). nb4 represents an integer of 1 to 5. When nb4 is 2 or more, the groups in the multiple parentheses may be the same or different. 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 with -O- or -CO-. nb3 represents an integer of 0 to 4, and when nb3 is 2 or more, a plurality of R b1 They may be the same or different. However, 1≦nb3+nb4≦5 is satisfied.

[0047] In formula (B1-A2), L b2 Hydrocarbon groups and Y b1 Examples of the cyclic hydrocarbon group include, within the upper limit of the carbon number, L in formula (B1). b2 Examples of hydrocarbon groups and Y b1 Examples of the cyclic hydrocarbon group are the same as those of L. b2 Hydrocarbon radical, Y b1The substituents which the methyl group and the cyclic hydrocarbon group may have are also defined as follows: b2 Hydrocarbon radical, Y b1 Examples of the substituent that the methyl group and the cyclic hydrocarbon group may have include the same as those mentioned above. In formula (B1-A2), L b2 represents preferably an alkanediyl group having 1 to 12 carbon atoms, in which -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-, and more preferably *-CO-OL b41 -(L b41 is a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms, in which -CH2- may be replaced by -O- or -CO-, and * is SO3 - represents the bonding site with the phenyl group to which L is bonded. b41 is preferably a single bond or a chain hydrocarbon group having 1 to 3 carbon atoms. In formula (B1-A2), Y b1 is preferably a cyclic hydrocarbon group having 3 to 18 carbon atoms (-CH2- contained in the cyclic hydrocarbon group may be replaced by -O- or -CO-), and more preferably, Y in formula (B1-A1) is b1 , and L b1 and more preferably, the groups represented by the above formulae (Y1) to (Y36). Y b1 The substituent that the cyclic hydrocarbon group may have is preferably a halogen atom or an alkyl group having 1 to 6 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O-, -S-, -CO- or -SO2-), more preferably a fluorine atom, an iodine atom or an alkyl group having 1 to 4 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O-, -S-, -CO- or -SO2-), still more preferably a fluorine atom, an iodine atom, a hydroxy group, an alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 4 carbon atoms, and still more preferably a fluorine atom, an iodine atom, a hydroxy group or an alkyl group having 1 to 4 carbon atoms. b2The substituent of may constitute a protecting group or leaving group (acid labile group or base labile group) commonly used in the art.

[0048] In formula (B1-A2), nb4 is preferably any integer of 1 to 4, more preferably any integer of 1 to 3, further preferably 1 or 2, and further more preferably 2. When nb4 is 1 or 2, -L b2 -Y b1 The bond position of SO3 - It is preferable that the structure be the following structure in which the m-position of the benzene ring is substituted with respect to the bonding position of the above. TIFF2025074940000047.tif28106[In the above formula, L b2 , Y b1 , R b1 , nb3 has the same meaning as in formula (B1-A2). If nb4 is 2 or more, multiple L b2 and Y b1 are preferably the same groups.

[0049] R b1 Examples of the alkyl group having 1 to 6 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 4, and more preferably 1 to 3. R b1 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R b1 are each independently preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), more preferably a fluorine atom, an iodine atom, or an alkyl group having 1 to 3 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), and further preferably a fluorine atom, an iodine atom, a hydroxy group, a methoxy group, or a methyl group. nb3 is an integer of 0 to 4, preferably an integer of 0 to 3, and more preferably an integer of 0 to 2. In one embodiment, 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 More preferably, nb3 is a fluorine atom or an iodine atom. When nb3 is 2, R b1 It is preferable that one of R is a halogen atom and the other is a halogen atom or an alkyl group having 1 to 4 carbon atoms. b1 It is more preferable that one of them is a fluorine atom or an iodine atom, and the other is a fluorine atom, an iodine atom, or an alkyl group having 1 to 3 carbon atoms.

[0050] Examples of the anion (B1-A2) include the following anions. Among them, the anions represented by the formulas (B2a-1) to (B2a-20) are preferred, and the anions represented by the formulas (B2a-1) to (B2a-11) and (B2a-16) to (B2a-20) are more preferred. TIFF2025074940000048.tif102153

[0051] In another embodiment of the acid generator (B), an anion in which the anion represented by formula (B1) is replaced with a sulfonimide anion, a sulfonylmethide anion, or a carboxylate anion is also preferably used as the acid generator (B). The sulfonylimide anion or sulfonylmethide anion is preferably a sulfonylimide anion or sulfonylmethide anion represented by formula (B1-A3) (hereinafter, sometimes referred to as "anion (B1-A3)"). TIFF2025074940000049.tif1290[In formula (B1-A3), A 1 represents a nitrogen atom or a carbon atom. L b2represents 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 an optionally substituted methyl group or an optionally substituted cyclic hydrocarbon group having 3 to 24 carbon atoms, in which -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-, and two -L b2’ -Y b1’ Together, A 1 may form a ring comprising: 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 in the brackets may be the same or different. In formula (B1-A3), L b2 ' and Y b1 Examples of L′ in formula (B1-A1) are b2 and Y b1 The same groups as those shown in the above are included. 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 represents -O-, -CO-O-, -O-CO-, -O-CO-O- or -O-; W 2 represents an alicyclic hydrocarbon group having 3 to 12 carbon atoms, -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-, and * represents a bonding site with SO2.) is preferable. 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 is more preferably a trifluoromethyl group or a group represented by Formulae (Y1) to (Y36) in Formula (B1-A1). nb5 is preferably 2 or 3. In formula (B1-A3), two L b2’ -Y b1’ Together, A 1 When a ring containing the formula (B1-A3′) is formed, examples of the anion include an anion represented by the formula (B1-A3′). TIFF2025074940000050.tif21122[In formula (B1-A3'), A 1 , Y b1 ', L b2 'nb5 has the same meaning as in formula (B1-A3). W b4 represents a disulfonylimide ring or disulfonylmethide ring having 3 to 12 carbon atoms which may have a fluorine atom.] W b4 The disulfonylimide ring or disulfonylmethide ring preferably has 3 to 6 carbon atoms, and the hydrogen atom of the methylene group contained in the ring is preferably substituted with a fluorine atom.

[0052] Examples of the anion represented by formula (B1-A3) include the following: Among these, the anions represented by formula (B1-a3-1) and formula (B1-a3-2) are preferred. TIFF2025074940000051.tif188163

[0053] Examples of carboxylate anions include the following: TIFF2025074940000052.tif41155

[0054] ZI +Examples of the organic cation include an organic onium cation, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among these, the organic sulfonium cation and the organic iodonium cation are preferred, and the arylsulfonium cation is more preferred. + As the organic cation of formula (I), Z + The cations are the same as those of the above.

[0055] The salt (B1) is a combination of the above-mentioned anion and the above-mentioned organic cation, which can be arbitrarily combined. The salt (B1) is preferably a combination of an anion represented by any of the anions represented by the formulas (B1a-1) to (B1a-3), (B1a-7) to (B1a-19), (B1a-22) to (B1a-70), (B2a-1) to (B2a-11), (B2a-16) to (B2a-20), (B1-3a-1) to (B1-3a-3), or (B1-3a-11) to (B1-3a-14) and a cation (b2-1), a cation (b2-2), a cation (b2-3), a cation (b2-4), or a cation (b2-5).

[0056] Compound (B) is preferably any of those represented by formulae (B1-1) to (B1-105), (B2-1) to (B2-20), and (B3-1) to (B3-20). Among these, those containing an arylsulfonium cation are preferred, and those represented by formulae (B1-1) to (B1-3), (B1-5) to (B1-7), (B1-11) to (B1-14), (B1-20) to (B1-26), (B1-29), (B1-31) to (B1-105), (B2-1) to (B2-20), and (B3-1) to (B3-28) are particularly preferred. TIFF2025074940000053.tif248168

[0057] TIFF2025074940000054.tif243160

[0058] TIFF2025074940000055.tif250155

[0059] TIFF2025074940000056.tif252160

[0060] TIFF2025074940000057.tif249158

[0061] TIFF2025074940000058.tif250151

[0062] TIFF2025074940000059.tif186160

[0063] When the acid generator contains salt (I) and compound (B), the ratio of the contents of salt (I) to compound (B) (mass ratio; salt (I):compound (B)) is, for example, 1:99 to 100:0, and may be 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, even more preferably 10:90 to 90:10, and particularly preferably 15:85 to 85:15.

[0064] [Resist Composition] The resist composition of the present invention contains an acid generator containing a salt (I). The resist composition of the present invention may further contain a compound having a phenolic hydroxyl group and / or a compound in which the hydroxyl group of the phenolic hydroxyl group is protected with an acid labile group, and 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)"), a resin containing a structural unit not having an acid labile group (hereinafter sometimes referred to as "resin (AX)"), and / or a resin other than resin (A). Here, the "acid labile group" means a group that has a leaving group and is released by contact with an acid, converting the structural unit into a structural unit having a hydrophilic group (e.g., a hydroxyl group or a carboxyl group). The resist composition of the present invention preferably contains a quencher such as a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (hereinafter may be referred to as "quencher (C)"), and preferably contains a solvent (hereinafter may be referred to as "solvent (E)").

[0065] <Acid generator> In the resist composition of the present invention, the total content of the acid generators is preferably 0.1% by mass or more and 99.9% by mass or less, more preferably 30% by mass or more and 100% by mass or less, more preferably 75% by mass or more and 99.9% by mass or less, and even more preferably 80% by mass or more and 99.9% by mass or less, based on the solid content of the resist composition. When the composition contains a resin (A) or a resin (AX) described below, the total content of the acid generators is preferably 1 part by mass or more and 200 parts by mass or less, more preferably 50 parts by mass or more and 200 parts by mass or less, and even more preferably 80 parts by mass or more and 200 parts by mass or less, based on 100 parts by mass of the total of the resin (A) and / or the resin (AX) described below.

[0066] <Compounds having a phenolic hydroxyl group> The resist composition of the present invention preferably contains a compound having a phenolic hydroxyl group and / or a compound in which the hydroxyl group of a phenolic hydroxyl group is protected with an acid labile group. Examples of the compound having a phenolic hydroxyl group and / or a compound in which the hydroxyl group of a phenolic hydroxyl group is protected with an acid labile group include compounds represented by formula (LX). TIFF2025074940000060.tif23121[In formula (LX), X ln1 and X lm1 each independently represents a single bond or a carbonyl group. R ln1 and R lm2 each independently represents a hydrogen atom or an acid labile group. Lx represents a hydrocarbon group having a total of 1 to 20 carbon atoms including a chain hydrocarbon group having 1 to 6 carbon atoms or an aromatic hydrocarbon group, and the chain hydrocarbon group and aromatic hydrocarbon group may have a substituent. R ln2 and R lm3each independently represents a halogen atom or a fluorinated alkyl group having 1 to 3 carbon atoms. ln1 represents an integer of 1 to 5, and when ln1 is 2 or more, the groups in multiple parentheses may be the same or different. ln2 represents an integer from 0 to 4, and satisfies 1≦ln1+ln2≦5. When ln2 is 2 or more, multiple R ln2 may be the same or different from each other. Im1 represents an integer of 1 to 3, and when lm1 is 2 or more, the groups in multiple parentheses may be the same or different. Im2 represents an integer of 1 to 5, and when Im2 is 2 or more, the groups in the parentheses may be the same or different. lm3 represents an integer between 0 and 4, and satisfies 1≦lm2+lm3≦5. When lm3 is 2 or more, multiple R lm3 may be the same or different. Examples of the acid labile group include a group represented by the formula (1) and a group represented by the formula (2) described below. Of these, the group represented by the formula (2) is preferred. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the fluorinated alkyl group include a trifluoromethyl group, a difluoromethyl group, a monofluoroalkyl group, a perfluoroethyl group, and a perfluoropropyl group. Examples of the chain hydrocarbon group include a straight-chain or branched alkyl group, an alkanediyl group, an alkanetriyl group, and an alkanetetroyl group. An example of the aromatic hydrocarbon group is a phenyl group. Examples of the hydrocarbon group including an aromatic hydrocarbon group include a phenyl group and a combination of a phenyl group with a linear or branched alkyl group, an alkanediyl group, an alkanetriyl group, and an alkanetetroyl group. The substituents include a hydroxy group or a halogen atom.

[0067] The compound having a phenolic hydroxyl group and / or the compound in which the phenolic hydroxyl group is protected with an acid labile group may be either a low molecular weight compound or a resin. The low molecular weight compound is a compound having a molecular weight of less than 10,000, preferably 2,500 or less. Examples of the compound having a phenolic hydroxyl group include compounds represented by the following formula. TIFF2025074940000061.tif72163 Examples of low molecular weight compounds in which the phenolic hydroxyl group is protected with an acid labile group include compounds represented by the following formula. TIFF2025074940000062.tif86166 When the resist composition of the present invention contains a low molecular weight compound having a phenolic hydroxyl group and / or a low molecular weight compound in which the hydroxyl group of a phenolic hydroxyl group is protected with an acid labile group, the content of the low molecular weight compound having a phenolic hydroxyl group and / or the low molecular weight compound in which the hydroxyl group of a phenolic hydroxyl group is protected with an acid labile group is, relative to the solids content of the resist composition, for example, 0.1 mass % or more and 90 mass % or less, preferably 0.3 mass % or more and 45 mass % or less, more preferably 0.5 mass % or more and 40 mass % or less, and even more preferably 1 mass % or more and 35 mass % or less.

[0068] When a compound having a phenolic hydroxyl group and / or a compound in which the hydroxyl group of a phenolic hydroxyl group is protected with an acid labile group is a resin, examples of the structural unit represented by formula (a2-A) and / or the structural unit represented by formula (a1-4) are given. TIFF2025074940000063.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, 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 a21 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group is -O-, -CO- or -NR a28 - may be replaced. 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 4, and when nA2 is 2 or greater, 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 from 0 to 2.

[0069] R a2 and R a27 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and a bromine atom. R a2 and R a27Examples of the alkyl group having 1 to 6 carbon atoms, which may have a halogen atom, 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. R a2 and R a27 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 further preferably a hydrogen atom or a methyl group.

[0070] A a21 Examples of the alkanediyl group 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 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, and the like. and branched alkanediyl groups such as butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, 2-methylbutane-1,4-diyl, heptane-1,6-diyl, octane-1,7-diyl, nonane-1,8-diyl, and decane-1,9-diyl. The number of carbon atoms in the alkanediyl group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, even more preferably 1 to 4, still more preferably 1 to 3, and even more preferably 1 or 2. A a21is preferably a methylene group or an ethylene group. R a28 Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a tert-butyl group. A a21 The alkanediyl group -CH2- is -O-, -CO- or -NR a28 When the hydrocarbon group is replaced with, the number of carbon atoms before the replacement is regarded as the number of carbon atoms of the hydrocarbon group. A a21 Examples of the alkanediyl group in which -CH2- is replaced by -O- or -CO- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a carbonyl group (a group in which -CH2- in a methylene group is replaced by -CO-), an oxy group (a group in which -CH2- in a methylene group is replaced by -O-), an amino group (a group in which -CH2- in an alkanediyl group is replaced by -NR a28 -), alkoxy group (a group in which -CH2- at any position in the alkyl group is replaced with -O-), alkoxycarbonyl group (a group in which -CH2-CH2- at any position in the alkyl group is replaced with -O-CO-), alkylcarbonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -CO-), alkylamino group (a group in which -CH2- in the alkyl group is replaced with -NR a28 These substituted groups include the same groups as those exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms. The alkylamino group includes alkylamino groups having 1 to 11 carbon atoms, such as a methylamino group, an ethylamino group, a propylamino group, a butylamino group, a pentylamino group, a hexylamino group, an octylamino group, etc. The number of carbon atoms in the alkylamino group is preferably 1 to 8, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. The alkanediylamino group includes an alkanediylamino group having 1 to 11 carbon atoms, such as a methyleneamino group, an ethyleneamino group, a propyleneamino group, etc. The number of carbon atoms in the alkanediylamino group is preferably 1 to 8, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. Among them, A a21 The -CH2- in the alkanediyl group is -O-, -CO- or -NR a28 The groups substituted are *-O-, *-CO-O-, *-O-CO-, *-CO-OA. a22 -CO-O-, *-O-CO-A a22 -O-, *-OA a22 -CO-O-, *-CO-OA a22 -O-CO-, *-O-CO-A a22 -O-CO-, and *-CO-O- and *-CO-OA are particularly well known. a22 -CO-O- or *-OA a22 -CO-O-, *-CO-NR a28 - is preferred, where A a22 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents R a2 represents the bonding site that bonds to the carbon atom to which A is attached. a22 The alkanediyl group of A is as follows, within the upper limit of the carbon number. a21 The same alkanediyl groups as those shown in the above are also included. A a21 is a single bond, *-CO-O- or *-CO-OA a22 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[0071] R a27Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, and a tert-butoxy group. The number of carbon atoms in the alkoxy group is preferably 1 to 4, more preferably 1 to 3, 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 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 further preferably a methoxymethyl group. R a27 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, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R a27 Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a27 The alkylcarbonyloxy group includes an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a27is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, 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 further preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group. nA2 may be 1, 2, 3 or 4, with 1, 2 or 3 being preferred, and 1 or 2 being more preferred. na22 is preferably 0, 1 or 2, and more preferably 0 or 1. mc is preferably 0 or 1. -X a2 -OH is a benzene ring, A a21 It is preferable that at least one of them is bonded to the m-position or p-position, and more preferable that it is bonded to the m-position. In the case of a naphthalene ring, A a21 When the bonding position of A is the 1st position, it may be bonded to any of the 2nd to 8th positions. a21 When the bonding position of A is the 2-position, it may be bonded to any of the 1-position and the 3-8-positions. a21 When the bonding position of A is the 1st position, at least one of them is preferably bonded to the 3rd to 6th positions, and more preferably bonded to the 3rd or 4th position. a21 When the bonding position is the 2-position, it is preferably bonded to the 4- to 7-positions, and more preferably bonded to the 5- or 6-position.

[0072] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577. The structural unit (a2-A) includes structural units represented by formulae (a2-2-1) to (a2-2-32), (a2-3-1) to (a2-3-24), and structural units represented by formulae (a2-2-1) to (a2-2-32), (a2-3-1) to (a2-3-24), and R in the structural unit (a2-A) a2and the like, in which the methyl group corresponding to the following formula (I) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. TIFF2025074940000064.tif107170

[0073] TIFF2025074940000065.tif83166 When the structural unit (a2-A) is contained in the resin, the content of the structural unit (a2-A) is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and even more preferably 20 mol% or more, based on the total structural units. Also, it is preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, it is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, even more preferably 15 to 65 mol%, and even more preferably 20 to 65 mol%. The structural unit (a2-A) may be a compound from which the structural unit (a2-A) is derived (e.g., -CH2-C(-R a2 )- is the double bond CH2=C(-R a2 The structural unit (a2-A) can be incorporated into the resin (A) by polymerizing the compound (a2-A') in the state of (a1-4). Alternatively, for example, the structural unit (a1-4) can be polymerized, followed by treatment with an acid such as p-toluenesulfonic acid, to incorporate the structural unit into the resin (A). Alternatively, the structural unit (a2-A) can be polymerized using acetoxystyrene or the like, followed by treatment with an alkali such as tetramethylammonium hydroxide, to incorporate the structural unit into the resin (A).

[0074] TIFF2025074940000066.tif31119[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 a17represents 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 is -O-, -CO- or -NR a18 - may be replaced. 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 -CO- 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 an integer of any one of 1 to 5, and when na1 is 2 or more, the groups in the multiple parentheses may be the same or different. na11 represents an integer of 0 to 4. When na11 is 2 or more, multiple R a17 may be the same or different from each other. mc represents an integer from 0 to 2.

[0075] R a1 and R a17 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and a bromine atom. R a1 and R a17Examples of the alkyl group having 1 to 6 carbon atoms, which may have a halogen atom, 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, further preferably a methyl group or an ethyl group, and even more preferably a methyl group. 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 further preferably a hydrogen atom or a methyl group. R a17 Examples of the alkoxy group in 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 further preferably a methoxy group. R a17 Examples of the alkoxyalkyl group in the formula (I) 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 further preferably a methoxymethyl group. R a17In the above, 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, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R a17 Examples of the alkylcarbonyl group in include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a17 In the above formula, 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. R a17 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, 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 further preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0076] A a11Examples of the alkanediyl group include branched alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, 2-methylbutane-1,4-diyl, heptane-1,6-diyl, octane-1,8-diyl, nonane-1,9-diyl, and decane-1,10-diyl. The number of carbon atoms in the alkanediyl group is preferably 1 to 6, more preferably 1 to 4, even more preferably 1 to 3, and even more preferably 1 or 2. Among them, A a11 is preferably a methylene group or an ethylene group. R a18 Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a tert-butyl group. A a11 The alkanediyl group -CH2- is -O-, -CO- or -NR a18 When the hydrocarbon group is replaced with, the number of carbon atoms before the replacement is regarded as the number of carbon atoms of the hydrocarbon group. A a11 Examples of the alkanediyl group in which -CH2- is replaced with -O- or -CO- include 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 ethylene group in which -CH2-CH2- is replaced with -CO-NR a18 Examples of the substituted groups include those exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms. For example, A a11 The -CH2- in the alkanediyl group is -O-, -CO- or -NR a28The groups substituted are *-O-, *-CO-O-, *-O-CO-, *-CO-OA. a12 -CO-O-, *-O-CO-A a12 -O-, *-OA a12 -CO-O-, *-CO-OA a12 -O-CO-, *-O-CO-A a12 -O-CO-, and *-CO-O- and *-CO-OA are particularly well known. a12 -CO-O- or *-OA a12 -CO-O-, *-CO-NR a18 - is preferred, where A a12 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents R a1 represents the bonding site that bonds to the carbon atom to which A is attached. a12 The alkanediyl group of A is as follows, within the upper limit of the carbon number. a11 The same alkanediyl groups as those shown in the above are also included. A a11 is a single bond, *-CO-O- or *-CO-OA a12 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred. 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 further preferably 0 or 1. mc is preferably 0 or 1.

[0077] 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 consisting of a combination thereof. 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, and an octyl group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups (* indicates a bonding site): TIFF2025074940000067.tif10151 Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group in which the above-mentioned alkyl group and alicyclic hydrocarbon group are combined (e.g., alkylcycloalkyl groups or cycloalkylalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, and norbornylethyl group), 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.), and aryl-cycloalkyl groups such as phenylcyclohexyl group. In particular, R a36 Examples of the alkyl group 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 groups. R a35 and R a36 Examples of the divalent hydrocarbon group having 2 to 20 carbon atoms that is formed by bonding together with the -CO- to which they are bonded include the following groups. * represents a bonding site, and one of the groups is R a34 This is the binding site for TIFF2025074940000068.tif15105

[0078] R a34 is preferably a hydrogen atom. R a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a methyl group or an ethyl group. R a36 The hydrocarbon group in 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, and more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. a36 The alkyl group and the alicyclic hydrocarbon group in R are preferably unsubstituted. a36 The aromatic hydrocarbon group in is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

[0079] -OC(R a34 )(R a35 )-OR a36 is eliminated on contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group or a carboxy group. -X a1 -OC(R a34 )(R a35 )-OR a36 In the case of a benzene ring, A a11 It is preferable that at least one of them is bonded to the o-position or the m-position, and more preferable that it is bonded to the p-position. In the case of a naphthalene ring, A a11 When the bonding position of A is the 1st position, it may be bonded to any of the 2nd to 8th positions. a11 When the bonding position of A is the 2-position, it may be bonded to any of the 1-position and the 3-8-positions. a11 When the bonding position of A is the 1st position, at least one of them is preferably bonded to the 3rd to 6th positions, and more preferably bonded to the 3rd or 4th position. a11 When the bonding position is the 2-position, it is preferably bonded to the 4- to 7-positions, and more preferably bonded to the 5- or 6-position.

[0080] Examples of the structural unit (a1-4) include structural units derived from monomers described in JP 2010-204646 A. Preferably, the structural units represented by formulas (a1-4-1) to (a1-4-42) and R in the structural unit (a1-4) are a1 and more preferably, the structural units represented by formulae (a1-4-1) to (a1-4-5), (a1-4-10), (a1-4-13), and (a1-4-14), respectively. TIFF2025074940000069.tif228165

[0081] When the resin contains the structural unit (a1-4), the content thereof is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, even more preferably 30 mol% or more, even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on the total of all structural units of the resin (A). Also, the content is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, even more preferably 80 mol% or less, even more preferably 75 mol% or less, even more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, the content is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, even more preferably 20 to 85 mol%, even more preferably 20 to 70 mol%, and particularly preferably 20 to 60 mol%.

[0082] When the resist composition of the present invention contains a resin, the resin may contain structural units other than the structural unit represented by formula (a2-A) and the structural unit represented by formula (a1-4). Examples of the structural units other than the structural unit represented by formula (a2-A) and the structural unit represented by formula (a1-4) include structural units having an acid labile group other than the structural unit represented by formula (a1-4) (hereinafter may be referred to as "structural unit (a1)"), structural units not having an acid labile group other than the structural unit represented by formula (a2-A) (hereinafter may be referred to as "structural unit (s)"), and structural units derived from other monomers known in the field.

[0083] <Structural unit (a1)> The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid labile group contained in the resin 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)). TIFF2025074940000070.tif2298[In formula (1), R a1 , R a2 and R a3 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 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, 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, alkenyl group, alicyclic hydrocarbon group and 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. * denotes a binding site.] TIFF2025074940000071.tif2278[In formula (2), R a1’ and R a2’ each independently represents 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. * denotes a binding site.]

[0084] 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, and an octyl group. 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, and a nonenyl group. R a1 , R a2 and R a3 The alicyclic hydrocarbon group in may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups (* indicates a bonding site). R a1 , R a2 and R a3 The alicyclic hydrocarbon group preferably has 3 to 16 carbon atoms. TIFF2025074940000072.tif10159R a1 , R a2 and R a3 Examples of the aromatic hydrocarbon group in include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group in which the above-mentioned alkyl group and an alicyclic hydrocarbon group are combined (for example, an alkylcycloalkyl group or a cycloalkylalkyl group such as a methylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, or a norbornylethyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, or the like), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (a p-cyclohexylphenyl group, a p-adamantylphenyl group, or the like), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. Preferably, ma is 0 and na is 1. R a1 and R a2 When they 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-. TIFF2025074940000073.tif26137

[0085] 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 formed by 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 bonded and X, -C(R a1’ )(R a2’)-XR a3’ Examples of the ring include the following: * represents a binding site. TIFF2025074940000074.tif19124R 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. R a1’ and R a2’ At least one of these is preferably a hydrogen atom. na' is preferably 0.

[0086] 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), R a1 , R a2 together with the carbon atom to which they are attached form an adamantyl group, R a3 is an alkyl group, ma=0, and na=1. In formula (1), R a1 and R a2 are each independently an alkyl group; R a3 is an adamantyl group, ma=0, and na=1. Specific examples of the group (1) include the following groups. * represents a bond. TIFF2025074940000075.tif150162

[0087] Specific examples of the group (2) include the following groups. * represents a bond. TIFF2025074940000076.tif55153

[0088] The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer having an acid labile group.

[0089] Of the (meth)acrylic monomers having an acid labile group, preferred are those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms. By using a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group in a resist composition, the resolution of the resist pattern can be improved.

[0090] 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. TIFF2025074940000077.tif44141 [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 , L a1 and L a2 are each independently -O- or *-O-(CH2) k1 represents --CO--O--, k1 represents an integer of 1 to 7, and * represents a 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 a04each 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.

[0091] The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R a01 , R a4 , R a5 The alkyl group may be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group. R a01 , R a4 and R a5 is preferably a hydrogen atom or a methyl group, and more preferably a methyl group. L a01 , L a1 and L a2 is preferably an oxygen atom or *-O-(CH2) k01 It is -CO-O- (wherein k01 is preferably an integer of any one of 1 to 4, more preferably 1), and more preferably an oxygen atom. R a02 , R a03 , R a04 , R a6 and R a7 The alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and combinations thereof in the formula (1) include R a1 , R a2 and Ra3 Examples of the groups include the same groups as those listed in the above. R a02 , R a03 , and R a04 The alkyl group in the formula (I) 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. R a6 and R a7 The alkyl group in the formula (I) 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. R a6 and R a7 The alkenyl group in is preferably an alkenyl group having 2 to 6 carbon atoms, and more preferably an ethenyl group, a propenyl group, an isopropenyl group, or a butenyl group. R a02 , R a03 , R a04 , R a6 and R a7 The alicyclic hydrocarbon group preferably has 5 to 12 carbon atoms, and more preferably 5 to 10 carbon atoms. R a02 , R a03 , R a04 , R a6 and R a7 The aromatic hydrocarbon group preferably has 6 to 12 carbon atoms, and more preferably 6 to 10 carbon atoms. In the group in which an alkyl group and an alicyclic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the alicyclic hydrocarbon group is preferably 18 or less. In the group in which an alkyl group and an aromatic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the aromatic hydrocarbon group is preferably 18 or less. R a02 and R a03 is preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group which may have a halogen atom. R a04is 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, and 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 is 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, ethyl group, isopropyl group, t-butyl group, ethenyl group, phenyl group or naphthyl group which may have a halogen atom, and even more preferably an ethyl group, isopropyl group, t-butyl group, ethenyl group or phenyl group which may have a halogen atom. m1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1' is preferably 0 or 1.

[0092] Examples of the structural unit (a1-0) include a structural unit represented by any one of formulas (a1-0-1) to (a1-0-24) and R a01 and structural units in which the methyl group corresponding to the formula (a1-0-1) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group (an alkyl group having a halogen atom) or another alkyl group. Structural units represented by any of formulas (a1-0-1) to (a1-0-10), (a1-0-13), (a1-0-14) and (a1-0-19) to (a1-0-24) are preferred. JPEG2025074940000078.jpg119160

[0093] Examples of the structural unit (a1-1) include structural units derived from monomers described in JP 2010-204646 A. Among them, structural units represented by any one of formulas (a1-1-1) to (a1-1-7) and R in the structural unit (a1-1) area4 In the above formula (a1-1-1), a methyl group is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. In the above formula (a1-1-2), a methyl group is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. In the above formula (a1-1-3), a methyl group is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. In the above formula (a1-1-4), a structural unit is more preferred. TIFF2025074940000079.tif38168

[0094] The structural unit (a1-2) includes a structural unit represented by any one of formulas (a1-2-1) to (a1-2-20) and R a5 and structural units in which a methyl group corresponding to the formula (a1-2-2), (a1-2-5), (a1-2-6), and (a1-2-10) to (a1-2-20) are replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. TIFF2025074940000080.tif91163 When the resin contains the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content of these units relative to the total structural units of the resin is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, even more preferably 30 mol% or more, even more preferably 40 mol% or more, and even more preferably 50 mol% or more. Also, 95 mol% or less is included, preferably 90 mol% or less, more preferably 85 mol% or less, even 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%, even more preferably 25 to 70 mol%, and even more preferably 30 to 70 mol%. When the resin 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, even more preferably 20 mol% or more, even more preferably 25 mol% or more, even more preferably 30 mol% or more, and even more preferably 35 mol% or more, based on the total structural units of the resin. Also, the content is 80 mol% or less, preferably 75 mol% or less, more preferably 70 mol% or less, even more preferably 65 mol% or less, and even more preferably 60 mol% or less. Specifically, the content is 5 to 80 mol%, preferably 5 to 75 mol%, and more preferably 10 to 70 mol%. When the resin contains the structural unit (a1-1) and / or the structural unit (a1-2), the total content of these units is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, even more preferably 25 mol% or more, even more preferably 30 mol% or more, even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on the total structural units of the resin (A). Also, 95 mol% or less is included, preferably 90 mol% or less, more preferably 85 mol% or less, even more preferably 80 mol% or less, even more preferably 75 mol% or less, even more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, 10 to 95 mol% is included, preferably 15 to 85 mol%, more preferably 15 to 80 mol%, even more preferably 20 to 80 mol%, even more preferably 20 to 75 mol%, and even more preferably 20 to 70 mol%.

[0095] An example of a structural unit derived from a (meth)acrylic monomer having the group (2) is a structural unit represented by formula (a1-5) (hereinafter, may be referred to as "structural unit (a1-5)"). TIFF2025074940000081.tif4759[In formula (a1-5), R a8represents 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 -(CH2) 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.

[0096] Examples of the halogen atom include a fluorine atom and a chlorine atom, with a fluorine atom being preferred. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group, and a trifluoromethyl group. 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 Of these, it is preferred that one is -O- and the other is -S-. It is preferable that s1 is 1. s1' is preferably an integer of 0 to 2. Z a1 is preferably a single bond or -CH2-CO-O-.

[0097] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP 2010-61117 A. Among them, the structural units represented by formulae (a1-5-1) to (a1-5-4) are preferred, and the structural unit represented by formula (a1-5-1) or (a1-5-2) is more preferred. TIFF2025074940000082.tif31130 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, even more preferably 5 mol% or more, even more preferably 10 mol% or more, even more preferably 20 mol% or more, and even more preferably 25 mol% or more, based on the total structural units of the resin (A). Also, 80 mol% or less is mentioned, preferably 70 mol% or less, more preferably 60 mol% or less, even more preferably 50 mol% or less, even more preferably 45 mol% or less, 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 even more preferred, and 5 to 30 mol% is even more preferred.

[0098] An example of the structural unit (a1) having a group (1) is a structural unit represented by formula (a1-6) (hereinafter, sometimes referred to as "structural unit (a1-6)"). TIFF2025074940000083.tif3481[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 a ring having 3 to 20 carbon atoms together with the carbon atoms to which they are attached. X a61 is a single bond, -CO-O-* or -CO-NR a65 -*, where * represents the bonding site with Ar, and R a65 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X a62 is a single bond, *-OL a61-or*-CO-OL a62 -, * represents the binding site with -r, 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.]

[0099] R a61 Examples of the halogen atom in include a fluorine atom, an iodine atom, a chlorine atom, and a bromine atom. Of these, a fluorine atom is preferred. R a61 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl 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, and a perfluorohexyl group. 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. TIFF2025074940000084.tif31110

[0100] L a61 and L a62 Examples of the alkanediyl group having 1 to 4 carbon atoms 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, and a 2-methylpropane-1,2-diyl group. L a61 and L a62is preferably each independently a methylene group or an ethylene group. X a61 is preferably a single bond or -CO-O-*, and more preferably a single bond. X a62 is preferably a single bond or *-OL a61 -, and more preferably a single bond.

[0101] Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms for 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, 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.

[0102] 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 an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group. Examples of the 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 further 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 further 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, and more preferably a methoxyethoxy group or an ethoxyethoxy group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group, etc. 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. The substituent is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, 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. Ar is preferably a phenylene group which may have a substituent, and more preferably a phenylene group which may have a hydroxy group.

[0103] Examples of the structural unit (a1-6) include structural units represented by formulae (a1-6-1) to (a1-6-44), preferably structural units represented by formulae (a1-6-1) to (a1-6-9), more preferably structural units represented by formulae (a1-6-1), (a1-6-2), (a1-6-4), (a1-6-5), (a1-6-7) or (a1-6-8), and even more preferably structural units represented by formulae (a1-6-1) or (a1-6-2). a61 The structural unit in which the hydrogen atom corresponding to is replaced by a methyl group, etc., and the structural unit in which R a61 The structural unit (a1-6) also includes a structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom. TIFF2025074940000085.tif226161

[0104] When the resin (A) contains the structural unit (a1-6), the content thereof 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, even more preferably 30 mol% or more, and even more preferably 40 mol% or more, based on the total structural units of the resin (A). Also, the content is 80 mol% or less, preferably 75 mol% or less, more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, the content is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, even more preferably 7 to 70 mol%, even more preferably 7 to 65 mol%, and particularly preferably 10 to 65 mol%.

[0105] Further, examples of the structural unit (a1) include the following structural units. TIFF2025074940000086.tif33167

[0106] When the resin (A) etc. contains the structural units represented by the 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, even more preferably 25 mol% or more, even more preferably 30 mol% or more, even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on the total structural units of the resin (A) etc. Also, the content is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, even more preferably 80 mol% or less, even more preferably 75 mol% or less, even more preferably 70 mol% or less, and even more preferably 60 mol% or less. Specifically, 10 to 95 mol% is preferred, 15 to 90 mol% is more preferred, 20 to 85 mol% is even more preferred, 20 to 70 mol% is even more preferred, and 20 to 60 mol% is particularly preferred.

[0107] Further, examples of the structural unit (a1) include the following structural units. TIFF2025074940000087.tif51120 When the resin (A) etc. contains the structural units represented by the 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, even more preferably 25 mol% or more, even more preferably 30 mol% or more, even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on the total structural units of the resin (A) etc. Also, 95 mol% or less is mentioned, preferably 90 mol% or less, more preferably 85 mol% or less, even more preferably 80 mol% or less, even more preferably 75 mol% or less, even more preferably 70 mol% or less, and even more preferably 60 mol% or less. Specifically, it is preferably 10 to 60 mol %, more preferably 15 to 55 mol %, even more preferably 20 to 50 mol %, even more preferably 20 to 45 mol %, and particularly preferably 20 to 40 mol %.

[0108] Structural unit(s) The structural unit (s) is derived from a monomer having no acid labile group (hereinafter, may be referred to as "monomer (s)"). As the monomer from which the structural unit (s) is 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 or a lactone ring. If a resin containing a structural unit having a hydroxy group and no acid labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit having a lactone ring and 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 adhesion to the substrate can be improved. In addition to the above-mentioned structural units, the structural unit (s) may also include a structural unit having a halogen atom (hereinafter sometimes referred to as "structural unit (a4)"), a structural unit having a non-leaving hydrocarbon group (hereinafter sometimes referred to as "structural unit (a5)"), a structural unit having a sultone structure (hereinafter sometimes referred to as "structural unit (a6)"), a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as "structural unit (a7)"), or other structural units known in the art.

[0109] <Structural unit (a2)> The structural unit (a2) is a structural unit represented by formula (a2) and has an alcoholic hydroxyl, a phenolic hydroxyl group or a phenolic carboxyl group. TIFF2025074940000088.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 is -O-, -CO- or -NR a28 - may be replaced. R a28 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. L a21represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms, the hydrocarbon group optionally having a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO2-. L a22 represents a chain hydrocarbon group having 1 to 12 carbon atoms which may have a single bond or a fluorine atom, and -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-. na2 represents an integer of 1 to 4. When na2 is 2 or more, a plurality of L a22 may be the same or different.

[0110] R a2 and A a21 Examples of the substituent include the same ones as those exemplified in formula (a2-A). R a28 is R in formula (a2-A). a27 Examples of the above-mentioned examples are the same as those given above.

[0111] A a21 is a single bond, *-CO-O- or *-CO-OA a22 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[0112] L a21 The hydrocarbon group in the formula (I) is a hydrocarbon group having a valence of (na2+1), and examples of such cyclic hydrocarbon groups include chain hydrocarbon groups, monocyclic or polycyclic (including spiro rings, fused rings or bridged rings) alicyclic hydrocarbon groups, and aromatic hydrocarbon groups, and may be groups 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). L a21 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 alkanepentyl group. L a21 Examples of the alkanediyl group include Aa21 The alkanediyl groups are the same as those shown in the above. L a21 Examples of the alkanetriyl group include a methanetriyl group, an ethanetriyl group, a propanetriyl group, a butanetriyl group, a pentanetriyl group, a hexanetriyl group, a heptanetriyl group, an octanetriyl group, a nonanetriyl group, a decanetriyl group, an undecanetriyl group, a dodecanetriyl group, a tridecanetriyl group, a tetradecanetriyl group, a pentadecanetriyl group, a hexadecanetriyl group, and a heptadecanetriyl group. Examples of the alkanetetrayl group include a methanetetrayl group, an ethanetetrayl group, a propanetetrayl group, a butanetetrayl group, a pentanetetrayl group, a hexanetetrayl group, a heptanetetrayl group, an octanetetrayl group, a nonanetetrayl group, a decanetetrayl group, an undecanetetrayl group, a dodecanetetrayl group, a tridecanetetrayl group, a tetradecanetetrayl group, a pentadecanetetrayl group, a hexadecanetetrayl group, and a heptadecanetetrayl group. Examples of the alkanol groups include a methane pentaylene group, an ethane pentaylene group, a propane pentaylene group, a butane pentaylene group, a pentane pentaylene group, and a hexane pentaylene group. Further examples include groups in which one or more hydrogen atoms of the above groups are replaced with bonding sites. L a21 The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 18, more preferably 1 to 12, even more preferably 1 to 10, still more preferably 1 to 9, even more preferably 1 to 8, even more preferably 1 to 6, even more preferably 1 to 5, and particularly preferably 1 to 4. L a21 Examples of the monocyclic and polycyclic divalent alicyclic hydrocarbon group in the formula (I) include the following alicyclic hydrocarbon groups. The binding site may be any position. TIFF2025074940000089.tif46168 For example, 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, and cyclodecanetetrayl group; Examples of polycyclic alicyclic hydrocarbon groups include 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]octanediyl group, norbornanetriyl group, adamantanetriyl group, decahydronaphthalenetriyl group, bicyclo[3.3.0]octanetriyl group, norbornanetetrayl group, adamantanetetrayl group, decahydronaphthalenetetrayl group, and bicyclo[3.3.0]octanetetrayl group. The alicyclic hydrocarbon group has preferably 3 to 20 carbon atoms, more preferably 3 to 18, even more preferably 3 to 16, still more preferably 3 to 12, still more preferably 6 to 12, and particularly preferably 6 to 10. L a21 Examples of the divalent aromatic hydrocarbon group in include 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. 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, still more preferably 6 to 12, and still more preferably 6 to 10. Examples of groups that combine two or more of these groups include a group that combines an alicyclic hydrocarbon group with a chain hydrocarbon group, a group that combines an aromatic hydrocarbon group with a chain hydrocarbon group, a group that combines an alicyclic hydrocarbon group with an aromatic hydrocarbon group, and a group that combines an alicyclic hydrocarbon group with a chain hydrocarbon group and an aromatic hydrocarbon group. In the combination, two or more of each of the alicyclic hydrocarbon group, aromatic hydrocarbon group, and chain hydrocarbon group may be combined. In addition, when any of the groups is A a21 and L a22 may be bound to L a21 The alkanediyl group of L may be replaced by -O- or -CO-. a21 In the case where the alkanediyl group is replaced by -O- or -CO-, for example, *-L a23 -X a21 -(L a23 represents an alkanediyl group having 1 to 8 carbon atoms; X a21 represents -O-, -O-CO-, -CO-O- or -O-CO-O-; * represents X a2 It is preferable that the bond is a bond with L a21Examples of the hydrocarbon group in which -CH2- is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a thiol group (a group in which -CH2- in a methyl group is replaced by -S-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced by -O-), an alkylthio group (a group in which -CH2- at any position in an alkyl group is replaced by -S-), alkoxycarbonyl group (a group in which -CH2-CH2- at any position in the alkyl group is replaced with -O-CO-), alkylsulfonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -SO2-), alkylcarbonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -CO-), alkylcarbonyloxy group (a group in which -CH2-CH2- at any position in the alkyl group is replaced with -CO-O-), alkoxycarbonyloxy group (alkyl a group in which -CH2-CH2-CH2- at any position in the alkyl group is replaced with -O-CO-O-), an oxy group (a group in which -CH2- in a methylene group is replaced with -O-), a carbonyl group (a group in which -CH2- in a methylene group is replaced with -CO-), a thio group (a group in which -CH2- in a methylene group is replaced with -S-), a sulfonyl group (a group in which -CH2- in a methylene group is replaced with -SO2-), an alkanediyloxy group (a group in which -CH2- at any position in an alkanediyl group is replaced with -O-) an alkanediyloxycarbonyl group (an alkanediyl group in which -CH2-CH2- at any position is replaced with -O-CO-), an alkanediylcarbonyl group (an alkanediyl group in which -CH2- at any position is replaced with -CO-), an alkanediylcarbonyloxy group (an alkanediyl group in which -CH2-CH2- at any position is replaced with -CO-O-), an alkanediylsulfonyl group (an alkanediyl group in which -CH2- at any position is replaced with -SO2-),Examples of such groups include an alkanediylthio group (a group in which -CH2- at any position in an alkanediyl group is replaced with -S-), a cycloalkoxy group, a cycloalkylalkoxy group, an aromatic hydrocarbon group-carbonyloxy group, an aromatic hydrocarbon group-carbonyl group, an aromatic hydrocarbon group-oxy group, and a group that combines two or more of these groups. Further examples include groups in which one or more hydrogen atoms of these groups are replaced with a bonding site. Examples of the alkoxy group include alkoxy groups having 1 to 27 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, etc. The number of carbon atoms in the alkoxy group is preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and even more preferably 1 to 3. The alkylthio group includes an alkylthio group having 1 to 27 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group, etc. The number of carbon atoms in the alkylthio group is preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 27 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, and butoxycarbonyl groups. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 28 carbon atoms, such as acetyl, propionyl, and butyryl groups. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 27 carbon atoms, such as acetyloxy, propionyloxy, and butyryloxy groups. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 3 to 26 carbon atoms, such as butoxycarbonyloxy. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkoxycarbonyloxy group is preferably 3 to 11, more preferably 3 to 6, and even more preferably 3 to 4. The alkylsulfonyl group includes alkylsulfonyl groups having 1 to 27 carbon atoms, such as a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, etc. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and even more preferably 1 to 3. The alkanediyloxy group includes an alkanediyloxy group having 1 to 27 carbon atoms, such as a methyleneoxy group, an ethyleneoxy group, a propanediyloxy group, a butanediyloxy group, a pentanediyloxy group, etc. The number of carbon atoms in the alkanediyloxy group is preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyloxycarbonyl group include alkanediyloxycarbonyl groups having 2 to 27 carbon atoms, such as methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propanediyloxycarbonyl group, butanediyloxycarbonyl group, etc. Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 28 carbon atoms, such as methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, pentanediylcarbonyl group, etc. Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 27 carbon atoms, such as methylenecarbonyloxy group, ethylenecarbonyloxy group, propanediylcarbonyloxy group, butanediylcarbonyloxy group, etc. The number of carbon atoms in the alkanediyloxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The alkanediylthio group includes an alkanediylthio group having 1 to 27 carbon atoms, such as a methylenethio group, an ethylenethio group, a propanediylthio group, etc. The number of carbon atoms in the alkanediylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. The alkanediylsulfonyl group includes an alkanediylsulfonyl group having 1 to 27 carbon atoms, such as a methylenesulfonyl group, an ethylenesulfonyl group, a propylenesulfonyl group, etc. The number of carbon atoms in the alkanediylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and even more preferably 1 to 3.

[0113] Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 27 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 27 carbon atoms, such as a cyclohexylmethoxy group. Examples of the aromatic hydrocarbon group-carbonyloxy group include aromatic hydrocarbon group-carbonyloxy groups having 7 to 27 carbon atoms, such as a benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 27 carbon atoms, such as a benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include aromatic hydrocarbon group-oxy groups having 6 to 27 carbon atoms, such as a phenyloxy group.

[0114] Examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced with -O-, -S-, -CO- or -SO2- include the following groups. Also included are the following groups in which -O- is replaced with -S- and -CO- is replaced with -SO2-. The bonding site may be any position. TIFF2025074940000090.tif47168 Examples of the combined group in which -CH2- is replaced by -O-, -S-, -CO- or -SO2- include the following groups: The binding site may be any position. TIFF2025074940000091.tif26164L a21 The hydrocarbon group in may have one or more substituents. Examples of the substituent include a halogen atom, a haloalkyl group having 1 to 6 carbon atoms, and an alkyl group having 1 to 12 carbon atoms (-CH2- contained in the alkyl group may be replaced by -O- or -CO-). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. L a21The hydrocarbon group in the formula (I) can have a halogen atom as a substituent, and thus can substantially have a substituent such as a haloalkyl group. Examples of the haloalkyl group include a chloromethyl group, a bromomethyl group, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, and a perfluorobutyl group. A haloalkyl group having 1 to 4 carbon atoms is preferable, and a haloalkyl group having 1 to 3 carbon atoms is more preferable. L a21 The hydrocarbon group of L a21 can substantially have a substituent such as an alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, still more preferably 1 to 4, and still more preferably 1 to 3. L a21 L is a group in which -CH2- in the hydrocarbon group is replaced with -O- or -CO-. a21 can substantially have a substituent such as a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, or a sulfonyl group. L a21 The substituent that the hydrocarbon group in the formula (I) may have is preferably a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 6 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), more preferably a fluorine atom, an iodine atom, a haloalkyl group having 1 to 3 carbon atoms, or an alkyl group having 1 to 4 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), and further preferably a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, or a methoxy group.

[0115] L a22Examples of the chain hydrocarbon group having 1 to 12 carbon atoms include linear alkyl 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, and dodecane-1,12-diyl group. Examples of the alkyl group include alkanediyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 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 in the chain hydrocarbon group is preferably 1 to 10, more preferably 1 to 8, even more preferably 1 to 6, and even more preferably 1 to 4. L a22 may have one fluorine atom or two or more fluorine atoms. L a22 The -CH2- in the chain hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-, and these replaced groups are within the range permitted by the upper limit of the carbon number of L a21 Examples of the above-mentioned examples are the same as those given above. na2 is preferably an integer of 1 to 4, and more preferably an integer of 1 to 3. L a21 In the case where R is a single bond or a chain hydrocarbon group, examples of the structural unit (a2) include the following structural units. a2 A structural unit in which a methyl group corresponding to the following formula is replaced with a hydrogen atom or the like is also a suitable structural unit of the structural unit (a2), similar to the structural unit shown below. TIFF2025074940000092.tif67168

[0116] When a resist pattern is produced from the resist composition of the present invention, when a high energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) is used as an exposure light source, the structural unit (a2) having a phenolic hydroxyl group is preferred, and the structural unit (a2-A) is more preferred. When an ArF excimer laser (193 nm) or the like is used, the structural unit (a2) having an alcoholic hydroxyl group is preferred, and the structural unit (a2-C) described below is more preferred. The structural unit (a2) may contain one type alone or two or more types.

[0117] Examples of the structural unit (a2) having an alcoholic hydroxy group include a structural unit represented by formula (a2-B) (hereinafter sometimes referred to as "structural unit (a2-B)"), a structural unit represented by formula (a2-C) (hereinafter sometimes referred to as "structural unit (a2-C)"), and a structural unit represented by formula (a2-D) (hereinafter sometimes referred to as "structural unit (a2-D)"). TIFF2025074940000093.tif45100[In formula (a2-B) and formula (a2-C), R a2 has the same meaning as formula (a2). R a27 has the same meaning as formula (a2-A). L a25 is -O- or *-O-(CH2) k2 represents --CO--O--, and k2 represents an integer of 1 to 7. * represents the bonding position 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 of 1 to 5. When nB2 is 2 or more, a plurality of X a2 may be the same or different from each other. nB22 represents an integer of 0 to 8. When nB22 is 2 or more, a plurality of Ra27 may be the same or different from each other. nC22 represents an integer of 0 to 10. When nC22 is 2 or more, multiple R a27 may be the same or different. L a25 is preferably -O-, -O-(CH2) f1 It is -CO-O- (wherein f1 represents an integer of 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 a27 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, 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 further 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 an integer of 0 to 3, more preferably 0, 1 or 2, and further preferably 0 or 1. nC22 is preferably an integer of 0 to 6, more preferably an integer of 0 to 3, and further preferably 0 or 1.

[0118] Examples of the structural unit (a2-B) and the structural unit (a2-C) include structural units derived from monomers described in JP-A-2010-204646, the following structural units, and R a2In particular, structural units represented by any one of formulae (a2-B-1) to (a2-B-5) and formulae (a2-C-1) to (a2-C-9) are preferred. TIFF2025074940000094.tif80164 When the resin (A) contains the structural unit (a2-B) or the formula (a2-C), the content thereof is 1 mol% or more, preferably 2 mol% or more, based on the total structural units of the resin (A). Also, 45 mol% or less is mentioned, preferably 40 mol% or less, more preferably 35 mol% or less, even more preferably 20 mol% or less, and even more preferably 10 mol% or less. Specifically, 1 to 45 mol% is mentioned, preferably 1 to 40 mol%, more preferably 1 to 35 mol%, even more preferably 1 to 20 mol% or 2 to 20 mol%, and even more preferably 1 to 10 mol% or 2 to 10 mol%.

[0119] TIFF2025074940000095.tif51106[In formula (a2-D), R a2 and A a21 have the same meaning as in formula (a2). R a27 has the same meaning as formula (a2-A). R a21 and R a22 each independently represents a fluorinated alkyl 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 an integer of 1 to 4. When nD2 is 2 or more, the groups in the parentheses may be the same or different. nD22 represents an integer of 0 to 4. When nD22 is 2 or more, a plurality of R a27 may be the same or different. R a21 and R a22Examples of the fluorinated alkyl groups are each independently a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 3,3,3-trifluoropropyl group, a 4,4,4-trifluorobutyl group, and the like. R a21 and R a22 As the alkyl group, a trifluoromethyl group is preferable. L a24 Examples of the alkanediyl group include a methylene group, an ethane-1,1-diyl group, a propane-1,1-diyl group, and a propane-2,2-diyl group. L a24 is preferably a single bond or a methylene group.

[0120] The structural unit (a2-D) is more preferably a structural unit represented by the following formula (a2-D1) (hereinafter, sometimes referred to as "structural unit (a2-D1)"). TIFF2025074940000096.tif51108[In formula (a2-D1), R a2 , A a21 , R a27 , nD2 and nD22 have the same meaning 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.

[0121] Examples of the structural unit (a2-D) include the structural units shown below. TIFF2025074940000097.tif62167

[0122] In the structural units represented by formulae (a2-D-1) to (a2-D-8), R a2 In the structural units represented by formulae (a2-D-9) to (a2-D-16), the hydrogen atom corresponding to R a2Specific examples of the structural unit (a2-D) include structural units in which the methyl group corresponding to the following formula is replaced with a hydrogen atom, etc. Among these, the structural units represented by formulae (a2-D-1) to (a2-D-8) are preferred, the structural units represented by formulae (a2-D-1) to (a2-D-4) are more preferred, and the structural unit represented by formula (a2-D-1) is even more preferred.

[0123] When the resin (A) contains the structural unit (a2-D), the content thereof is preferably 3 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more, based on the total structural units of the resin (A). Also, it is preferably 80 mol% or less, more preferably 75 mol% or less, even 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%, even more preferably 10 to 70 mol%, and even more preferably 10 to 65 mol%.

[0124] <Structural unit (a3)> The lactone ring of the structural unit (a3) ​​may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or may be a condensed ring of a monocyclic lactone ring and another ring. Preferred examples include a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)).

[0125] The structural unit (a3) ​​is preferably a structural unit represented by formula (a3-1), (a3-2), (a3-3) or (a3-4). One of these may be contained alone, or two or more of them may be contained. TIFF2025074940000098.tif51164 [In formula (a3-1), formula (a3-2), formula (a3-3) and formula (a3-4), L a4 , L a5 and L a6 are each independently -O- or *-O-(CH2) k3It represents a group represented by -CO-O- (k3 represents an integer of any of 1 to 7). L a7 , -O-, *-OL a8 -O-, *-OL a8 -CO-O-, *-OL a8 -CO-OL a9 -CO-O- or *-OL a8 -O-CO-L a9 Represents -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * indicates the bonding site with the carbonyl group. R a18 , R a19 , R a20 and R a24 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. 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 of 0 to 5. q1 represents an integer of 0 to 3. r1 represents an integer of 0 to 3. w1 represents an integer of 0 to 8. When p1, q1, r1 and / or w1 are 2 or more, multiple R a21 , R a22 , R a23 and / or R a25 may be the same or different.]

[0126] R a21 , R a22 , R a23 and R a25Examples of the aliphatic hydrocarbon group in include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, and a tert-butyl group. R a18 , R a19 , R a20 and R a24 Examples of the halogen atom and the alkyl group which may have a halogen atom in the formula (a1-0) include R a01 , R a4 , R a5 Examples of the above-mentioned examples are the same as those given above. L a8 and L a9 Examples of the alkanediyl group in the formula (I) 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 pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-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. L a4 , L a5 and L a6 are each independently preferably -O- or *-O-(CH2) k3 In the -CO-O- group, k3 is a group in which k3 is any integer of 1 to 4, more preferably -O- and *-O-CH2-CO-O-, and further preferably an oxygen atom. L a7 is preferably -O- or *-OL a8 It is —CO—O—, and more preferably —O—, —O—CH2—CO—O— or —O—C2H4—CO—O—. R a18 , R a19 , R a20 and R a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a21 is preferably a methyl group. R a22 , Ra23 and R a25 are each independently preferably a carboxy group, a cyano group, or a methyl group. p1, q1 and r1 each independently represent an integer of preferably 0 to 2, and more preferably 0 or 1. w1 is preferably an integer of 0 to 2, and more preferably 0 or 1. In particular, the formula (a3-4) is preferably the formula (a3-4)'. TIFF2025074940000099.tif4051 (in the formula, R a24 , L a7 has the same meaning as above.)

[0127] Examples of the structural unit (a3) ​​include structural units derived from monomers described in JP 2010-204646 A, JP 2000-122294 A, and JP 2012-41274 A. Examples of the structural unit (a3) ​​include structural units represented by any one of formulas (a3-1-1), (a3-1-2), (a3-2-1), (a3-2-2), (a3-3-1), (a3-3-2), and (a3-4-1) to (a3-4-12), and in the structural unit, R in formulas (a3-1) to (a3-4) a18 , R a19 , R a20 and R a24 A structural unit in which a methyl group corresponding to the following formula is replaced with a hydrogen atom is preferred. TIFF2025074940000100.tif108164 When the resin contains the structural unit (a3), the total content thereof is 1 mol% or more, preferably 3 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% relative to the total structural units of the resin. Also, 70 mol% or less, preferably 65 mol% or less, more preferably 60 mol% or less, even more preferably 50 mol% or less, even more preferably 40 mol% or less, even more preferably 30 mol% or less, even more preferably 25 mol% or less, and even more preferably 20 mol% or less. Specifically, 1 to 70 mol% is mentioned, preferably 1 to 65 mol%, more preferably 1 to 60 mol%, and even more preferably 3 to 60 mol%. The content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3) or the structural unit (a3-4) is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, and even more preferably 10 mol% or more, based on the total structural units of the resin (A). It is also preferably 60 mol% or less, more preferably 55 mol% or less, even more preferably 50 mol% or less, still more preferably 40 mol% or less, even more preferably 30 mol% or less, still more preferably 25 mol% or less, and even more preferably 20 mol% or less. Specifically, it is preferably 1 to 60 mol%, more preferably 3 to 50 mol%, and even more preferably 5 to 50 mol%.

[0128] <Structural unit (a4)> The structural unit represented by formula (a4) is shown below. TIFF2025074940000101.tif3454[In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having 1 to 24 carbon atoms and containing a halogen atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-.]

[0129] R 42 Examples of the saturated hydrocarbon group represented by the formula (I) include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these groups. Examples of the chain saturated hydrocarbon group include linear alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group, and branched alkyl groups such as an isopropyl group and an 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 a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic saturated hydrocarbon groups which are polycyclic cycloalkyl groups, such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bonding site): TIFF2025074940000102.tif10146 Examples of groups formed by combinations include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group. Examples of the alkanediyl group include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and hexane-1,6-diyl groups, and branched alkanediyl groups such as propane-1,2-diyl, butane-1,3-diyl, 2-methylpropane-1,2-diyl, 1-methylbutane-1,4-diyl, and 2-methylbutane-1,4-diyl groups. The terminal of the branched alkanediyl group may be a methyl group. R 42 Examples of the halogen atom contained in the saturated hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R42 Examples of the halogen atom contained in the saturated hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 42 Examples of the saturated hydrocarbon group in which -CH2- is replaced with -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 alkanediyloxy group, an alkanediyloxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyloxy group, a cycloalkoxy group, a cycloalkylalkoxy group, and a group combining two or more of these groups. Examples of these replaced groups include the same groups exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms.

[0130] The structural unit (a4) is R 42 is preferably a saturated hydrocarbon group having a fluorine atom, and R 42 However, examples of the structural unit (a4) which is a saturated hydrocarbon group having a fluorine atom include a structural unit represented by formula (a4-1) (hereinafter may be referred to as structural unit (a4-1)), a structural unit represented by formula (a4-2) (hereinafter may be referred to as structural unit (a4-2)), and a structural unit represented by formula (a4-3) (hereinafter may be referred to as structural unit (a4-3)). The structural unit represented by formula (a4-1) is a structural unit shown below. TIFF2025074940000103.tif4964[In 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 a fluorine atom-containing alkanediyl group having 1 to 8 carbon atoms or a fluorine atom-containing cycloalkanediyl group having 3 to 12 carbon atoms. R 42f represents a hydrogen atom or a fluorine atom.

[0131] L 41 Examples of the alkanediyl group in the formula (I) include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, and butane-1,4-diyl, and branched alkanediyl groups such as ethane-1,1-diyl, propane-1,2-diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl, and 2-methylpropane-1,2-diyl. The terminal of the branched alkanediyl group may be a methyl group. L 42f Examples of the alkanediyl group having a fluorine atom in the formula (I) include a methylene group having a fluorine atom, an ethylene group having a fluorine atom, a propane-1,3-diyl group having a fluorine atom, a butane-1,4-diyl group having a fluorine atom, a pentane-1,5-diyl group having a fluorine atom, a hexane-1,6-diyl group having a fluorine atom, a heptane-1,7-diyl group having a fluorine atom, and an octane-1,8-diyl group having a fluorine atom; Examples of branched alkanediyl groups having fluorine atoms include ethane-1,1-diyl groups having fluorine atoms, propane-1,1-diyl groups having fluorine atoms, propane-1,2-diyl groups having fluorine atoms, propane-2,2-diyl groups having fluorine atoms, pentane-2,4-diyl groups having fluorine atoms, 2-methylpropane-1,3-diyl groups having fluorine atoms, 2-methylpropane-1,2-diyl groups having fluorine atoms, pentane-1,4-diyl groups having fluorine atoms, and 2-methylbutane-1,4-diyl groups having fluorine atoms. The terminal of the branched alkanediyl group may be a methyl group which may have a fluorine atom. L 42f Examples of the cycloalkanediyl group having a fluorine atom in the formula (I) include monocyclic cycloalkanediyl groups 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, and a cyclooctane-1,5-diyl group having a fluorine atom; Examples of polycyclic cycloalkanediyl groups 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 contained in the alkanediyl group and cycloalkanediyl group having a fluorine atom in the above formula may be 1 or more, and is preferably 2 or more. L 42f The alkanediyl group and cycloalkanediyl group having a fluorine atom in the above formula (I) are preferably a perfluoroalkanediyl group and a perfluorocycloalkanediyl group, respectively.

[0132] L 42f Examples of the perfluoroalkanediyl group in the formula (I) 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, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluorooctane-3,3-diyl group, and perfluorooctane-4,4-diyl group. L 42fExamples of the perfluorocycloalkanediyl group in the formula (I) include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group.

[0133] 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.

[0134] The structural unit (a4-1) may be any of the structural units shown below and R in the structural unit (a4-1) in the structural unit shown below. 41 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF2025074940000104.tif97158The structural unit represented by formula (a4-2) is the structural unit shown below. TIFF2025074940000105.tif5674[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 contain a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -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 by -O- or -CO-. However, L 43f and R 43f At least one of L has a fluorine atom. 43f and R 43fThe total number of carbon atoms in the molecule is limited to 21.

[0135] L 43f and R 43f Examples of the saturated hydrocarbon group in include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these groups. 43f and R 43f Examples of saturated hydrocarbon groups in the formula are L 43f and R 43f As long as the upper limit of the total number of carbon atoms in 42 Examples of the saturated hydrocarbon group include the same groups as the exemplified saturated hydrocarbon groups.

[0136] L 43f The saturated hydrocarbon group is preferably an alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (L43f-1). TIFF2025074940000106.tif13119[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 contain a fluorine atom. L 47f represents a single bond or a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may contain a fluorine atom. X 46f and X 47f each independently represents -O-, -CO-, -CO-O- or -O-CO-. However, L 45f , L 46f , L 47f , X 46f and X 47f The total number of carbon atoms is 7 or less. * and ** are binding sites, ** is -O-CO-R 43f This is the binding site for

[0137] L in the group represented by formula (L43f-1) 45f , L 46f and L47f Examples of the divalent saturated hydrocarbon group represented by include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and a divalent saturated hydrocarbon group formed by combining an alkanediyl group and a divalent alicyclic saturated hydrocarbon group, etc. Specific 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, etc. It is preferred that s is 0.

[0138] Examples of the group represented by formula (L43f-1) include the following groups. In the following examples, * and ** each represent a bonding site, and ** represents -O-CO-R 43f This is the binding site for TIFF2025074940000107.tif47140

[0139] R 43f is preferably a saturated hydrocarbon group having a fluorine atom. In this case, examples of the structural unit represented by formula (a4-2) include structural units represented by formula (a4-2A) or (a4-2B). TIFF2025074940000108.tif69102 [In formula (a4-2A) and formula (a4-2B), R 41 and L 43f represents the same as in formula (a4-2). R 43fA represents a saturated hydrocarbon group having 1 to 20 carbon atoms and containing 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 A 43f It represents the binding site with R 43fBrepresents a saturated hydrocarbon group having 1 to 17 carbon atoms which may contain a fluorine atom. However, in formula (a4-2A), L 43f and R 43fA The total number of carbon atoms in formula (a4-2B) is 21 or less, and in formula (a4-2B), L 43f , A 43f , X 43 and R 43fB The total number of carbon atoms in A is 21 or less. 43f and R 43fB At least one of them has at least one fluorine atom. R 43fA The saturated hydrocarbon group represented by R in formula (a4) is as large as possible within the upper limit of the number of carbon atoms. 42 Examples of the saturated hydrocarbon groups include the saturated hydrocarbon groups exemplified by the above. R 43fA is preferably an alkyl group having 1 to 13 carbon atoms and containing a fluorine atom, a cycloalkyl group having 3 to 12 carbon atoms and containing a fluorine atom, or a group combining these, *-(CF2) n43f -R 42’ (* represents the bonding site with the carbonyl group. n43f represents an integer of 1 to 6. R 42’ represents a hydrogen atom or a fluorine atom.) or a perfluorocycloalkyl group having 3 to 12 carbon atoms is more preferable. A 43f and R 43fB The saturated hydrocarbon group represented by R in formula (a4) is as large as possible within the upper limit of the number of carbon atoms. 42 Examples of the saturated hydrocarbon groups include the saturated hydrocarbon groups exemplified by the above. A 43f is preferably a divalent chain saturated hydrocarbon group which may have a fluorine atom, a divalent alicyclic saturated hydrocarbon group, or a combination thereof, more preferably a divalent chain saturated hydrocarbon group which has a fluorine atom, and further preferably a fluorinated alkanediyl group having 1 to 6 carbon atoms. R 43fBThe saturated hydrocarbon group which may have a fluorine atom is preferably a chain saturated hydrocarbon group which may have a fluorine atom, an alicyclic saturated hydrocarbon group or a group combining these, 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 these, and 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- More preferred are fluorinated alkyl groups such as an 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, and a perfluorooctyl group; 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, and a perfluoroadamantylmethyl group. In formula (a4-2B), *-A 43f -X 43 -R 43fB An example of a structure that the group represented by the formula (I) can take is the following structure (* indicates the bonding site with the carbonyl group). TIFF2025074940000109.tif15170

[0140] The structural unit represented by formula (a4-2A) includes the structural units shown below and R in the structural unit represented by formula (a4-2A) in the structural units shown below. 41 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF2025074940000110.tif99167

[0141] The structural unit represented by formula (a4-2B) includes the structural units shown below and R in the structural unit represented by formula (a4-2B) in the structural units shown below. 41 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF2025074940000111.tif111163

[0142] The structural unit (a4) also includes a structural unit represented by formula (a4-3). TIFF2025074940000112.tif5677[In formula (a4-3), R 41 represents a hydrogen atom or a methyl group. L 44f each independently 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 each independently 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, L 44f and R 44f At least one of L has a fluorine atom. 44f and R 44f The total number of carbon atoms in each is limited to 21.

[0143] L 44f and R 44f Examples of the saturated hydrocarbon group in include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these groups. 44f and R 44f Examples of saturated hydrocarbon groups in the formula are L 43f and R 43f As long as the upper limit of the total number of carbon atoms in 42 Examples of the saturated hydrocarbon group include the same groups as the exemplified saturated hydrocarbon groups. L 44fis preferably an alkanediyl group having 1 to 13 carbon atoms (-CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), and is preferably -(CH2)1-, -(CH2) j2 -O-(CH2) j3 -or-(CH2) j4 -CO-O-(CH2) j5 - (j1 to j5 each independently represent an integer of 1 to 6), and more preferably an alkanediyl group having 1 to 4 carbon atoms (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 and having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom or an alicyclic saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom, further preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom, and even more preferably an alkyl group having 1 to 6 carbon atoms and having a fluorine atom.

[0144] Examples of the structural unit represented by formula (a4-3) include the following structural units and structural units represented by the following formulas: 41 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF2025074940000113.tif86170

[0145] The structural unit (a4) also includes a structural unit represented by the formula (a4-A). TIFF2025074940000114.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 R 1 represents the bonding site with the carbon atom to which it 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 is L 1 may be bonded to form an alicyclic hydrocarbon group having 3 to 6 carbon atoms, and -CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-. mi represents an integer of 1 to 4. When mi is 2 or more, the groups in the multiple parentheses may be the same or different.]

[0146] R 1 Examples of the alkyl group having 1 to 6 carbon atoms in the formula 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, a pentyl group, and a hexyl group. R 1 Examples of the halogen atom in include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 1 Examples of the alkyl group having 1 to 6 carbon atoms and having a halogen atom in the formula (I) 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, and a dibromomethyl group. 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.

[0147] L 1 Examples of the aliphatic hydrocarbon group in include chain hydrocarbon groups and monocyclic or polycyclic (including spiro rings, fused rings, bridged rings, etc.) alicyclic hydrocarbon groups, and may be groups combining two or more of these groups (for example, a hydrocarbon group formed from an alicyclic hydrocarbon group and a chain hydrocarbon group). Examples of the chain hydrocarbon group include chain hydrocarbon groups such as alkanediyl groups. 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; Examples of branched alkanediyl groups include ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group. The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 18, more preferably 1 to 12, even more preferably 1 to 10, still more preferably 1 to 9, even more preferably 1 to 8, even more preferably 1 to 6, even more preferably 1 to 5, and particularly preferably 1 to 4.

[0148] Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include the following alicyclic hydrocarbon groups: The binding site may be any position. TIFF2025074940000115.tif45164For example, alicyclic hydrocarbon groups such as a cycloalkanediyl group are included. 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. Examples of such groups include cycloalkanediyl 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]octanediyl group, spirocyclohexane-1,2'-cyclopentane-diyl group, and spiroadamantane-2,3'-cyclopentane-diyl group, and polycyclic alicyclic hydrocarbon groups such as spiro rings having cycloalkanediyl groups bonded to a norbornyl group or an adamantyl group via spiro bonds. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 18 carbon atoms, further preferably 3 to 16 carbon atoms, and further preferably 3 to 12 carbon atoms.

[0149] Examples of groups that combine two or more types include a group that combines an alicyclic hydrocarbon group and a chain hydrocarbon group. In the combination, two or more types of alicyclic hydrocarbon groups and chain hydrocarbon groups may be combined. In addition, when any group is X 11 may be bound to Examples of groups 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-, etc.), a group in which a chain hydrocarbon group is bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-chain hydrocarbon group-, etc.), 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-, etc.), a group in which an alicyclic hydrocarbon group and a chain hydrocarbon group are bonded to an alicyclic hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-, etc.), Examples of such an alkyl group include a group in which a hydroxyl group is bonded to an alicyclic hydrocarbon group (for example, *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group- etc.), a group in which an alicyclic hydrocarbon group, a chain hydrocarbon group and an alicyclic hydrocarbon group are bonded to an chain hydrocarbon group (for example, *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group- etc.), and a group in which a chain hydrocarbon group, an alicyclic hydrocarbon group and a chain hydrocarbon group are bonded to an alicyclic hydrocarbon group (for example, *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group- etc.). * is X 11 represents the binding site with

[0150] L 1 -CH2- contained in the aliphatic hydrocarbon group having 1 to 28 carbon atoms may be replaced by -O-, -S-, -SO2- or -CO-. L 1 When --CH2-- contained in the aliphatic hydrocarbon group having 1 to 28 carbon atoms is replaced with --O--, --S--, --SO2-- or --CO--, the number of carbon atoms before replacement is regarded as the number of carbon atoms of the aliphatic hydrocarbon group. Examples of groups in which -CH- in an aliphatic hydrocarbon group is replaced with -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 alkoxycarbonyloxy group, an oxy group, a carbonyl group (, a thio group, a sulfonyl group (, an alkanediyloxy group, an alkanediyloxycarbonyl group, an alkanediylcarbonyl group (, an alkanediylcarbonyloxy group, an alkanediylsulfonyl group, an alkanediylthio group, a cycloalkoxy group, a cycloalkylalkoxy group, and groups in which two or more of these groups are combined. Examples of these replaced groups include the same groups as those exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms. Furthermore, examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include the same groups as exemplified in this specification, within the upper limit of the number of carbon atoms permitted.

[0151] L 1 The aliphatic hydrocarbon group in may have one or more substituents. Examples of the substituent include a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 12 carbon atoms (-CH2- contained in the alkyl group may be replaced by -O- or -CO-). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the haloalkyl group having 1 to 4 carbon atoms include a fluorinated alkyl group having 1 to 4 carbon atoms, a chlorinated alkyl group having 1 to 4 carbon atoms, a brominated alkyl group having 1 to 4 carbon atoms, and an iodinated alkyl group having 1 to 4 carbon atoms. Examples of the haloalkyl group include a perfluoroalkyl group having 1 to 4 carbon atoms (such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a nonafluorobutyl group), a 2,2,2-trifluoroethyl group, a 3,3,3-trifluoropropyl group, a 4,4,4-trifluorobutyl group, and a 3,3,4,4,4-pentafluorobutyl group, a chloromethyl group, a bromomethyl group, and an iodomethyl group. The number of carbon atoms in the haloalkyl group is preferably 1 to 3, and more preferably 1 or 2. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 9, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. When -CH2- in the alkyl group is replaced with -O- or -CO-, the number of carbon atoms before the replacement is regarded as the total number of carbon atoms in the alkyl group. Examples of the replaced group include a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, and an alkylcarbonyloxy group. These replaced groups include the same groups as those exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms. The alkoxy group preferably has 1 to 9 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and further preferably 1 to 3 carbon atoms. The number of carbon atoms in 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 in 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 in the alkylcarbonyloxy group is preferably 2 to 9, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. L 1 The substituent that the aliphatic hydrocarbon group in the formula (I) may have is preferably a halogen atom, a haloalkyl group having 1 to 3 carbon atoms, or an alkyl group having 1 to 6 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), more preferably 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 (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), and further preferably a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, or a methoxy group. L 1 is R 3When the alkyl group does not form an alicyclic hydrocarbon group with the alkyl group, it is preferably a chain hydrocarbon group having 1 to 12 carbon atoms which may have a substituent (-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-), an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O- or -CO-), or a group formed by combining a chain 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 (-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced with -O- or -CO-). and more preferably a chain hydrocarbon group having 1 to 8 carbon atoms which may have a substituent, an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a substituent, or a group formed by combining a chain 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 chain hydrocarbon group may be replaced by -O- or -CO-), and even more preferably a chain hydrocarbon group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 6 to 12 carbon atoms, a group formed by combining a chain hydrocarbon group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 6 to 12 carbon atoms, or a group formed by combining an alicyclic hydrocarbon group having 6 to 12 carbon atoms, a chain hydrocarbon group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 6 to 12 carbon atoms.

[0152] R 2Examples of the fluorinated alkyl group having 1 to 8 carbon atoms in the formula (I) include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, a 1,1,2,2-tetrafluoropropyl group, a 1,1,2,2,3,3-hexafluoropropyl group, a perfluoroethylmethyl group, a 1-(trifluoromethyl)-1,2,2,2-tetrafluoroethyl group, a perfluoropropyl group, a 1,1,2,2-tetrafluorobutyl group, a 1,1,2,2,3,3-hexafluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a perfluorobutyl group, a 1,1-bis(trifluoro)methyl group, Examples of the fluorinated alkyl group include -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 fluorinated alkyl group is preferably 1 to 6, more preferably 1 to 5, even more preferably 1 to 4, and even more preferably 1 to 3. R 3 The fluorinated alkyl group having 1 to 6 carbon atoms in R is as long as the upper limit of the carbon number allows. 2 The same examples of the fluorinated alkyl groups having 1 to 6 carbon atoms as those given as examples of the fluorinated alkyl groups above are also included. R 2 is R 3 When is a fluorinated alkyl group having 1 to 6 carbon atoms, it is preferably a fluorinated alkyl group having 1 to 6 carbon atoms, more preferably a fluorinated alkyl group having 1 to 3 carbon atoms, still more preferably a trifluoromethyl group, a perfluoroethyl group or a perfluoropropyl group, and even more preferably a trifluoromethyl group. R2 is R 3 When is a hydrogen atom, it is preferably a fluorinated alkyl group having 1 to 6 carbon atoms, more preferably a fluorinated alkyl group having 1 to 5 carbon atoms, and even more preferably a fluorinated alkyl group having 3 to 5 carbon atoms. R 3 L 1 When R is bonded to form an alicyclic hydrocarbon group having 3 to 6 carbon atoms, 3 L 1 Examples of the group formed by bonding with include groups represented by the following formulas: In the following formulas, * and ** represent bonding sites, and one of the two ** represents a bonding site with a hydroxy group and the other represents a bonding site with R 2 represents the binding site with L 1A , L 1 It is a part of a hydrocarbon group and represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. TIFF2025074940000116.tif25130R 3 is preferably a hydrogen atom or a fluorinated alkyl group having 1 to 3 carbon atoms. mi is preferably an integer of 1 to 3, more preferably 1 or 2, and even more preferably 1.

[0153] Examples of the structural unit (a4-A) include the following structural units. In the following structural units, R 1 and R 1 Specific examples of the structural unit (a4-A) include structural units in which a hydrogen atom corresponding to the following is replaced with a halogen atom, a haloalkyl group or an alkyl group. TIFF2025074940000117.tif227160

[0154] When the resin has the structural unit (a4), the content thereof is preferably from 1 to 97 mol %, more preferably from 2 to 95 mol %, and even more preferably from 3 to 90 mol %, based on all structural units in the resin.

[0155] <Structural unit (a5)> The non-leaving hydrocarbon group contained in the structural unit (a5) may be a group containing a linear, branched or cyclic hydrocarbon group. Among these, the structural unit (a5) is preferably a group containing an alicyclic hydrocarbon group. An example of the structural unit (a5) is a structural unit represented by the formula (a5-1). TIFF2025074940000118.tif3971[In formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.]

[0156] R 52 The alicyclic hydrocarbon group in 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, a norbornyl group, and the like. 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. An example of the alicyclic hydrocarbon group having a substituent is a 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group, or a cyclohexyl group. L 55Examples of the divalent saturated hydrocarbon group in include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and a divalent chain saturated hydrocarbon group is preferred. Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl and norbornanediyl. L 55 Examples of the divalent saturated hydrocarbon group represented by formula (L1-1) to formula (L1-4) include groups represented by formula (L1-2) to (L1-4). In the following formulae, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom. TIFF2025074940000119.tif18165[In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents L x1 ) which represents the binding site with 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, L x1 and L x2 The total number of carbon atoms is 16 or less. In formula (L1-2), L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, L x3 and L x4 The total number of carbon atoms 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 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, L x5 , L x6 and L x7 The total number of carbon atoms is 15 or less. In formula (L1-4), L x8 and L x9 represents 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, L x8 , L x9 and W x1 The total number of carbon atoms 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, and more preferably a single bond. L x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and 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 x8is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and 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, and 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, and more preferably a cyclohexanediyl group or an adamantanediyl group. Examples of the group represented by formula (L1-1) include the divalent groups shown below. TIFF2025074940000120.tif36147Examples of the group represented by formula (L1-2) include the divalent groups shown below. TIFF2025074940000121.tif23130 Examples of the group represented by formula (L1-3) include the divalent groups shown below. TIFF2025074940000122.tif16147 Examples of the group represented by formula (L1-4) include the divalent groups shown below. TIFF2025074940000123.tif13168L 55 is preferably a single bond or a group represented by formula (L1-1). The structural unit (a5-1) may be any of the structural units shown below and R in the structural unit (a5-1) in the structural unit shown below. 51 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. When the resin contains the structural unit (a5), the content thereof is preferably from 1 to 30 mol %, more preferably from 2 to 20 mol %, and even more preferably from 3 to 15 mol %, based on the total structural units of the resin.

[0157] <Structural unit (a6)> The structural unit (a6) is a structural unit having a -SO2- group, and preferably has the -SO2- group in a side chain. The structural unit having a -SO2- group may have a linear structure having a -SO2- group, may have a branched structure having a -SO2- group, or may have a cyclic structure (monocyclic and polycyclic structure) having a -SO2- group. A structural unit having a cyclic structure having a -SO2- group is preferred, and a structural unit having a cyclic structure (sultone ring) containing -SO2-O- is more preferred. The sultone ring may be represented by the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and the formula (T 1 The bonding site can be any position. The sultone ring may be monocyclic, but is preferably polycyclic. A polycyclic sultone ring refers to a bridged ring containing -SO2-O- as an atomic group constituting the ring, and is represented by the formula (T 1 -1) and the formula (T 1 The sultone ring is represented by the formula (T 1 As in the ring represented by formula (2), the atomic group constituting the ring may further contain a heteroatom in addition to -SO2-O-. Examples of the heteroatom include an oxygen atom, a sulfur atom, or a nitrogen atom, and an oxygen atom is preferred. TIFF2025074940000125.tif3077 The sultone ring may have a substituent. 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. Examples of halogen atoms include fluorine, chlorine, bromine and iodine atoms. 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, and 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 perfluorosec-butyl group, a perfluorotert-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 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. Aralkyl groups include benzyl, phenethyl, phenylpropyl, naphthylmethyl and naphthylethyl groups. 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, and preferably, an alkoxycarbonyl group having 6 or less carbon atoms is used, and more preferably, a methoxycarbonyl group is used. Alkylcarbonyl groups include acetyl, propionyl and butyryl groups. From the viewpoint of ease of production of the monomer from which the structural unit (a6) is derived, a sultone ring having no substituent is preferred.

[0158] The sultone ring is preferably a ring represented by the following formula (T1'). TIFF2025074940000126.tif2665[In formula (T1'), X 11represents 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 an integer of 0 to 9. When ma is 2 or more, multiple R 41 may be the same or different. The binding site is at any position.] X 11 is preferably an oxygen atom or a methylene group, and more preferably a methylene group. R 41 Examples of the substituent include the same ones as the substituents on the sultone ring, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxyl group is preferred. ma is preferably 0 or 1, and more preferably 0. Examples of the ring represented by formula (T1') include the following rings. The binding site may be any position. Among them, the binding site is preferably the 1st or 3rd position. TIFF2025074940000127.tif44147

[0159] The structural unit having a -SO2- group preferably further has a group derived from a polymerizable group, such as a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, or a methacryloylthio group. Among these, the monomer from which the structural unit (a6) is derived is preferably a monomer having an ethylenically unsaturated bond, and more preferably a (meth)acrylic monomer.

[0160] The structural unit (a6) is preferably a structural unit represented by the formula (a6-0). TIFF2025074940000128.tif4075[In 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 is an oxygen atom, -N(R c )- or a sulfur atom. A x represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH- contained in the saturated hydrocarbon group is -O-, -CO- or -N(R d )- may also be replaced. 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 an integer of 0 to 9. When ma is 2 or more, multiple R 41 may be the same or different. R c and R d each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.] R x Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R x Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. An alkyl group having 1 to 4 carbon atoms is preferred, and a methyl group or an ethyl group is more preferred. R xExamples 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 perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group. R x is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom or a methyl group. A x Examples of the divalent saturated hydrocarbon group include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and may be a combination of two or more of these groups. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, linear alkanediyl groups such as 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, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; monocyclic divalent alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; Examples of the polycyclic divalent alicyclic saturated hydrocarbon groups include norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group. A x The bonding position of to the sultone ring may be any position, but is preferably the 1-position.

[0161] Examples of the structural unit (a6-0) include the following structural units. TIFF2025074940000129.tif93150

[0162] Of these, structural units represented by formulae (a6-1), (a6-2), (a6-6), (a6-7), (a6-8) and (a6-12) are preferred, and structural units represented by formulae (a6-1), (a6-2), (a6-7) and (a6-8) are more preferred. When the resin has the structural unit (a6), the content thereof is preferably from 1 to 50 mol %, more preferably from 2 to 40 mol %, and even more preferably from 3 to 30 mol %, based on the total structural units of the resin.

[0163] <Structural unit (a7)> The resin (A) etc. may further contain a structural unit (hereinafter, sometimes referred to as "structural unit (a7)") that decomposes upon exposure to generate an acid other than the structural unit (I). Specific examples of the structural unit (a7) include structural units described in JP 2016-79235 A, and it is preferable that the structural unit (a7) is a structural unit having a sulfonate group or a carboxylate group and an organic cation in a side chain, or a structural unit having a sulfonio group and an organic anion in a side chain.

[0164] The structural unit having a sulfonate group or carboxylate group and an organic cation in the side chain is preferably a structural unit represented by formula (a7-A). TIFF2025074940000130.tif26123[In formula (a7-A), R a7represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X a71 is 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 bond. * and ** represent binding sites, * represents R a7 represents the bonding site with the carbon atom to which it is bonded. L a71 and L a72 each independently represents 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 L a71 represents the binding site with na7 represents an integer of 0 to 2. When na7 is 2, the groups in the parentheses may be the same or different. RA - represents a sulfonate anion or a carboxyl anion. Z.A. + represents an organic cation.

[0165] R a7 and R a71Examples of the alkyl group having 1 to 6 carbon atoms in the formula 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, a pentyl group, and a hexyl group. R a7 Examples of the halogen atom in 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 the formula (I) 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, and a dibromomethyl group. R a7 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 even more preferably a hydrogen atom or a methyl group.

[0166] X a71 is a group represented by *-Ax-Ph-Ay-**, it is preferably a linking group represented by the following formula (X10). TIFF2025074940000131.tif3251[In formula (X10), Ax is R a7 represents a bond type bonded to the carbon atom to which is bonded, and represents one type of bond 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. Ay is L a71 represents a bond type that bonds with, and represents one type of bond 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 fluorinated alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. mx represents an integer of 0 to 4, and when mx is an integer of 2 or more, multiple Rx's may be the same or different. When either Ax or Ay is a single bond, the other is preferably one selected from the group consisting of an ether bond, a thioether bond, an ester bond, a carbonate ester bond, and an amide bond. When either Ax or Ay is an amide bond, -CO-NR a71 A bond represented by - is preferred. The bonding position of Ay in the phenylene group is preferably the m-position or p-position relative to the bonding position of Ax, and more preferably the p-position. Among these, 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 the substituent include a single bond and a substituent represented by the following formula (X 10 -1)~Formula(X 10 -10) is a group represented by * -R a7 represents the bonding site with the carbon atom to which L is bonded. a71 It represents the binding site with X 20 is -O- or -NR a71 - represents. TIFF2025074940000132.tif43161 expression (X 10 -1)~Formula(X 10 Specific examples of the group represented by -10) include the following groups. TIFF2025074940000133.tif87161Among them, X a71 is a single bond and the formula (X 10 -1'), expression (X 10 -3')~expression(X 10 -9'), which is preferably a single bond or a group represented by the formula (X 10 -1'), expression (X 10 -4'), expression (X10 -5'), expression (X 10 -6') and formula (X 10 -9'), a single bond, a group represented by the formula (X 10 -1'), a group represented by the formula (X 10 -5'), a group represented by the formula (X 10 -6') or formula (X 10 -9') is more preferable.

[0167] L a71 The hydrocarbon group is 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, to form X. a71 and X a72 Also, L a72 The hydrocarbon group is 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, to form X. a72 and R.A. - Examples of such groups include groups that bond to the L a71 and L a72 Examples of the chain hydrocarbon group include a group in which one hydrogen atom has been removed from an alkyl group or an alkenyl group. The alkyl group may be linear or branched, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl 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 pentanedecyl group, and a heptadecyl group. 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 chain hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 18 carbon atoms, and even more preferably 1 to 10 carbon atoms. L a71 and La72 Examples of the alicyclic hydrocarbon group include a group in which one hydrogen atom has been removed 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, and a cyclooctyl group. L a71 and L a72 Examples of the polycyclic cycloalkyl group include a cycloalkyl group having a bridged structure, a cycloalkyl group in which two or more rings are condensed, or a cycloalkyl group in which two rings are bonded by a spiro bond. Examples of the cycloalkyl group having a bridged 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 cycloalkyl group in which two rings are bonded by a spiro bond 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 is bonded by a spiro bond 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 the following formula: TIFF2025074940000134.tif28158 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 3 to 12, and even more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the alicyclic hydrocarbon group preferably has 6 to 18 carbon atoms, and more preferably 7 to 12. L a71 and L a72 The aromatic hydrocarbon group may be a group in which one hydrogen atom has been removed from an aryl group. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a fluorenyl group. The number of carbon atoms in the aromatic hydrocarbon group is preferably 5 to 14, more preferably 6 to 14, and further preferably 6 to 10. La71 and L a72 When --CH2-- in the hydrocarbon group is replaced with --O--, --CO--, --S-- or --SO2--, the number of carbon atoms before the replacement is regarded as the number of carbon atoms in the hydrocarbon group. L a71 and L a72 Among the hydrocarbon groups, examples of groups in which -CH- in a chain hydrocarbon group is replaced with -O-, -CO-, -S- or -SO- 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 alkanediyloxy group, an alkanediyloxycarbonyl group, an alkanediylcarbonyl group (, an alkanediylcarbonyloxy group, etc. These substituted groups include the same as the groups exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms. L a71 and L a72 Among the above hydrocarbon groups, examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced with -O-, -CO-, -S- or -SO2- include groups containing a cyclic ether, cyclic ketone, cyclic ester (lactone), cyclic thioether, cyclic acetal, and cyclic sulfonate ester (sultone) structure. Specific examples include alicyclic hydrocarbon groups represented by the following formula. The bonding position of the alicyclic hydrocarbon groups listed in the following formula may be any position. TIFF2025074940000135.tif46146L a71 and L a72 Among these hydrocarbon groups, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-, and 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 the group in which two or more of the chain hydrocarbon group, alicyclic hydrocarbon group, and aromatic hydrocarbon group are combined include a group in which the chain hydrocarbon group and the alicyclic hydrocarbon group are combined, a group in which the chain hydrocarbon group and the aromatic hydrocarbon group are combined, a group in which the alicyclic hydrocarbon group and the aromatic hydrocarbon group are combined, and a group in which the chain hydrocarbon group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group are combined. The group in which the alicyclic hydrocarbon group and the aromatic hydrocarbon group are combined may be a condensed ring. L a71 and L a72 The substituents which the hydrocarbon group 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 L is a group in which an alicyclic hydrocarbon group or an aromatic hydrocarbon group is combined with a chain hydrocarbon group, the chain hydrocarbon group may be regarded as a substituent that the alicyclic hydrocarbon group or the aromatic hydrocarbon group has. a71 and L a72 The -CH2- of the chain hydrocarbon group contained in the hydrocarbon group is replaced with -O-, -CO-, -S- or -SO2-, thereby forming L a71 and L a72 The hydrocarbon group may substantially have a substituent such as a hydroxy group, a carboxy group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a thiol group, or a sulfonyl group. na7 is preferably 0 or 1. ZA in formula (a7-A) + Examples of the cation include the same as the cation in the salt represented by formula (B1) etc.

[0168] In formula (a7-A), L a71 and L a72 When the hydrocarbon group is a saturated hydrocarbon group, in the formula (a7-B) described later, b7 The divalent linking group may include the same groups as those exemplified above. Examples of the structural unit represented by formula (a7-A) include a structural unit represented by formula (a7-A1). TIFF2025074940000136.tif30138[In formula (a7-A1), R a7 , X a71 , L a71 , X a72 , na7, R.A. - and Z.A. + has the same meaning as above. z7 represents an integer of 0 to 6. Q a7 , Q b7 , R z71 and R z72 each independently represents 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, z71 and R z72 may be the same or different.] Q a7 , Q b7 , R z71 and R z72 As the perfluoroalkyl group having 1 to 6 carbon atoms or the alkyl group having 1 to 6 carbon atoms in R a7 Examples of the groups include the same groups as those exemplified in the above.

[0169] Examples of the structural unit represented by formula (a7-A) include the following structural units, R a7 Examples of the structural units include those in which the group corresponding to the methyl group in the above formula (I) is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom) or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., a trifluoromethyl group, etc.), and the structural units described in WO 2012 / 050015. + represents an organic cation. TIFF2025074940000137.tif244163

[0170] TIFF2025074940000138.tif130157

[0171] The structural unit having a sulfonio group and an organic anion on the side chain is preferably a structural unit represented by formula (a7-B). TIFF2025074940000139.tif28104[In 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 represents a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent; R b72 and R b73 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. A - represents an organic anion. R a7 Examples of the halogen atom and the alkyl group which may have a halogen atom in the formula (a7-A) include the same halogen atom and the alkyl group which may have a halogen atom as in the formula (a7-A). R b71 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by the formula (I) include a phenylene group and a naphthylene group. R b72 and R b73 Examples of the hydrocarbon group represented by the formula (I) include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Examples of the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and groups formed by combining these groups include those similar to those described above. A b7 Examples of the divalent linking group represented by the formula (I) include divalent saturated hydrocarbon groups 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 divalent chain saturated hydrocarbon groups such as linear or branched alkanediyl groups, and monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and combinations of these are also possible. Specifically, straight-chain 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, and dodecane-1,12-diyl group; divalent monocyclic alicyclic saturated hydrocarbon groups such as monocyclic cycloalkanediyl groups, such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group; and divalent polycyclic alicyclic saturated hydrocarbon groups, such as polycyclic cycloalkanediyl groups, such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group. Examples of saturated hydrocarbon groups in which -CH2- has been replaced with -O-, -S-, or -CO- include the following divalent groups. However, the number of carbon atoms before the -CH2- in the saturated hydrocarbon group is replaced with -O-, -S-, or -CO- is 17 or less. In the following formulas, * and ** represent binding sites, * represents R b71 It represents the binding site with TIFF2025074940000140.tif123161[where, 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.

[0172] The structural unit containing a cation in formula (a7-B) includes the structural units represented by the following formula: a7 Examples of such structural units include those in which a group corresponding to the methyl group in the above formula (I) is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., a trifluoromethyl group, etc.). TIFF2025074940000141.tif75163

[0173] A - Examples of the organic anion represented by the formula (I) include a sulfonate anion, a sulfonylimide anion, a sulfonylmethide anion, and a carboxylate anion. - The organic anion represented by the formula (I) is preferably a sulfonate anion, and the sulfonate anion is more preferably the same as the anion exemplified for the acid generator (B). Examples of the sulfonylimide anion, sulfonylmethide anion, and carboxylate anion include the same anions exemplified for the acid generator (B).

[0174] Examples of the structural unit represented by formula (a7-B) include structural units represented below. TIFF2025074940000142.tif95157 When the resin (A) contains the structural unit (a7), the structural unit (a7) may be contained alone or in combination of two or more kinds. The total content of the structural unit (a7) is preferably 1 to 30 mol%, more preferably 1 to 25 mol%, even more preferably 2 to 20 mol%, still more preferably 3 to 15 mol%, and even more preferably 3 to 10 mol%, based on the total structural units of the resin (A1).

[0175] The resin may contain structural units other than those mentioned above, including those structural units well known in the art.

[0176] The resin is preferably a resin consisting of the structural unit (a2-A) and / or the structural unit (a1-4), or a resin containing the structural unit (a2-A) and / or the structural unit (a1-4).

[0177] Each structural unit constituting the resin may be used alone or in combination of two or more, and can be produced by a known polymerization method (e.g., radical polymerization method) using monomers that lead to these structural units. The content of each structural unit in the resin can be adjusted by the amount of monomer used in polymerization. The weight average molecular weight of the resin is preferably 2,000 or more (more preferably 2,500 or more, and even more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, and even more preferably 15,000 or less). In this specification, the weight average molecular weight is a value determined by gel permeation chromatography under the conditions described in the Examples. When the resist composition of the present invention contains a resin, the total resin content, relative to the solid content of the resist composition, is preferably from 1 mass % to 80 mass %, more preferably from 3 mass % to 60 mass %, and even more preferably from 5 mass % to 50 mass %.

[0178] <Other resins> The resist composition of the present invention may contain a resin other than the resin containing the structural unit (a2-A) and / or the structural unit (a1-4). Examples of resins other than the resin containing the structural unit (a2-A) and / or the structural unit (a1-4) include a resin containing the structural unit (a1) but not the structural unit (a2) (hereinafter, sometimes referred to as resin (AA)), and a resin containing the structural unit (a4) and / or the structural unit (a5) (hereinafter, sometimes referred to as resin (X)). The resin (AA) may contain, in addition to the structural unit (a1), the structural unit (a3), the structural unit (a4), the structural unit (a5), the structural unit (a6), the structural unit (a7), and the like. In addition, in the resin (AA), the content of each of the structural units (a1), (a3), (a4), (a5), (a6) and / or (a7) can be the same as the content relative to all structural units in the above-mentioned resin.

[0179] As the resin (X), a resin containing the structural unit (a4) is particularly preferred, that is, a resin containing a structural unit having a fluorine atom is preferred. Examples of structural units that may be further included in the resin (X) include structural units (a3), (a6), (a7), and structural units derived from other known monomers. Among them, the resin (X) is preferably a resin consisting only of the structural unit (a4) and / or the structural unit (a5), and more preferably a resin consisting only of the structural unit (a4). When the resin (X) contains the structural unit (a4), the content of the structural unit (a4) in the resin (X) is 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more, based on the total of all structural units in the resin (X). In addition, the content is 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, even more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, the content is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, even more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. When the resin (X) contains 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 even more preferably 45 mol% or more, based on the total of all structural units of the resin (X). Also, the content is 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, even more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, the content is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, even more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. When the resin (X) contains 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 even more preferably 80 mol% or more, based on the total of all structural units in the resin (X). It can also be 100 mol% or less. Specifically, it can be 40 to 100 mol%, preferably 60 to 100 mol%, more preferably 70 to 100 mol%, and even more preferably 80 to 100 mol%.The content of the structural unit (a2) which may be further contained is, for example, 1 to 45 mol %, preferably 2 to 30 mol %, and more preferably 2 to 20 mol %, based on the total of all structural units in the resin (X).

[0180] Each structural unit constituting the resin (AA) and 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 a monomer that derives these structural units. The content of each structural unit contained in the resin (AA) and the resin (X) can be adjusted by the amount of the monomer used for polymerization. The weight average molecular weight of resin (AA) is preferably 2,000 or more (more preferably 2,500 or more, even more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, even more preferably 15,000 or less). The weight average molecular weight of resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The method for measuring the weight average molecular weight of resin (AA) and resin (X) is the same as that for the resin. Furthermore, when the resist composition contains resin (AA) and / or resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, even more preferably 1 to 40 parts by mass, still more preferably 2 to 30 parts by mass, and even more preferably 2 to 8 parts by mass, relative to 100 parts by mass of the resin.

[0181] The content of resin (AX) in the resist composition is preferably 0% by mass or more and 60% by mass or less, more preferably 0% by mass or more and 50% by mass or less, based on the solid content of the resist composition. When a resin other than resin (AX) is contained, the total content of resin (AX) and the resin other than resin (AX) is preferably 0% by mass or more and 60% by mass or less, more preferably 0% by mass or more and 60% by mass or less, based on the solid content of the resist composition. The solid content of the resist composition and the resin content therein can be measured by known analytical means such as liquid chromatography or gas chromatography.

[0182] <Solvent (E)> The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, and more preferably 94% by mass or more and 99% by mass or less. The content of the solvent (E) can be measured by a known analytical method such as liquid chromatography or gas chromatography.

[0183] 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; etc. One type of solvent (E) may be used alone, or two or more types may be used.

[0184] <Quencher (C)> Examples of the quencher (C) include salts that generate an acid having a weaker acidity than the acid generated from the basic nitrogen-containing organic compound and the acid generator (salt (I) or compound (B)). When the resist composition contains the quencher (C), the content of the quencher (C) is preferably about 0.01 to 15 mass%, more preferably about 0.01 to 10 mass%, even more preferably about 0.1 to 8 mass%, and even more preferably about 0.1 to 7 mass%, based on the solid content of the resist composition. The basic nitrogen-containing organic compound includes amines and ammonium salts. The amines include aliphatic amines and aromatic amines. The aliphatic amines include primary amines, secondary amines, and tertiary amines.

[0185] Examples of amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributaryamine, ethylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldi Decylamine, 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-pyridinyl)amine ... Examples of the dipyridyl amine include 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, and bipyridine. Of these, diisopropylaniline is preferred, and 2,6-diisopropylaniline is more preferred. 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.

[0186] The acidity of a salt that generates an acid with a lower acidity than the acid generated from the acid generator 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 is a salt having an acid dissociation constant of the acid generated from the salt of usually -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 include a salt represented by the following formula, a salt 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 is preferably a salt that generates a carboxylic acid with a lower acidity than the acid generated from the acid generator (a salt having a carboxylic acid anion), more preferably a 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). JPEG2025074940000143.jpg95157

[0187] The weak acid inner salt (D) is preferably 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. Specifically, examples include salts represented by the following formula.

[0188] TIFF2025074940000144.tif1775[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 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 chain hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these groups. Examples of the chain hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, and a nonyl group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and may be either saturated or unsaturated. Examples of the alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclononyl, and cyclododecyl, norbornyl, and adamantyl groups. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-propylphenyl group, a 4-isopropylphenyl group, a 4-butylphenyl group, a 4-t-butylphenyl group, a 4-hexylphenyl group, a 4-cyclohexylphenyl group, an anthryl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group. Groups formed by combining these groups include alkyl-cycloalkyl groups, cycloalkyl-alkyl groups, and aralkyl groups (e.g., 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, and 6-phenyl-1-hexyl group). Examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, and a cyclohexanecarbonyl group. Examples of the acyloxy group include the above-mentioned acyl group to which an oxy group (-O-) is bonded. Examples of the alkoxycarbonyl group include the above alkoxy groups bonded to a carbonyl group (-CO-). Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. 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 preferably an integer of 0 to 2, more preferably 0. 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.

[0189] More specifically, the following salts are included: TIFF2025074940000145.tif72165

[0190] <Other Ingredients> The resist composition of the present invention may contain components other than the above-mentioned components (hereinafter, sometimes referred to as "other components (F)") as necessary. There are no particular limitations on the other components (F), and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, etc., can be used.

[0191] Preparation of Resist Composition The resist composition of the present invention can be prepared by mixing the salt (I), and, if necessary, the compound (B), the resin (A), a resin other than the resin (A), a compound having a phenolic hydroxyl group and / or a compound in which the hydroxyl group of the phenolic hydroxyl group is protected with an acid labile group, the solvent (E), the quencher (C) and other components (F). The order of mixing is arbitrary and is not particularly limited. The temperature during mixing can be selected from 10 to 40°C depending on the type of resin, the solubility of the resin in the solvent (E), and the like. The mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used. After mixing the components, it is preferable to filter the mixture using a filter having a pore size of about 0.003 to 0.2 μm.

[0192] <Method for Producing Resist Pattern> The method for producing a resist pattern of the present invention comprises the steps of: (1) 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) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) A step of developing the composition layer after heating. The resist composition can be applied onto a substrate using a commonly used device such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers, and organic substrates having a resist film or the like formed on the surface. Before applying the resist composition, the substrate may be cleaned, and an anti-reflective film or the like may be formed on the substrate. The composition after coating is dried to remove the solvent and 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-baking), or by using a vacuum device. The heating temperature is preferably 50 to 200°C, and the heating time is preferably 10 to 180 seconds. The pressure during drying under reduced pressure is preferably 1 to 1.0×10 5 It is preferable that the pressure is about 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, various types can be used, such as those that emit ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), and F2 excimer laser (wavelength 157 nm), those that convert the wavelength of laser light from a solid laser light source (YAG or semiconductor laser, etc.) to emit harmonic laser light in the far ultraviolet or vacuum ultraviolet range, and those that irradiate electron beams or extreme ultraviolet light (EUV). In this specification, irradiation with these types of radiation may be collectively referred to as "exposure". During exposure, exposure is usually performed through a mask corresponding to the desired pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask. The composition layer after exposure is subjected to a heat treatment (so-called post-exposure bake) in order to promote a deprotection reaction in the acid labile group. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C. A chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the composition after heating. In addition, before development, the steps of applying a resist composition, drying, exposing, and heating may be repeated on the composition layer after exposure. The composition layer after heating is usually developed using a developing device and a developer. Examples of the developing method include a dip method, a paddle method, a spray method, and a dynamic dispense method. 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 produced. When a positive resist pattern is produced from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline) may be used. The alkaline developer may contain a surfactant. After development, the resist pattern is preferably washed with ultrapure water, and then water remaining on the substrate and the pattern is removed. When producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as an "organic developer") is used as the developer. Examples of organic solvents contained in organic developers include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; and aromatic hydrocarbon solvents such as anisole. The content of the organic solvent in the organic developer is preferably from 90% by mass to 100% by mass, more preferably from 95% by mass to 100% by mass, and further preferably consists essentially of the organic solvent. Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and even more preferably substantially only butyl acetate and / or 2-heptanone. The organic developer may contain a surfactant and may contain a small amount of water. During development, the development may be stopped by replacing the organic developer with a different type of solvent. The resist pattern after development is preferably washed with a rinse solution. There are no particular limitations on the rinse solution as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent. After cleaning, it is preferable to remove any rinsing liquid remaining on the substrate and the pattern.

[0193] <Application> The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, and is particularly suitable as a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, and is useful for semiconductor microfabrication. EXAMPLES

[0194] The present invention will be described in more detail with reference to examples. In the examples, "%" and "parts" expressing the content or amount used are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography under the following analytical conditions: Column: TSKgel Multipore HXL-M x 3 + guard column (Tosoh Corporation) Eluent: Tetrahydrofuran Flow rate: 1.0mL / min Detector: RI detector Column temperature: 40℃ Injection volume: 100μl Molecular weight standard: Standard polystyrene (Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent 1100 model, MASS: Agilent LC / MSD model). In the following examples, the value of this molecular ion peak is indicated by "MASS".

[0195] Example 1: Synthesis of a salt represented by formula (I-1) TIFF2025074940000146.tif35135 3.84 parts of the compound represented by formula (I-1-a) and 50 parts of acetonitrile were mixed and stirred at 23 ° C. for 30 minutes. 6.49 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 4.65 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 10 parts of 1N hydrochloric acid were added to the resulting mixture, and the mixture was heated to 23 ° C. and stirred at 23 ° C. for 6 hours. 100 parts of chloroform and 50 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 50 parts of ion-exchanged water was added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The collected filtrate was concentrated, and the concentrated mass was separated using a column (Kanto Chemical Silica Gel 60N (spherical, neutral) 100-210 μm, developing solvent: n-heptane / ethyl acetate=2 / 1) to obtain 3.64 parts of the compound represented by formula (I-1-d). TIFF2025074940000147.tif45155 4.38 parts of the salt represented by formula (I-1-e) and 50 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.62 parts of the compound represented by formula (I-1-b) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 3.30 parts of the compound represented by formula (I-1-d) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 25 parts of a 5% aqueous oxalic acid solution were added to the obtained mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 25 parts of ion-exchanged water were added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and then 20 parts of tert-butyl methyl ether was added to the concentrated residue and stirred, and the supernatant was removed. The resulting residue was dissolved in acetonitrile and concentrated to obtain 6.44 parts of the salt represented by formula (I-1). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 487.1

[0196] Example 2: Synthesis of a salt represented by formula (I-2) TIFF2025074940000148.tif30158 5.13 parts of the salt represented by formula (I-2-e) and 50 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 3.24 parts of the compound represented by formula (I-1-b) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 2.32 parts of the compound represented by formula (I-1-c) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 25 parts of a 5% aqueous oxalic acid solution were added to the obtained mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 25 parts of ion-exchanged water were added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and then 20 parts of tert-butyl methyl ether was added to the concentrated residue and stirred, and the supernatant was removed. The resulting residue was dissolved in acetonitrile and concentrated to obtain 7.05 parts of the salt represented by formula (I-2). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 533.1

[0197] Example 3: Synthesis of salt represented by formula (I-3) TIFF2025074940000149.tif35134 3.84 parts of the compound represented by formula (I-1-a) and 50 parts of acetonitrile were mixed and stirred at 23 ° C. for 30 minutes. 6.49 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 2.96 parts of the compound represented by formula (I-3-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 10 parts of 1N hydrochloric acid were added to the resulting mixture, and the mixture was heated to 23 ° C. and stirred at 23 ° C. for 6 hours. 100 parts of chloroform and 50 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 50 parts of ion-exchanged water was added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The collected filtrate was concentrated, and the concentrated mass was separated using a column (Kanto Chemical Silica Gel 60N (spherical, neutral) 100-210 μm, developing solvent: n-heptane / ethyl acetate=2 / 1) to obtain 2.66 parts of the compound represented by formula (I-3-d). TIFF2025074940000150.tif44155 4.38 parts of the salt represented by formula (I-1-e) and 50 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.62 parts of the compound represented by formula (I-1-b) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 2.46 parts of the compound represented by formula (I-3-d) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 25 parts of a 5% aqueous oxalic acid solution were added to the obtained mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 25 parts of ion-exchanged water were added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and then 20 parts of tert-butyl methyl ether was added to the concentrated residue and stirred, and the supernatant was removed. The resulting residue was dissolved in acetonitrile and concentrated to obtain 5.12 parts of the salt represented by formula (I-3). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M -403.0

[0198] Example 4: Synthesis of salt represented by formula (I-14) TIFF2025074940000151.tif35139 1.76 parts of a compound represented by formula (I-14-c) and 50 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 3.24 parts of a compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 5.13 parts of a salt represented by formula (I-2-e) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 25 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 25 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The resulting organic layer was concentrated, and then 20 parts of tert-butyl methyl ether was added to the concentrated residue and stirred, and the supernatant was removed. The resulting residue was dissolved in acetonitrile and concentrated to obtain 5.33 parts of the salt represented by formula (I-14). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 389.0

[0199] Example 5: Synthesis of a salt represented by formula (I-20) TIFF2025074940000152.tif35160 5.61 parts of the salt represented by formula (I-20-e) and 50 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 3.24 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 2.32 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 100 parts of chloroform and 50 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 50 parts of ion-exchanged water was added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and then 20 parts of tert-butyl methyl ether was added to the concentrated residue and stirred, and the supernatant was removed. The obtained residue was dissolved in acetonitrile and concentrated to obtain 15.12 parts of the salt represented by formula (I-20). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 581.1

[0200] Example 6: Synthesis of a salt represented by formula (I-25) TIFF2025074940000153.tif44159 4.38 parts of the salt represented by formula (I-1-e) and 50 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.62 parts of the compound represented by formula (I-1-b) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 5.01 parts of the compound represented by formula (I-25-d) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 25 parts of a 5% aqueous oxalic acid solution were added to the obtained mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 25 parts of ion-exchanged water were added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and then 5 parts of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue and stirred, and the supernatant was removed. The resulting residue was dissolved in acetonitrile and concentrated to obtain 4.21 parts of the salt represented by the formula (I-25). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 657.2

[0201] Example 7: Synthesis of a salt represented by formula (I-24) TIFF2025074940000154.tif46160 4.38 parts of the salt represented by formula (I-1-e) and 50 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.62 parts of the compound represented by formula (I-1-b) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 3.34 parts of the compound represented by formula (I-24-d) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 25 parts of a 5% aqueous oxalic acid solution were added to the obtained mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 25 parts of ion-exchanged water were added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and then 5 parts of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue and stirred, and the supernatant was removed. The resulting residue was dissolved in acetonitrile and concentrated to obtain 4.98 parts of the salt represented by formula (I-24). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 491.1

[0202] Example 8: Synthesis of a salt represented by formula (I-276) TIFF2025074940000155.tif53161 7.00 parts of the salt represented by formula (I-51-e) and 50 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.62 parts of the compound represented by formula (I-1-b) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 3.30 parts of the compound represented by formula (I-1-d) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 25 parts of a 5% aqueous oxalic acid solution were added to the obtained mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 25 parts of ion-exchanged water were added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and then 20 parts of tert-butyl methyl ether was added to the concentrated residue and stirred, and the supernatant was removed. The resulting residue was dissolved in acetonitrile and concentrated to obtain 9.08 parts of a salt represented by the formula (I-276). MS(ESI(+)Spectrum):M + 525.0 MS(ESI(-)Spectrum):M - 487.1

[0203] Example 9: Synthesis of a salt represented by formula (I-951) TIFF2025074940000156.tif53161 6.00 parts of the salt represented by formula (I-52-e) and 50 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.62 parts of the compound represented by formula (I-1-b) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 3.30 parts of the compound represented by formula (I-1-d) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 25 parts of a 5% aqueous oxalic acid solution were added to the obtained mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 25 parts of ion-exchanged water were added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and then 20 parts of tert-butyl methyl ether was added to the concentrated residue and stirred, and the supernatant was removed. The resulting residue was dissolved in acetonitrile and concentrated to obtain 8.13 parts of a salt represented by the formula (I-951). MS(ESI(+)Spectrum):M + 425.0 MS(ESI(-)Spectrum):M - 487.1

[0204] Example 10: Synthesis of a salt represented by formula (I-976) TIFF2025074940000157.tif53161 6.72 parts of the salt represented by formula (I-52-e) and 50 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.62 parts of the compound represented by formula (I-1-b) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 3.30 parts of the compound represented by formula (I-1-d) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 25 parts of a 5% aqueous oxalic acid solution were added to the obtained mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 25 parts of ion-exchanged water were added to the obtained organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and then 20 parts of tert-butyl methyl ether was added to the concentrated residue and stirred, and the supernatant was removed. The resulting residue was dissolved in acetonitrile and concentrated to obtain 8.44 parts of a salt represented by the formula (I-976). MS(ESI(+)Spectrum):M + 496.9 MS(ESI(-)Spectrum):M - 487.1

[0205] Example 11: Synthesis of salt represented by formula (I-278) TIFF2025074940000158.tif47160 7.00 parts of the salt represented by formula (I-51-e) and 50 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.62 parts of the compound represented by formula (I-1-b) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 2.46 parts of the compound represented by formula (I-3-d) were added to the obtained mixed solution, and the mixture was further stirred at 50 ° C. for 3 ...

Claims

1. An acid generator comprising a salt represented by formula (I): [In formula (I), Q １ and Q. ２ each independently represents 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. R 11 and R 12 each independently represents 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. z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R 11 and R 12 may be the same or different from each other. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, and * represents C(R 11 ) (R 12 ) or C(Q １ ) (Q ２ ) binding site. L 1 represents a chain hydrocarbon group having 1 to 36 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or a combination thereof, and —CH 2 - is -O-, -S-, -SO ２ It may be replaced by --or --CO--. L ２ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the —CH ２ - may be replaced by -O- or -CO-. R ３ represents a group represented by formula (IC). m3 represents an integer of 2 to 6, and a plurality of R ３ may be the same or different from each other. Z ＋ represents an organic cation. [In formula (IC), R Ａ represents a saturated hydrocarbon group having 1 to 12 carbon atoms. u1 represents an integer of 0 to 2, and when u1 is 2, a plurality of R Ａ are either the same or different. s1 represents 1 or 2. t1 represents 0 or 1, provided that the sum of s1 and t1 is 1 or 2. * is L ２ represents the binding site with

2. L １ is a chain hydrocarbon group having 1 to 10 carbon atoms (provided that the chain hydrocarbon group contains -CH 2 2. The acid generator according to claim 1, wherein - may be replaced by -O- or -CO-.

3. L １ but, an aromatic hydrocarbon group having 6 to 10 carbon atoms; a group combining an alkanediyl group having 1 to 10 carbon atoms with an aromatic hydrocarbon group having 6 to 10 carbon atoms, a group consisting of an alkanetriyl group having 1 to 10 carbon atoms and one or two aromatic hydrocarbon groups having 6 to 10 carbon atoms; a group consisting of an alkanetetrayl group having 2 to 10 carbon atoms and one to three aromatic hydrocarbon groups having 6 to 10 carbon atoms, The aromatic hydrocarbon group having 6 to 10 carbon atoms may have a substituent, and the —CH ２ 2. The acid generator according to claim 1, wherein -- may be replaced by --O-- or --CO--.

4. The acid generator according to claim 1 , wherein m3 is 2 or 3.

5. Contains two or more salts of formula (I), R of one salt among two or more salts represented by formula (I) ３ is a group represented by formula (IC-1), R of one salt among two or more salts represented by formula (I) ３ is a group represented by formula (IC-2) or formula (IC-3): [In formula (IC-1), formula (IC-2) and formula (IC-3), *, R Ａ and u1 have the same meaning as in formula (IC). u1′ represents 0 or 1. * indicates a binding site.

6. A resist composition comprising the acid generator according to any one of claims 1 to 5.

7. 7. The resist composition according to claim 6, further comprising a compound having a phenolic hydroxyl group and / or a compound in which the phenolic hydroxyl group is protected with an acid labile group.

8. The resist composition according to claim 6, further comprising a resin containing one or more structural units represented by formula (a2). [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 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. L ａ２１ represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms, the hydrocarbon group may have a substituent, and the —CH ２ - is -O-, -CO-, -S- or -SO ２ It may be replaced with -. L ａ２２ represents a chain hydrocarbon group having 1 to 12 carbon atoms which may have a single bond or a fluorine atom, and —CH 2 - may be replaced by -O- or -CO-. na2 represents an integer of 1 to 4. When na2 is 2 or more, multiple L ａ２２ may be the same or different.

9. One or more structural units represented by formula (a2) 9. The resist composition according to claim 8, which comprises one or more structural units 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 4, 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.

10. One or more structural units represented by formula (a2) The resist composition according to claim 8, which contains a structural unit represented by formula (a2-D): [In formula (a2-D), 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. R ａ２１ and R ａ２２ each independently represents a fluorinated alkyl 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 an integer of 1 to 4. When nD2 is 2 or more, the groups in the parentheses may be the same or different. nD22 represents an integer of 0 to 4. When nD22 is 2 or more, a plurality of R ａ２７ may be the same or different.

11. 7. The resist composition according to claim 6, further comprising a salt which generates an acid having a weaker acidity than the acid generated from the acid generator containing the salt represented by formula (I).

12. (1) A step of applying the resist composition according to claim 6 onto a substrate; (2) A step of drying the applied resist 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:

13. A salt represented by formula (I): [In formula (I), Q １ and Q. ２ each independently represents 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. R 11 and R 12 each independently represents 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. z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R 11 and R 12 may be the same or different from each other. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, and * represents C(R 11 ) (R 12 ) or C(Q １ ) (Q ２ ) binding site. L 1 represents a chain hydrocarbon group having 1 to 36 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or a combination thereof, and —CH 2 - is -O-, -S-, -SO ２ It may be replaced by --or --CO--. L ２ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the —CH ２ - may be replaced by -O- or -CO-. R ３ represents a group represented by formula (IC). m3 represents an integer of 2 to 6, and a plurality of R ３ may be the same or different from each other. Z ＋ represents an organic cation. [In formula (IC), R Ａ represents a saturated hydrocarbon group having 1 to 12 carbon atoms. u1 represents an integer of 0 to 2, and when u1 is 2, a plurality of R Ａ are either the same or different. s1 represents 1 or 2. t1 represents 0 or 1, provided that the sum of s1 and t1 is 1 or 2. * indicates a binding site.

14. L １ is a chain hydrocarbon group having 1 to 10 carbon atoms (provided that the chain hydrocarbon group contains -CH 2 The salt according to claim 13, wherein - may be replaced by -O- or -CO-.

15. L １ but, an aromatic hydrocarbon group having 6 to 10 carbon atoms; a group combining an alkanediyl group having 1 to 10 carbon atoms with an aromatic hydrocarbon group having 6 to 10 carbon atoms, a group consisting of an alkanetriyl group having 1 to 10 carbon atoms and one or two aromatic hydrocarbon groups having 6 to 10 carbon atoms; a group consisting of an alkanetetrayl group having 2 to 10 carbon atoms and one to three aromatic hydrocarbon groups having 6 to 10 carbon atoms, The aromatic hydrocarbon group having 6 to 10 carbon atoms may have a substituent, and the —CH ２ The salt according to claim 13, wherein - may be replaced by -O- or -CO-.

16. The salt according to claim 13 or 14, wherein m3 is 2 or 3.

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