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

Abstract

To provide a salt, an acid generator, and a resist composition which allow a resist pattern having good line edge roughness (LER) to be produced.SOLUTION: The salt is represented by formula (I) [where Q1 and Q2 each independently represent a fluorine atom, a C1-6 perfluoroalkyl group or the like; R11 and R12 each independently represent a hydrogen atom, a fluorine atom, a C1-6 perfluoroalkyl group or the like; z represents an integer of 0-6; X0 represents *-CO-O-, *-O-CO-, *-O-CO-O- or the like; L1 represents a single bond or an optionally substituted C1-28 hydrocarbon group, provided that -CH2- in the group may be substituted with -O-, -S-, -SO2- or -CO-; R1 represents an optionally substituted C3-18 cyclic hydrocarbon group; m represents an integer of 1-4; and Z+ represents an organic cation].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 Art

[0002] Patent Document 1 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator. TIFF0007702842000001.tif32133

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a salt that forms a resist pattern having better line edge roughness (LER) than a resist pattern formed from a resist composition containing the above salt.

Means for Solving the Problems

[0005] The present invention includes the following inventions. [1] An acid generator containing a salt represented by formula (I). TIFF0007702842000002.tif25113[In formula (I), Q 1 and Q 2 each independently represents 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 from 0 to 6. When z is 2 or more, a plurality of R 11 and R 12 may be the same as or different from each other. X 0 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, where * represents a bonding site with C(R 11 )(R 12 ) or C(Q 1 )(Q 2 ). L 1 represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. R 1 represents a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. m represents an integer from 1 to 4. Z + represents an organic cation.] [2]L 1 is a single bond or *-L 2 -CO-O-(L 2 represents a cyclic hydrocarbon group having 3 to 18 carbon atoms or a group combining a cyclic hydrocarbon group having 3 to 18 carbon atoms and an alkanediyl group having 1 to 4 carbon atoms. The cyclic hydrocarbon group may have a substituent, -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. * represents a bond with X 0 .) The acid generator according to [1]. [3]L 2 is a group represented by the following formula (L 2 -1), formula (L 2 -2), formula (L 2 -3) or formula (L 2 -4) (* represents a bond.). The acid generator according to [2]. TIFF0007702842000003.tif3096[4]R 1The acid generator according to any one of [1] to [3], which is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. [5]R 1 In the alicyclic hydrocarbon group having 3 to 18 carbon atoms or the aromatic hydrocarbon group having 6 to 18 carbon atoms of [5], one or more substituents are at least one selected from a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O-, -S-, -CO- or -SO2-), the acid generator according to [4]. [6] A resist composition containing the acid generator according to any one of [1] to [5] and a resin having an acid-labile group. [7] The resist composition according to [6], wherein the resin having an acid-labile group contains at least one selected from the group consisting of a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), and a structural unit represented by formula (a1-2). TIFF0007702842000004.tif42139[In formula (a1-0), formula (a1-1), and formula (a1-2), L a01 、L a1 and L a2 each independently represents -O- or *-O-(CH2) k1 -CO-O-, k1 represents 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 a04 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these. R a6 and R a7Each 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. m1 represents any integer from 0 to 14. n1 represents any integer from 0 to 10. n1’ represents any integer from 0 to 3. [8] A resist composition according to [6] or [7], wherein the resin having an acid-labile group contains a structural unit represented by formula (a2-A). TIFF0007702842000005.tif4349 [In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents 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. A a50 represents a single bond or * -X a51 -(A a52 -X a52 ) nb - represents, and * represents the bonding site with the carbon atom to which -R a50 is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represent -O-, -CO-O-, or -O-CO-. nb represents 0 or 1. mb represents any integer from 0 to 4. When mb is any integer of 2 or more, a plurality of R a51 may be the same as or different from each other. The resist composition according to any one of [6] to [8], further containing a salt that generates an acid having a lower acidity than the acid generated from the acid generator.

[10] (1) A step of applying the resist composition according to any one of [6] to [9] onto a substrate, (2) A step of drying the applied composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer, A method for manufacturing a resist pattern, including the above steps.

[11] A salt represented by formula (I). TIFF0007702842000006.tif25113[In formula (I), Q 1 and Q 2 each independently represents 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 from 0 to 6. When z is 2 or more, a plurality of R 11 and R 12 may be the same as or different from each other. X 0 represents *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, where * represents a bonding site with C(R 11 )(R 12 ) or C(Q 1 )(Q 2 ). L 1 represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms that may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -SO2-, or -CO-. R 1 represents a cyclic hydrocarbon group having 3 to 18 carbon atoms that may have a substituent. m represents an integer from 1 to 4. Z + represents an organic cation.

Advantages of the Invention

[0006] By using the resist composition containing the salt of the present invention, a resist pattern can be produced with good line edge roughness (LER).

Modes for Carrying Out the Invention

[0007] In this specification, the “(meth)acrylic monomer” means “at least one of an acrylic monomer and a methacrylic monomer”. Expressions such as “(meth)acrylate” and “(meth)acrylic acid” also represent the same meaning. Among the groups described in this specification, those that can take both a linear structure and a branched structure may be either of them. When -CH2- contained in a hydrocarbon group or the like is replaced by -O-, -S-, -CO- or -SO2-, the same examples are applied to each group. The “combined group” means a group formed by bonding two or more of the exemplified groups, and the valences of these groups may be appropriately changed depending on the bonding form. “Derived from” or “derived” means that the polymerizable C═C bond contained in the molecule becomes a single bond (-C-C-) by polymerization. When stereoisomers exist, all stereoisomers are included.

[0008] 〔Salt Represented by Formula (I)〕 The present invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as “salt (I)”). Among salts (I), the side having a negative charge may be referred to as “anion (I)”, and the side having a positive charge may be referred to as “cation (I)”. TIFF0007702842000007.tif25113[In the formula, all symbols represent the same meanings as described above.]

[0009] In formula (I), Q 1 , Q 2 , R 11 and R 12Examples 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, and a perfluorohexyl group. 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, and a hexyl group. 1 and Q 2 are each independently preferably a perfluoroalkyl group having 1 to 6 carbon atoms or a fluorine atom, more preferably a trifluoromethyl group or a fluorine atom, and even more preferably a fluorine atom. R 11 and R 12 are each independently preferably a hydrogen atom or a fluorine atom, and more preferably a hydrogen atom. It is preferred that z is 0 or 1. X 0 is preferably *-CO-O-, *-O-CO-O- or *-O-CO-, and more preferably *-CO-O- or *-O-CO-O- (* is C(R 11 )(R 12 ) or C(Q 1 )(Q 2 ) represents the bond position with ).

[0010] L 1 Examples of the hydrocarbon group in include divalent chain hydrocarbon groups such as an alkanediyl group, monocyclic or polycyclic (including spiro ring) divalent alicyclic hydrocarbon groups, and divalent aromatic hydrocarbon groups, and may be a group consisting of a combination of two or more of these groups (for example, a divalent hydrocarbon group formed from an alicyclic hydrocarbon group and an alkanediyl group). Examples of the alkanediyl group include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group, and branched alkanediyl groups such as ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group. The number of carbon atoms in the alkanediyl group is preferably 1 to 18, more preferably 1 to 12, still more preferably 1 to 9, even more preferably 1 to 6, and even more preferably 1 to 4. Examples of the monocyclic or polycyclic divalent alicyclic hydrocarbon group include the following groups. The bonding site can be at any position. TIFF0007702842000008.tif42166 The monocyclic divalent alicyclic hydrocarbon group is preferably a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, etc., and the polycyclic divalent alicyclic hydrocarbon group is preferably a norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, and still more preferably 3 to 12. Examples of the divalent aromatic hydrocarbon group include aromatic hydrocarbon groups such as arylene groups like phenylene group, naphthylene group, anthrylene group, biphenylene group, and phenanthrylene group. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and still more preferably 6 to 10. Examples of the group formed by combining two or more types include a group formed by combining an alicyclic hydrocarbon group and an alkanediyl group, a group formed by combining an aromatic hydrocarbon group and an alkanediyl group, and a group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group. In the combination, two or more types of alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined respectively. Also, any group may be bonded to X 0 . Examples of the group formed by combining an alicyclic hydrocarbon group and an alkanediyl group include, for example, -divalent alicyclic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent alicyclic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent alicyclic hydrocarbon group-, etc. Examples of the group formed by combining an aromatic hydrocarbon group and an alkanediyl group include, for example, -divalent aromatic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent aromatic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent aromatic hydrocarbon group-, etc. Examples of the group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group include -aromatic hydrocarbon group-alicyclic hydrocarbon group-, -alicyclic hydrocarbon group-aromatic hydrocarbon group-, -alicyclic hydrocarbon group-aromatic hydrocarbon group-alicyclic hydrocarbon group-, etc. L 1 The -CH2- contained in the hydrocarbon group having 1 to 28 carbon atoms of L may be replaced by -O-, -S-, -SO2- or -CO-. L 1 When the -CH2- contained in the hydrocarbon group having 1 to 28 carbon atoms of L is replaced by -O-, -S-, -SO2- or -CO-, the number of carbon atoms before replacement is taken as the number of carbon atoms of the hydrocarbon group. Examples of the group in which -CH2- contained in the hydrocarbon group is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group (a group in which -CH2- contained in the methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- contained in the ethyl group is replaced by -O-CO-), a thiol group (a group in which -CH2- contained in the methyl group is replaced by -S-), an alkoxy group (a group in which -CH2- at any position contained in the alkyl group is replaced by -O-), an alkylthio group (a group in which -CH2 at any position contained in the alkyl is replaced by -S-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which -CH2- at any position contained in the alkyl group is replaced by -CO-), an alkylsulfonyl group (a group in which -CH2- at any position contained in the alkyl group is replaced by -SO2-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -CO-O-), an alkanedioxy group (a group in which -CH2- at any position contained in the alkanedioyl group is replaced by -O-), an alkanedioxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkanedioyl group is replaced by -O-CO-), an alkanedioylcarbonyl group (a group in which -CH2- at any position contained in the alkanedioyl group is replaced by -CO-), an alkanedioylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkanedioyl group is replaced by -CO-O-), an alkanedioylsulfonyl group (a group in which -CH2- at any position contained in the alkanedioyl group is replaced by -SO2-), an alkanediylthio group (a group in which -CH2- at any position contained in the alkanediyl group is replaced by -S-), a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, an aromatic hydrocarbon group-carbonyl-oxy group, a group formed by combining two or more of these groups, and the like. Examples of the alkoxy group include alkoxy groups having 1 to 17 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group and the like. The number of carbon atoms of the alkoxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, even more preferably 1 to 3, and even more preferably 1 to 3. Examples of the alkylthio group include alkylthio groups having 1 to 17 carbon atoms, such as methylthio group, ethylthio group, propylthio group, butylthio group and the like. The number of carbon atoms of the alkylthio group is preferably 1 to 11, more preferably 1 to 6, and still more preferably 1 to 4. The alkoxycarbonyl group, alkylcarbonyl group and alkylcarbonyloxy group represent groups in which a carbonyl group or carbonyloxy group is bonded to the above-described alkyl group or alkoxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group and the like. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 18 carbon atoms, such as acetyl group, propionyl group and butyryl group and the like. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as acetyloxy group, propionyloxy group, butyryloxy group and the like. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, even more preferably 2 or 3. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 17 carbon atoms, such as methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group and the like. The number of carbon atoms of the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-oxy group include alkanediyl-oxy groups having 1 to 17 carbon atoms, such as methylene-oxy group, ethylene-oxy group, propanediyl-oxy group, butanediyl-oxy group, pentanediyl-oxy group and the like. The number of carbon atoms of the alkanediyl-oxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-oxycarbonyl group include alkanediyl-oxycarbonyl groups having 2 to 17 carbon atoms, such as methylene-oxycarbonyl group, ethylene-oxycarbonyl group, propanediyl-oxycarbonyl group, butanediyl-oxycarbonyl group and the like. Examples of the alkanediyl-carbonyl group include alkanediyl-carbonyl groups having 2 to 18 carbon atoms, such as methylene-carbonyl group, ethylene-carbonyl group, propanediyl-carbonyl group, butanediyl-carbonyl group, pentanediyl-carbonyl group and the like. Examples of the alkanediyl-carbonyl-oxy group include alkanediyl-carbonyl-oxy groups having 2 to 17 carbon atoms, such as methylene-carbonyl-oxy group, ethylene-carbonyl-oxy group, propanediyl-carbonyl-oxy group, butanediyl-carbonyl-oxy group and the like. The number of carbon atoms of the alkanediyl-oxycarbonyl 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 of the alkanediyl-carbonyl 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 of the alkanediyl-carbonyl-oxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediylsulfonyl group include alkanediylsulfonyl groups having 1 to 17 carbon atoms, such as a methylenesulfonyl group, an ethylenesulfonyl group, and a propylenesulfonyl group. The number of carbon atoms of the alkanediylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediylthio group include alkanediylthio groups having 1 to 17 carbon atoms, such as a methylenethio group, an ethylenethio group, and a propylenethio group. The number of carbon atoms of 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. Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 17 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 17 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as a butoxycarbonyloxy group. Examples of the aromatic hydrocarbon group-carbonyl-oxy group include aromatic hydrocarbon group-carbonyl-oxy groups having 7 to 17 carbon atoms, such as a benzoyloxy group. In addition, examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include the following groups. -O- or -CO- in the groups represented below may be replaced by -S- or -SO2-, respectively. The bonding site can be at any position. TIFF0007702842000009.tif45166

[0011] L 1Examples of the substituent which may be included are a hydroxy group, a carboxy group, a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, 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, or a group formed by combining these groups, etc. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. 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, a nonyl group, etc. 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, a dodecyloxy group, etc. The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group having 2 to 13 carbon atoms represent a group in which a carbonyl group or a carbonyl-oxy group is bonded to the above-described alkyl group or alkoxy group. Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group, etc. Examples of the alkylcarbonyl group having 2 to 13 carbon atoms include an acetyl group, a propionyl group, a butyryl group, etc. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, a butyryloxy group, etc. The substituent is preferably an alkyl group having 1 to 4 carbon atoms, a hydroxy group or a halogen atom, more preferably an alkyl group having 1 to 4 carbon atoms or a halogen atom, and still more preferably a methyl group or a fluorine atom.

[0012] L 1is a single bond, an alkanediyl group having 1 to 6 carbon atoms (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), a group formed by combining an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-), or a group formed by combining an alkanediyl group having 1 to 6 carbon atoms and an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), and is preferably a single bond, an alkanediyl group having 1 to 4 carbon atoms (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), a group formed by combining an alkanediyl group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-), or a group formed by combining an alkanediyl group having 1 to 4 carbon atoms and an aromatic hydrocarbon group having 6 to 14 carbon atoms which may have a substituent (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-). Also, L 1 is a single bond or *-L 2 -CO-O-(L 2 represents a cyclic hydrocarbon group having 3 to 18 carbon atoms or a group formed by combining a cyclic hydrocarbon group having 3 to 18 carbon atoms and an alkanediyl group having 1 to 4 carbon atoms. The cyclic hydrocarbon group may have a substituent, -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. * represents a bond with X 0 .) is also preferable. In addition, the combinations of the alkandiyl group and the alicyclic hydrocarbon group or aromatic hydrocarbon group herein include *-alkandiyl group-alicyclic hydrocarbon group or aromatic hydrocarbon group-, *-alicyclic hydrocarbon group or aromatic hydrocarbon group-alkandiyl group-, *-alkandiyl group-alicyclic hydrocarbon group or aromatic hydrocarbon group-alkandiyl group-, etc. * represents a bond to X 0 represents a bond to.

[0013] L 2 Examples of the cyclic hydrocarbon group and alkandiyl group in L include the same groups as those exemplified above. L 2 is preferably a polycyclic divalent cyclic hydrocarbon group having 6 to 12 carbon atoms (the cyclic hydrocarbon group may have a substituent, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-), more preferably a polycyclic divalent alicyclic hydrocarbon group having 7 to 11 carbon atoms (the -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-), and further preferably a group represented by the following formula (L 2 -1), a group represented by the formula (L 2 -2), a group represented by the formula (L 2 -3), or a group represented by the formula (L 2 -4), and even more preferably a group represented by the formula (L 2 -2). * represents a bond. TIFF0007702842000010.tif3096

[0014] R 1 Examples of the cyclic hydrocarbon group having 3 to 18 carbon atoms in R include alicyclic hydrocarbon groups, aromatic hydrocarbon groups, etc.

[0015] The alicyclic hydrocarbon group may be monocyclic, polycyclic or spirocyclic, and may be saturated or unsaturated. Examples of the alicyclic hydrocarbon group include monocyclic cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cyclododecyl group, etc., and polycyclic cycloalkyl groups such as norbornyl group, adamantyl group, etc. Specifically, examples of the alicyclic hydrocarbon group include the following groups, etc. The bonding site can be at any position. TIFF0007702842000011.tif42166 The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, still more preferably 3 to 12, and even more preferably 3 to 10.

[0016] Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, binaphthyl group, etc. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 16, still more preferably 6 to 14, and even more preferably 6 to 10.

[0017] R 1 Examples of the substituent that the cyclic hydrocarbon group of R may have include a halogen atom, a cyano group, and an alkyl group having 1 to 12 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O-, -S-, -CO- or -SO2-). R 1 The cyclic hydrocarbon group in R may have one substituent or a plurality of substituents. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. 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, a nonyl group, etc. The number of carbon atoms of the alkyl group is preferably 1 to 9, more preferably 1 to 6, and still more preferably 1 to 4. When -CH2- contained in an alkyl group is replaced by -O-, -S-, -CO- or -SO2- as a substituent, the number of carbon atoms before replacement is defined as the total number of carbon atoms of the alkyl group. Examples of the replaced group include a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkylthio group, and a group formed by combining two or more of these groups. Examples of the alkoxy group, the alkoxycarbonyl group, the alkylcarbonyl group, the alkylcarbonyloxy group, and the alkylthio group include an alkoxy group having 1 to 11 carbon atoms, an alkoxycarbonyl group having 2 to 11 carbon atoms, an alkylcarbonyl group having 2 to 12 carbon atoms, an alkylcarbonyloxy group having 2 to 11 carbon atoms, and an alkylthio group having 1 to 11 carbon atoms. For example, groups similar to those described above can be mentioned. Preferred substituents include a halogen atom or an alkyl group having 1 to 12 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O-, -S-, -CO- or -SO2-). More preferred are a halogen atom or an alkyl group having 1 to 6 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-). Even more preferred are a fluorine atom, an iodine atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or an alkylcarbonyloxy group having 2 to 4 carbon atoms. R 1 is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. More preferably, it is an alicyclic hydrocarbon group having 3 to 10 carbon atoms which may have a substituent or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent. Even more preferably, it is a cyclohexyl group which may have a substituent or a phenyl group which may have a substituent. Even more preferably, it is a cyclohexyl group having at least one member selected from the group consisting of an unsubstituted cyclohexyl, an unsubstituted phenyl group, a fluorine atom, an iodine atom, a hydroxy group and a methoxy group, or a phenyl group having at least one member selected from the group consisting of a fluorine atom, an iodine atom, a hydroxy group and a methoxy group. R 1When the cyclohexyl group or phenyl group has a substituent, the number of substituents is preferably 1 to 3.

[0018] m is preferably 1 or 2.

[0019] Examples of the anion (I) include the following anions. Among them, anions represented by formula (Ia-1) to formula (Ia-8), formula (Ia-14), formula (Ia-17) to formula (Ia-25), formula (Ia-29) to formula (Ia-39) are preferred.

[0020] TIFF0007702842000012.tif202149

[0021] TIFF0007702842000013.tif165147

[0022] Z + Examples of the organic cation of Z + include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, cations represented by any of formula (b2-1) to formula (b2-4) (hereinafter, may be referred to as "cation (b2-1)" etc. according to the formula number) are included.

[0023] TIFF0007702842000014.tif47170In formula (b2-1) to formula (b2-4), R b4 ~R b6Each independently represents an acyclic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, and the hydrogen atoms contained in the acyclic hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atoms contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and the hydrogen atoms contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R b4 and R b5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and the -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, or an alkoxy group having 1 to 12 carbon atoms. m2 and n2 each independently represent any integer from 0 to 5. When m2 is 2 or more, the plurality of R b7 may be the same or different, and when n2 is 2 or more, the plurality of R b8 may be the same or different. R b9 and R b10 each independently represents an acyclic 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 the -CH2- contained in the ring may be replaced with -O-, -S-, or -CO-. R b11 represents a hydrogen atom, an acyclic 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. Rb12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atoms contained in the aliphatic hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atoms contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 may be bonded to each other to form a ring including -CH-CO- to which they are bonded, and -CH2- contained in the ring may be replaced with -O-, -S-, or -CO-. R b13 ~R b18 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. L b31 represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent any integer from 0 to 5. q2 and r2 each independently represent any integer from 0 to 4. u2 represents 0 or 1. When o2 is 2 or more, the plurality of R b13 may be the same or different, when p2 is 2 or more, the plurality of R b14 may be the same or different, when q2 is 2 or more, the plurality of R b15 may be the same or different, when r2 is 2 or more, the plurality of R b16 may be the same or different, when s2 is 2 or more, the plurality of R b17 may be the same or different, when t2 is 2 or more, the plurality of R b18 may be the same or different. When u2 is 1, it is preferable that r2 is 1 or more.

[0024] The aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. In particular, R b9 ~R b12 The chain hydrocarbon group is preferably a hydrocarbon group having 1 to 12 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group and the following groups. TIFF0007702842000015.tif11157 In particular, R b9 ~R b12 The alicyclic hydrocarbon group is preferably a hydrocarbon group having 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.

[0025] Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include methylcyclohexyl group, dimethylcyclohexyl group, 2-methyladamantan-2-yl group, 2-ethyladamantan-2-yl group, 2-isopropyladamantan-2-yl group, methylnorbornyl group and isobornyl group. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The alkyl fluoride group represents an alkyl group having 1 to 12 carbon atoms and having a fluorine atom, and examples thereof include fluoromethyl group, difluoromethyl group, trifluoromethyl group and perfluorobutyl. The number of carbon atoms of the alkyl fluoride group is preferably 1 to 9, more preferably 1 to 6, and still more preferably 1 to 4.

[0026] Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, biphenyl group, naphthyl group, and phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples of the aromatic hydrocarbon group having a chain hydrocarbon group include 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 examples of the aromatic hydrocarbon group having an alicyclic hydrocarbon group include 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 having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms are preferable. Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include p-methoxyphenyl group, etc. Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, naphthylethyl group, etc.

[0027] Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, and dodecyloxy group, etc. Examples of the alkylcarbonyl group include acetyl group, propionyl group, and butyryl group, etc. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, and iodine atom, etc. Examples of the alkylcarbonyloxy group include methylcarbonyloxy group, ethylcarbonyloxy group, propylcarbonyloxy group, isopropylcarbonyloxy group, butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, pentylcarbonyloxy group, hexylcarbonyloxy group, octylcarbonyloxy group, and 2-ethylhexylcarbonyloxy group, etc.

[0028] Rb4 and R b5 The ring formed by the combination of and the sulfur atom to which they are attached 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, preferably rings having 4 to 18 carbon atoms. Further, examples of the ring containing a sulfur atom include 3-membered to 12-membered rings, preferably 3-membered to 7-membered rings, and examples thereof include the following rings. * represents a bonding site. TIFF0007702842000016.tif24142

[0029] R b9 and R b10 The ring formed by the combination of and may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of this ring include 3-membered to 12-membered rings, preferably 3-membered to 7-membered rings. Examples thereof include thiolan-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring, 1,4-oxathian-4-ium ring and the like. R b11 and R b12 The ring formed by the combination of and may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of this ring include 3-membered to 12-membered rings, preferably 3-membered to 7-membered rings. Examples thereof include oxocycloheptane ring, oxocyclohexane ring, oxonorbornane ring, oxoadamantane ring and the like.

[0030] Among cations (b2-1) to (b2-4), preferably, it is cation (b2-1). Examples of cation (b2-1) include the following cations. TIFF0007702842000017.tif79158

[0031] TIFF0007702842000018.tif110165 Examples of cation (b2-2) include the following cations. TIFF0007702842000019.tif18150 Examples of cation (b2-3) include the following cations. TIFF0007702842000020.tif26140 Examples of the cation (b2-4) include the following cations. TIFF0007702842000021.tif127165

[0032] The salt (I) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. Preferred examples of the salt (I) include a combination of an anion represented by any of Formula (Ia-1) to Formula (Ia-8), Formula (Ia-14), Formula (Ia-17) to Formula (Ia-25), and Formula (Ia-29) to Formula (Ia-39), and the cation (b2-1), the cation (b2-2), the cation (b2-3), or the cation (b2-4).

[0033] Examples of the salt (I) include the salts shown in Table 1. In the following table, each symbol represents the symbol attached to the structure representing the above-mentioned anion or cation. For example, the salt (I-1) means a salt composed of the anion represented by Formula (Ia-1) and the cation represented by Formula (b2-c-1), and represents the following salt. TIFF0007702842000022.tif3280 [Table 1] TIFF0007702842000024.tif223154 TIFF0007702842000025.tif223154 TIFF0007702842000026.tif223154 TIFF0007702842000027.tif223154 TIFF0007702842000028.tif223154 TIFF0007702842000029.tif223154 TIFF0007702842000030.tif223154 TIFF0007702842000031.tif223154 TIFF0007702842000032.tif223154 TIFF0007702842000033.tif223154 TIFF0007702842000034.tif223154 TIFF0007702842000035.tif223154 TIFF0007702842000036.tif145152 Among them, Salt (I) is preferably Salt (I-1) to Salt (I-8), Salt (I-14), Salt (I-17) to Salt (I-33), Salt (I-39), Salt (I-42) to Salt (I-58), Salt (I-64), Salt (I-67) to Salt (I-83), Salt (I-89), Salt (I-92) to Salt (I-108), Salt (I-114), Salt (I-117) to Salt (I-133), Salt (I-139), Salt (I-142) to Salt (I-158), Salt (I-164), Salt (I-167) to Salt (I-183), Salt (I-189), Salt (I-192) to Salt (I-208), Salt (I-214), Salt (I-217) to Salt (I-233), Salt (I-239), Salt (I-242) to Salt (I-250), Salt (I-254) to Salt (I-264), Salt (I-268) to Salt (I-278), Salt (I-282) to Salt (I-292), Salt (I-296) to Salt (I-306), Salt (I-310) to Salt (I-320), Salt (I-324) to Salt (I-334), Salt (I-338) to Salt (I-348), Salt (I-352) to Salt (I-362), Salt (I-366) to Salt (I-376), Salt (I-380) to Salt (I-390), Salt (I-391) to Salt (I-398), Salt (I-404), Salt (I-407) to Salt (I-415), Salt (I-419) to Salt (I-437), Salt (I-443), Salt (I-446) to Salt (I-454), Salt (I-458) to Salt (I-476), Salt (I-482), Salt (I-485) to Salt (I-493), Salt (I-497) to Salt (I-515), Salt (I-521), Salt (I-524) to Salt (I-532), Salt (I-536) to Salt (I-546).

[0034] <Method for Producing Salt (I)> In Salt (I), X 0 is *-CO-O- (* is C(R 11 )(R12 ) or C(Q 1 )(Q 2 ) represents a binding site with. The salt (the salt represented by formula (I1)) which is ()) can be produced, for example, by reacting the salt represented by formula (I1-a) with carbonyldiimidazole in a solvent and then further reacting with the compound represented by formula (I1-b). TIFF0007702842000037.tif52146 (In the formula, all symbols represent the same meanings as described above respectively.) Examples of the solvent in this reaction include chloroform and acetonitrile. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0035] Examples of the salt represented by formula (I1-a) include salts represented below, and it can be produced by the method described in JP-A-2008-127367. TIFF0007702842000038.tif64148 Examples of the compound represented by formula (I1-b) include compounds represented by the following formula, and they can be easily obtained from the market. TIFF0007702842000039.tif68130

[0036] In salt (I), X 0 The salt in which is *-O-CO-O- (the salt represented by formula (I2)) can be produced, for example, by reacting the salt represented by formula (I2-a) with carbonyldiimidazole in a solvent and then further reacting with the compound represented by formula (I1-b). Also, the salt represented by formula (I2) can be produced, for example, by reacting the compound represented by formula (I1-b) with carbonyldiimidazole in a solvent and then further reacting with the salt represented by formula (I2-a). TIFF0007702842000040.tif80135 (In the formula, all symbols represent the same meanings as described above respectively.) Examples of the solvent in this reaction include chloroform and acetonitrile. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours. The salts represented by the formula (I2-a) include, for example, the salts represented below, and can be produced by the method described in JP-A-2012-193170. TIFF0007702842000041.tif63151

[0037] In salt (I), X 0 The salt in which is *-O-CO- (the salt represented by the formula (I3)) can be produced, for example, by reacting the compound represented by the formula (I3-b) with carbonyldiimidazole in a solvent and then further reacting it with the salt represented by the formula (I2-a). TIFF0007702842000042.tif33139 (In the formula, all the symbols have the same meanings as described above.) Examples of the solvent in this reaction include chloroform and acetonitrile. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0038] Examples of the compound represented by the formula (I3-b) include the compounds represented below, which can be easily obtained from the market and can also be easily produced by known production methods. TIFF0007702842000043.tif53166

[0039] In salt (I), X 0 The salt in which is *-O- (the salt represented by the formula (I4)) can be obtained by reacting the salt represented by the formula (I2-a) with the compound represented by the formula (I1-b) in a solvent in the presence of a base. TIFF0007702842000044.tif24147 (In the formula, all the symbols have the same meanings as described above.) Examples of the base in this reaction include potassium hydroxide. Examples of the solvent in this reaction include acetonitrile. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0040] In salt (I), L 1 is a group formed by combining an alkanediyl group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-). The salt can be produced by replacing the salt represented by formula (I1-a) or the salt represented by formula (I2-a) with the salt represented below when synthesizing the salts represented by formula (I1) to formula (I4). TIFF0007702842000045.tif209168

[0041] TIFF0007702842000046.tif164161

[0042] 〔Acid generator〕 The acid generator of the present invention is an acid generator containing salt (I). It may contain one kind of salt (I) or may contain two or more kinds of salt (I). In addition to salt (I), the acid generator of the present invention may contain an acid generator known in the resist field (hereinafter sometimes referred to as "acid generator (B)"). The acid generator (B) may be used alone or in combination of two or more kinds.

[0043] The acid generator (B) may be either nonionic or ionic. Examples of nonionic acid generators include sulfonate esters (such as 2-nitrobenzyl esters, aromatic sulfonates, oxime sulfonates, N-sulfonyloxyimides, sulfonyloxy ketones, diazonaphthoquinone 4-sulfonates), sulfones (such as disulfones, ketosulfones, sulfonyldiazomethane), etc. Representative examples of ionic acid generators include onium salts containing onium cations (such as diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). Examples of anions of onium salts include sulfonic acid anions, sulfonylimide anions, sulfonylmethide anions, etc.

[0044] As the acid generator (B), compounds that generate acid upon irradiation as 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, European Patent No. 126,712, etc. can be used. Also, compounds produced by known methods may be used. The acid generator (B) may be used in combination of two or more.

[0045] The acid generator (B) is preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as "acid generator (B1)"). TIFF0007702842000047.tif2862[In the formula (B1), Q b1 and Q b2 each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 6 carbon atoms. L b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, wherein -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. Y represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-. Z1 + represents an organic cation.

[0046] Q b1 and Q b2 Examples of the perfluoroalkyl group represented by Q and Q include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group and the like. Q b1 and Q b2 Examples of the alkyl group represented by Q and Q include a methyl group, an ethyl group, a propyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group and the like. The acid generator (B) is preferably a fluorine-containing difference generator, and Q b1 and Q b2 are each independently preferably a perfluoroalkyl group, more preferably a fluorine atom or a trifluoromethyl group, and even more preferably both are fluorine atoms.

[0047] L b1 Examples of the divalent saturated hydrocarbon group in L include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and a group formed by combining two or more of these groups may also be used. Specifically, linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, and heptadecane-1,17-diyl group; Branched alkanediyl groups such as ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; Monocyclic divalent alicyclic saturated hydrocarbon groups which are cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; Polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. may be mentioned.

[0048] L b1 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by L is replaced by -O- or -CO- include groups represented by any of formula (b1-1) to formula (b1-3). In the groups represented by formula (b1-1) to formula (b1-3) and the groups represented by formula (b1-4) to formula (b1-11) which are specific examples thereof, * and ** represent bonds, and * represents a bond with -Y.

[0049] TIFF0007702842000048.tif26117[In formula (b1-1), L b2represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms. L b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. However, the total number of carbon atoms of L b2 and L b3 is 22 or less. In formula (b1-2), L b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms. L b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. However, the total number of carbon atoms of L b4 and L b5 is 22 or less. In formula (b1-3), L b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. L b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. However, the total number of carbon atoms of L b6 and L b7 is 23 or less.

[0050] In the groups represented by formulas (b1-1) to (b1-3), when -CH2- contained in the saturated hydrocarbon group is replaced by -O- or -CO-, the number of carbon atoms before replacement is defined as the number of carbon atoms of the saturated hydrocarbon group. Examples of the divalent saturated hydrocarbon group include those similar to the divalent saturated hydrocarbon group of L b1 as described above.

[0051] L b2 is preferably a single bond. L b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom. L b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-.

[0052] L b1 As the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by L is replaced by -O- or -CO-, the group represented by formula (b1-1) or formula (b1-3) is preferable. Examples of the group represented by formula (b1-1) include the groups represented by formulas (b1-4) to (b1-8), respectively. TIFF0007702842000049.tif49119 [In formula (b1-4), L b8represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. In formula (b1-5), L b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the hydrogen atoms contained in the divalent saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. However, the total number of carbon atoms of L b9 and L b10 is 20 or less. In formula (b1-6), L b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atoms contained in the divalent saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. However, the total number of carbon atoms of L b11 and L b12 is 21 or less. In formula (b1-7), L b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms. L b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atoms contained in the divalent saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. However, the total number of carbon atoms of L b13 ~L b15 is 19 or less. In formula (b1-8), L b16represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-. L b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms. L b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted by a fluorine atom or a hydroxy group. However, L b16 ~L b18 The total number of carbon atoms of is 19 or less.] L b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b18is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

[0053] Examples of the group represented by the formula (b1-3) include groups represented by the formula (b1-9) to the formula (b1-11). TIFF0007702842000050.tif24140[In the formula (b1-9), L b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group. However, the total number of carbon atoms of L b19 and L b20 is 23 or less. In the formula (b1-10), L b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group. However, the total number of carbon atoms of L b21 , L b22 and Lb23 The total number of carbon atoms is 21 or less. In formula (b1-11), L b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms. L b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms, hydroxy groups or alkylcarbonyloxy groups. The -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atoms contained in the alkylcarbonyloxy group may be substituted with hydroxy groups. However, the total number of carbon atoms of L b24 , L b25 and L b26 is 21 or less.

[0054] In addition, in the group represented by formula (b1-9) to the group represented by formula (b1-11), when the hydrogen atoms contained in the saturated hydrocarbon group are substituted with alkylcarbonyloxy groups, the number of carbon atoms before replacement is taken as the number of carbon atoms of the saturated hydrocarbon group. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, an adamantylcarbonyloxy group and the like.

[0055] Examples of the group represented by formula (b1-4) include the following. TIFF0007702842000051.tif17151

[0056] Examples of the group represented by formula (b1-5) include the following. TIFF0007702842000052.tif72149

[0057] Examples of the group represented by formula (b1-6) include the following. TIFF0007702842000053.tif30151

[0058] Examples of the group represented by formula (b1-7) include the following. TIFF0007702842000054.tif64151

[0059] Examples of the group represented by formula (b1-8) include the following. TIFF0007702842000055.tif24151

[0060] Examples of the group represented by formula (b1-2) include the following. TIFF0007702842000056.tif30159

[0061] Examples of the group represented by formula (b1-9) include the following. TIFF0007702842000057.tif45136

[0062] Examples of the group represented by formula (b1-10) include the following. TIFF0007702842000058.tif87159

[0063] Examples of the group represented by formula (b1-11) include the following. TIFF0007702842000059.tif81157

[0064] Examples of the alicyclic hydrocarbon group represented by Y include the groups represented by formula (Y1) to formula (Y11), formula (Y36) to formula (Y38). When -CH2- contained in the alicyclic hydrocarbon group represented by Y is replaced by -O-, -SO2- or -CO-, the number thereof may be one or two or more. Examples of such groups include the groups represented by formula (Y12) to formula (Y35), formula (Y39) to formula (Y43). * represents the bonding position to L b1 represents the bonding position to As the alicyclic hydrocarbon group represented by TIFF0007702842000060.tif84169Y, a group represented by any of formula (Y1) to formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39) to formula (Y43) is preferable, a group represented by formula (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43) is more preferable, and a group represented by formula (Y11), formula (Y15), formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43) is still more preferable. When the alicyclic hydrocarbon group represented by Y is a spiro ring having an oxygen atom such as formula (Y28) to formula (Y35), formula (Y39), formula (Y40), formula (Y42), formula (Y43), etc., the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. Further, among the alkanediyl groups contained in the ketal structure, it is preferable that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

[0065] Examples of the substituent of the methyl group represented by Y include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-O-R b1 group or -(CH2) ja -O-CO-R b1 group (wherein, R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms or a group combining these. ja represents any integer from 0 to 4. The -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and the hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom.). Examples of the substituent of the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 16 carbon atoms which may be substituted with a hydroxy group (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-O-R b1 group or -(CH2) ja -O-CO-R b1 group (wherein R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms or a group combining these. ja represents any integer from 0 to 4. -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom.).

[0066] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, an adamantyl group and the like. The alicyclic hydrocarbon group may have a chain hydrocarbon group, and examples include a methylcyclohexyl group and a dimethylcyclohexyl group. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 12, more preferably 3 to 10. Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, phenanthryl group, etc. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group. Examples of the aromatic hydrocarbon group having a chain hydrocarbon group include 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. Examples of the aromatic hydrocarbon group having an alicyclic hydrocarbon group include p-cyclohexylphenyl group, p-adamantylphenyl group, etc. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 14, more preferably 6 to 10. Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, etc. The number of carbon atoms of the alkyl group is preferably 1 to 12, more preferably 1 to 6, and still more preferably 1 to 4. Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as hydroxymethyl group and hydroxyethyl group. Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, naphthylethyl group, etc. Examples of the group in which -CH2- contained in the alkyl group is replaced with -O-, -SO2- or -CO- etc. include alkoxy group, alkylsulfonyl group, alkoxycarbonyl group, alkylcarbonyl group, alkylcarbonyloxy group or a group combining these. Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, dodecyloxy group, etc. The number of carbon atoms of the alkoxy group is preferably 1 to 12, more preferably 1 to 6, and still more preferably 1 to 4. Examples of the alkylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, and a propylsulfonyl group. The number of carbon atoms in the sulfonyl group is preferably from 1 to 12, more preferably from 1 to 6, and still more preferably from 1 to 4. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. The number of carbon atoms in the alkoxycarbonyl group is preferably from 2 to 12, more preferably from 2 to 6, and still more preferably from 2 to 4. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The number of carbon atoms in the alkylcarbonyl group is preferably from 2 to 12, more preferably from 2 to 6, and still more preferably from 2 to 4. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The number of carbon atoms in the alkylcarbonyloxy group is preferably from 2 to 12, more preferably from 2 to 6, and still more preferably from 2 to 4. Examples of the combined group include a group formed by combining an alkoxy group and an alkyl group, a group formed by combining an alkoxy group and an alkoxy group, a group formed by combining an alkoxy group and an alkylcarbonyl group, and a group formed by combining an alkoxy group and an alkylcarbonyloxy group. Examples of the group formed by combining an alkoxy group and an alkyl group include an alkoxyalkyl group such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, and an ethoxymethyl group. The number of carbon atoms in the alkoxyalkyl group is preferably from 2 to 12, more preferably from 2 to 6, and still more preferably from 2 to 4. Examples of the group formed by combining an alkoxy group and an alkoxy group include an alkoxyalkoxy group such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, and an ethoxyethoxy group. The number of carbon atoms in the alkoxyalkoxy group is preferably from 2 to 12, more preferably from 2 to 6, and still more preferably from 2 to 4. Examples of the group combining an alkoxy group and an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group, and an ethoxypropionyl group. The number of carbon atoms in the alkoxyalkylcarbonyl group is preferably from 3 to 13, more preferably from 3 to 7, and still more preferably from 3 to 5. Examples of the group combining an alkoxy group and an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, and an ethoxypropionyloxy group. The number of carbon atoms in the alkoxyalkylcarbonyloxy group is preferably from 3 to 13, more preferably from 3 to 7, and still more preferably from 3 to 5. Examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -SO2- or -CO- etc. include the groups represented by formula (Y12) to formula (Y35), formula (Y39) to formula (Y43).

[0067] Examples of Y include the following. TIFF0007702842000061.tif160165

[0068] Y is preferably an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent, still more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and even more preferably an adamantyl group which may have a substituent, and -CH2- constituting the alicyclic hydrocarbon group or adamantyl group may be replaced by -CO-, -SO2- or -CO-. Specifically, Y is preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group or a group represented by formula (Y42), formula (Y100) to formula (Y114).

[0069] As the anion in the salt represented by formula (B1), anions represented by formula (B1-A-1) to formula (B1-A-59) [hereinafter, may be referred to as "anion (B1-A-1)" etc. according to the formula number.] are preferable, and an anion represented by any of formula (B1-A-1) to formula (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula (B1-A-24) to formula (B1-A-33), formula (B1-A-36) to formula (B1-A-40), formula (B1-A-47) to formula (B1-A-59) is more preferable. TIFF0007702842000062.tif231164

[0070] TIFF0007702842000063.tif238165

[0071] TIFF0007702842000064.tif168160Here, R i2 ~R i7 are, independently of each other, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R i8 is, for example, a chain hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q b1 and Q b2 represent the same meaning as described above. Specific examples of the anion in the salt represented by formula (B1) include the anions described in JP-A-2010-204646.

[0072] Preferably, as the anion in the salt represented by formula (B1), anions represented by formula (B1a-1) to formula (B1a-38) are exemplified. TIFF0007702842000065.tif238158

[0073] TIFF0007702842000066.tif129154

[0074] Among them, an anion represented by any of Formula (B1a-1) to Formula (B1a-3), Formula (B1a-7) to Formula (B1a-16), Formula (B1a-18), Formula (B1a-19), and Formula (B1a-22) to Formula (B1a-38) is preferable. Z1 + Examples of the organic cation of [Z1] + include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferable, and arylsulfonium cations are more preferable. Examples of the arylsulfonium cation include those similar to the cation of Z + in Formula (I).

[0075] The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the acid generator (B), preferably, a combination of an anion represented by any of Formula (I-a-1) to Formula (I-a-3), Formula (I-a-7) to Formula (I-a-16), Formula (I-a-18), Formula (I-a-19), and Formula (I-a-22) to Formula (I-a-38) and cation (b2-1), cation (b2-3), or cation (b2-4) is mentioned.

[0076] As the acid generator (B), preferably, those represented by Formula (B1-1) to Formula (B1-57) are mentioned. Among them, those containing an arylsulfonium cation are preferable, and those represented by Formula (B1-1) to Formula (B1-3), Formula (B1-5) to Formula (B1-7), Formula (B1-11) to Formula (B1-14), Formula (B1-20) to Formula (B1-26), Formula (B1-29), Formula (B1-31) to Formula (B1-57) are particularly preferable. TIFF0007702842000067.tif214167

[0077] TIFF0007702842000068.tif235160

[0078] TIFF0007702842000069.tif205166

[0079] When containing salt (I) and acid generator (B) as the acid generator, the ratio of the content of salt (I) to that of acid generator (B) (mass ratio; salt (I): acid generator (B)) is usually from 1:99 to 99:1, preferably from 2:98 to 98:2, more preferably from 5:95 to 95:5, still more preferably from 10:90 to 90:10, and particularly preferably from 15:85 to 85:15.

[0080] [[Resist composition]] The resist composition of the present invention contains an acid generator containing salt (I) and a resin having an acid-labile group (hereinafter sometimes referred to as "resin (A)"). Here, the "acid-labile group" means a group having a leaving group, and when contacted with an acid, the leaving group leaves and the constitutional unit is converted into a constitutional unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). The resist composition of the present invention preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") such as a salt that generates an acid having a lower acidity than the acid generated from the acid generator, and preferably contains a solvent (hereinafter sometimes referred to as "solvent (E)").

[0081] [[Acid generator]] In the resist composition of the present invention, the total content rate of the acid generator is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or less, still more preferably 3 parts by mass or more and 40 parts by mass or less, even more preferably 3 parts by mass or more and 35 parts by mass or less, and still even more preferably 5 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of resin (A) described later.

[0082] [[Resin (A)]] Resin (A) has a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"). Resin (A) preferably further contains a structural unit other than structural unit (a1). Examples of the structural unit other than structural unit (a1) include a structural unit having no acid-labile group (hereinafter sometimes referred to as "structural unit (s)"), a structural unit other than structural unit (a1) and structural unit (s) (for example, a structural unit having a halogen atom described later (hereinafter sometimes referred to as "structural unit (a4)"), a structural unit having a non-leaving hydrocarbon group described later (hereinafter sometimes referred to as "structural unit (a5)"), and a structural unit derived from other monomers known in the art, etc.).

[0083] 〈Structural unit (a1)〉 Structural unit (a1) is derived from a monomer having an acid-labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid-labile group contained in resin (A) is preferably a group represented by formula (1) (hereinafter also referred to as group (1)) and / or a group represented by formula (2) (hereinafter also referred to as group (2)). TIFF0007702842000070.tif1988[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 group combining these, or R a1 and R a2 are bonded to each other to form a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * represents a bonding site.] TIFF0007702842000071.tif2171[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 a heterocycle having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and -CH2- contained in the hydrocarbon group and the heterocycle may be replaced by -O- or -S-. 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 octynyl group, an isooctynyl 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. TIFF0007702842000072.tif10150R 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 formed by combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., an alkylcycloalkyl group or cycloalkylalkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), an aralkyl group such as benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), an aryl-cycloalkyl group such as phenylcyclohexyl group, and the like. Preferably, ma is 0 and na is 1. R a1 and R a2 When they are bonded to each other to form a non-aromatic hydrocarbon ring, examples of -C(R a1 )(R a2 )(R a3 ) include the following rings. The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * represents the bonding site with -O-. TIFF0007702842000073.tif30138

[0085] R a1’ 、R a2’ and R a3’ Examples of the hydrocarbon group in R The alkyl group and alicyclic hydrocarbon group are the same as those exemplified for R a1 、R a2 and R a3 . Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, phenanthryl group, etc. Examples of the combined group include a group combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., an alkylcycloalkyl group or cycloalkylalkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), an aralkyl group such as benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), an aryl-cycloalkyl group such as phenylcyclohexyl group, etc. R a2’ and R a3’ When they are bonded to each other to form a heterocyclic ring together with the carbon atom to which they are bonded and X, -C(R a1’ )(R a2’ )-X-R a3’ includes the following rings. * represents the bonding site. TIFF0007702842000074.tif18130R a1’ and R a2’ Preferably, at least one of them is a hydrogen atom. na' is preferably 0.

[0086] Examples of group (1) include the following groups. In formula (1), R a1 , R a2 and R a3 are alkyl groups, ma = 0, and na = 1. As such a group, a tert-butoxycarbonyl group is preferable. In formula (1), R a1 , R a2 together with the carbon atom to which they are bonded form an adamantyl group, R a3 is an alkyl group, ma = 0, and na = 1. In formula (1), R a1 and R a2are each independently an alkyl group, R a3 is an adamantyl group, ma = 0, and na = 1 group. Specific examples of the group (1) include the following groups. * represents a bonding site. TIFF0007702842000075.tif154163

[0087] Specific examples of the group (2) include the following groups. * represents a bonding site. TIFF0007702842000076.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] Among the (meth)acrylic monomers having an acid-labile group, those having an alicyclic hydrocarbon group with 5 to 20 carbon atoms are preferably mentioned. If a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

[0090] As the structural unit derived from the (meth)acrylic monomer having the group (1), the structural unit represented by the formula (a1-0) (hereinafter sometimes referred to as the structural unit (a1-0)), the structural unit represented by the formula (a1-1) (hereinafter sometimes referred to as the structural unit (a1-1)), or the structural unit represented by the formula (a1-2) (hereinafter sometimes referred to as the structural unit (a1-2)) can be mentioned. 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, it is at least one structural unit 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. TIFF0007702842000077.tif43140[In the formula (a1-0), the formula (a1-1), and the 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 a04 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. 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. 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] 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 and R a04 The alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group and combinations thereof in the formula (1) are Ra1 and R a2 and R a3 include groups similar to the groups exemplified by R a6 and R a7 The alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and the group formed by combining these in R a1 , R a2 and R a3 include groups similar to the groups exemplified by. R a02 , R a03 and R a04 The alkyl group in R R a6 and R a7 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 alkenyl group in is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably an ethenyl group, a propenyl group, an isopropenyl group, or a butenyl group. R a02 and R a03 and R a04 and R a6 and R a7 The number of carbon atoms of the alicyclic hydrocarbon group of is preferably 5 to 12, more preferably 5 to 10. R a02 and R a03 and R a04 and R a6 and R a7 The number of carbon atoms of the aromatic hydrocarbon group of is preferably 6 to 12, more preferably 6 to 10. The group formed by combining an alkyl group and an alicyclic hydrocarbon group preferably has a total number of carbon atoms of 18 or less when these alkyl group and alicyclic hydrocarbon group are combined. The group combining an alkyl group and an aromatic hydrocarbon group preferably has a total carbon number of 18 or less when combining these alkyl group and aromatic hydrocarbon group. R a02 and R a03 are preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group. R a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. R a6 and R a7 are each independently preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, a phenyl group or a naphthyl group, even more preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group or a phenyl group. m1 is preferably any integer from 0 to 3, more preferably 0 or 1. n1 is preferably any integer from 0 to 3, more preferably 0 or 1. n1’ is preferably 0 or 1.

[0092] Examples of the structural unit (a1-0) include a structural unit represented by any of formula (a1-0-1) to formula (a1-0-18) and a structural unit in which the methyl group corresponding to R a01 in the structural unit (a1-0) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group, and a structural unit represented by any of formula (a1-0-1) to formula (a1-0-10), formula (a1-0-13), formula (a1-0-14) is preferred. TIFF0007702842000078.tif96164

[0093] Examples of the structural unit (a1-1) include structural units derived from the monomers described in JP-A-2010-204646. Among them, the structural units represented by any of formulae (a1-1-1) to (a1-1-7) and the structural unit in which the methyl group corresponding to R a4 in the structural unit (a1-1) is replaced by a hydrogen atom are preferred, and the structural units represented by any of formulae (a1-1-1) to (a1-1-4) are more preferred. TIFF0007702842000079.tif38168

[0094] Examples of the structural unit (a1-2) include structural units represented by any of formulae (a1-2-1) to (a1-2-14) and structural units in which the methyl group corresponding to R a5 in the structural unit (a1-2) is replaced by a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group, and the structural units represented by any of formula (a1-2-2), formula (a1-2-5), formula (a1-2-6) and formulae (a1-2-10) to (a1-2-14) are preferred. TIFF0007702842000080.tif67163

[0095] When the resin (A) contains the structural unit (a1-0), its content is usually 5 to 80 mol%, preferably 5 to 75 mol%, more preferably 10 to 70 mol% based on all the structural units of the resin (A). When the resin (A) contains the structural unit (a1-1) and / or the structural unit (a1-2), their total content is usually 10 to 90 mol%, preferably 15 to 85 mol%, more preferably 20 to 80 mol%, still more preferably 20 to 75 mol%, and even more preferably 20 to 70 mol% based on all the structural units of the resin (A).

[0096] Examples of the structural unit having the group (2) in the structural unit (a1) include the structural unit represented by formula (a1-4) (hereinafter sometimes referred to as "structural unit (a1-4)"). TIFF0007702842000081.tif4766[In formula (a1-4), R a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a33 represents 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. A a30 represents a single bond or * -X a31 -(A a32 -X a32 ) nc -, where * represents the bonding site with the carbon atom to which -R a32 is bonded. A a32 represents an alkanediyl group having 1 to 6 carbon atoms. X a31 and X a32 each independently represent -O-, -CO-O- or -O-CO-. nc represents 0 or 1. la represents any integer from 0 to 4. When la is any integer of 2 or more, a plurality of R a33 may be the same as or different from each other. R a34 and R a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -C-O- to which they are bonded, and -CH2- contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced by -O- or -S-.

[0097] R a32 and R a33 Examples of the halogen atom in R R a32Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group and perfluorohexyl group. R a32 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group. R a33 Examples of the alkyl group in include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and still more preferably a methyl group. R a33 Examples of the alkoxy group in include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group and hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and still more preferably a methoxy group. R a33 Examples of the alkoxyalkyl group in include methoxymethyl group, ethoxyethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, sec-butoxymethyl group and tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and still more preferably a methoxymethyl group. R a33Examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group. R a33 Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group. R a33 Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably an acetyloxy group. R a33 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, 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.

[0098] *-X a31 -(A a32 -X a32 ) nc Examples of *- include *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a32 -CO-O-, *-O-CO-A a32 -O-, *-O-A a32 -CO-O-, *-CO-O-A a32 -O-CO-, *-O-CO-A a32 -O-CO- include. Among them, *-CO-O-, *-CO-O-A a32 -CO-O- or *-O-A a32-CO-O- is preferred.

[0099] 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 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, a 2-methylbutane-1,4-diyl group, and the like. A a32 is preferably a methylene group or an ethylene group.

[0100] A a30 is a single bond, *-CO-O- or *-CO-O-A a32 -CO-O- is preferably, more preferably a single bond, *-CO-O- or *-CO-O-CH2-CO-O-, and even more preferably a single bond or *-CO-O-.

[0101] la is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0. R a34 、R a35 and R a36 Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining these. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and the like. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and the like. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents the bonding site). As the aromatic hydrocarbon group, aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group can be mentioned. As the combined group, groups formed by combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, cycloalkylalkyl 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.), aryl-cycloalkyl groups such as phenylcyclohexyl group, etc. can be mentioned. In particular, R a36 includes 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.

[0102] 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 of R is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and alicyclic hydrocarbon group in R a36 are preferably unsubstituted. The aromatic hydrocarbon group in R a36 preferably has an aromatic ring having an aryloxy group having 6 to 10 carbon atoms. -OC(R a34 )(R a35 )-O-R a36is eliminated on contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group. -OC(R a34 )(R a35 )-OR a36 is preferably bonded to the o-position or p-position of the benzene ring, and more preferably bonded to the p-position.

[0103] 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 (a1-4-18) and R in the structural unit (a1-4) are a32 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. TIFF0007702842000083.tif99157

[0104] When the resin (A) contains the structural unit (a1-4), the content thereof 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 60 mol %, based on the total of all structural units in the resin (A).

[0105] 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)"). TIFF0007702842000084.tif4558 formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. Z a1 is a single bond or -(CH2) h3 -CO-L 54represents -, h3 represents any integer from 1 to 4, and * represents the binding site with L 51 represents the binding site with L L 51 L 52 L 53 and L 54 each independently represents -O- or -S-. s1 represents any integer from 1 to 3. s1’ represents any integer from 0 to 3.

[0106] Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is 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 Among them, it is preferable that one is -O- and the other is -S-. s1 is preferably 1. s1’ is preferably any integer from 0 to 2. Z a1 is preferably a single bond or *-CH2-CO-O-.

[0107] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP-A-2010-61117. Among them, the structural units represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and the structural unit represented by formula (a1-5-1) or formula (a1-5-2) is more preferable. TIFF0007702842000085.tif33133

[0108] When the resin (A) contains the structural unit (a1-5), its content is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, still more preferably 5 to 40 mol%, and even more preferably 5 to 30 mol% based on all the structural units of the resin (A).

[0109] Examples of the structural unit (a1) also include the following structural units. TIFF0007702842000086.tif31162

[0110] When the resin (A) contains structural units such as the above (a1-3-1) to (a1-3-7), its content is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, still more preferably 20 to 85 mol%, even more preferably 20 to 70 mol%, and particularly preferably 20 to 60 mol% based on all the structural units of the resin (A).

[0111] Examples of the structural unit (a1) also include the following structural units. TIFF0007702842000087.tif5195 When the resin (A) contains structural units such as the above (a1-6-1) to (a1-6-3), its content is preferably 10 to 60 mol%, more preferably 15 to 55 mol%, still more preferably 20 to 50 mol%, even more preferably 20 to 45 mol%, and particularly preferably 20 to 40 mol% based on all the structural units of the resin (A).

[0112] 〈Structural unit (s)〉 The structural unit (s) is derived from a monomer having no acid-labile group (hereinafter sometimes referred to as "monomer (s)"). As the monomer that leads to the structural unit (s), a monomer having no acid-labile group known in the resist field can be used. As the structural unit(s), it is preferable to have a hydroxy group or a lactone ring. By using a resin having a structural unit having a hydroxy group and not having an acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit having a lactone ring and not having an acid-labile group (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

[0113] 〈Structural unit (a2)〉 The hydroxy group of the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group. When producing a resist pattern from the resist composition of the present invention, when using a high-energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) as the exposure light source, as the structural unit (a2), a structural unit (a2) having a phenolic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-A) described later. Further, when using an ArF excimer laser (193 nm) or the like, as the structural unit (a2), a structural unit (a2) having an alcoholic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-1) described later. The structural unit (a2) may be contained alone or in two or more kinds.

[0114] Examples of the structural unit having a phenolic hydroxy group in the structural unit (a2) include a structural unit represented by the formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)"). TIFF0007702842000088.tif4753[In the formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51represents 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. A a50 is a single bond or *-X a51 -(A a52 -X a52 ) nb - and * represents the bonding position with the carbon atom to which -R a50 is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O- or -O-CO-. nb represents 0 or 1. mb represents any integer from 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same as or different from each other.

[0115] R a50 and R a51 Examples of the halogen atom in include a fluorine atom, a chlorine atom, a bromine atom and the like. R a50 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in 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 and a perfluorohexyl group. R a50is 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 a51 Examples of the alkyl group in a51 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 even more preferably a methyl group. R a51 Examples of the alkoxy group in a51 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 alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a51 Examples of the alkoxyalkyl group in a51 include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. R a51 Examples of the alkoxyalkoxy group in a51 include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group. R a51 Examples of the alkylcarbonyl group in a51 include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a51Examples 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 a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, 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.

[0116] *-X a51 -(A a52 -X a52 ) nb Examples of - include *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a52 -CO-O-, *-O-CO-A a52 -O-, *-O-A a52 -CO-O-, *-CO-O-A a52 -O-CO-, *-O-CO-A a52 -O-CO-, etc. Among them, *-CO-O-, *-CO-O-A a52 -CO-O- or *-O-A a52 -CO-O- is preferable.

[0117] A a52 Examples of the alkanediyl group in A 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, etc. A a52 is preferably a methylene group or an ethylene group.

[0118] Aa50 is a single bond, *-CO-O- or *-CO-OA a52 -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.

[0119] mb is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0. The hydroxy group is preferably bonded to the o- or p-position of the benzene ring, and more preferably to the p-position.

[0120] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577.

[0121] The structural unit (a2-A) includes structural units represented by formulae (a2-2-1) to (a2-2-16) and R in the structural unit (a2-A) in the structural units represented by formulae (a2-2-1) to (a2-2-16). a50 The structural unit (a2-A) includes a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), and a structural unit represented by formula (a2-2-12) to (a2-2-14), as well as a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), and a structural unit represented by formula (a2-2-12) to (a2-2-14), a50It is preferable that the methyl group corresponding to R is replaced with a hydrogen atom, and in the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-8), the structural units represented by formulas (a2-2-12) to (a2-2-14), and the structural unit represented by formula (a2-2-3) or the structural unit represented by formula (a2-2-8), the structural units represented by formulas (a2-2-12) to (a2-2-14), R in the structural unit (a2-A) a50 More preferably, it is a structural unit in which the methyl group corresponding to R is replaced with a hydrogen atom, and in the structural unit represented by formula (a2-2-8) and the structural unit represented by formula (a2-2-8), R in the structural unit (a2-A) a50 Even more preferably, it is a structural unit in which the methyl group corresponding to R is replaced with a hydrogen atom. TIFF0007702842000089.tif57169

[0122] When the resin (A) contains the structural unit (a2-A), the content of the structural unit (a2-A) 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% with respect to all the structural units. The structural unit (a2-A) can be incorporated into the resin (A) by, for example, polymerizing using the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Also, after polymerizing using acetoxystyrene or the like and then treating with an alkali such as tetramethylammonium hydroxide, the structural unit (a2-A) can be incorporated into the resin (A).

[0123] Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include the structural unit represented by formula (a2-1) (hereinafter sometimes referred to as "structural unit (a2-1)"). TIFF0007702842000090.tif4461In formula (a2-1), L a3 represents -O- or *-O-(CH2) k2 -CO-O-, k2 represents any integer from 1 to 7. * represents the bonding position with -CO-. R a14 represents a hydrogen atom or a methyl group. R a15 and R a16 each independently represent a hydrogen atom, a methyl group, or a hydroxy group. o1 represents any integer from 0 to 10.

[0124] In formula (a2-1), L a3 is preferably -O-, -O-(CH2) f1 -CO-O- (wherein f1 represents any integer from 1 to 4), more preferably -O-. R a14 is preferably a methyl group. R a15 is preferably a hydrogen atom. R a16 is preferably a hydrogen atom or a hydroxy group. o1 is preferably any integer from 0 to 3, more preferably 0 or 1.

[0125] Examples of the structural unit (a2-1) include structural units derived from the monomers described in JP-A-2010-204646. The structural unit represented by any of formulas (a2-1-1) to (a2-1-6) is preferable, the structural unit represented by any of formulas (a2-1-1) to (a2-1-4) is more preferable, and the structural unit represented by formula (a2-1-1) or formula (a2-1-3) is even more preferable. TIFF0007702842000091.tif50139

[0126] When the resin (A) contains the structural unit (a2-1), its content is usually 1 to 45 mol%, preferably 1 to 40 mol%, more preferably 1 to 35 mol%, even more preferably 1 to 20 mol%, and even more preferably 1 to 10 mol% based on all the structural units of the resin (A).

[0127] <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. Preferably, a γ-butyrolactone ring, an adamantanlactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)) can be mentioned.

[0128] The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), or the formula (a3-4). These may be contained alone or in combination of two or more. TIFF0007702842000092.tif49159[In the formula (a3-1), the formula (a3-2), the formula (a3-3), and the formula (a3-4), L a4 , L a5 and L a6 each independently represents a group represented by -O- or *-O-(CH2) k3 -CO-O- (where k3 represents an integer of 1 to 7). L a7 represents -O-, *-O-L a8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O- or *-O-L a8 -O-CO-L a9 -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * represents the bonding position to the carbonyl group. R a18 , R a19 and R a20 each independently represents a hydrogen atom or a methyl group. R a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. X a3 represents -CH2- or an oxygen atom. Ra21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms. R a22 、R a23 and R a25 each independently represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. p1 represents any integer from 0 to 5. q1 represents any integer from 0 to 3. r1 represents any integer from 0 to 3. w1 represents any integer from 0 to 8. When p1, q1, r1 and / or w1 is 2 or more, a plurality of R a21 、R a22 、R a23 and / or R a25 may be the same as or different from each other.

[0129] R a21 、R a22 、R a23 and R a25 Examples of the aliphatic hydrocarbon group in R R a24 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group and tert-butyl group. R a24 Examples of the halogen atom in R R a24 include fluorine atom, chlorine atom, bromine atom and iodine atom.

[0130] L a8 and L a9 Examples of the alkanediyl group in 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, a 2-methylbutane-1,4-diyl group, and the like.

[0131] In formulas (a3-1) to (a3-3), L a4 ~L a6 is each independently preferably -O- or, *-O-(CH2) k3 -CO-O- wherein k3 is an integer from 1 to 4, more preferably -O- and, *-O-CH2-CO-O-, even more preferably an oxygen atom. R a18 ~R a21 is preferably a methyl group. R a22 and R a23 are each independently preferably a carboxy group, a cyano group or a methyl group. p1, q1 and r1 are each independently preferably an integer from 0 to 2, more preferably 0 or 1.

[0132] In formula (a3-4), R a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, even more preferably a hydrogen atom or a methyl group. R a25 is preferably a carboxy group, a cyano group or a methyl group. L a7 is preferably -O- or *-O-L a8 -CO-O-, more preferably -O-, -O-CH2-CO-O- or -O-C2H4-CO-O-. w1 is preferably any integer from 0 to 2, more preferably 0 or 1. In particular, formula (a3-4) is preferably formula (a3-4)’. TIFF0007702842000093.tif3848 (wherein R a24 , L a7 represents the same meaning as above.)

[0133] Examples of the structural unit (a3) include structural units derived from the monomers described in JP-A-2010-204646, the monomers described in JP-A-2000-122294, and the monomers described in JP-A-2012-41274. Examples of the structural unit (a3) include structural units represented by any of formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3-1), formula (a3-3-2), and formula (a3-4-1) to formula (a3-4-12), and, in the above structural units, structural units in which the methyl groups corresponding to R a18 , R a19 , R a20 and R a24 are replaced with hydrogen atoms are preferred.

[0134] TIFF0007702842000094.tif116165

[0135] When the resin (A) contains the structural unit (a3), the total content is usually 5 to 70 mol%, preferably 10 to 65 mol%, more preferably 10 to 60 mol% with respect to all the structural units of the resin (A). Also, 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 5 to 60 mol%, more preferably 5 to 50 mol%, still more preferably 10 to 50 mol% with respect to all the structural units of the resin (A).

[0136] 〈Structural unit (a4)〉 Examples of the structural unit (a4) include the following structural units. TIFF0007702842000095.tif2758[In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having a halogen atom with 1 to 24 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-.] R 42 The saturated hydrocarbon group represented by includes a chain saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and a group formed by combining these, etc.

[0137] Examples of the chain saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic alicyclic saturated hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group; polycyclic alicyclic saturated hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents the bonding site). TIFF0007702842000096.tif10146Examples of the group formed by combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, and -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group, etc.

[0138] Examples of the structural unit (a4) include a structural unit represented by formula (a4-0), a structural unit represented by formula (a4-1), and a structural unit represented by formula (a4-4). TIFF0007702842000097.tif4349[In formula (a4-0), R 54 represents a hydrogen atom or a methyl group. L4a represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. L 3a represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms. R 64 represents a hydrogen atom or a fluorine atom.

[0139] L 4a Examples of the alkanediyl group in L include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, and a butane-1,4-diyl group, and branched alkanediyl groups such as an ethane-1,1-diyl group, a propane-1,2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group.

[0140] L 3a Examples of the perfluoroalkanediyl group in L include a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, a perfluoropropane-2,2-diyl group, a perfluorobutane-1,4-diyl group, a perfluorobutane-2,2-diyl group, a perfluorobutane-1,2-diyl group, a perfluoropentane-1,5-diyl group, a perfluoropentane-2,2-diyl group, a perfluoropentane-3,3-diyl group, a perfluorohexane-1,6-diyl group, a perfluorohexane-2,2-diyl group, a perfluorohexane-3,3-diyl group, a perfluoroheptane-1,7-diyl group, a perfluoroheptane-2,2-diyl group, a perfluoroheptane-3,4-diyl group, a perfluoroheptane-4,4-diyl group, a perfluorooctane-1,8-diyl group, a perfluorooctane-2,2-diyl group, a perfluorooctane-3,3-diyl group, and a perfluorooctane-4,4-diyl group. L 3aExamples of the perfluorocycloalkanediyl group include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantanediyl group, and the like.

[0141] L 4a is preferably a single bond, a methylene group or an ethylene group, and more preferably a single bond or a methylene group. L 3a is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

[0142] Examples of the structural unit (a4-0) include the structural units shown below and the structural units in which the methyl group corresponding to R in the following structural units is replaced by a hydrogen atom in the structural unit (a4-0). 54 TIFF0007702842000098.tif95166

[0143] TIFF0007702842000099.tif4866[In formula (a4-1), R a41 represents a hydrogen atom or a methyl group. R a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. A a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by formula (a-g1). However, at least one of A a41 and R a42 has a halogen atom (preferably a fluorine atom) as a substituent. TIFF0007702842000100.tif1487[In formula (a-g1), s represents 0 or 1. A a42 and A a44Each independently represents a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. A a43 represents a single bond or a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. X a41 and X a42 each independently represents -O-, -CO-, -CO-O- or -O-CO-. However, the total number of carbon atoms of A a42 A a43 A a44 X a41 and X a42 is 7 or less. ]] * is a bonding site, and the * on the right is the bonding site with -O-CO-R a42 .

[0144] R a42 Examples of the saturated hydrocarbon group in R include a chain hydrocarbon group, a monocyclic or polycyclic saturated alicyclic hydrocarbon group, and a group formed by combining these.

[0145] Examples of the chain hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic saturated alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; polycyclic alicyclic hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bonding site). Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more saturated alicyclic hydrocarbon groups, such as -alkanediyl group-saturated alicyclic hydrocarbon group, -saturated alicyclic hydrocarbon group-alkyl group, -alkanediyl group-saturated alicyclic hydrocarbon group-alkyl group.

[0146] R a42 Examples of the substituent that R has include at least one selected from the group consisting of a halogen atom and a group represented by the formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable. TIFF0007702842000102.tif855[In the formula (a-g3), X a43 represents an oxygen atom, a carbonyl group, *-O-CO- or *-CO-O-. A a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. * is the bonding site with R a42 .] However, in R a42 -X a43 -A a45 , when R a42 does not have a halogen atom, A a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which has at least one halogen atom.

[0147] A a45 Examples of the saturated hydrocarbon group in A include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and octadecyl group; monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group; and polycyclic alicyclic hydrocarbon groups such as decahydronaphthyl group, adamantyl group, norbornyl group, and the following group (* represents the bonding site). TIFF0007702842000103.tif10160Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, -alkanediyl group-alicyclic hydrocarbon group-alkyl group, and the like.

[0148] R a42 is preferably a saturated hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and / or a saturated hydrocarbon group having a group represented by the formula (a-g3). R a42 When it is a saturated hydrocarbon group having a halogen atom, it is preferably a saturated hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, still more preferably a perfluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group. R a42 When it is a saturated hydrocarbon group having a group represented by the formula (a-g3), including the number of carbon atoms contained in the group represented by the formula (a-g3), the total number of carbon atoms of R a42 is preferably 15 or less, more preferably 12 or less. When having a group represented by the formula (a-g3) as a substituent, the number thereof is preferably 1.

[0149] R a42 When it is a saturated hydrocarbon group having a group represented by the formula (a-g3), R a42 is more preferably a group represented by the formula (a-g2). TIFF0007702842000104.tif871[In the formula (a-g2), A a46 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. X a44 represents -O-CO- or -CO-O- (** represents the bonding site with A a46 ).). A a47represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. However, A a46 , A a47 and X a44 have a total carbon number of 18 or less, and at least one of A a46 and A a47 has at least one halogen atom. * represents the bonding site with the carbonyl group.]

[0150] A a46 preferably has 1 to 6 carbon atoms in the saturated hydrocarbon group, more preferably 1 to 3 carbon atoms. A a47 preferably has 4 to 15 carbon atoms in the saturated hydrocarbon group, more preferably 5 to 12 carbon atoms, and A a47 is more preferably a cyclohexyl group or an adamantyl group.

[0151] The preferred structure of the group represented by the formula (a-g2) is the following structure (* is the bonding site with the carbonyl group). TIFF0007702842000105.tif14160

[0152] As the alkanediyl group in A a41 , linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group; branched alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, 2-methylbutane-1,4-diyl group can be mentioned. As the substituent in the alkanediyl group represented by A a41 , a hydroxy group and an alkoxy group having 1 to 6 carbon atoms etc. can be mentioned. A a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and still more preferably an ethylene group.

[0153] A in the group represented by formula (a-g1) a42 , A a43 and A a44 Examples of the divalent saturated hydrocarbon group represented by, and A include linear or branched alkanediyl groups, monocyclic divalent alicyclic saturated hydrocarbon groups, and divalent saturated hydrocarbon groups formed by combining an alkanediyl group and a divalent alicyclic saturated hydrocarbon group. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, etc. may be mentioned. A a42 , A a43 and A a44 Examples of the substituent of the divalent saturated hydrocarbon group represented by, and A include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. s is preferably 0.

[0154] In the group represented by formula (a-g1), X a42 Examples of the group which is -O-, -CO-, -CO-O- or -O-CO- include the following groups. In the following examples, * and ** each represent a bonding site, and ** is the bonding site with -O-CO-R a42 . TIFF0007702842000106.tif47140

[0155] Examples of the structural unit represented by formula (a4-1) include the following structural units and the structural units in which the methyl group corresponding to R in the structural unit represented by formula (a4-1) below is replaced by a hydrogen atom. a41 TIFF0007702842000107.tif99146

[0156] TIFF0007702842000108.tif132150

[0157] ​Examples of the structural unit represented by formula (a4-1) include the structural unit represented by formula (a4-2) and the structural unit represented by formula (a4-3). TIFF0007702842000109.tif4356[In formula (a4-2), R f5 represents a hydrogen atom or a methyl group. L 44 represents an alkanediyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. R f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and having a fluorine atom. However, the upper limit of the total carbon number of L 44 and R f6 is 21.]

[0158] L 44 The alkanediyl group having 1 to 6 carbon atoms of is the same as the group exemplified by A a41 R f6 The saturated hydrocarbon group of is the same as the group exemplified by R 42 L 44 As the alkanediyl group in, an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.

[0159] Examples of the structural unit represented by formula (a4-2) include, for example, the structural units represented by formulas (a4-1-1) to (a4-1-11). The structural unit in which the methyl group corresponding to R f5 in the structural unit (a4-2) is replaced by a hydrogen atom is also included as the structural unit represented by formula (a4-2).

[0160] TIFF0007702842000110.tif5671[In formula (a4-3), R f7 represents a hydrogen atom or a methyl group. L 5 represents an alkanediyl group having 1 to 6 carbon atoms. A f13 ​​represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms which may have a fluorine atom. X f12 represents *-O-CO- or *-CO-O- (* represents the bonding site with A f13 .). A f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom. However, at least one of A f13 and A f14 has a fluorine atom, and the upper limit of the total carbon number of L 5 , A f13 and A f14 is 20.]

[0161] L 5 Examples of the alkanediyl group in include the same groups as those exemplified for the alkanediyl group of A a41 .

[0162] A f13 Examples of the divalent saturated hydrocarbon group which may have a fluorine atom in include preferably a divalent chain saturated hydrocarbon group which may have a fluorine atom and a divalent alicyclic saturated hydrocarbon group which may have a fluorine atom, more preferably a perfluoroalkanediyl group. Examples of the divalent chain saturated hydrocarbon group which may have a fluorine atom include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group and a pentanediyl group; perfluoroalkanediyl groups such as a difluoromethylene group, a perfluoroethylene group, a perfluoropropanediyl group, a perfluorobutanediyl group and a perfluoropentanediyl group. The divalent alicyclic saturated hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic group include an adamantanediyl group, a norbornanediyl group, a perfluoroadamantanediyl group.

[0163] A f14The saturated hydrocarbon group and the saturated hydrocarbon group which may have a fluorine atom are R a42 The groups similar to those exemplified by a42 can be mentioned. Among them, alkyl fluoride groups such as trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group and perfluorooctyl group; cyclopropylmethyl group, cyclopropyl group, cyclobutylmethyl group, cyclopentyl group, cyclohexyl group, perfluorocyclohexyl group, adamantyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl group, norbornylmethyl group, perfluoroadamantyl group, perfluoroadamantylmethyl group etc. are preferable.

[0164] In formula (a4-3), L 5 is preferably an ethylene group. A f13 The divalent saturated hydrocarbon group of A preferably includes a divalent chain saturated hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and a divalent chain saturated hydrocarbon group having 2 to 3 carbon atoms is more preferable. A f14 The saturated hydrocarbon group of A preferably includes a chain saturated hydrocarbon group having 3 to 12 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and a group including a chain saturated hydrocarbon group having 3 to 10 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms is more preferable. Among them, A f14 is preferably a group including an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably, cyclopropylmethyl group, cyclopentyl group, cyclohexyl group, norbornyl group and adamantyl group.

[0165] Examples of the structural unit represented by the formula (a4-3) include structural units represented by the formulas (a4-1'-1) to (a4-1'-11), respectively. The methyl group corresponding to R in the structural unit (a4-3) f7 replaced by a hydrogen atom is also included as a structural unit represented by the formula (a4-3).

[0166] Examples of the structural unit (a4) also include a structural unit represented by the formula (a4-4). TIFF0007702842000111.tif4466[In the formula (a4-4), R f21 represents a hydrogen atom or a methyl group. A f21 represents -(CH2) j1 -, -(CH2) j2 -O-(CH2) j3 - or -(CH2) j4 -CO-O-(CH2) j5 -. j1 to j5 each independently represent an integer from 1 to 6. R f22 represents a saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom.]

[0167] The saturated hydrocarbon group of R f22 includes the same ones as the saturated hydrocarbon group represented by R a42 . R f22 is 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, more 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.

[0168] In the formula (a4-4), A f21 is preferably -(CH2) j1 -, more preferably an ethylene group or a methylene group, and even more preferably a methylene group.

[0169] Examples of the structural unit represented by formula (a4-4) include structural units represented by the following structural units and the following formulas, in which the methyl group corresponding to R in structural unit (a4-4) is replaced with a hydrogen atom. f21 Examples thereof include a structural unit in which the methyl group corresponding to R in structural unit (a4-4) is replaced with a hydrogen atom. TIFF0007702842000112.tif86160

[0170] When the resin (A) has the structural unit (a4), its content is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and even more preferably 3 to 10 mol% based on all the structural units of the resin (A).

[0171] 〈Structural unit (a5)〉 Examples of the non-leaving hydrocarbon group of the structural unit (a5) include a group having a linear, branched or cyclic hydrocarbon group. Among them, the structural unit (a5) preferably has a group having an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by formula (a5-1). TIFF0007702842000113.tif3554[In formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atoms contained in the alicyclic hydrocarbon group may be substituted with aliphatic hydrocarbon groups having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.]

[0172] R 52 The alicyclic hydrocarbon group in R may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group, etc. The aliphatic hydrocarbon group having 1 to 8 carbon atoms includes, for example, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Examples of the alicyclic hydrocarbon group having a substituent include 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

[0173] L 55 Examples of the divalent saturated hydrocarbon group in L include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and preferably a divalent chain saturated hydrocarbon group. Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl group and norbornanediyl group.

[0174] L 55 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by L is replaced by -O- or -CO- include the groups represented by formula (L1-1) to formula (L1-4). In the following formulas, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom. In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents a bonding site with L x1 .). L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, the total number of carbon atoms in L x1 and L x2 is 16 or less. In formula (L1-2), L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, the total number of carbon atoms in L x3 and L x4 is 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, the total number of carbon atoms in L x5 , L x6 and L x7 is 15 or less. In formula (L1-4), L x8 and L x9 each 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, the total number of carbon atoms in L x8 , L x9 and W x1 is 15 or less.

[0175] L x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond. L x3is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. L x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. W x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

[0176] Examples of the group represented by formula (L1-1) include the following divalent groups. TIFF0007702842000115.tif53136

[0177] Examples of the group represented by formula (L1-2) include the following divalent groups. TIFF0007702842000116.tif23130

[0178] Examples of the group represented by formula (L1-3) include the following divalent groups. TIFF0007702842000117.tif16146

[0179] Examples of the group represented by the formula (L1-4) include the following divalent groups. TIFF0007702842000118.tif26114

[0180] L 55 is preferably a single bond or a group represented by the formula (L1-1).

[0181] Examples of the structural unit (a5-1) include the following structural units and structural units in which the methyl group corresponding to R in the structural unit (a5-1) below is replaced by a hydrogen atom. 51 When the resin (A) has the structural unit (a5), its content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and even more preferably 3 to 15 mol% based on all the structural units of the resin (A). TIFF0007702842000119.tif110150

[0182] 〈Structural unit (a6)〉 The structural unit (a6) is a structural unit having a -SO2- group, and preferably has a -SO2- group in the side chain. The structural unit having a -SO2- group may have a linear structure having a -SO2- group, a branched structure having a -SO2- group, or a cyclic structure (monocyclic and polycyclic structures) having a -SO2- group. Preferably, it is a structural unit having a cyclic structure having a -SO2- group, and more preferably, it is a structural unit having a cyclic structure (sultone ring) containing -SO2-O-.

[0183] Examples of the sultone ring include rings represented by the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and formula (T 1 -4). The bonding site can be at any position. The sultone ring may be monocyclic, but is preferably polycyclic. The polycyclic sultone ring means a bridged ring containing -SO2-O- as an atomic group constituting the ring, and the formula (T 1 -1) and formula (T1 Examples of the ring represented by the formula (T-2) include sultone rings. The sultone ring may contain, in addition to -SO2-O-, other heteroatoms as atomic groups constituting the ring, like the ring represented by the formula (T-2). 1 Examples of the heteroatom include an oxygen atom, a sulfur atom, or a nitrogen atom, preferably an oxygen atom. TIFF0007702842000120.tif3187

[0184] 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, etc.

[0185] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group. Preferably, it is an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group. Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group. Preferably, it is a trifluoromethyl group. Examples of the alkyl group having a hydroxy group include a hydroxymethyl group and a hydroxyalkyl group such as 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, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, and 2-methyl-6-ethylphenyl group. Examples of the aralkyl group include a benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group. Examples of the alkoxycarbonyl group include a group in which an alkoxy group such as a methoxycarbonyl group or an ethoxycarbonyl group is bonded to a carbonyl group, preferably an alkoxycarbonyl group having 6 or less carbon atoms, more preferably a methoxycarbonyl group. Examples of the alkylcarbonyl group include an acetyl group, propionyl group, and butyryl group.

[0186] From the viewpoint that the production of the monomer leading to the structural unit (a6) is easy, a sultone ring having no substituent is preferred. As the sultone ring, a ring represented by the following formula (T1') is preferred. TIFF0007702842000121.tif3172[In the formula (T1'), X 11 represents an oxygen atom, sulfur atom, or methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. The bonding site is at an arbitrary position.] X 11 is preferably an oxygen atom or a methylene group, more preferably a methylene group. R41 Examples thereof include the same as the substituents of the sultone ring, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group is preferable.

[0187] As the sultone ring, a ring represented by the formula (T1) is more preferable. TIFF0007702842000122.tif3149[In the formula (T1), R 8 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. m represents any integer from 0 to 9. When m is 2 or more, a plurality of R 8 may be the same or different. The bonding site is at an arbitrary position.]

[0188] R 8 is the same as R 41 Examples thereof include the same as those of R. ma in the formula (T1') and m in the formula (T1) are preferably 0 or 1, and more preferably 0.

[0189] Examples of the ring represented by the formula (T1') and the ring represented by the formula (T1) include the following rings. The bonding site is at an arbitrary position. TIFF0007702842000123.tif47144

[0190] The structural unit having a sultone ring preferably has the following group. * in the following group represents a bonding site. TIFF0007702842000124.tif45144

[0191] The structural unit having a -SO2- group preferably further has a group derived from a polymerizable group. Examples of the polymerizable group include a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, a methacryloylthio group, and the like. Among them, the monomer that leads to the structural unit (a6) is preferably a monomer having an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer.

[0192] The structural unit (a6) is preferably a structural unit represented by the formula (Ix). TIFF0007702842000125.tif4956[In the formula (Ix), R x represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. A xx represents an oxygen atom, -N(R c )-, or a sulfur atom. A x represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -CO-, or -N(R d ). X 11 represents an oxygen atom, a sulfur atom, or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. R c and R d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.]

[0193] R x Examples of the halogen atom of R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R x Examples of the alkyl group of R include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group, etc. Preferably, it is an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group. R x Examples of the alkyl group having a halogen atom of R include, for example, a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, etc. R x R is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

[0194] A x Examples of the divalent saturated hydrocarbon group of A include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and combinations of two or more of these groups may also be used. Specifically, linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1,17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group; Branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; Monocyclic divalent alicyclic saturated hydrocarbon groups which are cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; Polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. can be mentioned.

[0195] R 41 、X 11 And ma are the same as those in formula (T1'). Examples of the sultone ring include the above-mentioned ones, and among them, the above-mentioned ones with specific bonding positions are preferred.

[0196] Examples of the structural unit (a6) include the following structural units. TIFF0007702842000126.tif93150

[0197] Among them, the structural units represented by formula (a6-1), formula (a6-2), formula (a6-6), formula (a6-7), formula (a6-8) and formula (a6-12) are preferred, and the structural units represented by formula (a6-1), formula (a6-2), formula (a6-7) and (a6-8) are more preferred. When the resin (A) has the structural unit (a6), its content is preferably 1 to 50 mol%, more preferably 2 to 40 mol%, and still more preferably 3 to 30 mol% based on all the structural units of the resin (A).

[0198] <Structural unit (II)> The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as "structural unit (II)"). Specific examples of the structural unit (II) include the structural units described in JP-A-2016-79235, and a structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain or a structural unit having a sulfonio group and an organic anion in the side chain is preferable.

[0199] The structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain is preferably a structural unit represented by formula (II-2-A'). TIFF0007702842000127.tif3089[In formula (II-2-A'), X III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom or a hydroxy group. A x1 represents an alkanediyl group having 1 to 8 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be replaced by a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. RA - represents a sulfonate group or a carboxylate group. R III3represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. ZA + represents an organic cation.

[0200] R III3 Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R III3 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R include the same ones as the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R. a8 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R include the same ones as the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R. A x1 Examples of the alkanediyl group having 1 to 8 carbon atoms represented by A include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-2,2-diyl group, a pentane-2,4-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, a 2-methylbutane-1,4-diyl group, and the like. A x1 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted on A include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, and the like.

[0201] X III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and combinations thereof may also be possible. Specifically, linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group; branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; divalent monocyclic alicyclic saturated hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; Examples thereof include divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group.

[0202] Examples of those in which -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- include divalent groups represented by formula (X1) to formula (X53). However, the number of carbon atoms before -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- is 17 or less respectively. In the following formula, * and ** represent bonding sites, and * represents the bonding site with A x1 and represents the bonding site with A. TIFF0007702842000128.tif145161

[0203] X 3 represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms. X 4 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. X 5 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. X 6 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 7 represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 8 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

[0204] ZA + Examples of the organic cation represented by ZA include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, cations represented by any of the above-described formulas (b2-1) to (b2-4) (hereinafter, may be referred to as "cation (b2-1)" etc. according to the formula number) can be mentioned.

[0205] The structural unit represented by formula (II-2-A') is preferably the structural unit represented by formula (II-2-A). JPEG0007702842000129.jpg37109[In formula (II-2-A), R III3 、X III3 and ZA + represent the same meanings as described above. z represents any integer from 0 to 6. R III2 and R III4 each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms, and when z is 2 or more, a plurality of R III2 and R III4 may be the same as or different from each other. Q a and Q b each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.]

[0206] R III2 、R III4 、Q a and Q bExamples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by include the same groups as the perfluoroalkyl group having 1 to 6 carbon atoms represented by Q described below. b1 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by include the same groups as the perfluoroalkyl group having 1 to 6 carbon atoms represented by Q described below.

[0207] The structural unit represented by formula (II-2-A) is preferably the structural unit represented by formula (II-2-A-1). TIFF0007702842000130.tif5576[In formula (II-2-A-1), R III2 、R III3 、R III4 、Q a 、Q b 、z and ZA + have the same meanings as described above. R III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms. X I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, in which -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom or a hydroxy group.

[0208] R III5 Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by include linear or branched alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group. X I2 Examples of the divalent saturated hydrocarbon group represented by include the same groups as the divalent saturated hydrocarbon group represented by X III3 described below.

[0209] As the structural unit represented by formula (II-2-A-1), the structural unit represented by formula (II-2-A-2) is preferable. TIFF0007702842000131.tif5287[In formula (II-2-A-2), R III3 、RIII5 and ZA + represents the same meaning as described above. m and nA each independently represent 1 or 2.

[0210] Examples of the structural unit represented by formula (II-2-A') include, for example, the following structural units, R III3 wherein the group corresponding to the methyl group of R is replaced with a hydrogen atom, a halogen atom (for example, a fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (for example, a trifluoromethyl group, etc.), and the structural units described in International Publication No. 2012 / 050015. ZA + represents an organic cation. TIFF0007702842000132.tif86163

[0211] The structural unit having a sulfonio group and an organic anion in the side chain is preferably a structural unit represented by formula (II-1-1). TIFF0007702842000133.tif3689[In formula (II-1-1), A II1 represents a single bond or a divalent linking group. R II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms. R II2 and R II3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and R II2 and R II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. R II4 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A - represents an organic anion. R II1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R include a phenylene group and a naphthylene group. R II2 and R II3Examples of the hydrocarbon group represented by include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Examples of the alkyl group and the alicyclic hydrocarbon group are the same as those described above. 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 formed by combining the above-described alkyl group and alicyclic hydrocarbon group, an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. R II4 Examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R II4 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by are the same as those of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by . a8 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by are the same as those of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by . A II1 Examples of the divalent linking group represented by include, for example, a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S- or -CO-. Specifically, examples are the same as those of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by . III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by are the same as those of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by .

[0212] Examples of the structural unit containing the cation in formula (II-1-1) include the structural units represented below, R II4Examples of the structural unit in which the group corresponding to the methyl group is replaced with a hydrogen atom, a halogen atom (e.g., fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., trifluoromethyl group) etc. are given. TIFF0007702842000134.tif85130

[0213] A - Examples of the organic anion represented by A include sulfonate anion, sulfonylimide anion, sulfonylmethide anion, and carboxylate anion etc. A - The organic anion represented by A is preferably a sulfonate anion, and examples of the sulfonate anion include the same ones as the anion represented by the aforementioned formula (B1).

[0214] A - Examples of the sulfonylimide anion represented by A include the following. TIFF0007702842000135.tif36136 Examples of the sulfonylmethide anion include the following. TIFF0007702842000136.tif29123 Examples of the carboxylate anion include the following. TIFF0007702842000137.tif51152

[0215] Examples of the structural unit represented by the formula (II-1-1) include the structural units represented below etc. TIFF0007702842000138.tif88149

[0216] When the resin (A) contains the structural unit (II), the content of the structural unit (II) is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and still more preferably 3 to 10 mol% with respect to all the structural units of the resin (A).

[0217] The resin (A) may have a structural unit other than the above-mentioned structural units, and examples of such a structural unit include the structural units well-known in the art.

[0218] The resin (A) is preferably a resin composed of a structural unit (a1) and a structural unit (s), that is, a copolymer of a monomer (a1) and a monomer (s). The structural unit (a1) is preferably at least one selected from the group consisting of a structural unit (a1-0), a structural unit (a1-1), and a structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group), more preferably at least two, and still more preferably at least two selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). The structural unit (s) is preferably at least one selected from the group consisting of a structural unit (a2) and a structural unit (a3). The structural unit (a2) is preferably a structural unit represented by the formula (a2-1) or a structural unit represented by the formula (a2-A). The structural unit (a3) is preferably at least one selected from the group consisting of a structural unit represented by the formula (a3-1), a structural unit represented by the formula (a3-2), and a structural unit represented by the formula (a3-4).

[0219] Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, a radical polymerization method) using a monomer that leads to these structural units. The content of each structural unit of the resin (A) can be adjusted by the amount of the monomer used in the polymerization. The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more), and 50,000 or less (more preferably 30,000 or less, still more preferably 15,000 or less). In this specification, the weight average molecular weight is a value determined by gel permeation chromatography under the conditions described in the examples.

[0220] <Resin other than resin (A)> The resist composition of the present invention may contain a resin other than the resin (A). Examples of the resin other than the resin (A) include a resin containing a structural unit (a4) or a structural unit (a5) (hereinafter sometimes referred to as resin (X)).

[0221] Among them, the resin containing the structural unit (a4) is preferable as the resin (X). In the resin (X), the content of the structural unit (a4) is preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 45 mol% or more based on the total of all the structural units of the resin (X). Examples of the structural unit that the resin (X) may further have include a structural unit (a2), a structural unit (a3), and a structural unit derived from other known monomers. Among them, the resin (X) is preferably a resin composed of only the structural unit (a4) and / or the structural unit (a5), and more preferably a resin composed of only the structural unit (a4). Each structural unit constituting the resin (X) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, radical polymerization method) using a monomer that induces these structural units. The content of each structural unit of the resin (X) can be adjusted by the amount of the monomer used in the polymerization. The weight average molecular weight of the resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The measuring means for the weight average molecular weight of the resin (X) is the same as that of the resin (A). When the resist composition contains the resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, still more preferably 1 to 40 parts by mass, even more preferably 1 to 30 parts by mass, and still even more preferably 1 to 8 parts by mass with respect to 100 parts by mass of the resin (A).

[0222] The content of the resin (A) in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. When a resin other than the resin (A) is included, the total content of the resin (A) and the resin other than the resin (A) is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. The solid content of the resist composition and the content of the resin relative thereto can be measured by known analytical means such as liquid chromatography or gas chromatography.

[0223] <Solvent (E)> The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, more preferably 94% by mass or more and 99% by mass or less. The content of the solvent (E) can be measured by known analytical means such as liquid chromatography or gas chromatography. Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate, and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. One kind of the solvent (E) may be used alone, or two or more kinds may be used.

[0224] <Quencher (C)> Examples of the quencher (C) include salts that generate an acid having a lower acidity than the acid generated from the acid generator (B), and basic nitrogen-containing organic compounds. The content of the quencher (C) is preferably about 0.01 to 15% by mass, more preferably about 0.01 to 10% by mass, still more preferably about 0.1 to 8% by mass, and still more preferably about 0.1 to 7% by mass, based on the solid content of the resist composition.

[0225] The acidity of the salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is represented by the acid dissociation constant (pKa). The salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is a salt in which the acid dissociation constant of the acid generated from the salt is usually -3 < pKa, preferably -1 < pKa < 7, and more preferably 0 < pKa < 5. Examples of the salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) include salts represented by the following formula, salts represented by formula (D) described in JP-A-2015-147926 (hereinafter sometimes referred to as "weak acid inner salt (D)"), and salts described in JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502, and JP-A-2011-191745. As the salt that generates an acid with a lower acidity than the acid generated from the acid generator (B), preferably, it is a salt that generates a carboxylic acid with a lower acidity than the acid generated from the acid generator (B) (a salt having a carboxylate anion), and more preferably, it is the weak acid inner salt (D). TIFF0007702842000139.tif116167

[0226] The weak acid inner salt (D) is preferably a diphenyliodonium salt having an iodonium cation to which two phenyl groups are bonded and a carboxylate anion substituted on at least one of the two phenyl groups bonded to the iodonium cation. Specifically, the following salts are included. TIFF0007702842000140.tif72165

[0227] Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Examples of the amines include aliphatic amines and aromatic amines. Examples of the aliphatic amines include primary amines, secondary amines, and tertiary amines. Examples of the amine include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridyl)ethane, 1,2-di(4-pyridyl)ethane, 1,2-di(2-pyridyl)ethene, 1,2-di(4-pyridyl)ethene, 1,3-di(4-pyridyl)propane, 1,2-di(4-pyridyloxy)ethane, di(2-pyridyl)ketone, 4,4'-dipyridylsulfide, 4,4'-dipyridyldisulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, bipyridine and the like. Aromatic amines such as diisopropylaniline are preferable, and 2,6-diisopropylaniline is more preferable. Examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate, choline, and the like.

[0228] <Other Components> The resist composition of the present invention may contain, if necessary, components other than the above-described components (hereinafter sometimes referred to as "other components (F)"). There is no particular limitation on the other components (F), and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, etc. can be used.

[0229] <Preparation of Resist Composition> The resist composition of the present invention can be prepared by mixing the salt (I), the resin (A), the acid generator (B), and, if necessary, a resin other than the resin (A) used, the solvent (E), the quencher (C), and the other components (F). The mixing order is arbitrary and not particularly limited. The temperature at the time of mixing can be appropriately selected from 10 to 40°C according to the type of resin, etc. and the solubility of the resin, etc. in the solvent (E). The mixing time can be appropriately selected from 0.5 to 24 hours according to the mixing temperature. Note that the mixing means is also not particularly limited, and stirring and mixing, etc. can be used. After mixing the respective components, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

[0230] <Method for Producing Resist Pattern> The method for producing a resist pattern of the present invention is (1) a step of applying the resist composition of the present invention onto a substrate, (2) a step of drying the applied composition to form a composition layer, (3) a step of exposing the composition layer, (4) A step of heating the composition layer after exposure, and (5) A step of developing the composition layer after heating. To apply the resist composition onto a substrate, it can usually be performed by a commonly used apparatus such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers and organic substrates having a resist film formed on the surface. Before applying the resist composition, the substrate may be cleaned, or an antireflection film or the like may be formed on the substrate. By drying the applied composition, the solvent is removed to form a composition layer. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-bake), or by using a decompression device. The heating temperature is preferably 50 to 200 °C, and the heating time is preferably 10 to 180 seconds. Also, the pressure during decompression drying is preferably about 1 to 1.0×10 5 Pa. The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. As the exposure light source, those that emit laser light in the ultraviolet region such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), and an F2 excimer laser (wavelength 157 nm), those that convert the laser light from a solid laser light source (such as a YAG or semiconductor laser) into harmonic laser light in the far ultraviolet region or vacuum ultraviolet region and emit it, those that irradiate electron beams, extreme ultraviolet light (EUV), etc., various ones can be used. In this specification, irradiating these radiations may be collectively referred to as "exposure". During exposure, usually, exposure is performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask. The composition layer after exposure is subjected to heat treatment (so-called post-exposure bake) to promote the deprotection reaction at the acid-labile groups. The heating temperature is usually about 50 to 200 °C, preferably about 70 to 150 °C. Chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the composition after heating. Further, before development, the steps of coating, drying, exposing, and heating the resist composition may be repeatedly performed on the composition layer after exposure. The composition layer after heating is usually developed using a developing solution with a developing apparatus. Examples of the developing method include dip method, paddle method, spray method, dynamic dispense method, etc. The developing temperature is preferably, for example, 5 to 60 °C, and the developing time is preferably, for example, 5 to 300 seconds. By selecting the type of the developing solution as follows, a positive resist pattern or a negative resist pattern can be manufactured. When manufacturing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developing solution. The alkaline developer may be various alkaline aqueous solutions used in this field. For example, aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline) etc. are mentioned. The alkaline developer may contain a surfactant. It is preferable to wash the resist pattern with ultrapure water after development, and then remove the water remaining on the substrate and the pattern. When manufacturing a negative resist pattern from the resist composition of the present invention, a developing solution containing an organic solvent (hereinafter sometimes referred to as "organic-based developing solution") is used as the developing solution. Examples of the organic solvent contained in the organic-based developing solution include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole, etc. In the organic developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and still more preferably substantially only the organic solvent. Among them, as the organic developer, a developer containing butyl acetate and / or 2-heptanone is preferable. In the organic developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and still more preferably substantially only butyl acetate and / or 2-heptanone. The organic developer may contain a surfactant. Further, the organic developer may contain a trace amount of water. During development, development may be stopped by substituting with a solvent of a type different from the organic developer. It is preferable to wash the resist pattern after development with a rinse solution. The rinse solution is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent. After washing, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

[0231] <Usage> 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, particularly as a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for semiconductor microfabrication.

Examples

[0232] The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing the content or the amount used are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows. Column: TSKgel Multipore HXL-M x 3 + guard column (manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Detector: RI detector Column temperature: 40 °C Injection volume: 100 μl Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC is Agilent 1100 series, MASS is Agilent LC / MSD type). In the following examples, the value of this molecular ion peak is indicated as "MASS".

[0233] Example 1: Synthesis of the salt represented by formula (I-2) 2.19 parts of the salt represented by formula (I-2-a) and 20 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by formula (I-2-b) was added, and the mixture was further stirred at 50 °C for 2 hours. To the resulting mixed solution, 0.88 part of the compound represented by formula (I-2-c) was added, and the mixture was further stirred at 50 °C for 3 hours and then cooled to 23 °C. To the resulting mixture, 10 parts of 5% aqueous oxalic acid solution was added and stirred at 23 °C for 30 minutes, and then the layers were separated to obtain the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and then the layers were separated to obtain the organic layer. This washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 °C for 30 minutes. Then, the supernatant was removed and concentrated to obtain 2.32 parts of the salt represented by formula (I-2). MS(ESI(+)Spectrum): M + 263.1 MS(ESI(-)Spectrum): M - 333.1

[0234] Example 2: Synthesis of the salt represented by formula (I-4) 2.19 parts of the salt represented by TIFF0007702842000142 in the form of (I-2-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by the formula (I-2-b) was added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 1.06 parts of the compound represented by the formula (I-4-c) was added, and further stirred at 50°C for 3 hours, and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes, and then separated to extract the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, and then separated to extract the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23°C for 30 minutes, the supernatant was removed, and concentrated to obtain 2.44 parts of the salt represented by the formula (I-4). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 369.0

[0235] Example 3: Synthesis of the salt represented by the formula (I-25) 3.17 parts of the salt represented by TIFF0007702842000143 in the form of (I-25-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by the formula (I-2-b) was added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 0.91 part of the compound represented by the formula (I-25-c) was added, and further stirred at 50°C for 3 hours, and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes, and then separated to extract the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, and then separated to extract the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23°C for 30 minutes, the supernatant was removed, and concentrated to obtain 3.36 parts of the salt represented by the formula (I-25). MS(ESI(+)Spectrum): M + 263.1 MS(ESI(-)Spectrum): M - 517.2

[0236] Example 4: Synthesis of the salt represented by formula (I-18) 3.09 parts of the salt represented by formula (I-18-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by formula (I-2-b) was added, and the mixture was further stirred at 50°C for 2 hours. To the resulting mixed solution, 0.88 part of the compound represented by formula (I-2-c) was added, and the mixture was further stirred at 50°C for 3 hours and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% aqueous oxalic acid solution was added and the mixture was stirred at 23°C for 30 minutes, and then the layers were separated to obtain the organic layer. 10 parts of ion-exchanged water was added to the obtained organic layer and the mixture was stirred at 23°C for 30 minutes, and then the layers were separated to obtain the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23°C for 30 minutes, and then the supernatant was removed and concentrated to obtain 3.28 parts of the salt represented by formula (I-18). MS(ESI(+)Spectrum): M + 263.1 MS(ESI(-)Spectrum): M - 513.1

[0237] Example 5: Synthesis of the salt represented by formula (I-21) 3.09 parts of the salt represented by TIFF0007702842000145.tif71148 (I-18-a) and 20 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by the formula (I-2-b) was added, and further stirred at 50 °C for 2 hours. To the resulting mixed solution, 1.06 parts of the compound represented by the formula (I-4-c) was added, and further stirred at 50 °C for 3 hours, then cooled to 23 °C. To the resulting mixture, 10 parts of 5% aqueous oxalic acid solution was added and stirred at 23 °C for 30 minutes, then separated to extract the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, then separated to extract the organic layer. This washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 3.43 parts of the salt represented by the formula (I-21). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 549.1

[0238] Example 6: Synthesis of the salt represented by the formula (I-23) 3.09 parts of the salt represented by TIFF0007702842000146.tif71141 (I-18-a) and 20 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by the formula (I-2-b) was added, and further stirred at 50 °C for 2 hours. To the resulting mixed solution, 1.51 parts of the compound represented by the formula (I-23-c) was added, and further stirred at 50 °C for 3 hours, then cooled to 23 °C. To the resulting mixture, 10 parts of 5% aqueous oxalic acid solution was added and stirred at 23 °C for 30 minutes, then separated to extract the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, then separated to extract the organic layer. This washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 3.12 parts of the salt represented by the formula (I-23). MS(ESI(+)Spectrum): M + 263.1 MS(ESI(-)Spectrum): M - 639.0

[0239] Example 7: Synthesis of the salt represented by formula (I-255) 3.09 parts of the salt represented by formula (I-18-a) and 20 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by formula (I-2-b) was added, and further stirred at 50 °C for 2 hours. To the resulting mixed solution, 1.51 parts of the compound represented by formula (I-32-c) was added, and further stirred at 50 °C for 3 hours, and then cooled to 23 °C. To the resulting mixture, 10 parts of 5% aqueous oxalic acid solution was added and stirred at 23 °C for 30 minutes, and then separated to extract the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and then separated to extract the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 3.24 parts of the salt represented by formula (I-255). MS(ESI(+)Spectrum): M + 263.1 MS(ESI(-)Spectrum): M - 639.0

[0240] Example 8: Synthesis of the salt represented by formula (I-257) 3.09 parts of the salt represented by TIFF0007702842000148.tif68137 (I-18-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by the formula (I-2-b) was added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 1.66 parts of the compound represented by the formula (I-34-c) was added, and further stirred at 50°C for 3 hours and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes, and then liquid separation was carried out to take out the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, and then liquid separation was carried out to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23°C for 30 minutes, the supernatant was removed, and concentrated to obtain 2.88 parts of the salt represented by the formula (I-257). MS(ESI(+)Spectrum):M + 263.1 MS(ESI(-)Spectrum):M - 669.0

[0241] Example 9: Synthesis of the salt represented by the formula (I-259) 3.09 parts of the salt represented by TIFF0007702842000149.tif66141 (I-18-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by the formula (I-2-b) was added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 2.14 parts of the compound represented by the formula (I-36-c) was added, and further stirred at 50°C for 3 hours and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes, and then liquid separation was carried out to take out the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, and then liquid separation was carried out to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23°C for 30 minutes, the supernatant was removed, and concentrated to obtain 3.68 parts of the salt represented by the formula (I-259). MS(ESI(+) Spectrum): M + 263.1 MS(ESI(-) Spectrum): M - 764.9

[0242] Example 10: Synthesis of the salt represented by formula (I-261) 3.09 parts of the salt represented by formula (I-18-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by formula (I-2-b) was added, and the mixture was further stirred at 50°C for 2 hours. To the resulting mixed solution, 2.22 parts of the compound represented by formula (I-38-c) was added, and the mixture was further stirred at 50°C for 3 hours and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% aqueous oxalic acid solution was added and the mixture was stirred at 23°C for 30 minutes, followed by liquid separation to take out the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and the mixture was stirred at 23°C for 30 minutes, followed by liquid separation to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mass was fractionated by column (silica gel 60N (spherical, neutral) 100 - 210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: chloroform / methanol = 1 / 1) to obtain 0.48 part of the salt represented by formula (I-261). MS(ESI(+) Spectrum): M + 263.1 MS(ESI(-) Spectrum): M - 780.9

[0243] Example 11: Synthesis of the salt represented by formula (I-489) 4.40 parts of the salt represented by TIFF0007702842000151.tif70139 (I-489-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by the formula (I-2-b) was added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 1.06 parts of the compound represented by the formula (I-4-c) was added, and further stirred at 50°C for 3 hours, and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes, and then separated to take out the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, and then separated to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23°C for 30 minutes, the supernatant was removed, and concentrated to obtain 4.83 parts of the salt represented by the formula (I-489). MS(ESI(+)Spectrum):M + 525.0 MS(ESI(-)Spectrum):M - 549.1

[0244] Example 12: Synthesis of the salt represented by the formula (I-491) 4.40 parts of the salt represented by TIFF0007702842000152.tif69158 (I-489-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by the formula (I-2-b) was added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 1.51 parts of the compound represented by the formula (I-23-c) was added, and further stirred at 50°C for 3 hours, and then cooled to 23°C. To the resulting mixture, 10 parts of a 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes, and then separated to take out the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, and then separated to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23°C for 30 minutes, the supernatant was removed, and concentrated to obtain 4.18 parts of the salt represented by the formula (I-491). MS(ESI(+) Spectrum): M + 525.0 MS(ESI(-) Spectrum): M - 639.0

[0245] Example 13: Synthesis of the salt represented by formula (I-528) 4.18 parts of the salt represented by formula (I-528-a) and 20 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by formula (I-2-b) was added, and the mixture was further stirred at 50 °C for 2 hours. To the resulting mixed solution, 1.06 parts of the compound represented by formula (I-4-c) was added, and the mixture was further stirred at 50 °C for 3 hours and then cooled to 23 °C. To the resulting mixture, 10 parts of a 5% aqueous oxalic acid solution was added and the mixture was stirred at 23 °C for 30 minutes, and then liquid separation was carried out to take out the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and the mixture was stirred at 23 °C for 30 minutes, and then liquid separation was carried out to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 °C for 30 minutes, and then the supernatant was removed and concentrated to obtain 4.51 parts of the salt represented by formula (I-528). MS(ESI(+) Spectrum): M + 481.0 MS(ESI(-) Spectrum): M - 549.1

[0246] Example 14: Synthesis of the salt represented by formula (I-530) 4.18 parts of the salt represented by TIFF0007702842000154.tif69152 (I-528-a) and 20 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.89 part of the compound represented by the formula (I-2-b) was added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 1.51 parts of the compound represented by the formula (I-23-c) was added, and further stirred at 50°C for 3 hours, then cooled to 23°C. To the resulting mixture, 10 parts of a 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. To the resulting organic layer, 10 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. This water washing operation was repeated 5 times. The resulting organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23°C for 30 minutes, then the supernatant was removed and concentrated to obtain 3.62 parts of the salt represented by the formula (I-530). MS(ESI(+)Spectrum):M + 481.0 MS(ESI(-)Spectrum):M - 639.0

[0247] Synthesis of Resin The compounds (monomers) used in the synthesis of Resin (A) are shown below. Hereinafter, these compounds will be referred to as "monomer (a1-2-6)" etc. according to their formula numbers. TIFF0007702842000155.tif48154

[0248] Synthesis Example 1 [Synthesis of Resin A1] As monomers, monomer (a1-2-6), monomer (a2-1-3), monomer (a3-4-2) and monomer (a1-4-2) were used and mixed so that their molar ratio [monomer (a1-2-6): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-2)] was 53:3:12:32. Further, 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed into this monomer mixture. To the resulting mixture, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were heated at 73 °C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) 2.0 times the mass of the total monomers was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was obtained by filtration and recovery with a weight average molecular weight of about 5.3×10 3 Resin A1 with a yield of 88% was obtained. This resin A1 has the following structural units. TIFF0007702842000156.tif37128

[0249] Synthesis Example 2 [Synthesis of Resin A2] As monomers, monomer (a1-2-6), monomer (a2-1-3), monomer (a3-4-2) and monomer (a1-4-13) were used and mixed so that their molar ratio [monomer (a1-2-6): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-13)] was 53:3:12:32. Further, 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed into this monomer mixture. To the obtained mixture, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1.2 mol% and 3.6 mol%, respectively, with respect to the total monomer amount, and these were heated at 73 °C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) 2.0 times the mass of the total monomers was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered and recovered to obtain resin A2 having a weight average molecular weight of about 5.1×10 3 and the resin A2 was obtained in a yield of 79%. This resin A2 has the following structural units. TIFF0007702842000157.tif38128

[0250] <Preparation of Resist Composition> As shown in Table 2, the following components were mixed, and the obtained mixture was filtered through a fluororesin filter with a pore size of 0.2 μm to prepare a resist composition.

Table 2

[0251] <Resin> A1, A2: Resin A1, Resin A2 <Salt (I)> I-2: Salt represented by formula (I-2) I-4: Salt represented by formula (I-4) I-18: Salt represented by formula (I-18) I-21: Salt represented by formula (I-21) I-23: Salt represented by formula (I-23) I-25: Salt represented by formula (I-25) I-255: Salt represented by formula (I-255) I-257: Salt represented by formula (I-257) I-259: Salt represented by formula (I-259) I-261: Salt represented by formula (I-261) I-489: Salt represented by formula (I-489) I-491: Salt represented by formula (I-491) I-528: Salt represented by formula (I-528) I-530: Salt represented by formula (I-530) <Acid generator> IX-1 IX-2 TIFF0007702842000159.tif45147<Quencher (C)> C1: Synthesized by the method described in JP-A-2011-39502 TIFF0007702842000160.tif4355D1: (Manufactured by Tokyo Chemical Industry Co., Ltd.) TIFF0007702842000161.tif1932<Solvent> 400 parts of propylene glycol monomethyl ether acetate 100 parts of propylene glycol monomethyl ether 5 parts of γ-butyrolactone

[0252] (Electron beam exposure evaluation of resist composition) A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 °C for 60 seconds. The resist composition was spin-coated on this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, it was prebaked on a direct hot plate at the temperature shown in the "PB" column of Table 2 for 60 seconds to form a composition layer. Using an electron beam lithography machine ["ELS-F125 125 keV" manufactured by Elionix, Inc.], the exposure amount was changed stepwise on the composition layer formed on the wafer, and direct drawing was performed so as to obtain a line and space pattern (pitch 60 nm / line width 30 nm) after development. After exposure, post-exposure baking was performed for 60 seconds at the temperature shown in the "PEB" column of Table 2 on a hot plate. Next, the composition layer on this silicon wafer was developed by the dynamic dispense method at 23°C for 20 seconds using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as the developer to obtain a resist pattern. The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the exposure dose at which the line width and space width of the line and space pattern with a pitch of 60 nm became 1:1 was defined as the effective sensitivity.

[0253] Line edge roughness evaluation (LER): The swing width of the unevenness on the side wall surface of the resist pattern manufactured with the effective sensitivity was measured with a scanning electron microscope to determine the line edge roughness. The results are shown in Table 3.

Table 3

Industrial Applicability

[0254] The resist composition containing the salt of the present invention can obtain a resist pattern having good line edge roughness (LER), and thus is suitable for semiconductor microfabrication and extremely useful industrially.

Claims

1. An acid generator containing a salt represented by formula (I). [In formula (I), Q １ and Q ２ each independently represents 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 from 0 to 6, and when z is 2 or more, a plurality of Rs １１ and Rs １２ may be the same as or different from each other. X ０ represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, where * represents a bonding site with C(R １１ )(R １２ ), or C(Q １ )(Q ２ ). L １ represents a single bond or *-L2-CO-O-, L2 represents a cyclic hydrocarbon group having 3 to 18 carbon atoms or a group combining a cyclic hydrocarbon group having 3 to 18 carbon atoms and an alkanediyl group having 1 to 4 carbon atoms, the cyclic hydrocarbon group may have a substituent, and -CH 2 - may be replaced by -O-, -S-, -SO ２ - or -CO-. * represents a bond with X0. R １ represents a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. m represents an integer of any one of 1 to 4. Z ＋ represents an organic cation.]

2. L ２ is a group represented by the following formula (L ２ -1), formula (L ２ -2), formula (L ２ -3) or formula (L ２ -4) (* represents a bond). The acid generator according to claim 1.

3. R １ The acid generator according to claim 1 or 2, wherein R is an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent.

4. R １ The alicyclic hydrocarbon group having 3 to 18 carbon atoms or the aromatic hydrocarbon group having 6 to 18 carbon atoms of ２ - may be replaced by -O-, -S-, -CO- or -SO ２ -). The acid generator according to claim 3, which is at least one selected from the above.

5. A resist composition containing the acid generator according to any one of Claims 1 to 4 and a resin having an acid-labile group.

6. The resist composition according to Claim 5, wherein the resin having an acid-labile group contains at least one selected from the group consisting of a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), and a structural unit represented by formula (a1-2). [In formula (a1-0), formula (a1-1), and formula (a1-2), L a01 , L ａ１ and L ａ２ each independently represents -O- or *-O-(CH ２ ), ｋ１ -CO-O-, k1 represents any integer from 1 to 7, and * represents the bonding site with -CO-. R a01 , R ａ４ and R ａ５ each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a02 , R a03 and R a04 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these. 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. m1 represents an integer of any one of 0 to 14. n1 represents an integer of any one of 0 to 10. n1' represents an integer of any one of 0 to 3. ]

7. The resist composition according to Claim 5 or 6, wherein the resin having an acid-labile group contains a structural unit represented by formula (a2-A). [In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents 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. A a50 represents a single bond or *-X a51 -(A a52 -X a52 ) nｂ -, where * represents the bonding site with the carbon atom to which -R a50 is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O- or -O-CO-. nb represents 0 or 1. mb represents an integer of any one of 0 to 4. When mb is any integer of 2 or more, a plurality of Rs a51 may be the same as or different from each other.]

8. The resist composition according to any one of Claims 5 to 7, further containing a salt that generates an acid having a lower acidity than the acid generated from the acid generator.

9. (1) A step of applying the resist composition according to any one of Claims 5 to 8 onto a substrate, (2) A step of drying the applied composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer, A method for manufacturing a resist pattern, including these steps.

10. A salt represented by formula (I). [In formula (I), Q １ and Q ２ each independently represents 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 any integer from 0 to 6, and when z is 2 or more, a plurality of Rs １１ and Rs １２ may be the same as or different from each other. X ０ represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, where * represents a bonding site with C(R １１ )(R １２ ), or C(Q １ )(Q ２ ). L １ represents a single bond or *-L2-CO-O-, where L2 represents a cyclic hydrocarbon group having 3 to 18 carbon atoms or a group combining a cyclic hydrocarbon group having 3 to 18 carbon atoms and an alkanediyl group having 1 to 4 carbon atoms. The cyclic hydrocarbon group may have a substituent, and -CH 2 - may be replaced by -O-, -S-, -SO ２ - or -CO-. * represents a bond with X0. R １ represents a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent. m represents an integer of any one of 1 to 4. Z ＋ represents an organic cation.]

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