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

Abstract

To provide a salt capable of producing a resist pattern having good line edge roughness (LER), and an acid generator and a resist composition containing the salt.SOLUTION: A salt represented by a formula (I), an acid generator, and a resist composition are provided. [In the formula, Q1 and Q2 each represent a fluorine atom or the like; R1 and R2 each independently represent a hydrogen atom or the like; z represents an integer of 0-6; X1 represents *-CO-O- or the like; L1 represents a single bond or the like; w1 and w2 each represent an integer of 1-3; X2 represents -O- or -S-; L2 represents an alkanediyl group; L3 represents a single bond or an alkanediyl group; R3 represents an optionally substituted hydrocarbon group; 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 technology]

[0002] Patent Document 1 describes a resist composition that contains a salt represented by the following formula as an acid generator. TIFF0007681957000001.tif3158 Patent Document 2 describes a resist composition that contains a salt represented by the following formula as an acid generator. TIFF0007681957000002.tif33133 [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-067076 A [Patent Document 2] JP 2013-032339 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a salt that enables the production of a resist pattern with better line edge roughness (LER) than a resist pattern formed from a resist composition containing the above salt. [Means for solving the problem]

[0005] The present invention includes the following inventions. [1] A salt represented by formula (I). TIFF0007681957000003.tif45110[In formula (I), Q 1 and Q 2each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. R 1 and R 2 each independently represents a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R 1 and R 2 may be the same or different from each other. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, and * represents C(R 1 )(R 2 ) or C(Q 1 )(Q 2 ) binding site. L 1 represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH 2 -, -O-, -S-, -SO 2 It may be replaced by - or -CO-. w1 and w2 each independently represent an integer of 1 to 3. X 2 represents -O- or -S-. L 2 represents an alkanediyl group having 1 to 6 carbon atoms. L 3 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms. R 3 represents a hydrocarbon group having 1 to 36 carbon atoms which may have a substituent, and -CH 2 - is -O-, -S-, -CO- or -SO 2 - may be replaced. Z + represents an organic cation. [2] The salt according to [1], wherein w1 is 1 or 2. [3] R 3 is an alkyl group having 1 to 6 carbon atoms. [4] L 1 is a single bond or *-L 4 -CO-O-(However, L 4 represents a hydrocarbon group having 1 to 22 carbon atoms which may have a substituent, and -CH 2 -, -O-, -S-, -SO 2 The salt according to any one of [1] to [3], wherein - may be replaced by - or -CO-. [5] An acid generator comprising the salt according to any one of [1] to [4]. [6] A resist composition comprising the acid generator according 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 comprises at least one member selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2): TIFF0007681957000004.tif4598 [In formula (a1-1) and formula (a1-2), L a1 and L a2 are each independently -O- or *-O-(CH 2 ) k1 It represents --CO--O--, k1 represents an integer of 1 to 7, and * represents a bond to --CO--. R a4 and R a5 each independently represents a hydrogen atom or a methyl group. 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 combination thereof. m1 represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3. [8] The resist composition according to [6] or [7], wherein the resin having an acid labile group contains a structural unit represented by formula (a2-A): TIFF0007681957000005.tif4551[In formula (a2-A), R a50represents 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 is a single bond or * -X a51 -(A a52 -X a52 ) nb - stands for -R. a50 represents the bonding site with the carbon atom to which it 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 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different.] [9] The resist composition according to any one of [6] to [8], further comprising a salt that generates an acid having a weaker 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) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) A method for producing a resist pattern, comprising the step of developing the composition layer after heating. Effect of the Invention

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

[0007] In this specification, the term "(meth)acrylic monomer" refers to a compound represented by "CH 2 Monomers with the structure =CH-CO- and "CH 2 =C(CH 3 (Meth)acrylate" and "(meth)acrylic acid" respectively mean "at least one selected from the group consisting of acrylates and methacrylates" and "at least one selected from the group consisting of acrylic acid and methacrylic acid". 2 =C(CH 3 )-CO-" or "CH 2 When a structural unit having "=CH-CO-" is exemplified, a structural unit having both groups is also exemplified. In addition, in the groups described in this specification, those that can have both a straight chain structure and a branched structure may have either. "Derived from" or "derived from" refers to a polymerizable C=C bond contained in the molecule becoming a -CC- group by polymerization. In the case where stereoisomers exist, all stereoisomers are included. In addition, a "combined group" refers to a group in which two or more of the exemplified groups are combined with their valences appropriately changed. In this specification, the term "solids content of a resist composition" refers to the sum of the components excluding the solvent (E), which will be described later, from the total amount of the resist composition.

[0008] <Salt represented by formula (I)> The present invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)"). In salt (I), the negatively charged side is sometimes called the "anion (I)" and the positively charged side is sometimes called the "cation (I)". TIFF0007681957000006.tif46113 [wherein all symbols have the same meanings as defined above.]

[0009] In formula (I), Q 1 , Q 2 , R 1 and R 2 Examples of the perfluoroalkyl group include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Q 1 and Q 2 are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom. R 1 and R 2 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 1 is preferably *-CO-O-, *-O-CO-O- or *-O-CO-, and more preferably *-CO-O- or *-O-CO-O- (* is C(R 1 )(R 2 ) or C(Q 1 )(Q 2 ) represents the bond position with ).

[0010] L 1 Examples of the divalent hydrocarbon group in include a divalent chain hydrocarbon group such as an alkanediyl group, a monocyclic or polycyclic (including spiro ring) divalent alicyclic hydrocarbon group, and a divalent aromatic hydrocarbon group, 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 a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, and a heptadecane-1,17-diyl group; and Examples of branched alkanediyl groups include ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group. The chain hydrocarbon group preferably has 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, even more preferably 1 to 9 carbon atoms, still more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms. Examples of the monocyclic or polycyclic divalent alicyclic hydrocarbon group include monocyclic divalent alicyclic hydrocarbon groups such as cycloalkanediyl groups, such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, and a cyclooctane-1,5-diyl group; and Examples of the polycyclic divalent alicyclic hydrocarbon group include a norbornane-1,4-diyl group, a norbornane-2,5-diyl group, an adamantane-1,5-diyl group, and an adamantane-2,6-diyl group. Examples of the alicyclic hydrocarbon group include the following groups: The bond may be at any position. The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 3 to 16 carbon atoms, and further preferably 3 to 12 carbon atoms. Examples of the divalent aromatic hydrocarbon group include aromatic hydrocarbon groups such as arylene groups such as a phenylene group, a naphthylene group, an anthrylene group, a biphenylene group, a phenanthrylene group, etc. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and further preferably 6 to 10. Examples of the group combining two or more types include a group combining an alicyclic hydrocarbon group with an alkanediyl group, a group combining an aromatic hydrocarbon group with an alkanediyl group, and a group combining an alicyclic hydrocarbon group with an aromatic hydrocarbon group. In the combination, two or more types of each of the alicyclic hydrocarbon group, aromatic hydrocarbon group, and chain hydrocarbon group may be combined. In addition, when any group is X 1 may be bound to Examples of groups combining an alicyclic hydrocarbon group and an alkanediyl group include -divalent alicyclic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent alicyclic hydrocarbon group-alkanediyl group-, and -alkanediyl group-divalent alicyclic hydrocarbon group-. Examples of groups combining an aromatic hydrocarbon group and an alkanediyl group include -divalent aromatic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent aromatic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent aromatic hydrocarbon group-, and the like. Examples of groups combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group include -aromatic hydrocarbon group-alicyclic hydrocarbon group-, -alicyclic hydrocarbon group-aromatic hydrocarbon group-, -alicyclic hydrocarbon group-aromatic hydrocarbon group-, and -alicyclic hydrocarbon group-aromatic hydrocarbon group-alicyclic hydrocarbon group-. L 1 -CH contained in a divalent hydrocarbon group having 1 to 28 carbon atoms 2 -, -O-, -S-, -SO 2 It may be replaced by - or -CO-. L 1 -CH contained in the hydrocarbon group having 1 to 28 carbon atoms 2 - is -O-, -S-, -SO 2 When it is replaced by - or -CO-, the number of carbon atoms before the replacement is regarded as the number of carbon atoms of the hydrocarbon group. -CH contained in the hydrocarbon group 2 -, -O-, -S-, -SO 2 The group substituted for - or -CO- is a hydroxy group (-CH 2 - is replaced by -O-), carboxy group (-CH contained in ethyl group) 2 -CH 2 - is replaced by -O-CO-), alkoxy group (-CH 2 - is replaced by -O-), alkoxycarbonyl group (-CH 2 -CH 2 - is replaced by -O-CO-), alkylcarbonyl group (-CH 2 - is replaced by -CO-), alkylcarbonyloxy group (-CH 2 -CH 2 - is replaced by -CO-O-), alkanediyloxy group (-CH at any position in the alkanediyl group) 2 - is replaced by -O-), alkanediyloxycarbonyl group (-CH 2 -CH 2 - is replaced by -O-CO-), alkanediylcarbonyl group (-CH at any position in the alkanediyl group) 2 - is replaced by -CO-), alkanediylcarbonyloxy group (-CH at any position in the alkanediyl group) 2 -CH 2 - is replaced by -CO-O-), alkylthio group (-CH 2 Examples of such groups include a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, an aromatic hydrocarbon group-carbonyloxy group, and a combination of two or more of these groups. The alkoxy group includes an alkoxy group having 1 to 17 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, and an undecyloxy group. The alkoxycarbonyl group, alkylcarbonyl group and alkylcarbonyloxy group represent groups in which a carbonyl group or a carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 18 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkanediyloxy group includes an alkanediyloxy group having 1 to 17 carbon atoms, such as a methyleneoxy group, an ethyleneoxy group, a propanediyloxy group, a butanediyloxy group, and a pentanediyloxy group. Examples of the alkanediyloxycarbonyl group include alkanediyloxycarbonyl groups having 2 to 17 carbon atoms, such as methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propanediyloxycarbonyl group, butanediyloxycarbonyl group, etc. Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 18 carbon atoms, such as methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, pentanediylcarbonyl group, etc. Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 17 carbon atoms, such as methylenecarbonyloxy group, ethylenecarbonyloxy group, propanediylcarbonyloxy group, butanediylcarbonyloxy group, etc. The alkylthio group includes an alkylthio group having 1 to 17 carbon atoms, such as a methylthio group, an ethylthio group, and a propylthio group. 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-carbonyloxy group include aromatic hydrocarbon group-carbonyloxy groups having 7 to 17 carbon atoms, such as a benzoyloxy group. In addition, -CH contained in alicyclic hydrocarbon groups 2 - is -O-, -S-, -CO- or -SO 2 Examples of the group substituted with - include the following groups: The bond can be in any position. TIFF0007681957000008.tif47156

[0011] L 1 Examples of the substituent that may be possessed by the alkyl group include 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 combination thereof. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, and a nonyl group. Examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, and a dodecyloxy group. The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group having 2 to 13 carbon atoms represent groups in which a carbonyl group or a carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. Examples of the alkylcarbonyl group having 2 to 13 carbon atoms include an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, and a butyryloxy group. 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 further preferably a methyl group or a fluorine atom.

[0012] L 1 represents a single bond, an alkanediyl group having 1 to 6 carbon atoms (provided that the -CH 2 - may be replaced by -O- or -CO-), a group formed by combining an alkanediyl group having 1 to 6 carbon atoms with an alicyclic hydrocarbon group having 3 to 18 carbon atoms (with the proviso that -CH 2 - may be replaced by -O- or -CO-, and -CH contained in the alicyclic hydrocarbon group 2 -, -O-, -S-, -SO 2 - or -CO-) or a group formed by combining an alkanediyl group having 1 to 6 carbon atoms with an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent (provided that the -CH 2- may be replaced by -O- or -CO-), and a single bond, an alkanediyl group having 1 to 4 carbon atoms, or a group formed by combining an alkanediyl group having 1 to 4 carbon atoms with an alicyclic hydrocarbon group having 3 to 18 carbon atoms (with the proviso that -CH 2 - may be replaced by -O- or -CO-, and -CH contained in the alicyclic hydrocarbon group 2 - may be replaced by -O- or -CO-; or a group formed by combining an alkanediyl group having 1 to 4 carbon atoms with an aromatic hydrocarbon group having 6 to 14 carbon atoms which may have a substituent (provided that the -CH 2 - may be replaced by -O- or -CO-.) is more preferable. In this case, examples of the group formed by combining an alkanediyl group with an alicyclic hydrocarbon group or an aromatic hydrocarbon group include *-alkanediyl group-alicyclic hydrocarbon group or aromatic hydrocarbon group-, *-alicyclic hydrocarbon group or aromatic hydrocarbon group-alkanediyl group-, *-alkanediyl group-alicyclic hydrocarbon group or aromatic hydrocarbon group-alkanediyl group-, etc. * is X 1 Represents a bond with . For example, L 1 teeth, * -L 4 -CO-O-(However, L 4 represents a hydrocarbon group having 1 to 22 carbon atoms which may have a substituent, and -CH 2 -, -O-, -S-, -SO 2 In this case, L may be replaced by - or -CO-. 4 represents an alkanediyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that the -CH 2 -, -O-, -S-, -SO 2 - or -CO-), an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, 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 (with the proviso that -CH 2- may be replaced by -O- or -CO-, and -CH contained in the alicyclic hydrocarbon group 2 -, -O-, -S-, -SO 2 - or -CO-) or a group formed by combining an alkanediyl group having 1 to 4 carbon atoms with an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent (with the proviso that the -CH 2 - may be replaced by -O- or -CO-.) is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that the -CH 2 - may be replaced by -O- or -CO-), an aromatic hydrocarbon group having 6 to 14 carbon atoms which may have a substituent, a group formed by combining an alkanediyl group having 1 to 4 carbon atoms with an alicyclic hydrocarbon group having 3 to 18 carbon atoms (with the proviso that -CH 2 - may be replaced by -O- or -CO-, and -CH contained in the alicyclic hydrocarbon group 2 - may be replaced by -O- or -CO-; or a group formed by combining an alkanediyl group having 1 to 4 carbon atoms with an aromatic hydrocarbon group having 6 to 14 carbon atoms which may have a substituent (provided that the -CH 2 - may be replaced by -O- or -CO-.

[0013] L 2 and L 3Examples of the alkanediyl group having 1 to 6 carbon atoms include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and hexane-1,6-diyl groups, and linear alkanediyl groups having an alkyl group (particularly an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, etc.) as a side chain. Specifically, 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, propane-2,3-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, pentane-2,4-diyl group, and 2-methylbutane-1,4-diyl group are included. The number of carbon atoms in the alkanediyl group is preferably 1 to 4, and more preferably 1 to 3. L 2 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 1 to 3 carbon atoms, and further preferably a methylene group. L 3 is preferably a single bond or an alkanediyl group having 1 to 4 carbon atoms, more preferably a single bond, a methylene group or an ethylene group, and even more preferably a single bond or a methylene group. It is preferable that w1 and w2 each independently represent 1 or 2, and it is more preferable that either w1 or w2 represents 1.

[0014] R 3 Examples of the hydrocarbon group in include aliphatic hydrocarbon groups (chain hydrocarbon groups such as alkyl groups, alkenyl groups, and alkynyl groups, and alicyclic hydrocarbon groups), aromatic hydrocarbon groups, and groups formed by combining these. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, a 2-ethylhexyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, and an n-dodecyl group. Examples of the alkenyl group include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, tert-butenyl, pentenyl, hexenyl, heptenyl, octynyl, isooctynyl, and nonenyl groups. Examples of the alkynyl group include an ethynyl group, a propynyl group, an isopropynyl group, a butynyl group, an isobutynyl group, a tert-butynyl group, a pentynyl group, a hexynyl group, an octynyl group, and a nonynyl group. The chain hydrocarbon group preferably has 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, even more preferably 1 to 9 carbon atoms, still more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms. The alicyclic hydrocarbon group may be any of monocyclic, polycyclic and spirocyclic, and may be any of saturated and unsaturated. Examples of the monocyclic alicyclic hydrocarbon group include monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl and cyclododecyl. Examples of the polycyclic alicyclic hydrocarbon group include polycyclic cycloalkyl groups such as decahydronaphthyl, adamantyl and norbornyl. Examples of the alicyclic hydrocarbon group include the following groups: The bond may be at any position. The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 3 to 16 carbon atoms, and further preferably 3 to 12 carbon atoms. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, a biphenyl group, an anthryl group, a phenanthryl group, a binaphthyl group, etc. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and further preferably 6 to 10. In the case of a combination of groups, the above groups may contain groups having different valences (such as an alkanediyl group, an alkanetriyl group, a cycloalkanediyl group, and a cycloalkanetriyl group). Groups formed by combination include groups that combine an aromatic hydrocarbon group with a chain hydrocarbon group (e.g., aromatic hydrocarbon group-alkanediyl group-*, alkyl group-aromatic hydrocarbon group-*), groups that combine an alicyclic hydrocarbon group with a chain hydrocarbon group (e.g., alicyclic hydrocarbon group-alkanediyl group-*, alkyl group-alicyclic hydrocarbon group-*), and groups that combine an aromatic hydrocarbon group with a alicyclic hydrocarbon group (e.g., aromatic hydrocarbon group-alicyclic hydrocarbon group-*, alicyclic hydrocarbon group-aromatic hydrocarbon group-*). * represents a bonding site. The aromatic hydrocarbon group -alkanediyl group-* includes aralkyl groups such as benzyl group and phenethyl group. Examples of the alkyl group-aromatic hydrocarbon group-* include a tolyl group, a xylyl group, and a cumenyl group. Examples of the alicyclic hydrocarbon group -alkanediyl group-* include cycloalkylalkyl groups such as a cyclohexylmethyl group, a cyclohexylethyl group, a 1-(adamantan-1-yl)methyl group, and a 1-(adamantan-1-yl)-1-methylethyl group. Examples of the alkyl group-alicyclic hydrocarbon group-* include cycloalkyl groups having an alkyl group such as a methylcyclohexyl group, a dimethylcyclohexyl group, and a 2-alkyladamantan-2-yl group. Examples of the aromatic hydrocarbon group-alicyclic hydrocarbon group-* include a phenyladamantyl group. Examples of the alicyclic hydrocarbon group-aromatic hydrocarbon group-* include an adamantylphenyl group. In addition, in the combination, two or more of the alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined. 3 may be bound to -CH contained in the hydrocarbon group 2 -, -O-, -S-, -SO 2 When the carbon atom is replaced by - or -CO-, the number of carbon atoms before the replacement is regarded as the total number of carbon atoms in the hydrocarbon group. -CH contained in the hydrocarbon group 2 -, -O-, -S-, -SO 2 The group substituted for - or -CO- is a hydroxy group (-CH 2 - is replaced by -O-), carboxy group (-CH contained in ethyl group) 2 -CH 2 - is replaced by -O-CO-), alkoxy group (-CH 2 - is replaced by -O-), alkoxycarbonyl group (-CH 2 -CH 2 - is replaced by -O-CO-), alkylcarbonyl group (-CH 2 - is replaced by -CO-), alkylcarbonyloxy group (-CH 2 -CH 2 - is replaced by -CO-O-), alkanediyloxy group (-CH at any position in the alkanediyl group) 2 - is replaced by -O-), alkanediyloxycarbonyl group (-CH 2 -CH 2 - is replaced by -O-CO-), alkanediylcarbonyl group (-CH at any position in the alkanediyl group) 2 - is replaced by -CO-), alkanediylcarbonyloxy group (-CH at any position in the alkanediyl group) 2 -CH 2- is replaced by -CO-O-), alkylthio group (-CH 2 Examples of the alkyl group include a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, an aromatic hydrocarbon group-carbonyloxy group, and a combination of two or more of these groups. The alkoxy group includes an alkoxy group having 1 to 17 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, and an undecyloxy group. The alkoxycarbonyl group, alkylcarbonyl group and alkylcarbonyloxy group represent groups in which a carbonyl group or a carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 18 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkanediyloxy group includes an alkanediyloxy group having 1 to 17 carbon atoms, such as a methyleneoxy group, an ethyleneoxy group, a propanediyloxy group, a butanediyloxy group, and a pentanediyloxy group. Examples of the alkanediyloxycarbonyl group include alkanediyloxycarbonyl groups having 2 to 17 carbon atoms, such as methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propanediyloxycarbonyl group, butanediyloxycarbonyl group, etc. Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 18 carbon atoms, such as methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, pentanediylcarbonyl group, etc. Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 17 carbon atoms, such as methylenecarbonyloxy group, ethylenecarbonyloxy group, propanediylcarbonyloxy group, butanediylcarbonyloxy group, etc. The alkylthio group includes an alkylthio group having 1 to 17 carbon atoms, such as a methylthio group, an ethylthio group, and a propylthio group. 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-carbonyloxy group include aromatic hydrocarbon group-carbonyloxy groups having 7 to 17 carbon atoms, such as a benzoyloxy group. In addition, -CH contained in alicyclic hydrocarbon groups 2 - is -O-, -S-, -CO- or -SO 2 Examples of the group substituted with - include the following groups: The bond can be in any position. TIFF0007681957000010.tif47156

[0015] R 3The substituent that the hydrocarbon group may have is, for example, a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms (including the —CH 2 - is -O-, -S-, -CO- or -SO 2 - may be substituted. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group having 1 to 12 carbon atoms include 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 in the alkyl group is preferably 1 to 9, more preferably 1 to 6, and further preferably 1 to 4. As a substituent, -CH contained in an alkyl group 2 - is -O-, -S-, -CO- or -SO 2 When -CH is substituted, the number of carbon atoms before the substitution is the total number of carbon atoms in the alkyl group. 2 - is -O-, -S-, -CO- or -SO 2 The group substituted for - is a hydroxy group (-CH 2 - is replaced by -O-), carboxy group (-CH contained in ethyl group) 2 -CH 2 - is replaced by -O-CO-), alkoxy group (-CH 2 - is replaced by -O-), alkoxycarbonyl group (-CH 2 -CH 2 - is replaced by -O-CO-), alkylcarbonyl group (-CH 2 - is replaced by -CO-), alkylcarbonyloxy group (-CH 2 -CH 2 - is replaced by -CO-O-), alkylthio group (-CH 2 - is replaced with -S-. The alkoxy group includes an alkoxy group having 1 to 11 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, and an undecyloxy group. The alkoxycarbonyl group, alkylcarbonyl group and alkylcarbonyloxy group represent groups in which a carbonyl group or a carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 11 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 12 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 11 carbon atoms, such as an acetyloxy group, a propionyloxy group, and a butyryloxy group. Examples of the alkylthio group include alkylthio groups having 1 to 11 carbon atoms, such as a methylthio group, an ethylthio group, and a propylthio group. R 3 The hydrocarbon group in may have one or more substituents.

[0016] R 3 represents an alkyl group having 1 to 12 carbon atoms which may have a substituent (provided that the —CH 2 - is -O-, -S-, -CO- or -SO 2 -), or a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (provided that the -CH 2 - is -O-, -S-, -CO- or -SO 2 -), and preferably an alkyl group having 1 to 6 carbon atoms, or a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a fluorine atom or a hydroxyl group (with the proviso that the -CH 2- may be replaced by -O-, -S-, -CO- or -SO 2 ) is more preferably the case, and even more preferably an alkyl group having 1 to 6 carbon atoms.

[0017] Examples of the cyclic hydrocarbon group include cyclic hydrocarbon groups such as monocyclic or polycyclic alicyclic hydrocarbon groups having 3 to 18 carbon atoms and aromatic hydrocarbon groups having 6 to 18 carbon atoms, or groups combining these.

[0018] Examples of the alicyclic hydrocarbon group, aromatic hydrocarbon group, and groups combining these are the same as those described above.

[0019] A cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (however, -CH contained in the cyclic hydrocarbon group 2 - may be replaced by -O-, -S-, -CO- or -SO 2 -.) includes A cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a fluorine atom or a hydroxy group (wherein -CH contained in the cyclic hydrocarbon group 2 - may be replaced by -O-, -S-, -CO- or -SO 2 -.) is preferably the case, An alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a fluorine atom or a hydroxy group (wherein -CH contained in the alicyclic hydrocarbon group 2 - may be replaced by -O- or -CO-.), or More preferably, it is an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a fluorine atom or a hydroxy group.

[0020] Examples of the anion (I) include anions represented by the following formulas (Ia-1) to (Ia-32). TIFF0007681957000011.tif193160

[0021] TIFF0007681957000012.tif241155

[0022] Z + Examples of the organic cation include organic onium cation, organic sulfonium cation, organic iodonium cation, organic ammonium cation, benzothiazolium cation, and organic phosphonium cation. Among these, organic sulfonium cation and organic iodonium cation are preferred, and arylsulfonium cation is more preferred. Specific examples include cations represented by any of formulas (b2-1) to (b2-4) (hereinafter, sometimes referred to as "cation (b2-1)" depending on the formula number).

[0023] TIFF0007681957000013.tif46164In equations (b2-1) to (b2-4), R b4 ~R b6 each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, a hydrogen atom contained in the chain hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, 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 -CH 2 - may be replaced by -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 an integer of 0 to 5. When m2 is 2 or more, multiple R b7may be the same or different, and when n2 is 2 or more, a plurality of R b8 may be the same or different. R b9 and R b10 each independently represents a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms. R b9 and R b10 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and the -CH 2 - in the ring may be replaced by -O-, -S- or -CO-. R b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the chain hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 may be bonded to each other to form a ring including -CH-CO- to which they are bonded, and the -CH 2 - in the ring may be replaced by -O-, -S- or -CO-. R b13 ~R b18 each independently represents a hydroxy group, an aliphatic hydrocarbon 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, a plurality of R b13are the same or different, and when p2 is 2 or more, multiple R b14 are the same or different, and when q2 is 2 or more, multiple R b15 are the same or different, and when r2 is 2 or more, multiple R b16 are the same or different, and when s2 is 2 or more, multiple R b17 are the same or different, and when t2 is 2 or more, multiple R b18 are the same or different.

[0024] The aliphatic hydrocarbon group refers to a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl. In particular, R b9 ~R b12 The chain hydrocarbon group preferably has 1 to 12 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups: TIFF0007681957000014.tif10158 In particular, R b9 ~R b12 The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, and more preferably has 4 to 12 carbon atoms.

[0025] Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group, a 2-ethyladamantan-2-yl group, a 2-isopropyladamantan-2-yl group, a methylnorbornyl group, an isobornyl group, etc. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms in the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.

[0026] Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a biphenyl group, a naphthyl group, and a phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples thereof include aromatic hydrocarbon groups having a chain hydrocarbon group (such as a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group) and aromatic hydrocarbon groups having an alicyclic hydrocarbon group (such as a p-cyclohexylphenyl group and a p-adamantylphenyl group). When the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms are preferred. An example of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group is a p-methoxyphenyl group. Examples of the chain hydrocarbon group in which a hydrogen atom has been substituted with an aromatic hydrocarbon group include aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.

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

[0028] R b4 and R b5 The ring formed by R and R bonding to each other together with the sulfur atom to which they are bonded may be any of 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. For example, the following rings can be mentioned. * represents a bond. TIFF0007681957000015.tif23143

[0029] R b9 and R b10 The ring formed by R and R together 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. For example, a thiolan-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, a 1,4-oxathian-4-ium ring, etc. can be mentioned. R b11 and R b12 The ring formed by R and R together 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 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, an oxoadamantane ring, etc.

[0030] Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferred. Examples of the cation (b2-1) include the following cations. TIFF0007681957000016.tif80158

[0031] TIFF0007681957000017.tif73143 TIFF0007681957000018.tif2780

[0032] Examples of the cation (b2-2) include the following cations. TIFF0007681957000019.tif18150

[0033] Examples of the cation (b2-3) include the following cations. TIFF0007681957000020.tif26140

[0034] Examples of the cation (b2-4) include the following cations. TIFF0007681957000021.tif82164

[0035] The salt (I) is a combination of the above-mentioned anion and the above-mentioned organic cation, which can be arbitrarily combined. The salt (I) is preferably a combination of an anion represented by any one of formulas (Ia-1), (Ia-2), (Ia-6) to (Ia-9), (Ia-14), (Ia-15), and (Ia-17) to (Ia-24) and a cation (b2-1), (b2-2), or (b2-3).

[0036] Examples of the salt (I) include salts shown in Table 1. In the table below, each symbol represents the symbol attached to the structure representing the above-mentioned anion and cation. For example, salt (I-1) means a salt consisting of an anion represented by formula (Ia-1) and a cation represented by formula (b2-c-1), and represents the salt shown below. TIFF0007681957000022.tif3187 [Table 1] TIFF0007681957000024.tif223154 TIFF0007681957000025.tif223154 TIFF0007681957000026.tif223154 TIFF0007681957000027.tif223154 TIFF0007681957000028.tif135152 Among them, salt (I) includes salt (I-1), salt (I-2), salt (I-6) to salt (I-9), salt (I-14), salt (I-15), salt (I-17) to salt (I-24), salt (I-25), salt (I-26), salt (I-30) to salt (I-33), salt (I-38), salt (I-39), salt (I-41) to salt (I-48), salt (I-49), salt (I-50), salt (I-54) to salt (I-57), salt (I-62), salt (I-63), salt (I-65) to salt (I-72), salt (I-73), salt (I-74), salt (I-78) to salt (I-81), salt (I-86), salt ( I-87), salt (I-89) to salt (I-96), salt (I-97), salt (I-98), salt (I-102) to salt (I-105), salt (I-110), salt (I-111), salt (I-113) to salt (I-120), salt (I-121), salt (I-122), salt (I-126) to salt (I-129), salt (I-134), salt (I-135), salt (I-137) to salt (I-144), salt (I-145), salt (I-146), salt (I-150) to salt (I-153), salt (I-158), salt (I-159), salt (I-161) to salt (I-168) are preferred.

[0037] <Method for producing salt (I)> In the salt (I), X 1 The salt in which * is --CO-O- (salt represented by formula (I1)) can be produced, for example, by reacting a salt represented by formula (I1-a) with carbonyldiimidazole in a solvent, and then reacting the resulting mixture with a compound represented by formula (I1-b). TIFF0007681957000029.tif54167 (wherein all symbols have the same meanings as defined above.) Solvents for this reaction include chloroform, acetonitrile, and the like. The reaction temperature is usually 5° C. to 80° C., and the reaction time is usually 0.5 hours to 24 hours.

[0038] Examples of the salt represented by formula (I1-a) include the salts represented by the following formulas, and can be produced by the method described in JP-A-2008-127367. TIFF0007681957000030.tif33137 Examples of the compound represented by formula (I1-b) include salts represented by the following formula, which are readily available on the market and can be easily produced by known methods. TIFF0007681957000031.tif26160

[0039] In the salt (I), X 1 The salt in which * is --O--CO--O-- (salt represented by formula (I2)) can be produced, for example, by reacting a salt represented by formula (I2-a) with carbonyldiimidazole in a solvent, and then reacting the resulting mixture with a compound represented by formula (I1-b). In addition, the salt represented by formula (I2) can also be produced, for example, by reacting a compound represented by formula (I1-b) with carbonyldiimidazole in a solvent, and then further reacting the resulting mixture with a salt represented by formula (I2-a). TIFF0007681957000032.tif87160 (wherein all symbols have the same meanings as above.) Solvents for this reaction include chloroform, acetonitrile, and the like. The reaction temperature is usually 5° C. to 80° C., and the reaction time is usually 0.5 hours to 24 hours. Examples of the salt represented by formula (I2-a) include the salts represented by the following formulas, and can be produced by the method described in JP-A-2012-193170. TIFF0007681957000033.tif34139

[0040] In the salt (I), X 1 The salt in which * is --O--CO- (salt represented by formula (I3)) can be produced, for example, by reacting a compound represented by formula (I3-b) with carbonyldiimidazole in a solvent, and then further reacting it with a salt represented by formula (I2-a). TIFF0007681957000034.tif46156 (wherein all symbols have the same meanings as defined above.) Solvents for this reaction include chloroform, acetonitrile, and the like. The reaction temperature is usually 5° C. to 80° C., and the reaction time is usually 0.5 hours to 24 hours. Examples of the compound represented by formula (I3-b) include the compounds represented by the following formula, and are readily available on the market. TIFF0007681957000035.tif22108

[0041] In the salt (I), X 1 The salt in which is -O- (salt represented by formula (I4)) can be obtained by reacting a salt represented by formula (I2-a) with a compound represented by formula (I1-b) in a solvent in the presence of a base. TIFF0007681957000036.tif38155 (wherein all symbols have the same meanings as defined above.) The base in this reaction includes potassium hydroxide and the like. The solvent for this reaction may be acetonitrile or the like. The reaction temperature is usually 5° C. to 80° C., and the reaction time is usually 0.5 hours to 24 hours.

[0042] In the salt (I), L 1 is a group formed by combining an alkanediyl group having 1 to 4 carbon atoms with an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that the -CH 2- may be replaced by -O- or -CO-, and -CH contained in the alicyclic hydrocarbon group 2 -, -O-, -S-, -SO 2 The salt represented by the formula (I1) to (I4) may be prepared by replacing the salt represented by the formula (I1-a) or the salt represented by the formula (I2-a) with the salt represented by the following formula (I1-a) or (I2-a) in the synthesis of the salts represented by the formula (I1) to (I4). TIFF0007681957000037.tif250131

[0043] <Acid generator> The acid generator of the present invention is an acid generator containing a salt (I). It may contain one type of salt (I) or may contain two or more types of salt (I). The acid generator of the present invention may contain, in addition to the salt (I), 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.

[0044] The acid generator (B) may be either nonionic or ionic. Examples of nonionic acid generators include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane), etc. Examples of ionic acid generators include onium salts containing onium cations (e.g., diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). Examples of anions of onium salts include sulfonate anion, sulfonylimide anion, sulfonylmethide anion, etc.

[0045] As the acid generator (B), compounds that generate acid by radiation, such as those described in JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent No. 3914407, and European Patent No. 126,712, can be used. Compounds produced by known methods can also be used. Two or more types of acid generators (B) can be used in combination.

[0046] The acid generator (B) is preferably a fluorine-containing acid generator, and more preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)", excluding salt (I)). TIFF0007681957000038.tif2861[In formula (B1), Q b1 and Q b2 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and the -CH 2 - may be replaced by -O- or -CO-, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted by a fluorine atom or a hydroxy group. Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, and -CH 2 - is -O-, -S(O) 2 It may be replaced by - or -CO-. Z1 + represents an organic cation.

[0047] Q b1 and Q b2Examples of the perfluoroalkyl group represented by the formula (I) include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Q b1 and Q b2 and are preferably each independently a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

[0048] L b1 Examples of the divalent saturated hydrocarbon group in include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and may be a group formed by combining two or more of these groups. Specific examples of such straight-chain alkanediyl groups include methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, and heptadecane-1,17-diyl groups; branched alkanediyl groups such as ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; monocyclic divalent alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; Examples of the polycyclic divalent alicyclic saturated hydrocarbon groups include norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.

[0049] L b1 -CH contained in a divalent saturated hydrocarbon group represented by 2 Examples of the group in which - is replaced by -O- or -CO- include groups represented by any of the groups represented by formulae (b1-1) to (b1-3). In the groups represented by formulae (b1-1) to (b1-3) and specific examples thereof, formulae (b1-4) to (b1-11), * and ** represent bonds, and * represents a bond to -Y.

[0050] TIFF0007681957000039.tif26118[In formula (b1-1), L b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, and -CH 2 - may be replaced by -O- or -CO-. However, L b2 and L b3 The total number of carbon atoms 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 a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, and -CH 2 - may be replaced by -O- or -CO-. However, L b4 and L b5 The total number of carbon atoms 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 a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. L b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, and -CH 2 - may be replaced by -O- or -CO-. However, L b6 and L b7 The total number of carbon atoms is 23 or less. * and ** represent bonds, and * represents a bond to Y.]

[0051] In the groups represented by formulae (b1-1) to (b1-3), —CH 2 When - is replaced with -O- or -CO-, the number of carbon atoms before the replacement is regarded as the number of carbon atoms of the saturated hydrocarbon group. As the divalent saturated hydrocarbon group, L b1 The divalent saturated hydrocarbon group may be the same as that of the above. 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. Lb7 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 hydroxyl group, and -CH contained in the divalent saturated hydrocarbon group is 2 - may be replaced by -O- or -CO-.

[0052] L b1 -CH contained in a divalent saturated hydrocarbon group represented by 2 The group in which - is replaced by -O- or -CO- is preferably a group represented by formula (b1-1) or formula (b1-3). Examples of the group represented by formula (b1-1) include the groups represented by formulas (b1-4) to (b1-8). TIFF0007681957000040.tif49120[In formula (b1-4), L b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. In formula (b1-5), L b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the -CH 2 - may be replaced by -O- or -CO-. L b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b9 and L b10 The total number of carbon atoms 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 a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b11and L b12 The total number of carbon atoms 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 the -CH 2 - may be replaced by -O- or -CO-. L b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b13 ~L b15 The total number of carbon atoms is 19 or less. In formula (b1-8), L b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the -CH 2 - 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 with a fluorine atom or a hydroxy group. However, L b16 ~L b18 The total number of carbon atoms is 19 or less. * and ** represent bonds, and * represents a bond to Y.] L b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b11is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

[0053] Examples of the group represented by formula (b1-3) include the groups represented by formulas (b1-9) to (b1-11). TIFF0007681957000041.tif23140[In 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 hydroxyl group, or an alkylcarbonyloxy group. 2 - may be replaced by -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be replaced by a hydroxy group. However, L b19 and L b20The total number of carbon atoms is 23 or less. In formula (b1-10), L b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and 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 hydroxyl group, or an alkylcarbonyloxy group. 2 - may be replaced by -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be replaced by a hydroxy group. However, L b21 , L b22 and L b23 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 a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group, or an alkylcarbonyloxy group. 2 - may be replaced by -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be replaced by a hydroxy group. However, L b24 , L b25 and L b26 The total number of carbon atoms is 21 or less. * and ** represent bonds, and * represents a bond to Y.]

[0054] In the group represented by the formula (b1-9) to the group represented by the formula (b1-11), when a hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the number of carbon atoms before substitution is defined 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 the formula (b1-4) include the following. TIFF0007681957000042.tif16150 (* and ** represent a bond, and * represents a bond to Y.)

[0056] Examples of the group represented by the formula (b1-5) include the following. TIFF0007681957000043.tif72148 (* and ** represent a bond, and * represents a bond to Y.)

[0057] Examples of the group represented by the formula (b1-6) include the following. TIFF0007681957000044.tif29150 (* and ** represent a bond, and * represents a bond to Y.)

[0058] Examples of the group represented by the formula (b1-7) include the following. TIFF0007681957000045.tif64150 (* and ** represent a bond, and * represents a bond to Y.)

[0059] Examples of the group represented by the formula (b1-8) include the following. TIFF0007681957000046.tif23150 (* and ** represent a bond, and * represents a bond to Y.)

[0060] Examples of the group represented by the formula (b1-2) include the following. TIFF0007681957000047.tif31161 (* and ** represent bonds, * represents a bond to Y.)

[0061] Examples of the group represented by formula (b1-9) include the following. TIFF0007681957000048.tif44137 (* and ** represent bonds, * represents a bond to Y.)

[0062] Examples of the group represented by formula (b1-10) include the following. TIFF0007681957000049.tif89157 (* and ** represent bonds, * represents a bond to Y.)

[0063] Examples of the group represented by formula (b1-11) include the following. TIFF0007681957000050.tif82158 (* and ** represent bonds, * represents a bond to Y.)

[0064] Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulae (Y1) to (Y11) and (Y36) to (Y38). -CH contained in the alicyclic hydrocarbon group represented by Y 2 - is -O-, -S(O) 2 When it is replaced by - or -CO-, the number may be 1 or 2 or more. Examples of such a group include groups represented by formulae (Y12) to (Y35) and formulae (Y39) to (Y43). * is L b1 Represents a bond with . The alicyclic hydrocarbon group represented by Y is preferably a group represented by any one of formulas (Y1) to (Y20), (Y26), (Y27), (Y30), (Y31), (Y39) to (Y43), and more preferably a group represented by formulas (Y11), (Y15), (Y16), (Y20), (Y22), (Y23), (Y24), (Y25), (Y26), (Y27), (Y30), (Y31), (Y39), (Y32), (Y33), (Y34), (Y35), (Y36), (Y37), (Y38), (Y39), (Y40), (Y41), (Y42), (Y43), (Y44), (Y45), (Y46), (Y47), (Y48), (Y49), (Y50), (Y51), (Y52), (Y53), (Y54), (Y55), (Y56), (Y57), (Y58), (Y59), (Y60), (Y61), (Y62), (Y63), (Y64), (Y65), (Y66), (Y67), (Y68), (Y69), (Y70), (Y71), (Y72), (Y73), (Y74), (Y75), (Y76), (Y77), (Y78), (Y79), (Y80), (Y81), (Y82), (Y83), (Y84), (Y85), (Y86), (Y87), (Y88), (Y89), (Y90), (Y91), (Y92), (Y93), (Y94), (Y95), (Y96), (Y97), (Y98), (Y99), (Y100), (Y101), (102), (103), (104), (105), (106 and more preferably 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). When the alicyclic hydrocarbon group represented by Y is a spiro ring having an oxygen atom such as those of formulae (Y28) to (Y35), (Y39) to (Y40), (Y42) or (Y43), the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. In addition, 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] The substituent of the methyl group represented by Y is a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, -(CH 2 ) ja -CO-OR b1 Group or -(CH 2 ) ja -O-CO-R b1 group (in the formula, 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 combination thereof, and -CH contained in the alkyl group and the alicyclic hydrocarbon group 2 -, -O-, -SO 2 - 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. ja represents an integer of 0 to 4.) 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 (in the alkyl group, -CH 2 - 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, -(CH 2 ) ja -CO-O-R b1 group or -(CH 2 ) 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, and -CH 2 - contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO 2 - 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. ja represents any integer from 0 to 4.).

[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, such as 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 a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples thereof include aromatic hydrocarbon groups having a chain hydrocarbon group with 1 to 18 carbon atoms (tolyl group, xylyl group, cumenyl group, mesityl group, p-methylphenyl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and aromatic hydrocarbon groups having an alicyclic hydrocarbon group with 3 to 18 carbon atoms (p-adamantylphenyl group, p-cyclohexylphenyl group, etc.). The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 14, and more preferably 6 to 10. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 4. Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. -CH in the alkyl group 2 - is -O-, -S(O) 2 Examples of the group substituted with - or -CO- include an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, or a combination thereof. 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. The number of carbon atoms in the alkoxy group is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 4. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group and the like. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group and the like. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group and the like. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the combined group include a group combining an alkoxy group and an alkyl group, a group combining an alkoxy group and an alkoxy group, a group combining an alkoxy group and an alkylcarbonyl group, a group combining an alkoxy group and an alkylcarbonyloxy group and the like. Examples of the group combining an alkoxy group and an alkyl group include an alkoxyalkyl group such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, an ethoxymethyl group and the like. The number of carbon atoms of the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the group combining an alkoxy group and an alkoxy group include an alkoxyalkoxy group such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group and the like. The number of carbon atoms of the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the group combining an alkoxy group and an alkylcarbonyl group include an alkoxyalkylcarbonyl group such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group, an ethoxypropionyl group and the like. The number of carbon atoms of the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and still more preferably 3 to 5. Examples of the group combining an alkoxy group and an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as methoxyacetyloxy group, methoxypropionyloxy group, ethoxyacetyloxy group, ethoxypropionyloxy group, etc. The number of carbon atoms of the alkoxyalkylcarbonyloxy group is preferably 3 to 13, more preferably 3 to 7, and still more preferably 3 to 5. -CH 2 - in the alicyclic hydrocarbon group replaced by -O-, -S(O) 2 - or -CO- etc. include groups represented by formula (Y12) to formula (Y35), formula (Y39) to formula (Y43), etc.

[0067] Examples of Y include the following. TIFF0007681957000052.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. -CH 2 - constituting the alicyclic hydrocarbon group or adamantyl group may be replaced by -CO-, -S(O) 2 - 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), and formula (B1-A-47) to formula (B1-A-59) is more preferable.

[0070] TIFF0007681957000053.tif143153

[0071] TIFF0007681957000054.tif66157

[0072] TIFF0007681957000055.tif100158

[0073] TIFF0007681957000056.tif121153

[0074] TIFF0007681957000057.tif50144

[0075] TIFF0007681957000058.tif183167

[0076] Here, R i2 ~R i7 are, independently of each other, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R i8 is, for example, 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.

[0077] Preferable anions in the salt represented by formula (B1) include the anions represented by formulas (B1a-1) to (B1a-38). TIFF0007681957000059.tif125153

[0078] TIFF0007681957000060.tif92138

[0079] TIFF0007681957000061.tif137155

[0080] TIFF0007681957000062.tif33149

[0081] Among these, anions represented by any one of Formulae (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38) are preferred.

[0082] Z1 + Examples of the organic cation include an organic onium cation, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferred, and an arylsulfonium cation is more preferred. The arylsulfonium cation is represented by the formula (I) Z + The cations are the same as those in the above.

[0083] The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, which can be combined arbitrarily. The acid generator (B) is preferably a combination of an anion represented by any one of formulas (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38) and a cation (b2-1) or a cation (b2-3).

[0084] The acid generator (B) is preferably any of those represented by formulas (B1-1) to (B1-56). Of these, those containing an arylsulfonium cation are preferred, and those represented by formulas (B1-1) to (B1-3), (B1-5) to (B1-7), (B1-11) to (B1-14), (B1-20) to (B1-26), (B1-29), and (B1-31) to (B1-56) are particularly preferred. TIFF0007681957000063.tif61150

[0085] TIFF0007681957000064.tif72163

[0086] TIFF0007681957000065.tif79150

[0087] TIFF0007681957000066.tif64150

[0088] TIFF0007681957000067.tif87145

[0089] TIFF0007681957000068.tif62153

[0090] TIFF0007681957000069.tif66163

[0091] TIFF0007681957000070.tif92158

[0092] When the acid generator contains a salt (I) and an acid generator (B), the content ratio of the salt (I) to the acid generator (B) (mass ratio; salt (I):acid generator (B)) is usually 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, still more preferably 10:90 to 90:10, and particularly preferably 15:85 to 85:15. In the resist composition of the present invention, the total content of the acid generators 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, and even more preferably 3 parts by mass or more and 35 parts by mass or less, relative to 100 parts by mass of the resin (A) described below.

[0093] <Resist Composition> The resist composition of the present invention contains an acid generator containing a salt (I) and a resin having an acid labile group (hereinafter sometimes referred to as "resin (A)"). Here, the "acid labile group" refers to a group that has a leaving group and that is eliminated by contact with an acid, converting the structural unit into a structural unit having a hydrophilic group (e.g., a hydroxyl group or a carboxyl group). The resist composition of the present invention preferably contains a quencher such as a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (hereinafter may be referred to as "quencher (C)"), and preferably contains a solvent (hereinafter may be referred to as "solvent (E)").

[0094] <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 the structural unit (a1). Examples of structural units other than the structural unit (a1) include a structural unit not having an acid labile group (hereinafter, sometimes referred to as "structural unit (s)"), structural units other than the structural unit (a1) and the structural unit (s) (for example, a structural unit having a halogen atom (hereinafter, sometimes referred to as "structural unit (a4)") described below, a structural unit having a non-leaving hydrocarbon group (hereinafter, sometimes referred to as "structural unit (a5)") described below, and other structural units derived from monomers known in the art.

[0095] <Structural unit (a1)> The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid labile group contained in the resin (A) is 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)). TIFF0007681957000071.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 combination thereof, or R a1 and R a2 are bonded to each other to form, together with the carbon atom to which they are bonded, a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * denotes a binding site.] TIFF0007681957000072.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 heterocyclic ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and the —CH 2 - 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.]

[0096] R a1 , R a2 and R a3Examples 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. TIFF0007681957000073.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 in which the above-mentioned alkyl group and an alicyclic hydrocarbon group are combined (for example, an alkylcycloalkyl group or a cycloalkylalkyl group such as a methylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, or a norbornylethyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, or the like), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (a p-cyclohexylphenyl group, a p-adamantylphenyl group, or the like), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. Preferably, ma is 0 and na is 1. R a1 and R a2 When they are bonded to each other to form a non-aromatic hydrocarbon ring, -C(R a1 )(R a2 )(R a3 ) includes the following rings. The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * represents the bonding site with -O-. TIFF0007681957000074.tif30138

[0097] R a1’ , R a2’ and R a3’ Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. The alkyl group and the alicyclic hydrocarbon group are R a1 , R a2 and R a3 Examples of the groups include the same groups as those listed in the 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 in which the above-mentioned alkyl group and an alicyclic hydrocarbon group are combined (for example, an alkylcycloalkyl group or a cycloalkylalkyl group such as a methylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, or a norbornylethyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, or the like), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (a p-cyclohexylphenyl group, a p-adamantylphenyl group, or the like), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. R a2’ and R a3’ When they are bonded to each other to form a heterocycle together with the carbon atom to which they are attached and X, -C(R a1’ )(R a2’ )-XR a3’ Examples of the ring include the following: * represents a binding site. TIFF0007681957000075.tif18130R a1’ and R a2’ At least one of these is preferably a hydrogen atom. na' is preferably 0.

[0098] Examples of the group (1) include the following groups. In formula (1), R a1 , R a2 and R a3 is an alkyl group, ma = 0, and na = 1. As the group, a tert-butoxycarbonyl group is preferable. In formula (1), R a1 , R a2 together with the carbon atom to which they are attached form an adamantyl group, R a3 is an alkyl group, ma=0, and na=1. In formula (1), R a1 and R a2are each independently an alkyl group; R a3 is an adamantyl group, ma=0, and na=1. Specific examples of the group (1) include the following groups: * represents a binding site. TIFF0007681957000076.tif171163

[0099] Specific examples of the group (2) include the following groups: * represents a bonding site. TIFF0007681957000077.tif68162

[0100] 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.

[0101] Of the (meth)acrylic monomers having an acid labile group, preferred are those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms. By using a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group in a resist composition, the resolution of the resist pattern can be improved.

[0102] Examples of the structural unit derived from the (meth)acrylic monomer having the group (1) include a structural unit represented by formula (a1-0) (hereinafter, sometimes referred to as structural unit (a1-0)), a structural unit represented by formula (a1-1) (hereinafter, sometimes referred to as structural unit (a1-1)), or a structural unit represented by formula (a1-2) (hereinafter, sometimes referred to as structural unit (a1-2)). Preferably, 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. TIFF0007681957000078.tif44144 [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 , L a1 and L a2are each independently -O- or *-O-(CH 2 ) 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 or a methyl group. 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.

[0103] R a01 , R a4 and R a5 is preferably a methyl group. L a01 , L a1 and L a2 is preferably an oxygen atom or -O-(CH 2 ) k01 It is -CO-O- (wherein k01 is preferably an integer of any one of 1 to 4, more preferably 1), and more preferably an oxygen atom. R a02 , R a03 , R a04 , R a6 and R a7 The alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group and combinations thereof in the formula (1) are R a1 , R a2 and R a3Examples of the groups include the same groups as those listed in the above. R a02 , R a03 , and R a04 The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a6 and R a7 The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, or a t-butyl group, and even more preferably an ethyl group, an isopropyl group, or a t-butyl group. R a6 and R a7 The alkenyl group in the formula (I) is preferably an alkenyl group having 2 to 6 carbon atoms, and more preferably an ethenyl group, a propenyl group, an isopropenyl group, or a butenyl group. R a02 , R a03 , R a04 , R a6 and R a7 The alicyclic hydrocarbon group preferably has 5 to 12 carbon atoms, and more preferably 5 to 10 carbon atoms. R a02 , R a03 , R a04 , R a6 and R a7 The aromatic hydrocarbon group preferably has 6 to 12 carbon atoms, and more preferably 6 to 10 carbon atoms. In the group in which an alkyl group and an alicyclic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the alicyclic hydrocarbon group is preferably 18 or less. In the group in which an alkyl group and an aromatic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the aromatic hydrocarbon group is preferably 18 or less. R a02 and R a03 is preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group. R a04is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. R a6 and R a7 are 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, and further preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, or a phenyl group. m1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1' is preferably 0 or 1.

[0104] Examples of the structural unit (a1-0) include a structural unit represented by any one of formulas (a1-0-1) to (a1-0-18) and R a01 and structural units in which a methyl group corresponding to the formula (a1-0-1) is replaced with a hydrogen atom, and structural units represented by any one of formulas (a1-0-1) to (a1-0-10), (a1-0-13) and (a1-0-14) are preferred. TIFF0007681957000079.tif98166

[0105] Examples of the structural unit (a1-1) include structural units derived from monomers described in JP 2010-204646 A. Among them, structural units represented by any one of formulas (a1-1-1) to (a1-1-7) and R in the structural unit (a1-1) are a4 In the above formula (a1-1-1), a structural unit in which a methyl group is replaced with a hydrogen atom is preferred, and a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) is more preferred. TIFF0007681957000080.tif40166

[0106] Examples of the structural unit (a1-2) include a structural unit represented by any of formula (a1-2-1) to formula (a1-2-12) and a structural unit in which the methyl group corresponding to R in the structural unit (a1-2) is replaced with a hydrogen atom. Among them, the structural units represented by any of formula (a1-2-2), formula (a1-2-5), formula (a1-2-6), and formula (a1-2-10) to formula (a1-2-12) are preferred. a5 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). TIFF0007681957000081.tif75155

[0107] 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).

[0108] Examples of the structural unit having the group (2) in the structural unit (a1) include a structural unit represented by formula (a1-4) (hereinafter sometimes referred to as "structural unit (a1-4)"). TIFF0007681957000082.tif4462[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 * -Xa31 -(A a32 -X a32 ) nc - stands for -R. a32 represents the bonding site with the carbon atom to which it is bonded. A a32 represents an alkanediyl group having 1 to 6 carbon atoms. X a31 and X a32 each independently represents -O-, -CO-O-, or -O-CO-. nc represents 0 or 1. la represents an integer of 0 to 4. When la is an integer of 2 or more, a plurality of R a33 may be the same or different from each other. R a34 and R a35 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -CO- to which they are bonded, and the -CH 2 - may be replaced by -O- or -S-.

[0109] R a32 and R a33 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and a bromine atom. R a32 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) 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. Ra32 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and further preferably a hydrogen atom or a methyl group. R a33 Examples of the alkyl group in 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. R a33 Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group. R a33 Examples of the alkoxyalkyl group in the formula (I) include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and further preferably a methoxymethyl group. R a33 In the above, examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R a33 Examples of the alkylcarbonyl group in include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a33In the above formula, examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R 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 further preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0110] *-X a31 -(A a32 -X a32 ) nc - includes *-O-, *-CO-O-, *-O-CO-, *-CO-OA a32 -CO-O-, *-O-CO-A a32 -O-, *-OA a32 -CO-O-, *-CO-OA a32 -O-CO-, *-O-CO-A a32 -O-CO-, and *-CO-O- and *-CO-OA are particularly well known. a32 -CO-O- or *-OA a32 -CO-O- is preferred.

[0111] A a32 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a32 is preferably a methylene group or an ethylene group.

[0112] Aa30 is a single bond, *-CO-O- or *-CO-O-A a32 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH 2 -CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[0113] 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, etc. 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, etc. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents the bonding site), etc. TIFF0007681957000083.tif10151 Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, a phenanthryl group, etc. Examples of the combined group include a group combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, a cycloalkylalkyl 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.), an aryl-cycloalkyl group such as a phenylcyclohexyl group, etc. In particular, R a36Examples of the alkyl group include an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these groups.

[0114] R a34 is preferably a hydrogen atom. R a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a methyl group or an ethyl group. R a36 The hydrocarbon group in R is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. a36 The alkyl group and the alicyclic hydrocarbon group in R are preferably unsubstituted. a36 The aromatic hydrocarbon group in is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms. -OC(R a34 )(R a35 )-OR a36 is 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.

[0115] Examples of the structural unit (a1-4) include structural units derived from monomers described in JP-A-2010-204646. Preferably, the structural units represented by the formulas (a1-4-1) to (a1-4-18) and R a32and 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. TIFF0007681957000084.tif102168

[0116] 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).

[0117] 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)"). TIFF0007681957000085.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 *-(CH 2 ) h3 -CO-L 54 -, h3 represents an integer of 1 to 4, * represents L 51 It represents the binding site with L 51 , L 52 , L 53 and L 54 each independently represents -O- or -S-. s1 represents an integer of 1 to 3. s1' represents an integer of 0 to 3.

[0118] Examples of the halogen atom include a fluorine atom and a chlorine atom, with a fluorine atom being preferred. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group, and a trifluoromethyl group. In formula (a1-5), R a8 is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group. L 51 is preferably an oxygen atom. L 52 and L 53 Of these, it is preferred that one is -O- and the other is -S-. It is preferable that s1 is 1. s1' is preferably an integer of 0 to 2. Z a1 is a single bond or -CH 2 -CO-O- is preferred.

[0119] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP 2010-61117 A. Among them, the structural units represented by formulae (a1-5-1) to (a1-5-4) are preferred, and the structural unit represented by formula (a1-5-1) or (a1-5-2) is more preferred. TIFF0007681957000086.tif33133

[0120] When the resin (A) contains the structural unit (a1-5), the content thereof is preferably 1 to 50 mol %, more preferably 3 to 45 mol %, even more preferably 5 to 40 mol %, and still more preferably 5 to 30 mol %, based on all structural units in the resin (A).

[0121] Further, examples of the structural unit (a1) include the following structural units. TIFF0007681957000087.tif31162

[0122] When the resin (A) contains structural units such as the above (a1-3-1) to (a1-3-7), the 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).

[0123] In addition, examples of the structural unit (a1) also include the following structural units. TIFF0007681957000088.tif5295 When the resin (A) contains structural units such as the above (a1-6-1) to (a1-6-3), the 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).

[0124] 〈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. The structural unit (s) preferably has a hydroxy group or a lactone ring. By using a resin having a structural unit having a hydroxy group and no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit having a lactone ring and no acid-labile group (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

[0125] 〈Structural unit (a2)〉 The hydroxy group of the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group. When a resist pattern is produced from the resist composition of the present invention, when a high energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) is used as an exposure light source, the structural unit (a2) having a phenolic hydroxyl group is preferable, and the structural unit (a2-A) described below is more preferable. When an ArF excimer laser (193 nm) or the like is used, the structural unit (a2) having an alcoholic hydroxyl group is preferable, and the structural unit (a2-1) described below is more preferable. The structural unit (a2) may contain one type alone or two or more types.

[0126] In the structural unit (a2), an example of a structural unit having a phenolic hydroxy group is a structural unit represented by formula (a2-A) (hereinafter, may be referred to as "structural unit (a2-A)"). TIFF0007681957000089.tif4551[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 is a single bond or *-X a51 -(A a52 -X a52 ) nb - stands for -R. a50 represents the bond position with respect to the carbon atom to which it 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 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different.]

[0127] R a50 and R a51 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and a bromine atom. R a50 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) 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 a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and further preferably a hydrogen atom or a methyl group. R a51 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group. R a51 Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, 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 further preferably a methoxy group. R a51Examples of the alkoxyalkyl group in the formula (I) include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and further preferably a methoxymethyl group. R a51 In the above, examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R a51 Examples of the alkylcarbonyl group in include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a51 In the above formula, examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R 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 further preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0128] *-X a51 -(A a52 -X a52 ) nb- includes *-O-, *-CO-O-, *-O-CO-, *-CO-OA a52 -CO-O-, *-O-CO-A a52 -O-, *-OA a52 -CO-O-, *-CO-OA a52 -O-CO-, *-O-CO-A a52 -O-CO-, and *-CO-O- and *-CO-OA are particularly well known. a52 -CO-O- or *-OA a52 -CO-O- is preferred.

[0129] A a52 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a52 is preferably a methylene group or an ethylene group.

[0130] A a50 is a single bond, *-CO-O- or *-CO-OA a52 -CO-O- is preferred, and a single bond, *-CO-O- or *-CO-O-CH 2 It is more preferably -CO-O-, and further preferably a single bond or *-CO-O-.

[0131] 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.

[0132] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577.

[0133] 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), and in these structural units, R in the structural unit (a2-A) can be exemplified. a50 It is preferable that the structural unit is a structural unit in which a methyl group corresponding to the following formula is replaced with a hydrogen atom. TIFF0007681957000090.tif63169

[0134] When the structural unit (a2-A) is contained in the resin (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 still more preferably 20 to 65 mol %, based on all structural units. The structural unit (a2-A) can be incorporated into the resin (A) by, for example, polymerizing the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Alternatively, the structural unit (a2-A) can be incorporated into the resin (A) by polymerizing the structural unit (a1-4) and then treating with an alkali such as tetramethylammonium hydroxide.

[0135] An example of the structural unit (a2) having an alcoholic hydroxy group is a structural unit represented by formula (a2-1) (hereinafter sometimes referred to as "structural unit (a2-1)"). TIFF0007681957000091.tif4359 formula (a2-1), L a3 is -O- or *-O-(CH 2 ) k2 represents -CO-O-, k2 represents an integer of any one of 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 represents a hydrogen atom, a methyl group, or a hydroxy group. o1 represents an integer of 0 to 10.

[0136] In formula (a2-1), L a3 is preferably -O-, -O-(CH 2 ) f1 It is -CO-O- (wherein f1 represents an integer of 1 to 4), and more preferably -O-. R a14 is preferably a methyl group. R a15 is preferably a hydrogen atom. R a16 is preferably a hydrogen atom or a hydroxy group. o1 is preferably an integer of 0 to 3, and more preferably 0 or 1.

[0137] Examples of the structural unit (a2-1) include structural units derived from monomers described in JP 2010-204646 A. A structural unit represented by any one of formulas (a2-1-1) to (a2-1-6) is preferred, a structural unit represented by any one of formulas (a2-1-1) to (a2-1-4) is more preferred, and a structural unit represented by formula (a2-1-1) or formula (a2-1-3) is even more preferred. TIFF0007681957000092.tif50140

[0138] When the resin (A) contains the structural unit (a2-1), the content thereof 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 still more preferably 1 to 10 mol %, based on all structural units in the resin (A).

[0139] <Structural unit (a3)> The lactone ring of the structural unit (a3) ​​may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or may be a condensed ring of a monocyclic lactone ring and another ring. Preferred examples include a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)).

[0140] The structural unit (a3) ​​is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3) or formula (a3-4). One of these may be contained alone, or two or more of them may be contained. TIFF0007681957000093.tif49157[In formula (a3-1), formula (a3-2), formula (a3-3) and formula (a3-4), L a4 , L a5 and L a6 are each independently -O- or *-O-(CH 2 ) k3 It represents a group represented by -CO-O- (k3 represents an integer of any of 1 to 7). L a7 , -O-, *-OL a8 -O-, *-OL a8 -CO-O-, *-OL a8 -CO-OL a9 -CO-O- or *-OL a8 -O-CO-L a9 Represents -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * indicates the bond 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 is -CH 2- or an oxygen atom. R a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms. R a22 , R a23 and R a25 each independently represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. p1 represents an integer of 0 to 5. q1 represents an integer of 0 to 3. r1 represents an integer of 0 to 3. w1 represents an integer of 0 to 8. When p1, q1, r1 and / or w1 are 2 or more, multiple R a21 , R a22 , R a23 and / or R a25 may be the same or different.]

[0141] R a21 , R a22 , R a23 and R a25 Examples of the aliphatic hydrocarbon group in include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, and a tert-butyl group. R a24 Examples of the halogen atom in include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R a24 Examples of the alkyl group in 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, and preferably includes an alkyl group having 1 to 4 carbon atoms, and more preferably includes a methyl group or an ethyl group. R a24Examples of the alkyl group having a halogen atom in the formula (I) include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.

[0142] L a8 and L a9 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group.

[0143] In formulas (a3-1) to (a3-3), L a4 ~L a6 are each independently preferably -O- or *-O-(CH 2 ) k3 In the -CO-O- group, k3 is an integer of 1 to 4, and more preferably -O- and *-O-CH 2 It is 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 each independently represent an integer of preferably 0 to 2, and more preferably 0 or 1.

[0144] In formula (a3-4), R a24is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a25 is preferably a carboxy group, a cyano group or a methyl group. L a7 is preferably -O- or *-OL a8 -CO-O-, more preferably -O-, -O-CH 2 -CO-O- or -OC 2 H 4 -CO-O-. w1 is preferably an integer of 0 to 2, and more preferably 0 or 1. In particular, the formula (a3-4) is preferably the formula (a3-4)'. TIFF0007681957000094.tif4455 (in the formula, R a24 , L a7 has the same meaning as above.)

[0145] Examples of the structural unit (a3) ​​include structural units derived from monomers described in JP 2010-204646 A, JP 2000-122294 A, and JP 2012-41274 A. Examples of the structural unit (a3) ​​include structural units represented by any one of formulas (a3-1-1), (a3-1-2), (a3-2-1), (a3-2-2), (a3-3-1), (a3-3-2), and (a3-4-1) to (a3-4-12), and in the structural unit, R in formulas (a3-1) to (a3-4) a18 , R a19 , R a20 and R a24 A structural unit in which a methyl group corresponding to the following formula is replaced with a hydrogen atom is preferred.

[0146] TIFF0007681957000095.tif115165

[0147] When the resin (A) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol %, preferably 10 to 65 mol %, and more preferably 10 to 60 mol %, based on all structural units in the resin (A). Furthermore, 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 from 5 to 60 mol %, more preferably from 5 to 50 mol %, and even more preferably from 10 to 50 mol %, based on the total structural units of the resin (A).

[0148] <Structural unit (a4)> Examples of the structural unit (a4) include the following structural units. TIFF0007681957000096.tif3166[In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having 1 to 24 carbon atoms and containing a halogen atom, and -CH 2 - may be replaced by -O- or -CO-. R 42 Examples of the saturated hydrocarbon group represented by the formula (I) include chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these groups.

[0149] 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, and a cyclooctyl group; and polycyclic alicyclic saturated hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bonding site): TIFF0007681957000097.tif10146 Examples of groups formed by combinations include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group.

[0150] 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). TIFF0007681957000098.tif4551[In formula (a4-0), R 54 represents a hydrogen atom or a methyl group. L 4a 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.

[0151] L 4a Examples of the alkanediyl group in the formula (I) 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.

[0152] L 3aExamples of the perfluoroalkanediyl group in the formula (I) include a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, a perfluoropropane-2,2-diyl group, a perfluorobutane-1,4-diyl group, a perfluorobutane-2,2-diyl group, a perfluorobutane-1,2-diyl group, a perfluoropentane-1,5-diyl group, a perfluoropentane-2,2-diyl group, a perfluoropentane-3 ,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluorooctane-3,3-diyl group, and perfluorooctane-4,4-diyl group. L 3a Examples of the perfluorocycloalkanediyl group in the formula (I) include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group.

[0153] 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.

[0154] The structural unit (a4-0) includes the structural units shown below and R in the structural unit (a4-0) in the structural units shown below. 54 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF0007681957000099.tif95166

[0155] TIFF0007681957000100.tif5070[In formula (a4-1), R a41 represents a hydrogen atom or a methyl group. R a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH 2 - may be replaced by -O- or -CO-. A a41 represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by formula (a-g1), a41 and R a42 At least one of the groups has a halogen atom (preferably a fluorine atom) as a substituent. TIFF0007681957000101.tif16100 [In formula (a-g1), s represents 0 or 1. A a42 and A a44 each 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, A a42 , A a43 , A a44 , X a41 and X a42 The total number of carbon atoms is 7 or less. * indicates the binding site, and the * on the right is -O-CO-R a42 This is the binding site for

[0156] R a42 Examples of the saturated hydrocarbon group in include chain hydrocarbon groups, monocyclic or polycyclic saturated alicyclic hydrocarbon groups, and groups formed by combining these groups.

[0157] 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; and polycyclic alicyclic hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bonding site): TIFF0007681957000102.tif10160 Examples of groups formed by combinations include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more saturated alicyclic hydrocarbon groups, such as -alkanediyl group-saturated alicyclic hydrocarbon group, -saturated alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-saturated alicyclic hydrocarbon group-alkyl group.

[0158] R a42 The substituents of may be at least one selected from the group consisting of halogen atoms and groups represented by formula (a-g3): Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and preferably a fluorine atom. TIFF0007681957000103.tif961[In 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. * stands for R a42 represents the binding site for However, R a42 -X a43 -A a45 In R a42 When A does not have a halogen atom, a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms and at least one halogen atom.

[0159] A a45 Examples of the saturated hydrocarbon group in the formula (I) include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group; Examples of such groups include monocyclic alicyclic hydrocarbon groups, such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic hydrocarbon groups, such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* indicates a bonding site): TIFF0007681957000104.tif10160 Examples of groups formed by combinations include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

[0160] R a42 is preferably a saturated hydrocarbon group which may have a halogen atom, and more preferably a saturated hydrocarbon group having an alkyl group having a halogen atom and / or a group represented by formula (a-g3). R a42 When 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, further 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 a42is a saturated hydrocarbon group having a group represented by formula (a-g3), the number of carbon atoms contained in the group represented by formula (a-g3) is a42 The total number of carbon atoms is preferably not more than 15, more preferably not more than 12. In the case where the group represented by formula (a-g3) is contained as a substituent, the number thereof is preferably 1.

[0161] R a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), R a42 is more preferably a group represented by formula (a-g2). TIFF0007681957000105.tif871[In 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 A a46 ) which represents the binding site with A a47 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. However, A a46 , A a47 and X a44 The total number of carbon atoms in A is 18 or less. a46 and A a47 At least one of these has at least one halogen atom. * indicates the bonding site with the carbonyl group.]

[0162] A a46 The saturated hydrocarbon group preferably has 1 to 6 carbon atoms, and more preferably has 1 to 3 carbon atoms. A a47 The saturated hydrocarbon group preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms. a47 is more preferably a cyclohexyl group or an adamantyl group.

[0163] A preferred structure of the group represented by formula (a-g2) is the following structure (* indicates the bonding site with the carbonyl group). TIFF0007681957000106.tif14160

[0164] A a41 Examples of the alkanediyl group in the formula (I) include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group; and branched alkanediyl groups such as a propane-1,2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a 1-methylbutane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a41 Examples of the substituent in the alkanediyl group represented by the formula (I) include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. A a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and further preferably an ethylene group.

[0165] A in the group represented by formula (a-g1) a42 , A a43 and A a44 Examples of the divalent saturated hydrocarbon group represented by include a linear or branched alkanediyl group, a monocyclic divalent alicyclic saturated hydrocarbon group, and a divalent saturated hydrocarbon group formed by combining an alkanediyl group and a divalent alicyclic saturated hydrocarbon group, etc. Specific examples include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, etc. A a42 , A a43 and A a44 Examples of the substituent of the divalent saturated hydrocarbon group represented by the formula (1) include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. It is preferred that s is 0.

[0166] In the group represented by formula (a-g1), X a42Examples of the group in which is -O-, -CO-, -CO-O-, or -O-CO- include the following groups. In the following examples, * and ** each represent a bonding site, and ** represents -O-CO-R a42 This is the binding site for TIFF0007681957000107.tif47140

[0167] The structural unit represented by formula (a4-1) includes the structural units shown below and R in the structural unit represented by formula (a4-1) in the structural units shown below. a41 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF0007681957000108.tif92135

[0168] TIFF0007681957000109.tif132150

[0169] Examples of the structural unit represented by formula (a4-1) include a structural unit represented by formula (a4-2) and a structural unit represented by formula (a4-3). TIFF0007681957000110.tif4661[In formula (a4-2), R f5 represents a hydrogen atom or a methyl group. L 44 represents an alkanediyl group having 1 to 6 carbon atoms, and the -CH 2 - may be replaced by -O- or -CO-. R f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and containing a fluorine atom. However, L 44 and R f6 The total number of carbon atoms in the molecule is limited to 21.

[0170] L 44 The alkanediyl group having 1 to 6 carbon atoms is represented by A a41 Examples of the groups include the same groups as those exemplified in the above. R f6 The saturated hydrocarbon group of R 42 Examples of the groups include the same groups as those exemplified in the above. L 44 As the alkanediyl group in 44 , an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.

[0171] Examples of the structural unit represented by the formula (a4-2) include structural units represented by the formulas (a4-1-1) to (a4-1-11), respectively. In the structural unit (a4-2), R f5 A structural unit in which the methyl group corresponding to f5 is replaced by a hydrogen atom is also included as the structural unit represented by the formula (a4-2).

[0172] TIFF0007681957000111.tif5975 [In the 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 number of carbon atoms of L 5 , A f13 and A f14 is 20.]

[0173] L 5 Examples of the alkanediyl group in 5 include the same groups as those exemplified for the alkanediyl group of A a41 .

[0174] A f13The divalent saturated hydrocarbon group which may have a fluorine atom in is 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, and 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; and 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, and a perfluoroadamantanediyl group.

[0175] A f14 The saturated hydrocarbon group and the saturated hydrocarbon group which may have a fluorine atom are represented by R a42Among them, 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, Preferred are fluorinated alkyl groups such as a hexyl group, a perfluorohexyl group, a heptyl group, a perfluoroheptyl group, an octyl group, and a perfluorooctyl group, a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, a perfluorocyclohexyl group, an adamantyl group, an adamantylmethyl group, an adamantyldimethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, and a perfluoroadamantylmethyl group.

[0176] In formula (a4-3), L 5 is preferably an ethylene group. A f13 The divalent saturated hydrocarbon group is preferably a group containing a divalent chain saturated hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a divalent chain saturated hydrocarbon group having 2 to 3 carbon atoms. A f14 The saturated hydrocarbon group of is preferably a group containing a chain saturated hydrocarbon group having 3 to 12 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a chain saturated hydrocarbon group having 3 to 10 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms. f14 is preferably a group containing an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, or an adamantyl group.

[0177] Examples of the structural unit represented by formula (a4-3) include structural units represented by formulas (a4-1'-1) to (a4-1'-11). R in the structural unit (a4-3) f7 The structural unit represented by formula (a4-3) also includes a structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom.

[0178] The structural unit (a4) also includes a structural unit represented by the formula (a4-4). TIFF0007681957000112.tif4669[In formula (a4-4), R f21 represents a hydrogen atom or a methyl group. A f21 is -(CH 2 ) j1 -, -(CH 2 ) j2 -O-(CH 2 ) j3 -or-(CH 2 ) j4 -CO-O-(CH 2 ) j5 - represents. j1 to j5 each independently represent an integer of 1 to 6. R f22 represents a saturated hydrocarbon group having 1 to 10 carbon atoms and containing a fluorine atom.]

[0179] R f22 The saturated hydrocarbon group of R a42 The saturated hydrocarbon group represented by 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 further preferably an alkyl group having 1 to 6 carbon atoms and having a fluorine atom.

[0180] In formula (a4-4), A f21 As an example, -(CH 2 ) j1 - is preferred, an ethylene group or a methylene group is more preferred, and a methylene group is even more preferred.

[0181] Examples of the structural unit represented by formula (a4-4) include the following structural units and structural units represented by the following formulas: f21 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF0007681957000113.tif86160

[0182] When the resin (A) has the structural unit (a4), the content thereof is preferably from 1 to 20 mol %, more preferably from 2 to 15 mol %, and even more preferably from 3 to 10 mol %, based on all structural units in the resin (A).

[0183] <Structural unit (a5)> The non-leaving hydrocarbon group contained in the structural unit (a5) may be a group containing a linear, branched or cyclic hydrocarbon group. Among these, the structural unit (a5) is preferably a group containing an alicyclic hydrocarbon group. An example of the structural unit (a5) is a structural unit represented by the formula (a5-1). TIFF0007681957000114.tif3961[In formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the -CH 2 - may be replaced by -O- or -CO-.

[0184] R 52The alicyclic hydrocarbon group in may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group, a norbornyl group, and the like. Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, and a 2-ethylhexyl group. An example of the alicyclic hydrocarbon group having a substituent is a 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group, or a cyclohexyl group.

[0185] L 55 Examples of the divalent saturated hydrocarbon group in include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and a divalent chain saturated hydrocarbon group is preferred. Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl and norbornanediyl.

[0186] L 55 -CH contained in the divalent saturated hydrocarbon group represented by 2 Examples of the group in which - is replaced by -O- or -CO- include groups represented by formulae (L1-1) to (L1-4). In the following formulae, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom. TIFF0007681957000115.tif18165 formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents L x1 ) which represents the binding site with L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, L x1 and L x2 The total number of carbon atoms is 16 or less. In formula (L1-2), L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, L x3 and L x4 The total number of carbon atoms is 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, L x5 , L x6 and L x7 The total number of carbon atoms is 15 or less. In formula (L1-4), L x8 and L x9 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, L x8 , L x9 and W x1 The total number of carbon atoms is 15 or less.

[0187] Lx1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond. L x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group. L x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group. L x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group. W x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, and more preferably a cyclohexanediyl group or an adamantanediyl group.

[0188] Examples of the group represented by formula (L1-1) include the divalent groups shown below. TIFF0007681957000116.tif53136

[0189] Examples of the group represented by formula (L1-2) include the divalent groups shown below. TIFF0007681957000117.tif23130

[0190] Examples of the group represented by formula (L1-3) include the divalent groups shown below. TIFF0007681957000118.tif16145

[0191] Examples of the group represented by formula (L1-4) include the divalent groups shown below. TIFF0007681957000119.tif26114

[0192] L 55 is preferably a single bond or a group represented by formula (L1-1).

[0193] The structural unit (a5-1) may be any of the structural units shown below and R in the structural unit (a5-1) in the structural unit shown below. 51 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF0007681957000120.tif77158

[0194] TIFF0007681957000121.tif39159 When the resin (A) has the structural unit (a5), the content thereof is preferably from 1 to 30 mol %, more preferably from 2 to 20 mol %, and even more preferably from 3 to 15 mol %, based on all structural units in the resin (A).

[0195] <Structural unit (II)> Resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter, may be referred to as "structural unit (II)"). Specific examples of structural unit (II) include structural units described in JP-A-2016-79235, and are preferably structural units having a sulfonate group or 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.

[0196] The structural unit having a sulfonate group or carboxylate group and an organic cation in the side chain is preferably a structural unit represented by formula (II-2-A'). TIFF0007681957000122.tif3294[In formula (II-2-A'), X III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the -CH 2 - 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 substituted by a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. RA - represents a sulfonate group or a carboxylate group. R III3 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. Z.A. + represents an organic cation.

[0197] R III3 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R III3 The alkyl group having 1 to 6 carbon atoms which may have a halogen atom and is represented by the formula: a8 Examples of the alkyl group include the same alkyl groups having 1 to 6 carbon atoms which may have a halogen atom and are represented by the following formula: A x1 Examples of the alkanediyl group having 1 to 8 carbon atoms represented by the formula (I) 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, and a 2-methylbutane-1,4-diyl group. A x1 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted 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.

[0198] X III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by the formula (I) include linear or branched alkanediyl groups, and monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and combinations of these may also be used. Specific examples of such alkanediyl groups include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl groups; branched alkanediyl groups such as butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl groups; divalent monocyclic alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group; Examples of the divalent polycyclic alicyclic saturated hydrocarbon groups include norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.

[0199] -CH contained in saturated hydrocarbon groups 2 Examples of the divalent groups in which - is replaced by -O-, -S- or -CO- include the divalent groups represented by the formulae (X1) to (X53). However, -CH 2The number of carbon atoms before - is replaced by -O-, -S-, or -CO- is 17 or less. In the following formula, * and ** represent binding sites, * represents A x1 It represents the binding site with TIFF0007681957000123.tif145161

[0200] 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.

[0201] Z.A. + Examples of the organic cation represented by the formula (b2-1) include an organic onium cation, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferred, and an arylsulfonium cation is more preferred. Specifically, examples of the organic cation represented by the formula (b2-1) to the formula (b2-4) above (hereinafter, may be referred to as "cation (b2-1)" depending on the formula number) are included.

[0202] The structural unit represented by formula (II-2-A') is preferably a structural unit represented by formula (II-2-A). JPEG0007681957000124.jpg37109 [In formula (II-2-A), R III3 , X III3 and Z.A. + has the same meaning as above. z represents an integer of 0 to 6. R III2 and R III4 each independently represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms; when z is 2 or more, a plurality of R III2 and R III4 may be the same or different from each other. Q a and Q b each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.]

[0203] R III2 , R III4 , Q a and Q b As the perfluoroalkyl group having 1 to 6 carbon atoms represented by the formula b1 Examples of the perfluoroalkyl group include those having 1 to 6 carbon atoms represented by the following formula:

[0204] The structural unit represented by formula (II-2-A) is preferably a structural unit represented by formula (II-2-A-1). TIFF0007681957000125.tif5981 [In formula (II-2-A-1), R III2 , R III3 , R III4 , Q a , Q b , z and Z A + has the same meaning as 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, and the -CH 2 - may be replaced by -O-, -S- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted by a halogen atom or a hydroxy group.

[0205] R III5Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by the formula (I) include linear or branched alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. X I2 As the divalent saturated hydrocarbon group represented by the formula: III3 Examples of the divalent saturated hydrocarbon group include those similar to those represented by the following formula:

[0206] The structural unit represented by formula (II-2-A-1) is preferably a structural unit represented by formula (II-2-A-2). TIFF0007681957000126.tif5287 [In formula (II-2-A-2), R III3 , R III5 and Z.A. + has the same meaning as above. m and n each independently represent 1 or 2.

[0207] Examples of the structural unit represented by formula (II-2-A') include the following structural units, R III3 Examples of the structural units include those in which the group corresponding to the methyl group in the above formula (1) is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., a trifluoromethyl group, etc.), and the structural units described in WO 2012 / 050015. + represents an organic cation. TIFF0007681957000127.tif86163

[0208] 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). TIFF0007681957000128.tif3588[In formula (II-1-1), A II1 represents a single bond or a divalent linking group. R II1represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms. R II2 and R II3 each independently represents a hydrocarbon group having 1 to 18 carbon atoms; R II2 and R II3 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. 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 the formula (I) include a phenylene group and a naphthylene group. R II2 and R II3 Examples of the hydrocarbon group represented by the formula (I) include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Examples of the alkyl group and the alicyclic hydrocarbon group include the same as those mentioned 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 combination of the above-mentioned alkyl group and alicyclic hydrocarbon group, aralkyl groups such as a benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), and aryl-cycloalkyl groups such as a phenylcyclohexyl group. R II4 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R II4 The alkyl group having 1 to 6 carbon atoms which may have a halogen atom and is represented by the formula: a8Examples of the alkyl group include the same alkyl groups having 1 to 6 carbon atoms which may have a halogen atom and are represented by the following formula: A II1 Examples of the divalent linking group represented by the formula (I) include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms. 2 - may be replaced by -O-, -S- or -CO-. III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms include those represented by the following formula:

[0209] The structural unit containing a cation in formula (II-1-1) is a structural unit represented by the following formula: R II4 Examples of such structural units include those in which a group corresponding to the methyl group in the above formula (I) is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., a trifluoromethyl group, etc.). TIFF0007681957000129.tif85130

[0210] A - Examples of the organic anion represented by the formula (I) include a sulfonate anion, a sulfonylimide anion, a sulfonylmethide anion, and a carboxylate anion. - The organic anion represented by the formula (B1) is preferably a sulfonate anion, and examples of the sulfonate anion include the same anions as those represented by the formula (B1) above.

[0211] A - Examples of the sulfonylimide anion represented by the formula (I) include the following. TIFF0007681957000130.tif36136

[0212] Examples of sulfonylmethide anions include the following: TIFF0007681957000131.tif29123

[0213] Examples of carboxylate anions include the following: TIFF0007681957000132.tif44153

[0214] Examples of the structural unit represented by formula (II-1-1) include structural units represented below. TIFF0007681957000133.tif88149

[0215] 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 even more preferably 3 to 10 mol %, based on the total structural units of the resin (A).

[0216] The resin (A) may have structural units other than the above-mentioned structural units, and examples of such structural units include structural units well known in the art.

[0217] The resin (A) is preferably a resin composed of the structural unit (a1) and the structural unit (s), that is, a copolymer of the monomer (a1) and the monomer (s). The structural unit (a1) is preferably at least one selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group), more preferably at least two, and even 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 the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably a structural unit represented by formula (a2-1) or a structural unit represented by formula (a2-A). The structural unit (a3) ​​is preferably at least one selected from the group consisting of the structural unit represented by formula (a3-1), the structural unit represented by formula (a3-2), and the structural unit represented by formula (a3-4).

[0218] 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 (e.g., radical polymerization method) using a monomer that leads to these structural units. The content of each structural unit contained in the resin (A) can be adjusted by the amount of the monomer used for polymerization. The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, and even more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, and even more preferably 15,000 or less). In the present specification, the weight average molecular weight is a value determined by gel permeation chromatography under the conditions described in the Examples.

[0219] <Resins other than resin (A)> The resist composition of the present invention may contain a resin other than the resin (A). Examples of resins other than resin (A) include resins containing the structural unit (a4) or the structural unit (a5) (hereinafter, sometimes referred to as resin (X)).

[0220] As the resin (X), a resin containing the structural unit (a4) is particularly preferred. In the resin (X), the content of the structural unit (a4) is preferably 30 mol % or more, more preferably 40 mol % or more, and even more preferably 45 mol % or more, based on the total of all structural units in the resin (X). Examples of structural units that may be further contained in the resin (X) include the structural unit (a2), the structural unit (a3), and structural units derived from other known monomers. Among these, the resin (X) is preferably a resin consisting only of the structural unit (a4) and / or the structural unit (a5), and more preferably a resin consisting only of 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 (e.g., radical polymerization method) using a monomer that derives these structural units. The content of each structural unit in the resin (X) can be adjusted by the amount of the monomer used for 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 method for measuring the weight average molecular weight of the resin (X) is the same as that for the resin (A). When the resist composition contains resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, even more preferably 1 to 40 parts by mass, still more preferably 1 to 30 parts by mass, and even more preferably 1 to 8 parts by mass, relative to 100 parts by mass of resin (A).

[0221] The content of 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 resin (A) is contained, the total content of resin (A) and the resin other than 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 resin content therein can be measured by a known analytical means such as liquid chromatography or gas chromatography.

[0222] <Solvent (E)> The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, and more preferably 94% by mass or more and 99% by mass or less. The content of the solvent (E) can be measured by a known analytical method such as liquid chromatography or gas chromatography. Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate, and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone; cyclic esters such as γ-butyrolactone; etc. One type of solvent (E) may be used alone, or two or more types may be used.

[0223] <Quencher (C)> Examples of the quencher (C) include a basic nitrogen-containing organic compound and a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B). When the resist composition contains the quencher (C), the content of the quencher (C) is preferably about 0.01 to 15 mass%, more preferably about 0.01 to 10 mass%, even more preferably about 0.01 to 7 mass%, and even more preferably about 0.1 to 3 mass%, based on the solid content of the resist composition. The basic nitrogen-containing organic compound includes amines and ammonium salts. The amines include aliphatic amines and aromatic amines. The aliphatic amines include primary amines, secondary amines, and tertiary amines. Examples of amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributaryamine, ethylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldi Decylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridinyl)amine ... Examples of the dipyridyl amine include 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, and bipyridine. Of these, diisopropylaniline is preferred, and 2,6-diisopropylaniline is more preferred. Examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate, choline, and the like.

[0224] The acidity of a salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is indicated by the acid dissociation constant (pKa). A salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is a salt having an acid dissociation constant of the acid generated from the salt usually of -3 < pKa, preferably -1 < pKa < 7, and more preferably 0 < pKa < 5. Examples of the salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) include salts represented by the following formula, salts represented by formula (D) described in JP-A-2015-147926 (hereinafter sometimes referred to as "weak acid inner salt (D)"), and salts described in JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502, and JP-A-2011-191745. 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 carboxylic acid anion), and more preferably, it is the weak acid inner salt (D). TIFF0007681957000134.tif89165

[0225] Examples of the weak acid inner salt (D) include the following salts. TIFF0007681957000135.tif72165

[0226] 〈Other Components〉 The resist composition of the present invention may contain components other than the above-mentioned components (hereinafter, sometimes referred to as "other components (F)") as necessary. There are no particular limitations on the other components (F), and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, etc., can be used.

[0227] 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, the resin other than the resin (A), the solvent (E), the quencher (C), and other components (F). The order of mixing is arbitrary and is not particularly limited. The temperature during mixing can be selected from 10 to 40°C depending on the type of resin, the solubility of the resin in the solvent (E), and the like. The mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used. After mixing the components, it is preferable to filter the mixture using a filter having a pore size of about 0.003 to 0.2 μm.

[0228] <Method for Producing Resist Pattern> The method for producing a resist pattern of the present invention comprises the steps of: (1) applying the resist composition of the present invention onto a substrate; (2) A step of drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) A step of developing the composition layer after heating. The resist composition can be applied onto a substrate using a commonly used device such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers. Before applying the resist composition, the substrate may be cleaned, and an anti-reflective film or the like may be formed on the substrate. The composition after coating is dried to remove the solvent and form a composition layer. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or by using a vacuum device. The heating temperature is preferably 50 to 200°C, and the heating time is preferably 10 to 180 seconds. The pressure during drying under reduced pressure is preferably 1 to 1.0×10 5 It is preferable that the pressure is about Pa. The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. The exposure light source may be a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), or a F 2 Various lasers can be used, such as those that emit ultraviolet laser light such as an excimer laser (wavelength 157 nm), those that convert the wavelength of laser light from a solid-state laser light source (YAG or semiconductor laser, etc.) to emit harmonic laser light in the far ultraviolet or vacuum ultraviolet range, and those that irradiate electron beams or extreme ultraviolet light (EUV). In this specification, irradiation with these types of radiation may be collectively referred to as "exposure." During exposure, exposure is usually performed through a mask corresponding to the desired pattern. When the exposure light source is an electron beam, exposure may be performed by direct writing without using a mask. The composition layer after exposure is subjected to a heat treatment (so-called post-exposure bake) in order to promote the deprotection reaction of the acid labile groups. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C. The composition layer after heating is usually developed using a developing device and a developer. Examples of the developing method include a dip method, a paddle method, a spray method, and a dynamic dispense method. The developing temperature is preferably, for example, 5 to 60° C., and the developing time is preferably, for example, 5 to 300 seconds. By selecting the type of developer as follows, a positive resist pattern or a negative resist pattern can be produced. When a positive resist pattern is produced from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline) may be used. The alkaline developer may contain a surfactant. After development, the resist pattern is preferably washed with ultrapure water, and then water remaining on the substrate and the pattern is removed. When producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as an "organic developer") is used as the developer. Examples of organic solvents contained in organic developers include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; and aromatic hydrocarbon solvents such as anisole. The content of the organic solvent in the organic developer is preferably from 90% by mass to 100% by mass, more preferably from 95% by mass to 100% by mass, and further preferably consists essentially of the organic solvent. Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and even more preferably substantially only butyl acetate and / or 2-heptanone. The organic developer may contain a surfactant and may contain a small amount of water. During development, the development may be stopped by replacing the organic developer with a different type of solvent. The resist pattern after development is preferably washed with a rinse solution. There are no particular limitations on the rinse solution as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent. After cleaning, it is preferable to remove any rinsing liquid remaining on the substrate and the pattern.

[0229] <Application> The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, in particular as a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for semiconductor microfabrication. EXAMPLES

[0230] The present invention will be described in more detail with reference to examples. In the examples, "%" and "parts" expressing the content or amount used are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography under the following analytical conditions: Column: TSKgel Multipore HXL-M x 3 + guard column (Tosoh Corporation) Eluent: Tetrahydrofuran Flow rate: 1.0mL / min Detector: RI detector Column temperature: 40℃ Injection volume: 100μl Molecular weight standard: Standard polystyrene (Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent 1100 model, MASS: Agilent LC / MSD model). In the following examples, the value of this molecular ion peak is indicated by "MASS".

[0231] Example 1: Synthesis of a salt represented by formula (I-1) TIFF0007681957000136.tif45159 4.38 parts of the salt represented by formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 1.76 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed and the mixture was concentrated to obtain 2.66 parts of the salt represented by formula (I-1). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 333.0

[0232] Example 2: Synthesis of a salt represented by formula (I-2) TIFF0007681957000137.tif47160 4.38 parts of the salt represented by formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 1.74 parts of the compound represented by formula (I-2-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed and the mixture was concentrated to obtain 3.69 parts of the salt represented by formula (I-2). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 331.0

[0233] Example 3: Synthesis of salt represented by formula (I-6) TIFF0007681957000138.tif46157 4.38 parts of the salt represented by formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 2.18 parts of the compound represented by formula (I-6-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed and the mixture was concentrated to obtain 2.83 parts of the salt represented by formula (I-6). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 375.0

[0234] Example 4: Synthesis of salt represented by formula (I-19) TIFF0007681957000139.tif40168 6.17 parts of the salt represented by formula (I-19-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 1.76 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed and the mixture was concentrated to obtain 3.89 parts of the salt represented by formula (I-19). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 511.1

[0235] Example 5: Synthesis of a salt represented by formula (I-21) TIFF0007681957000140.tif67156 6.02 parts of the salt represented by formula (I-21-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 1.76 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed and the mixture was concentrated to obtain 2.48 parts of the salt represented by formula (I-21). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 541.1

[0236] Example 6: Synthesis of a salt represented by formula (I-23) TIFF0007681957000141.tif75158 6.19 parts of the salt represented by formula (I-23-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 1.76 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed and the mixture was concentrated to obtain 3.12 parts of the salt represented by formula (I-23). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 513.0

[0237] Example 7: Synthesis of a salt represented by formula (I-17) TIFF0007681957000142.tif47161 4.24 parts of the salt represented by formula (I-17-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 1.76 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed. The mixture was concentrated to obtain 2.91 parts of the salt represented by formula (I-17). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 363.0

[0238] Example 8: Synthesis of a salt represented by formula (I-24) TIFF0007681957000143.tif80157 6.19 parts of the salt represented by formula (I-23-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 1.74 parts of the compound represented by formula (I-2-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed and the mixture was concentrated to obtain 4.39 parts of the salt represented by formula (I-24). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 511.1

[0239] Example 9: Synthesis of a salt represented by formula (I-71) TIFF0007681957000144.tif80158 6.36 parts of the salt represented by formula (I-71-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 1.76 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed and the mixture was concentrated to obtain 6.02 parts of the salt represented by formula (I-71). MASS(ESI(+)Spectrum):M + 281.1 MASS(ESI(-)Spectrum):M - 513.0

[0240] Example 10: Synthesis of a salt represented by formula (I-72) TIFF0007681957000145.tif85160 6.36 parts of the salt represented by formula (I-71-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 1.74 parts of the compound represented by formula (I-2-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed. The mixture was concentrated to obtain 6.22 parts of the salt represented by formula (I-72). MASS(ESI(+)Spectrum):M + 281.1 MASS(ESI(-)Spectrum):M - 511.1

[0241] Example 11: Synthesis of a salt represented by formula (I-95) TIFF0007681957000146.tif82158 6.72 parts of the salt represented by formula (I-95-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 1.76 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed and the mixture was concentrated to obtain 6.88 parts of the salt represented by formula (I-95). MASS(ESI(+)Spectrum):M + 317.1 MASS(ESI(-)Spectrum):M - 513.0

[0242] Example 12: Synthesis of a salt represented by formula (I-96) TIFF0007681957000147.tif85160 6.72 parts of the salt represented by formula (I-95-a) and 30 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 1.74 parts of the compound represented by formula (I-2-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 15 parts of a 5% aqueous oxalic acid solution were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. 15 parts of ion-exchanged water were added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue. The mixture was stirred at 23° C. for 30 minutes, and then the supernatant was removed. The mixture was concentrated to obtain 6.89 parts of the salt represented by formula (I-96). MASS(ESI(+)Spectrum):M + 317.1 MASS(ESI(-)Spectrum):M - 511.1

[0243] Resin synthesis The compounds (monomers) used in the synthesis of resin (A) are shown below. Hereinafter, these compounds will be referred to as "monomer (a1-1-3)" etc. according to their formula numbers. TIFF0007681957000148.tif4082

[0244] Synthesis Example 1 [Synthesis of Resin A1] Monomer (a1-4-2), monomer (a1-1-3) and monomer (a1-2-6) were used as monomers, and mixed in a molar ratio of 38:24:38 [monomer (a1-4-2):monomer (a1-1-3):monomer (a1-2-6)]. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture relative to the total mass of all monomers. Azobisisobutyronitrile was added as an initiator to the obtained mixture in an amount of 7 mol% relative to the total mole number of all monomers, and polymerization was carried out by heating at 85°C for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction liquid, which was stirred for 6 hours and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 5.3 × 10 3 Resin A1 (copolymer) having the following structural units was obtained in a yield of 78%. TIFF0007681957000149.tif29126

[0245] Synthesis Example 2 [Synthesis of Resin A2] Monomer (a1-4-2) and monomer (a1-2-6) were used as monomers, and mixed so that the molar ratio [monomer (a1-4-2):monomer (a1-2-6)] was 38:62. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture relative to the total mass of all monomers. Azobisisobutyronitrile was added as an initiator to the obtained mixture so that the amount was 7 mol% relative to the total mole number of all monomers, and polymerization was carried out by heating at 85°C for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction liquid, and the mixture was stirred for 6 hours and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 5.4 x 10 3 Resin A2 (copolymer) having the following structural units was obtained in a yield of 89%. TIFF0007681957000150.tif2886

[0246] <Preparation of resist composition> As shown in Table 2, the following components were mixed and the resulting mixture was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition. [Table 2]

[0247] <Resin> A1, A2: Resin A1, Resin A2 <Salt (I)> I-1: A salt represented by formula (I-1) I-2: A salt represented by formula (I-2) I-6: A salt represented by formula (I-6) I-17: A salt represented by formula (I-17) I-19: A salt represented by formula (I-19) I-21: A salt represented by formula (I-21) I-23: A salt represented by formula (I-23) I-24: A salt represented by formula (I-24) I-71: A salt represented by formula (I-71) I-72: A salt represented by formula (I-72) I-95: A salt represented by the formula (I-95) I-96: A salt represented by the formula (I-96) <Acid generator> B1-X1, B1-X2, B1-X3: TIFF0007681957000152.tif34162<Quencher(C)> C1: Synthesized by the method described in JP 2011-39502 A TIFF0007681957000153.tif3646<solvent> Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 100 parts γ-Butyrolactone 5 parts

[0248] (Electron beam exposure evaluation of resist composition) A 6-inch silicon wafer was treated with hexamethyldisilazane on a direct hot plate at 90°C for 60 seconds. The resist composition was spin-coated on the silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, the wafer was pre-baked on a direct hot plate at the temperature shown in the "PB" column of Table 2 for 60 seconds to form a composition layer. An electron beam lithography machine (ELS-F125 125keV, manufactured by Elionix Co., Ltd.) was used to directly draw the composition layer formed on the wafer by gradually changing the exposure dose so that a line and space pattern (pitch 60 nm / line width 30 nm) would be formed after development. After exposure, post-exposure baking was performed on a hot plate for 60 seconds at the temperature shown in the "PEB" column in Table 2. Next, the composition layer on the silicon wafer was developed by a dynamic dispense method at 23°C for 20 seconds using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developer to obtain a resist pattern. The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the exposure amount 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.

[0249] Line edge roughness evaluation (LER): The amplitude of unevenness on the sidewall of the resist pattern produced at the effective sensitivity was measured with a scanning electron microscope to obtain the line edge roughness. The results are shown in Table 3. [Table 3] Compared with Comparative Compositions 1 to 3, Compositions 1 to 13 had a smaller fluctuation in unevenness on the sidewall surface of the resist pattern, and the line edge roughness was evaluated as good. [Industrial Applicability]

[0250] A resist composition containing the salt of the present invention is capable of obtaining a resist pattern with good line edge roughness (LER), and is therefore suitable for semiconductor microfabrication and extremely useful industrially.

Claims

1. A salt represented by formula (I): [In formula (I), Q １ and Q. ２ each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. R １ and R ２ each independently represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms. z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R １ and R ２ may be the same or different from each other. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, and * represents C(R １ ) (R ２ ) or C(Q １ ) (Q ２ ) binding site. L 1 represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and —CH 2 - is -O-, -S-, -SO ２ It may be replaced by --or --CO--. w1 and w2 each independently represent an integer of 1 to 3. X 2 represents --O-- or --S--. L 2 represents an alkanediyl group having 1 to 6 carbon atoms. L ３ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms. R ３ represents an alkyl group having 1 to 6 carbon atoms. Z ＋ represents an organic cation.

2. The salt according to claim 1, wherein w1 is 1 or 2.

3. L 1 is a single bond or *-L ４ -CO-O- (wherein L ４ represents a hydrocarbon group having 1 to 22 carbon atoms which may have a substituent, and —CH 2 - is -O-, -S-, -SO ２ 3. The salt according to claim 1 or 2, wherein:

4. An acid generator comprising the salt according to any one of claims 1 to 3.

5. A resist composition comprising the acid generator according to claim 4 and a resin having an acid labile group.

6. 6. The resist composition according to claim 5, wherein the resin having an acid labile group comprises at least one member selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2): [In formula (a1-1) and formula (a1-2), L a1 and L a2 are each independently -O- or *-O-(CH ２ ) k1 It represents --CO--O--, k1 represents an integer of 1 to 7, and * represents a bond to --CO--. R a4 and R a5 each independently represents a hydrogen atom or a methyl group. 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 combination thereof. m1 represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3.

7. 7. The resist composition according to claim 5, 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 is a single bond or *-X a51 - (A a52 -X a52 ) nｂ -, * is -R a50 represents the bonding site with the carbon atom to which it 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 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different.

8. 8. The resist composition according to claim 5, further comprising a salt capable of generating an acid having a weaker 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) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) developing the composition layer after heating; A method for producing a resist pattern comprising the steps of:

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