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

Abstract

To provide a salt that can produce a resist pattern having excellent CD uniformity (CDU), an acid generator and a resist composition comprising the same.SOLUTION: The present invention discloses a salt represented by formula (I), an acid generator and a resist composition [where R1 and R2 each denote -O-R10, -O-CO-R10 or the like. L1 is a C1-6 alkanediyl group. R4, R5, R7 and R8 each denote a halogen atom, a fluorinated alkyl group or a hydrocarbon group, the hydrocarbon group may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced with -O- or -CO-. R10 denotes an acid-stable hydrocarbon group. X1 and X2 each denote O or S. m1 is an integer of 1-5, m2 and m8 each denote an integer of 0-5, m4, m5 and m7 each denote an integer of 0-4. 1≤m1+m7≤5 and 0≤m2+m8≤5. AI- is an organic anion].SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes a resist composition containing a salt represented by the following formula as an acid generator. TIFF0007702818000001.tif2685 Patent Document 2 describes a resist composition containing a salt represented by the following formula as an acid generator. TIFF0007702818000002.tif2889 Non-Patent Document 1 describes a salt represented by the following formula. TIFF0007702818000003.tif1185

[0003] Patent Document 3 describes a salt represented by the following formula. TIFF0007702818000004.tif2481 Patent Document 4 describes a salt represented by the following formula. TIFF0007702818000005.tif1155 Patent Document 5 describes a salt represented by the following formula. TIFF0007702818000006.tif1762

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Non-Patent Document

[0005]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a salt that forms a resist pattern with better CD uniformity (CDU) than a resist pattern formed from a resist composition containing the above salt.

Means for Solving the Problems

[0007] The present invention includes the following inventions. [1] A salt represented by formula (I). TIFF0007702818000007.tif30138[In formula (I), R 1 and R 2 each independently represents -O-R 10 , -O-CO-R 10 , -O-CO-O-R 10 , -O-L 1 -CO-O-R 10 . L 1 represents an alkanediyl group having 1 to 6 carbon atoms. R 4 , R 5 , R 7 and R 8 each independently represents a halogen atom, a fluorinated alkyl group having 1 to 6 carbon atoms, or a hydrocarbon group having 1 to 18 carbon atoms, and the hydrocarbon group may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO-, or -SO2-. R 10 represents an acid-stable hydrocarbon group. X 1 and X 2 each independently represents an oxygen atom or a sulfur atom. m1 represents an integer from 1 to 5. When m1 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. m2 represents an integer from 0 to 5. When m2 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. m4 represents an integer from 0 to 4. When m4 is 2 or more, the plurality of Rs 4 may be the same as or different from each other. m5 represents an integer from 0 to 4. When m5 is 2 or more, the plurality of Rs 5 may be the same as or different from each other. m7 represents an integer from 0 to 4. When m7 is 2 or more, the plurality of Rs 7 may be the same as or different from each other. m8 represents an integer from 0 to 5. When m8 is 2 or more, the plurality of Rs 8 may be the same as or different from each other. However, 1 ≤ m1 + m7 ≤ 5 and 0 ≤ m2 + m8 ≤ 5. AI - represents an organic anion. [2] X 1 and X 2 are oxygen atoms, and the salt described in [1]. [3] R 1 and R 2 are -O-CO-O-R 10 or -O-L 1 -CO-O-R 10 and the salt described in [1] or [2]. [4] R 10 The acid-stable hydrocarbon group of is the group represented by the formula (3a), and the salt described in any one of [1] to [3]. TIFF0007702818000008.tif1958 [In the formula (3a), R 1a and R 2a each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, or R 1a and R 2a are bonded to each other to form a hydrocarbon ring having 3 to 36 carbon atoms which may have an alkyl group having 1 to 12 carbon atoms. R3a represents a hydrogen atom, or R 1a and R 2a and R 3a are bonded to each other to form a hydrocarbon ring having 3 to 36 carbon atoms which may have an alkyl group having 1 to 12 carbon atoms. * represents a bond.] [5] The salt according to any one of [1] to [4], wherein m1 is 1 and m2 is 0 or 1. [6] The salt according to any one of [1] to [5], wherein m2 is 0 and R 8 is a branched alkyl group having 3 or 4 carbon atoms. [7] The bond positions of R 1 and R 2 are bonded to the p-position with respect to the bond positions of X 1 and X 2 The salt according to any one of [1] to [6]. [8] Either m4 or m5 is 1 or 2. When m4 is 1 or 2, the bond position of at least one R 4 is bonded to the o-position with respect to the bond position of X 1 and when m5 is 1 or 2, the bond position of at least one R 5 is bonded to the o-position with respect to the bond position of X 2 The salt according to any one of [1] to [7]. [9] The salt according to any one of [1] to [8], wherein AI - is a sulfonate anion, a sulfonylimide anion, a sulfonylmethide anion or a carboxylate anion.

[10] The salt according to any one of [1] to [9], wherein AI - is a sulfonate anion, and the sulfonate anion is an anion represented by formula (I-A). TIFF0007702818000009.tif2352[In formula (I-A), Q 1 and Q 2 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L 1represents a saturated hydrocarbon group having 1 to 24 carbon atoms, wherein -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. Y 1 represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-. An acid generator containing the salt according to any one of

[11] [1] to

[10] . A resist composition containing the acid generator according to

[12]

[11] and a resin having an acid-labile group. The resist composition according to

[12] , wherein the resin having an acid-labile group contains at least one selected from the group consisting of a structural unit represented by the formula (a1-1) and a structural unit represented by the formula (a1-2). TIFF0007702818000010.tif4394[In the formula (a1-1) and the formula (a1-2), L a1 and L a2 each independently represents -O- or *-O-(CH2) k1 -CO-O-, k1 represents an integer of any one of 1 to 7, and * represents a bond with -CO-. R a4 and R a5 each independently represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R 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 combining these. m1 represents an integer of any one of 0 to 14. n1 represents an integer of any one of 0 to 10. n1’ represents an integer of any one of 0 to 3.

[14] The resist composition according to

[12] or

[13] , wherein the resin having an acid-labile group contains a structural unit represented by formula (a2-A). TIFF0007702818000011.tif4753[In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 represents a single bond or * -X a51 -(A a52 -X a52 ) nb - represents, and * represents a bond with the carbon atom to which -R a50 is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represent -O-, -CO-O-, or -O-CO-. nb represents 0 or 1. mb represents any integer from 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same as or different from each other. ]

[15] The resist composition according to any one of

[12] to

[14] , further containing a salt that generates an acid having a lower acidity than the acid generated from the acid generator.

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

[12] to

[15] onto a substrate, (2) A step of drying the applied composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and A method for manufacturing a resist pattern, comprising the step of developing the composition layer after heating.

Advantages of the Invention

[0008] By using the resist composition containing the salt of the present invention, a resist pattern can be manufactured with good CD uniformity (CDU).

Embodiments for Carrying Out the Invention

[0009] In the present specification, the “(meth)acrylic monomer” means “at least one of an acrylic monomer and a methacrylic monomer”. Expressions such as “(meth)acrylate” and “(meth)acrylic acid” also represent the same meaning. Among the groups described in the present specification, those that can take both a linear structure and a branched structure may be either of them. When -CH2- contained in a hydrocarbon group or the like is replaced by -O-, -S-, -CO- or -SO2-, the same examples are applied to each group. The “combined group” means a group formed by bonding two or more of the exemplified groups, and the valences of those groups may be appropriately changed depending on the bonding form. “Derived from” or “induced from” refers to the fact that the polymerizable C═C bond contained in the molecule becomes a -C-C- group by polymerization. When stereoisomers exist, all stereoisomers are included.

[0010] 〔Salt represented by formula (I)〕 The present invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as “salt (I)”). Among salts (I), the side having a negative charge may be referred to as “anion (I)”, and the side having a positive charge may be referred to as “cation (I)”. TIFF0007702818000012.tif30138[In the formula, all symbols represent the same meaning as described above respectively.]

[0011] In formula (I), R 1 and R 2 The L contained in 1Examples 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, and a hexane-1,6-diyl group; and branched alkanediyl groups such as an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-2,2-diyl group, a pentane-2,4-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. L 1 is preferably an alkanediyl group having 1 to 3 carbon atoms, more preferably a methylene group.

[0012] R 1 and R 2 The acid-stable hydrocarbon group represented by R 10 in R means a group in which the group represented by R 10 does not leave even when contacted with an acid (e.g., trifluoromethanesulfonic acid). As the acid-stable hydrocarbon group, a group represented by the formula (3a) (hereinafter, sometimes referred to as "acid-stable hydrocarbon group (3a)") is preferable. TIFF0007702818000013.tif1958[In the formula (3a), R 1a and R 2a each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, or R 1a and R 2a are bonded to each other to form a hydrocarbon ring having 3 to 36 carbon atoms which may have an alkyl group having 1 to 12 carbon atoms. R 3a represents a hydrogen atom, or R 1a and R 2a and R 3a are bonded to each other to form a hydrocarbon ring having 3 to 36 carbon atoms which may have an alkyl group having 1 to 12 carbon atoms. * represents a bond.]

[0013] R 1a 、R 1b 、R 2aand R 2b Examples of the hydrocarbon group of 2b include chain hydrocarbon groups such as alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these. Examples of the alkyl group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group, nonyl group, etc. The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 12, more preferably 1 to 9, still more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 2. The alicyclic hydrocarbon group may be monocyclic, polycyclic, or spiro ring, and may be saturated or unsaturated. Examples of the alicyclic hydrocarbon group include the groups represented below. The bonding site can be at any position. TIFF0007702818000014.tif44168Specifically, examples of the alicyclic hydrocarbon group include monocyclic cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cyclododecyl group, etc., and polycyclic cycloalkyl groups such as norbornyl group, adamantyl group, etc. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, and still more preferably 3 to 12. Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, binaphthyl group, etc. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and still more preferably 6 to 10.

[0014] Examples of the group formed by combining these include groups formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group such as cyclopentylmethyl group, adamantylmethyl group, etc., and groups formed by combining an aromatic hydrocarbon group and a chain hydrocarbon group such as benzyl group, phenethyl group, etc. In the case of a group formed by combination, two or more of the above groups may be combined, and the above group may contain groups with different valences (divalent or trivalent groups (chain hydrocarbon groups, alicyclic saturated hydrocarbon groups, aromatic hydrocarbon groups), etc.). R 1a and R 2a 、R 1a and R 2a and R 3a 、R 1b and R 2b or R 1b and R 2b and R 3b When the hydrocarbon ring formed by the mutual connection of and has an alkyl group, the number of carbon atoms excluding the number of carbon atoms of the alkyl group is defined as the total number of carbon atoms of the hydrocarbon ring. R 1a 、R 2a 、R 1b or R 2b When is a hydrocarbon group, the number of carbon atoms of the hydrocarbon group is preferably, independently of each other, 1 to 16, more preferably 1 to 14, and even more preferably 1 to 12. R 1a and R 2a 、R 1b and R 2b 、R 1a and R 2a and R 3a or R 1b and R 2b and R 3b When they are mutually connected to form a hydrocarbon ring, the number of carbon atoms of the hydrocarbon ring is preferably, independently of each other, 3 to 24, more preferably 3 to 18, and even more preferably 3 to 16. R 1a and R 2a 、R 1a and R 2a and R 3a 、R 1b and R 2b or R 1b and R 2b and R 3b Examples of the alkyl group that may be present when they are mutually connected to form a hydrocarbon ring include the same groups as described above. R 1a and R 2a 、R1a and R 2a and R 3a , R 1b and R 2b or R 1b and R 2b and R 3b and are bonded to each other to form a hydrocarbon ring, -C(R 1a )(R 2a )(R 3a ) or -C(R 1b )(R 2b )(R 3b ) includes the following groups, etc. * represents the bonding site. TIFF0007702818000015.tif28161R 1a , R 2a , R 1b and R 2b are each independently a hydrogen atom or a hydrocarbon group having 1 to 14 carbon atoms, or R 1a and R 2a , R 1b and R 2b are bonded to each other to preferably form a hydrocarbon ring having 3 to 24 carbon atoms which may have an alkyl group having 1 to 12 carbon atoms, and are each independently a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, or R 1a and R 2a , R 1b and R 2b are bonded to each other to more preferably form a hydrocarbon ring having 3 to 16 carbon atoms which may have an alkyl group having 1 to 6 carbon atoms. R 3a and R 3b are each independently a hydrogen atom, or R 1a and R 2a and R 3a or R 1b and R 2b and R 3b are bonded to each other to preferably form a hydrocarbon ring having 3 to 24 carbon atoms which may have an alkyl group having 1 to 12 carbon atoms, and is a hydrogen atom, or R 1a and R 2a and R 3a or R 1b and R 2b and R 3band more preferably bond to each other to form a hydrocarbon ring having 3 to 16 carbon atoms which may have an alkyl group having 1 to 6 carbon atoms. When the hydrocarbon ring has an alkyl group, the bonding position of the alkyl group is a carbon atom other than the carbon atom to which the bond to the oxygen atom or carbonyl group is bonded. R 1 and R 2 is -O-CO-R 10 , -O-CO-OR 10 , -OL 1 -CO-OR 10 is preferably -O-CO-OR 10 Or -OL 1 -CO-OR 10 It is more preferable that: R 1 and R 2 The bond positions of X 1 and X 2 The bonding position of X may be either o-position, m-position or p-position. 1 and X 2 It is preferable that the bond is at the p-position relative to the bonding position of the above.

[0015] R 4 , R 5 , R 7 and R 8 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 4 , R 5 , R 7 and R 8 The fluorinated alkyl group having 1 to 12 carbon atoms refers to an alkyl group having 1 to 12 carbon atoms and containing a fluorine atom, and examples thereof include perfluoroalkyl groups having 1 to 12 carbon atoms (trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group), as well as 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, and 3,3,4,4,4-pentafluorobutyl group. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 6, more preferably 1 to 4, and further preferably 1 to 3. R 4 、R 5 、R 7 and R 8 Examples of the hydrocarbon group having 1 to 18 carbon atoms for R include chain hydrocarbon groups such as alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, etc. The number of carbon atoms of the alkyl group is preferably 1 to 12, more preferably 1 to 9, still more preferably 1 to 6, and even more preferably 1 to 4. The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, etc. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, etc. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, and still more preferably 3 to 12. Specifically, examples of the alicyclic hydrocarbon group include the groups represented below, etc. The bonding site can be at any position. TIFF0007702818000016.tif44168Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, binaphthyl group, etc. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and still more preferably 6 to 10. Examples of the group formed by combination include a group combining an aromatic hydrocarbon group and an aliphatic hydrocarbon group (e.g., aromatic hydrocarbon group - alkane diyl group - *, alkyl group - aromatic hydrocarbon group - *), a group combining an alicyclic hydrocarbon group and an aliphatic hydrocarbon group (e.g., alicyclic hydrocarbon group - alkane diyl group - *, alkyl group - alicyclic hydrocarbon group - *), and a group combining an aromatic hydrocarbon group and an alicyclic hydrocarbon group (e.g., aromatic hydrocarbon group - alicyclic hydrocarbon group - *, alicyclic hydrocarbon group - aromatic hydrocarbon group - *). * represents a bonding site. Examples of the aromatic hydrocarbon group - alkane diyl group - * include aralkyl groups such as benzyl group and phenethyl group. Examples of the alkyl group - aromatic hydrocarbon group - * include tolyl group, xylyl group, cumenyl group, etc. Examples of the alicyclic hydrocarbon group - alkane diyl group - * include cycloalkylalkyl groups such as cyclohexylmethyl group, cyclohexylethyl group, 1-(adamantan-1-yl)methyl group, 1-(adamantan-1-yl)-1-methylethyl, etc. Examples of the alkyl group - alicyclic hydrocarbon group - * include cycloalkyl groups having an alkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, 2-alkyladamantan-2-yl group, etc. Examples of the aromatic hydrocarbon group - alicyclic hydrocarbon group - * include phenylcyclohexyl group, etc. Examples of the alicyclic hydrocarbon group - aromatic hydrocarbon group - * include cyclohexylphenyl group, etc. In the combination, two or more alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and aliphatic hydrocarbon groups may be combined respectively. Further, -CH2- contained in the cyclic hydrocarbon group and the aliphatic hydrocarbon group (alkane diyl group, alkyl group) may be replaced by -O-, -S-, -CO- or -SO2-. Any of the combined groups may be bonded to the benzene ring. Examples of the group in which -CH2- contained in the hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include a hydroxy group (a group in which -CH2- contained in the methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- contained in the ethyl group is replaced by -O-CO-), a thiol group (a group in which -CH2- contained in the methyl group is replaced by -S-), an alkoxy group (a group in which -CH2- at any position contained in the alkyl group is replaced by -O-), an alkylthio group (a group in which -CH2- at any position contained in the alkyl group is replaced by -S-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -O-CO-), an alkylsulfonyl group (a group in which -CH2- at any position contained in the alkyl group is replaced by -SO2-), an alkylcarbonyl group (a group in which -CH2- at any position contained in the alkyl group is replaced by -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -CO-O-), a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, an aromatic hydrocarbon group-carbonyl-oxy group, a group formed by combining two or more of these groups, and the like. Examples of the alkoxy group include alkoxy groups having 1 to 17 carbon atoms, such as 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 the like. The number of carbon atoms of the alkoxy group is preferably 1 to 11, more preferably 1 to 6, and still more preferably 1 to 4. Examples of the alkylthio group include alkylthio groups having 1 to 17 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group and the like. The number of carbon atoms of the alkylthio group is preferably 1 to 11, more preferably 1 to 6, and still more preferably 1 to 4. The alkoxycarbonyl group, the alkylcarbonyl group and the alkylcarbonyloxy group represent a group in which a carbonyl group or a carbonyloxy group is bonded to the above-described alkyl group or alkoxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group and the like. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 18 carbon atoms, such as acetyl group, propionyl group and butyryl group and the like. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as acetyloxy group, propionyloxy group, butyryloxy group and the like. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, and still more preferably 2 to 4. 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. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 17 carbon atoms, such as methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group and the like. The number of carbon atoms of the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, and still more preferably 1 to 4. Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 17 carbon atoms, such as cyclohexyloxy group and the like. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 17 carbon atoms, such as cyclohexylmethoxy group and the like. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as butoxycarbonyloxy group and the like. Examples of the aromatic hydrocarbon group-carbonyl-oxy group include aromatic hydrocarbon group-carbonyl-oxy groups having 7 to 17 carbon atoms, such as benzoyloxy group and the like. In addition, examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O- or -CO- include the groups represented below. The -O- or -CO- in the groups represented below may each be replaced by -S- or -SO2-. The bonding position can be any position. When -CH2- contained in the hydrocarbon group is replaced by -O- or -CO-, the carbon number before replacement is defined as the total carbon number of the hydrocarbon group. Also, the number may be one or two or more. R 4 、R 5 、R 7 and R 8 Examples of the substituent that the hydrocarbon groups of R, R, R, and R may have include a halogen atom, a cyano group, and an alkyl group having 1 to 12 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-). Examples of the halogen atom include the same groups as those described above. Examples of the alkyl group having 1 to 12 carbon atoms include the same groups as those described above. When -CH2- contained in the alkyl group as a substituent is replaced by -O- or -CO-, the carbon number before replacement is defined as the total carbon number of the alkyl group. Examples of the replaced group include a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, and the like. Examples of the alkoxy group, the alkoxycarbonyl group, the alkylcarbonyl group, and the alkylcarbonyloxy group include the same groups as those described above. The hydrocarbon group may have one substituent or a plurality of substituents.

[0016] X 1 is preferably an oxygen atom. X 2 is preferably an oxygen atom. X 1 and X 2 The bonding positions of +It may be any of the ortho, meta, and para positions with respect to the bonding position. Among them, I + is preferably bonded to the meta or para position with respect to the bonding position. m1 is preferably 1 or 2, and more preferably 1. m2 is preferably 0, 1, or 2, and preferably 0 or 1. m4 is preferably 0, 1, 2, or 4. When m4 is 1 or 2, at least one R 4 bonding position is preferably bonded to the ortho position with respect to the bonding position of X 1 When m4 is 2, one R 4 bonding position is preferably bonded to the ortho position with respect to the bonding position of X 1 and the other R 4 bonding position is preferably bonded to the meta position with respect to the bonding position of X 1 . m5 is preferably 0 or 1, 2, or 4. When m5 is 1 or 2, at least one R 5 bonding position is preferably bonded to the ortho position with respect to the bonding position of X 2 When m5 is 2, one R 5 bonding position is preferably bonded to the ortho position with respect to the bonding position of X 2 and the other R 5 bonding position is preferably bonded to the meta position with respect to the bonding position of X 2 . m7 is preferably 0, 1, or 2, and more preferably 0 or 1. m8 is preferably 0 or 1. R 4 and R 5is each independently preferably a halogen atom, a C1-C4 fluoroalkyl group or a C1-C6 alkyl group (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), more preferably a halogen atom, a C1-C4 fluoroalkyl group or a C1-C4 alkyl group (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), and even more preferably a fluorine atom, an iodine atom, a trifluoromethyl group or a C1-C4 alkyl group. R 7 and R 8 are each independently preferably a halogen atom, a C1-C4 fluoroalkyl group or a C1-C6 alkyl group (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), more preferably a halogen atom, a C1-C4 fluoroalkyl group or a C1-C4 alkyl group (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), even more preferably a fluorine atom, an iodine atom, a C1-C4 perfluoroalkyl group or a C1-C4 alkyl group (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), and still even more preferably a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a t-butyl group, a hydroxy group or a methoxy group. R 7 and R 8 The bonding position of + may be any of the ortho, meta and para positions relative to the bonding position of + . Among them, it is preferably bonded to the ortho position relative to the bonding position of m2 is 0, and R 8 is preferably a branched C3 or C4 alkyl group.

[0017] Examples of the cation of the salt (I) include cations represented by the following formulas (I-c-1) to (I-c-45). TIFF0007702818000018.tif141155

[0018] TIFF0007702818000019.tif238159

[0019] TIFF0007702818000020.tif225162

[0020] TIFF0007702818000021.tif157168

[0021] AI - Examples of the organic anion represented by AI include sulfonate anions, sulfonylimide anions, sulfonylmethide anions, carboxylic acid anions, and the like. AI - The organic anion represented by AI is preferably, independently of each other, a sulfonate anion, and more preferably, independently of each other, an anion represented by formula (I-A). TIFF0007702818000022.tif2965[In formula (I-A), Q 1 and Q 2 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L 1 represents a saturated hydrocarbon group having 1 to 24 carbon atoms, wherein -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. Y 1 represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, wherein -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-.]

[0022] In the anion represented by formula (I-A), when -CH2- contained in the saturated hydrocarbon group is replaced by -O- or -CO-, the number of carbon atoms before replacement is defined as the number of carbon atoms of the saturated hydrocarbon group. Further, when -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -SO2- or -CO-, the number of carbon atoms before replacement is defined as the number of carbon atoms of the alicyclic hydrocarbon group.

[0023] Q 1 and Q 2 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms for Q and Q include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Q 1 and Q 2 are each independently preferably a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

[0024] L 1 Examples of the divalent saturated hydrocarbon group for L include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and a group formed by combining two or more of these groups. Specifically, 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; branched alkanediyl groups such as an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-2,2-diyl group, a pentane-2,4-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group; A monocyclic divalent alicyclic saturated hydrocarbon group which is a cycloalkanediyl group such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, or a cyclooctane-1,5-diyl group; Examples thereof include polycyclic divalent alicyclic saturated hydrocarbon groups such as 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.

[0025] L 1 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by is replaced by -O- or -CO- include groups represented by any of formula (b1-1) to formula (b1-3). In the groups represented by formula (b1-1) to formula (b1-3) and the groups represented by formula (b1-4) to formula (b1-11) which are specific examples thereof, * and ** represent bonding sites, and * represents -Y 1 and represents a bond to.

[0026] TIFF0007702818000023.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 hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. However, the total number of carbon atoms of L b2 and L b3 is 22 or less. In formula (b1-2), L b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b5represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. However, L b4 and L b5 The total number of carbon atoms of is 22 or less. In formula (b1-3), L b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. L b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. However, L b6 and L b7 The total number of carbon atoms of is 23 or less.]

[0027] In the groups represented by formula (b1-1) to formula (b1-3), when -CH2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the number of carbon atoms before replacement is taken as the number of carbon atoms of the saturated hydrocarbon group. Examples of the divalent saturated hydrocarbon group include the same ones as the divalent saturated hydrocarbon group of L b1 . 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 the hydrogen atoms contained in the divalent saturated hydrocarbon group may be substituted with fluorine atoms. L b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b6is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms. L b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L 1 As the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by is replaced with -O- or -CO-, the group represented by the formula (b1-1) or the formula (b1-3) is preferable.

[0028] Examples of the group represented by the formula (b1-1) include the groups represented by the formulas (b1-4) to (b1-8). TIFF0007702818000024.tif48120[In the formula (b1-4), L b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. In the formula (b1-5), L b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and the hydrogen atoms contained in the divalent saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. However, b9 L b10 and the total carbon number of L b10 is 20 or less. In the formula (b1-6), L b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b12represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atoms contained in the divalent saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. However, the total number of carbon atoms in L b11 and L b12 is 21 or less. In formula (b1-7), L b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms. L b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atoms contained in the divalent saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. However, the total number of carbon atoms in L b13 to L b15 is 19 or less. In formula (b1-8), L b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -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 the hydrogen atoms contained in the divalent saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. However, the total number of carbon atoms in L b16 to L b18 is 19 or less.

[0029] 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 b10is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

[0030] Examples of the group represented by the formula (b1-3) include the groups represented by the formulas (b1-9) to (b1-11), respectively. TIFF0007702818000025.tif23139 [In the formula (b1-9), L b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b20represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms, hydroxy groups or alkylcarbonyloxy groups. The -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atoms contained in the alkylcarbonyloxy group may be substituted with hydroxy groups. However, L b19 and L b20 have a total carbon number of 23 or less. In formula (b1-10), L b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms. L b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms, hydroxy groups or alkylcarbonyloxy groups. The -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atoms contained in the alkylcarbonyloxy group may be substituted with hydroxy groups. However, L b21 , L b22 and L b23 have a total carbon number of 21 or less. In formula (b1-11), L b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms. L b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b26represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms, hydroxy groups or alkylcarbonyloxy groups. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atoms contained in the alkylcarbonyloxy group may be substituted with hydroxy groups. However, L b24 、L b25 and L b26 have a total carbon number of 21 or less.

[0031] In the groups represented by formulas (b1-9) to (b1-11), when the hydrogen atoms contained in the saturated hydrocarbon group are substituted with alkylcarbonyloxy groups, the carbon number before substitution is taken as the carbon number of the saturated hydrocarbon group.

[0032] Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, an adamantylcarbonyloxy group and the like.

[0033] Examples of the group represented by formula (b1-4) include the following. TIFF0007702818000026.tif16154

[0034] Examples of the group represented by formula (b1-5) include the following. TIFF0007702818000027.tif69148

[0035] Examples of the group represented by formula (b1-6) include the following. TIFF0007702818000028.tif44148

[0036] Examples of the group represented by formula (b1-7) include the following. TIFF0007702818000029.tif63153

[0037] Examples of the group represented by formula (b1-8) include the following. TIFF0007702818000030.tif23150

[0038] Examples of the group represented by formula (b1-2) include the following. TIFF0007702818000031.tif31161

[0039] Examples of the group represented by formula (b1-9) include the following. TIFF0007702818000032.tif44137

[0040] Examples of the group represented by formula (b1-10) include the following. TIFF0007702818000033.tif92165

[0041] Examples of the group represented by formula (b1-11) include the following. TIFF0007702818000034.tif85164

[0042] Y 1 Examples of the alicyclic hydrocarbon group represented by include the groups represented by formula (Y1) to formula (Y11), formula (Y36) to formula (Y38). Y 1 When -CH2- contained in the alicyclic hydrocarbon group represented by is replaced by -O-, -SO2- or -CO-, the number thereof may be one or more than two. Examples of such groups include the groups represented by formula (Y12) to formula (Y35), formula (Y39) to formula (Y43). * represents the bonding position with L 1 represents the bonding position with.

[0043] TIFF0007702818000035.tif81163Y 1The alicyclic hydrocarbon group represented by is preferably a group represented by any of formula (Y1) to formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39) to formula (Y43), more preferably a group represented by formula (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43), and still 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). Y 1 When the alicyclic hydrocarbon group represented by is a spiro ring such as formula (Y28) to formula (Y35), formula (Y39), formula (Y40), formula (Y42), formula (Y43), etc., the alkanediyl group between two oxygen atoms preferably has one or more fluorine atoms. Further, among the alkanediyl groups contained in the ketal structure, it is preferable that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

[0044] Y 1 Examples of the substituent of the methyl group represented by include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-O-R b1 group or -(CH2) ja -O-CO-R b1 group (wherein R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms or a group combining these. ja represents any integer from 0 to 4. The -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -S(O)2- or -CO-, and the hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom.). Y 1Examples of the substituent of the alicyclic hydrocarbon group represented by 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, -CH2- may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-O-R b1 group or -(CH2) ja -O-CO-R b1 group (wherein R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these. ja represents any integer from 0 to 4. -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -S(O)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.).

[0045] 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, etc. The alicyclic hydrocarbon group may have a chain hydrocarbon group, such as a methylcyclohexyl group, a dimethylcyclohexyl group, etc. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 12, more preferably 3 to 10. Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group. Examples of the aromatic hydrocarbon group having a chain hydrocarbon group include tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, and the like. Examples of the aromatic hydrocarbon group having an alicyclic hydrocarbon group include p-cyclohexylphenyl group, p-adamantylphenyl group, and the like. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 14, more preferably 6 to 10. Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, and the like. The number of carbon atoms of the alkyl group is preferably 1 to 12, more preferably 1 to 9, still more preferably 1 to 6, and even more preferably 1 to 4. Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as hydroxymethyl group and hydroxyethyl group. Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group. Examples of the group in which -CH2- contained in the alkyl group is replaced with -O-, -SO2-, -CO-, or the like include alkoxy group, alkylsulfonyl group, alkoxycarbonyl group, alkylcarbonyl group, alkylcarbonyloxy group, or a group combining these. Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, and dodecyloxy group. The number of carbon atoms of the alkoxy group is preferably 1 to 12, more preferably 1 to 6, still more preferably 1 to 4. Examples of the alkylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, and a propylsulfonyl group. The number of carbon atoms in the sulfonyl group is preferably from 1 to 12, more preferably from 1 to 6, and still more preferably from 1 to 4. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. The number of carbon atoms in the alkoxycarbonyl group is preferably from 2 to 12, more preferably from 2 to 6, and still more preferably from 2 to 4. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The number of carbon atoms in the alkylcarbonyl group is preferably from 2 to 12, more preferably from 2 to 6, and still more preferably from 2 to 4. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The number of carbon atoms in the alkylcarbonyloxy group is preferably from 2 to 12, more preferably from 2 to 6, and still more preferably from 2 to 4. Examples of the combined group include a group formed by combining an alkoxy group and an alkyl group, a group formed by combining an alkoxy group and an alkoxy group, a group formed by combining an alkoxy group and an alkylcarbonyl group, and a group formed by combining an alkoxy group and an alkylcarbonyloxy group. Examples of the group formed by combining an alkoxy group and an alkyl group include an alkoxyalkyl group such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, and an ethoxymethyl group. The number of carbon atoms in the alkoxyalkyl group is preferably from 2 to 12, more preferably from 2 to 6, and still more preferably from 2 to 4. Examples of the group formed by combining an alkoxy group and an alkoxy group include an alkoxyalkoxy group such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, and an ethoxyethoxy group. The number of carbon atoms in the alkoxyalkoxy group is preferably from 2 to 12, more preferably from 2 to 6, and still more preferably from 2 to 4. Examples of the group combining an alkoxy group and an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group, and an ethoxypropionyl group. The number of carbon atoms of the alkoxyalkylcarbonyl group is preferably from 3 to 13, more preferably from 3 to 7, and even more preferably from 3 to 5. Examples of the group combining an alkoxy group and an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, and an ethoxypropionyloxy group. The number of carbon atoms of the alkoxyalkylcarbonyloxy group is preferably from 3 to 13, more preferably from 3 to 7, and even more preferably from 3 to 5. Examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced with -O-, -S(O)2-, -CO- or the like include the groups represented by formula (Y12) to formula (Y35) and formula (Y39) to formula (Y43).

[0046] Y 1 Examples thereof include the following. TIFF0007702818000036.tif160165

[0047] Y 1 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, even more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, still more preferably an alicyclic hydrocarbon group substituted with a hydroxy group, and even still more preferably an adamantyl group which may have a substituent, and -CH2- constituting the alicyclic hydrocarbon group or adamantyl group may be replaced with -CO-, -S(O)2- or -CO-. Y 1 Specifically, Y is preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group or the group represented by (Y42), (Y100) to (Y114), and particularly preferably a hydroxyadamantyl group or an oxoadamantyl group, or a group containing these.

[0048] Examples of the anion represented by formula (I-A) include anions represented by formula (I-A-1) to formula (I-A-59) (hereinafter sometimes referred to as "anion (I-A-1)" etc. according to the formula number). An anion represented by any of formula (I-A-1) to formula (I-A-4), formula (I-A-9), formula (I-A-10), formula (I-A-24) to formula (I-A-33), formula (I-A-36) to formula (I-A-40), and formula (I-A-47) to formula (I-A-59) is more preferable. TIFF0007702818000037.tif72140

[0049] TIFF0007702818000038.tif77163

[0050] TIFF0007702818000039.tif85163

[0051] TIFF0007702818000040.tif239155

[0052] TIFF0007702818000041.tif95149

[0053] Here, R i2 ~R i7 are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. 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 1 and Q 2 represent the same meaning as described above. Specific examples of the anion represented by formula (I-A) include the anions described in JP-A-2010-204646.

[0054] As the anion represented by formula (I-A), anions represented by formula (I-a-1) to formula (I-a-38) are preferable. TIFF0007702818000042.tif90160

[0055] TIFF0007702818000043.tif101146

[0056] TIFF0007702818000044.tif110168

[0057] TIFF0007702818000045.tif102167

[0058] Among them, anions represented by any of formula (I-a-1) to formula (I-a-3), formula (I-a-7) to formula (I-a-19), and formula (I-a-22) to formula (I-a-38) are preferable.

[0059] AI - Examples of the sulfonylimide anion represented by include the following. TIFF0007702818000046.tif38135AI - Examples of the sulfonylmethide anion represented by include the following. TIFF0007702818000047.tif31127AI - Examples of the carboxylic acid anion represented by include the following. TIFF0007702818000048.tif43156

[0060] Specific examples of salt (I) include salts obtained by arbitrarily combining the above-mentioned cations and anions. Specific examples of salt (I) are shown in the following table. In the following table, each symbol represents the symbol attached to the structure representing the above-mentioned anion or cation, and "~" indicates that each of the salt (I) and the anion (I) corresponds. For example, the salt (I-1) is a salt composed of the anion represented by the formula (I-a-1) and the cation represented by the formula (I-c-1), the salt (I-2) is a salt composed of the anion represented by the formula (I-a-2) and the cation represented by the formula (I-c-1), and the salt (I-39) is a salt composed of the anion represented by the formula (I-a-1) and the cation represented by the formula (I-c-2). TIFF0007702818000049.tif26146 [Table 1] TIFF0007702818000051.tif145157

[0061] Among them, the salt (I) is preferably a salt formed by combining an anion represented by any one of the formulas (I-a-1) to (I-a-4), (I-a-7) to (I-a-11), (I-a-14) to (I-a-30), and (I-a-35) to (I-a-38) with a cation represented by any one of the formulas (I-c-1) to (I-c-45). Specifically, salts (I-1) to (I-4), salts (I-7) to (I-11), salts (I-14) to (I-30), salts (I-35) to (I-38), salts (I-39) to (I-42), salts (I-45) to (I-49), salts (I-52) to (I-68), salts (I-73) to (I-76), salts (I-77) to (I-80), salts (I-83) to (I-87), salts (I-90) to (I-106), salts (I-111) to (I-114), salts (I-115) to (I-118), salts (I-121) to (I-125), salts (I-128) to (I-144), salts (I-149) to (I-152), salts (I-153) to (I-156), salts (I-159) to (I-163), salts (I-166) to (I-182), salts (I-187) to (I-190), salts (I-191) to (I-194), salts (I-197) to (I-201), salts (I-204) to (I-220), salts (I-225) to (I-228), salts (I-229) to (I-232), salts (I-235) to (I-239), salts (I-242) to (I-258), salts (I-263) to (I-266), salts (I-267) to (I-270), salts (I-273) to (I-277), salts (I-280) to (I-296), salts (I-301) to (I-304), salts (I-305) to (I-308), salts (I-311) to (I-315), salts (I-318) to (I-334), salts (I-339) to (I-342), salts (I-343) to (I-346), salts (I-349) to (I-353), salts (I-356) to (I-372), salts (I-377) to (I-380), salts (I-381) to (I-384), salts (I-387) to (I-391), salts (I-394) to (I-410), salts (I-415) to (I-418), salts (I-419) to (I-422), salts (I-425) to (I-429), salts (I-432) to (I-448), salts (I-453) to (I-456).Salts (I-457) to (I-460), salts (I-463) to (I-467), salts (I-470) to (I-486), salts (I-491) to (I-494), salts (I-495) to (I-498), salts (I-501) to (I-505), salts (I-508) to (I-524), salts (I-529) to (I-532), salts (I-533) to (I-536), salts (I-539) to (I-543), salts (I-546) to (I-562), salts (I-567) to (I-570), salts (I-571) to (I-574), salts (I-577) to (I-581), salts (I-584) to (I-600), salts (I-605) to (I-608), salts (I-609) to (I-612), salts (I-615) to (I-619), salts (I-622) to (I-638), salts (I-643) to (I-646), salts (I-647) to (I-650), salts (I-653) to (I-657), salts (I-660) to (I-676), salts (I-681) to (I-684), salts (I-685) to (I-688), salts (I-691) to (I-695), salts (I-698) to (I-714), salts (I-719) to (I-722), salts (I-723) to (I-726), salts (I-729) to (I-733), salts (I-736) to (I-752), salts (I-757) to (I-760), salts (I-761) to (I-764), salts (I-767) to (I-771), salts (I-774) to (I-790), salts (I-795) to (I-798), salts (I-799) to (I-802), salts (I-805) to (I-809), salts (I-812) to (I-828), salts (I-833) to (I-836), salts (I-837) to (I-840), salts (I-843) to (I-847), salts (I-850) to (I-866), salts (I-871) to (I-874), salts (I-875) to (I-878), salts (I-881) to (I-885), salts (I-888) to (I-904), salts (I-909) to (I-912), salts (I-913) to (I-916), salts (I-919) to (I-923), salts (I-926) to (I-942), salts (I-947) to (I-950), salts (I-951) to (I-954), salts (I-957) to (I-961), salts (I-964) to (I-980)Salts (I-985) to (I-988), salts (I-989) to (I-992), salts (I-995) to (I-999), salts (I-1002) to (I-1018), salts (I-1023) to (I-1026), salts (I-1027) to (I-1030), salts (I-1033) to (I-1037), salts (I-1040) to (I-1056), salts (I-1061) to (I-1064), salts (I-1065) to (I-1068), salts (I-1071) to (I-1075), salts (I-1078) to (I-1094), salts (I-1099) to (I-1102), salts (I-1103) to (I-1106), salts (I-1109) to (I-1113), salts (I-1116) to (I-1132), salts (I-1137) to (I-1140), salts (I-1141) to (I-1144), salts (I-1147) to (I-1151), salts (I-1154) to (I-1170), salts (I-1175) to (I-1178), salts (I-1179) to (I-1182), salts (I-1185) to (I-1189), salts (I-1192) to (I-1208), salts (I-1213) to (I-1216), salts (I-1217) to (I-1220), salts (I-1223) to (I-1227), salts (I-1230) to (I-1246), salts (I-1251) to (I-1254), salts (I-1255) to (I-1258), salts (I-1261) to (I-1265), salts (I-1268) to (I-1284), salts (I-1289) to (I-1292), salts (I-1293) to (I-1296), salts (I-1299) to (I-1303), salts (I-1306) to (I-1322), salts (I-1327) to (I-1330), salts (I-1331) to (I-1334), salts (I-1337) to (I-1341), salts (I-1344) to (I-1360), salts (I-1365) to (I-1368), salts (I-1369) to (I-1372), salts (I-1375) to (I-1379), salts (I-1382) to (I-1398), salts (I-1403) to (I-1406), salts (I-1407) to (I-1410), salts (I-1413) to (I-1417), salts (I-1420) to (I-1436), salts (I-1441) to (I-1444), salts (I-1445) to (I-1448)Salts (I-1451) to (I-1455), salts (I-1458) to (I-1474), salts (I-1479) to (I-1482), salts (I-1483) to (I-1486), salts (I-1489) to (I-1493), salts (I-1496) to (I-1512), salts (I-1517) to (I-1520), salts (I-1521) to (I-1524), salts (I-1527) to (I-1531), salts (I-1534) to (I-1550), salts (I-1555) to (I-1558), salts (I-1559) to (I-1562), salts (I-1565) to (I-1569), salts (I-1572) to (I-1588), salts (I-1593) to (I-1596), salts (I-1597) to (I-1600), salts (I-1603) to (I-1607), salts (I-1610) to (I-1626), salts (I-1631) to (I-1634), salts (I-1635) to (I-1638), salts (I-1641) to (I-1645), salts (I-1648) to (I-1664), salts (I-1669) to (I-1672), salts (I-1673) to (I-1676), salts (I-1679) to (I-1683), salts (I-1686) to (I-1702), salts (I-1707) to (I-1710) are preferred.

[0062] <Method for producing salt (I)> Salt (I) can be produced by reacting a salt represented by formula (I-a) and a salt represented by formula (I-b) in a solvent. TIFF0007702818000052.tif38162[Wherein, all symbols have the same meanings as described above. R A , R B and R C each independently represents a hydrocarbon group having 1 to 12 carbon atoms, or R A , R B and R C may together form an aromatic ring. R D represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.] Examples of the solvent include chloroform, monochlorobenzene, acetonitrile, water and the like. The reaction temperature is generally 15°C to 80°C, and the reaction time is generally 0.5 to 24 hours.

[0063] Examples of the salt represented by the formula (I-b) include salts represented by the following formula. These salts can be easily produced by the same method as described in JP-A-2011-116747 and JP-A-2016-047815, or by known production methods. TIFF0007702818000053.tif81162

[0064] TIFF0007702818000054.tif122155

[0065] In the salt (I-a), R 1 and R 2 are -O-L 1 -CO-O-R 10 The salt represented by the formula (I-a1) can be produced by reacting the salt represented by the formula (I-c) with the compound represented by the formula (I-d) in a solvent in the presence of a base catalyst. TIFF0007702818000055.tif62157[In the formula, all the symbols have the same meanings as described above.] Examples of the base include potassium carbonate, potassium iodide, pyridine, triethylamine, and the like. Examples of the solvent include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, water, and the like. The reaction temperature is generally 15°C to 80°C, and the reaction time is generally 0.5 to 24 hours.

[0066] Examples of the compound represented by the formula (I-d) include compounds represented by the following, which can be easily obtained from the market and can also be easily produced by known production methods. TIFF0007702818000056.tif13165

[0067] The salt represented by formula (I-c) can be produced by reacting the salt represented by formula (I-e), the compound represented by formula (I-f1), and the compound represented by formula (I-f2) in a solvent in the presence of a catalyst. TIFF0007702818000057.tif75153[Wherein all the symbols have the same meanings as described above.] Examples of the catalyst include potassium carbonate and sodium hydride. Examples of the solvent include chloroform, monochlorobenzene, acetonitrile, and water. The reaction temperature is usually 15°C to 100°C, and the reaction time is usually 0.5 to 24 hours.

[0068] Examples of the salt represented by formula (I-e) include salts represented by the following formula, etc., which can be easily obtained from the market and can also be easily produced by known production methods. TIFF0007702818000058.tif36165

[0069] Examples of the compound represented by formula (I-f1) and the compound represented by formula (I-f2) include compounds represented by the following, etc., which can be easily obtained from the market. TIFF0007702818000059.tif20104

[0070] The salt represented by formula (I-c) can also be produced by reacting the salt represented by formula (I-e), the compound represented by formula (I-f4), and the compound represented by formula (I-f5) in a solvent in the presence of potassium carbonate, and then subjecting the reaction product to acid treatment. TIFF0007702818000060.tif90167[Wherein all the symbols have the same meanings as described above. R ac represents an acid-labile group.] Examples of the solvent include chloroform, monochlorobenzene, acetonitrile, and water. The reaction temperature is usually 15°C to 100°C, and the reaction time is usually 0.5 to 24 hours. Examples of the acid include p-toluenesulfonic acid and hydrochloric acid.

[0071] Examples of the compound represented by formula (I-f4) and the compound represented by formula (I-f5) include the compounds represented below, and they can be easily obtained from the market. TIFF0007702818000061.tif78146

[0072] In salt (I-a), R 1 and R 2 being -O-CO-R 10 The salt represented by formula (I-a2) can be produced by reacting the salt represented by formula (I-c) and the compound represented by formula (I-d2) in a solvent in the presence of a base catalyst. TIFF0007702818000062.tif62157 [In the formula, all the symbols have the same meanings as described above.] Examples of the base include potassium carbonate, potassium iodide, pyridine, and triethylamine. Examples of the solvent include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, and water. The reaction temperature is usually 15°C to 80°C, and the reaction time is usually 0.5 to 24 hours.

[0073] Examples of the compound represented by formula (I-d2) include the compounds represented below, and they can be easily obtained from the market and can also be easily produced by known production methods. TIFF0007702818000063.tif18136

[0074] In salt (I-a), R 1 and R 2 being -O-R 10 The salt represented by formula (I-a3) can be produced by reacting the salt represented by formula (I-c) and the compound represented by formula (I-d3) in a solvent in the presence of a base catalyst. TIFF0007702818000064.tif62157 [In the formula, all the symbols have the same meanings as described above.] Examples of the base include sodium hydroxide and potassium hydroxide. Examples of the solvent include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, and water. The reaction temperature is generally 15°C to 80°C, and the reaction time is generally 0.5 to 24 hours.

[0075] Examples of the compound represented by the formula (I-d3) include the compounds represented below, which can be easily obtained from the market and can also be easily produced by known production methods. TIFF0007702818000065.tif14137

[0076] In the salt (I-a), R 1 and R 2 being -O-CO-O-R 10 The salt (represented by the formula (I-a4)) can be produced by reacting the salt represented by the formula (I-c) and the compound represented by the formula (I-d3) in a solvent in the presence of carbonyldiimidazole. TIFF0007702818000066.tif72161 [In the formula, all the symbols have the same meanings as described above.] Examples of the solvent include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, and water. The reaction temperature is generally 15°C to 80°C, and the reaction time is generally 0.5 to 24 hours.

[0077] [Acid generator] The acid generator of the present invention is an acid generator containing the salt (I). It may contain one kind of the salt (I) or may contain two or more kinds of the salt (I). In addition to the salt (I), the acid generator of the present invention may contain an acid generator known in the resist field (hereinafter sometimes referred to as "acid generator (B)"). The acid generator (B) may be used alone or in combination of two or more.

[0078] Either a nonionic or an ionic acid generator may be used as the acid generator (B). Examples of the nonionic acid generator include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxy ketone, diazonaphthoquinone 4-sulfonate), sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane), and the like. Representative examples of the ionic acid generator include onium salts containing an onium cation (e.g., diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of the anion of the onium salt include sulfonic acid anion, sulfonylimide anion, sulfonylmethide anion, and the like.

[0079] As the acid generator (B), compounds that generate an acid by radiation described in, for example, JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Patent No. 3,779,778, U.S. Patent No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. can be used. Further, compounds produced by known methods may be used. The acid generator (B) may be used in combination of two or more.

[0080] The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as "acid generator (B1)". However, excluding the salt (I).) TIFF0007702818000067.tif2962[In the 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, wherein -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be replaced 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, wherein -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S(O)2- or -CO-. Z1 + represents an organic cation.

[0081] Q in formula (B1) b1 Q b2 L b1 and Y are the same as Q 1 Q 2 L 1 and Y 1 in formula (I-A) described above, respectively. Examples of the sulfonate anion in formula (B1) include the same anions as those represented by formula (I-A).

[0082] Z1 + Examples of the organic cation of Z1 include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred.

[0083] Z +Examples of the organic cation include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, organic phosphonium cations, and the like. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, cations represented by any of formula (b2-1) to formula (b2-4) (hereinafter, may be referred to as "cation (b2-1)" etc. according to the formula number) can be mentioned.

[0084] In TIFF0007702818000068.tif46166, in formula (b2-1) to formula (b2-4), R b4 ~R b6 each independently represents 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, and the 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, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R b4 and R b5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH2- contained in the ring may be replaced with -O-, -S-, or -CO-. R b7 and 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, a plurality of 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 -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the chain hydrocarbon group may be substituted by an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted by an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 may be bonded to each other to form a ring including the -CH-CO- to which they are bonded, and the -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b13 ~R b18 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. 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, a plurality of Rs b14 are the same or different, and when q2 is 2 or more, a plurality of Rs b15 are the same or different, and when r2 is 2 or more, a plurality of Rs b16 are the same or different, and when s2 is 2 or more, a plurality of Rs b17 are the same or different, and when t2 is 2 or more, a plurality of Rs b18 are the same or different. An aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, and 2-ethylhexyl group. In particular, the b9 R~ b12 chain hydrocarbon group of is preferably C1-C12. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups. TIFF0007702818000069.tif10158 In particular, the b9 R~ b12 alicyclic hydrocarbon group of is preferably C3-C18, more preferably C4-C12. Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include methylcyclohexyl group, dimethylcyclohexyl group, 2-methyladamantan-2-yl group, 2-ethyladamantan-2-yl group, 2-isopropyladamantan-2-yl group, methylnorbornyl group, and isobornyl group. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The alkyl fluoride group represents an alkyl group having 1 to 12 carbon atoms with a fluorine atom, and examples thereof include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, and a perfluorobutyl group. The number of carbon atoms of the alkyl fluoride group is preferably 1 to 9, more preferably 1 to 6, and still more preferably 1 to 4. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a biphenyl group, a naphthyl group, and a phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples of the aromatic hydrocarbon group having a chain hydrocarbon group with 1 to 18 carbon atoms include a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group. Examples of the aromatic hydrocarbon group having an alicyclic hydrocarbon group with 3 to 18 carbon atoms include a p-cyclohexylphenyl group and a p-adamantylphenyl group. When the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group with 1 to 18 carbon atoms and an alicyclic hydrocarbon group with 3 to 18 carbon atoms are preferred. Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group. Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. 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 methylcarbonyloxy group, ethylcarbonyloxy group, propylcarbonyloxy group, isopropylcarbonyloxy group, butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, pentylcarbonyloxy group, hexylcarbonyloxy group, octylcarbonyloxy group, 2-ethylhexylcarbonyloxy group, and the like. R b4 and R b5 The ring formed by R and R being bonded 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. Examples thereof include the following rings. * represents a bond. TIFF0007702818000070.tif23143R 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. Examples thereof include thiolan-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring, 1,4-oxathian-4-ium ring, and the like. R b11 and R b12 The ring formed by 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 thereof include oxocycloheptane ring, oxocyclohexane ring, oxonorbornane ring, oxoadamantane ring, and the like.

[0085] Among the cations (b2-1) to (b2-4), preferably, the cation (b2-1) is used. Examples of the cation (b2-1) include the following cations. TIFF0007702818000071.tif79158

[0086] TIFF0007702818000072.tif105158

[0087] Examples of the cation (b2-2) include the following cations. TIFF0007702818000073.tif18150

[0088] Examples of the cation (b2-3) include the following cations. TIFF0007702818000074.tif24126

[0089] Examples of the cation (b2-4) include the following cations. TIFF0007702818000075.tif127165

[0090] The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. Preferred examples of the acid generator (B) include a combination of an anion represented by any of Formula (I-a-1) to Formula (I-a-3), Formula (I-a-7) to Formula (I-a-16), Formula (I-a-18), Formula (I-a-19), and Formula (I-a-22) to Formula (I-a-38), and the cation (b2-1), the cation (b2-3), or the cation (b2-4).

[0091] Preferred examples of the acid generator (B) include those represented by Formula (B1-1) to Formula (B1-56). Among them, those containing an arylsulfonium cation are preferred, and those represented by Formula (B1-1) to Formula (B1-3), Formula (B1-5) to Formula (B1-7), Formula (B1-11) to Formula (B1-14), Formula (B1-20) to Formula (B1-26), Formula (B1-29), and Formula (B1-31) to Formula (B1-56) are particularly preferred. TIFF0007702818000076.tif98161

[0092] TIFF0007702818000077.tif152164

[0093] TIFF0007702818000078.tif92158

[0094] TIFF0007702818000079.tif130161

[0095] TIFF0007702818000080.tif99130

[0096] TIFF0007702818000081.tif92158

[0097] When containing salt (I) and acid generator (B) as the acid generator, the ratio of the content of salt (I) to the content of acid generator (B) (mass ratio; salt (I): acid generator (B)) is usually from 1:99 to 99:1, preferably from 2:98 to 98:2, more preferably from 5:95 to 95:5, still more preferably from 10:90 to 90:10, and particularly preferably from 15:85 to 85:15.

[0098] 〔Resist composition〕 The resist composition of the present invention contains an acid generator containing salt (I) and a resin having an acid-labile group (hereinafter sometimes referred to as "resin (A)"). Here, the "acid-labile group" means a group having a leaving group, and upon contact with an acid, the leaving group leaves and the constitutional unit is converted into a constitutional unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). The resist composition of the present invention preferably contains a quencher such as a salt that generates an acid having a lower acidity than the acid generated from the acid generator (hereinafter sometimes referred to as "quencher (C)"), and preferably contains a solvent (hereinafter sometimes referred to as "solvent (E)").

[0099] <Acid generator> In the resist composition of the present invention, the total content of the acid generator is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or less, still more preferably 3 parts by mass or more and 40 parts by mass or less, even more preferably 3 parts by mass or more and 35 parts by mass or less, and particularly preferably 5 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the resin (A) described below.

[0100] <Resin (A)> The resin (A) has a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"). The resin (A) preferably further contains a structural unit other than the structural unit (a1). Examples of the structural unit other than the structural unit (a1) include a structural unit having no acid-labile group (hereinafter sometimes referred to as "structural unit (s)"), a structural unit other than the structural unit (a1) and the structural unit (s) (for example, a structural unit having a halogen atom described below (hereinafter sometimes referred to as "structural unit (a4)")), a structural unit having a non-leaving hydrocarbon group described below (hereinafter sometimes referred to as "structural unit (a5)"), and structural units derived from other monomers known in the art.

[0101] 〈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 the formula (1) (hereinafter also referred to as "group (1)") and / or a group represented by the formula (2) (hereinafter also referred to as "group (2)"). TIFF0007702818000082.tif2298[In the formula (1), R a1 , R a2 and R a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, or R a1 and R a2 are bonded to each other to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * represents a bond.] TIFF0007702818000083.tif2378[In formula (2), R a1’ and R a2’ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R a3’ represents a hydrocarbon group having 1 to 20 carbon atoms, or R a2’ and R a3’ are bonded to each other to form a heterocyclic group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and the -CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced by -O- or -S-. X represents an oxygen atom or a sulfur atom. na’ represents 0 or 1. * represents a bond.]

[0102] R a1 , R a2 and R a3 Examples of the alkyl group in R R a1 , R a2 and R a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and the like. R a1 , R a2 and R a3 The alicyclic hydrocarbon group in R a1 , R a2 and R a3The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 16. TIFF0007702818000084.tif10159R a1 , R a2 and R a3 Examples of the aromatic hydrocarbon group in R, R, and R include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group. Examples of the combined group include a group combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, alkylcycloalkyl group or cycloalkylalkyl group), aralkyl group such as benzyl group, 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.), aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl group such as phenylcyclohexyl group, etc. Preferably, ma is 0 and na is 1. R a1 and R a2 When R and R are bonded to each other to form an alicyclic hydrocarbon group, examples of -C(R)(R)(R) include the following groups. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * represents a bond to -O-. a1 )(R a2 )(R a3 ) TIFF0007702818000085.tif35157

[0103] R a1’ , R a2’ and R a3’ Examples of the hydrocarbon group in R, R, and R include alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and groups formed by combining these. The alkyl group and alicyclic hydrocarbon group are the same as those exemplified for R, R, and R. a1 , R a2 and R a3 ​Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group. Examples of the combined group include a group formed by combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, alkylcycloalkyl group or cycloalkylalkyl group), aralkyl group such as benzyl group, 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.), aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl group such as phenylcyclohexyl group, and the like. R a2’ and R a3’ When R and R are bonded to each other to form a heterocyclic ring together with the carbon atom to which they are bonded and X, examples of -C(R a1’ )(R a2’ )-X-R a3’ include the following groups. * represents a bond. TIFF0007702818000086.tif18124R a1’ and R a2’ Among them, at least one is preferably a hydrogen atom. na' is preferably 0.

[0104] Examples of the group (1) include the following groups. In formula (1), a group in which R a1 , R a2 and R a3 are alkyl groups, ma = 0, and na = 1. As the group, tert-butoxycarbonyl group is preferable. In formula (1), a group in which R a1 , R a2 together with the carbon atom to which they are bonded form an adamantyl group, R a3 is an alkyl group, ma = 0, and na = 1. In formula (1), R a1 and R a2are each independently an alkyl group, R a3 is an adamantyl group, ma = 0, and na = 1 group. Specific examples of the group (1) include the following groups. * represents a bond. TIFF0007702818000087.tif154163

[0105] Specific examples of the group (2) include the following groups. * represents a bond. TIFF0007702818000088.tif68162

[0106] 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.

[0107] Among the (meth)acrylic monomers having an acid-labile group, preferably those having an alicyclic hydrocarbon group with 5 to 20 carbon atoms are mentioned. If a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

[0108] As the structural unit derived from the (meth)acrylic monomer having the group (1), preferably, a structural unit represented by the formula (a1-0) (hereinafter, may be referred to as a structural unit (a1-0)), a structural unit represented by the formula (a1-1) (hereinafter, may be referred to as a structural unit (a1-1)), or a structural unit represented by the formula (a1-2) (hereinafter, may be referred to as a structural unit (a1-2)) is mentioned. More preferably, it is at least one structural unit selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). These may be used alone or in combination of two or more. TIFF0007702818000089.tif46149[In the formula (a1-0), the formula (a1-1), and the formula (a1-2), L a01 、L a1 and L a2Each independently represents -O- or *-O-(CH2) k1 -CO-O-, k1 represents an integer from 1 to 7, and * represents a bond with -CO-. R a01 R a4 and R a5 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a02 R a03 and R a04 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. 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 from 0 to 14. n1 represents an integer from 0 to 10. n1’ represents an integer from 0 to 3.]

[0109] R a01 R a4 and R a5 are preferably a hydrogen atom or a methyl group, and more preferably a methyl group. L a01 L a1 and L a2 are preferably an oxygen atom or *-O-(CH2) k01 -CO-O- (where k01 is preferably an integer from 1 to 4, more preferably 1), and more preferably an oxygen atom. R a02 R a03 and R a04 As the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and the group formed by combining these in R a1 R a2 and R a3Groups similar to the groups exemplified above can be mentioned. R a6 and R a7 As the alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group and the group combining these in R of formula (1), R of formula (1) a1 R a2 and R a3 Groups similar to the groups exemplified above can be mentioned. R a02 R a03 and R a04 The alkyl group in R, R and R is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and still more preferably a methyl group. R a6 and R a7 The alkyl group in R and R is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group or a t-butyl group, and still more preferably an ethyl group, an isopropyl group or a t-butyl group. R a02 R a03 R a04 R a6 and R a7 The number of carbon atoms of the alicyclic hydrocarbon group of R, R, R, R, R and R is preferably 5 to 12, more preferably 5 to 10. R a02 R a03 R a04 R a6 and R a7 The number of carbon atoms of the aromatic hydrocarbon group of R, R, R, R, R and R is preferably 6 to 12, more preferably 6 to 10. For the group combining an alkyl group and an alicyclic hydrocarbon group, it is preferable that the total number of carbon atoms of these alkyl group and alicyclic hydrocarbon group is 18 or less. For the group combining an alkyl group and an aromatic hydrocarbon group, it is preferable that the total number of carbon atoms of these alkyl group and aromatic hydrocarbon group is 18 or less. R a02 and R a03 are preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group. R a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. R a6 and R a7 are 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 even more preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group or a phenyl group. m1 is preferably any integer from 0 to 3, more preferably 0 or 1. n1 is preferably any integer from 0 to 3, more preferably 0 or 1. n1’ is preferably 0 or 1.

[0110] Examples of the structural unit (a1-0) include a structural unit represented by any of the formulas (a1-0-1) to (a1-0-18) and a structural unit in which the methyl group corresponding to R a01 in the structural unit (a1-0) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group, and a structural unit represented by any of the formulas (a1-0-1) to (a1-0-10), (a1-0-13), (a1-0-14) is preferred. TIFF0007702818000090.tif99159

[0111] Examples of the structural unit (a1-1) include a structural unit derived from the monomer described in JP-A-2010-204646. Among them, a structural unit represented by any of the formulas (a1-1-1) to (a1-1-7) and a structural unit in which the methyl group corresponding to R a4 in the structural unit (a1-1) is replaced with a hydrogen atom is preferred, and a structural unit represented by any of the formulas (a1-1-1) to (a1-1-4) is more preferred. TIFF0007702818000091.tif39167

[0112] Examples of the structural unit (a1-2) include a structural unit represented by any of formulae (a1-2-1) to (a1-2-14) and a structural unit in which the methyl group corresponding to R in the structural unit (a1-2) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group, and a structural unit represented by any of formula (a1-2-2), formula (a1-2-5), formula (a1-2-6) and formulae (a1-2-10) to (a1-2-14) is preferable. a5 Examples of the structural unit (a1-2) include a structural unit represented by any of formulae (a1-2-1) to (a1-2-14) and a structural unit in which the methyl group corresponding to R in the structural unit (a1-2) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group, and a structural unit represented by any of formula (a1-2-2), formula (a1-2-5), formula (a1-2-6) and formulae (a1-2-10) to (a1-2-14) is preferable. TIFF0007702818000092.tif67163

[0113] When the resin (A) contains the structural unit (a1-0), the content thereof is usually 5 to 60 mol%, preferably 5 to 50 mol%, more preferably 10 to 40 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), the total content thereof is usually 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, still more preferably 25 to 75 mol%, even more preferably 30 to 75 mol% based on all the structural units of the resin (A).

[0114] 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)"). TIFF0007702818000093.tif3854[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 is a single bond or * -X a31 -(A a32 -X a32 ) nc -, where * represents the bonding site with the carbon atom to which -R a32 is bonded. A a32 represents an alkanediyl group having 1 to 6 carbon atoms. X a31 and X a32 each independently represent -O-, -CO-O- or -O-CO-. nc represents 0 or 1. la represents any integer from 0 to 4. When la is any integer of 2 or more, a plurality of R a33 may be the same as or different from each other. R a34 and R a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -C-O- to which they are bonded, and -CH2- contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced by -O- or -S-.

[0115] R a32 and R a33 Examples of the halogen atom in R R a32Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group and perfluorohexyl group. R a32 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group. R a33 Examples of the alkyl group in include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group. R a33 Examples of the alkoxy group in include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group and hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and still more preferably a methoxy group. R a33 Examples of the alkoxyalkyl group in include methoxymethyl group, ethoxyethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, sec-butoxymethyl group and tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and still more preferably a methoxymethyl group. R a33Examples of the alkoxyalkoxy group in [compound name] include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethyl group or an ethoxyethyl group. R a33 Examples of the alkylcarbonyl group in [compound name] include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group. R a33 Examples of the alkylcarbonyloxy group in [compound name] include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably an acetyloxy group. R a33 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0116] *-X a31 -(A a32 -X a32 ) nc Examples of - include *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a32 -CO-O-, *-O-CO-A a32 -O-, *-O-A a32 -CO-O-, *-CO-O-A a32 -O-CO-, *-O-CO-A a32 -O-CO-. Among them, *-CO-O-, *-CO-O-A a32 -CO-O- or *-O-A a32-CO-O- is preferred.

[0117] Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a32 is preferably a methylene group or an ethylene group.

[0118] A a30 is a single bond, *-CO-O- or *-CO-O-A a32 -CO-O- is preferred, more preferably a single bond, *-CO-O- or *-CO-O-CH2-CO-O-, and even more preferably a single bond or *-CO-O-.

[0119] 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, and an octyl group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bonding site). As the aromatic hydrocarbon group, aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, phenanthryl group, etc. can be mentioned. As the combined group, groups combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, cycloalkylalkyl group), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, etc. can be mentioned. In particular, R a36 includes an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these.

[0120] R a34 is preferably a hydrogen atom. R a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, more preferably a methyl group or an ethyl group. R a36 The hydrocarbon group of R is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and the alicyclic hydrocarbon group in R a36 are preferably unsubstituted. The aromatic hydrocarbon group in R a36 preferably has an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

[0121] -OC(R a34 )(R a35)-O-R a36 Desorbs upon contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group. -OC(R a34 )(R a35 )-O-R a36 Preferably binds to the o-position or p-position of the benzene ring, more preferably binds to the p-position.

[0122] 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 Formula (a1-4-1) to Formula (a1-4-18) and the hydrogen atom corresponding to R in the structural unit (a1-4) a32 are replaced by a halogen atom, a haloalkyl group or an alkyl group, and more preferably, the structural units represented by Formula (a1-4-1) to Formula (a1-4-5), Formula (a1-4-10), Formula (a1-4-13), and Formula (a1-4-14). TIFF0007702818000095.tif99157

[0123] When the resin (A) has the structural unit (a1-4), its content is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, still more preferably 20 to 85 mol%, still more preferably 20 to 70 mol%, and particularly preferably 20 to 60 mol% based on the total of all the structural units of the resin (A).

[0124] Examples of the structural unit derived from the (meth)acrylic monomer having the group (2) also include the structural unit represented by Formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)"). TIFF0007702818000096.tif4253In Formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. Z a1 is a single bond or *-(CH2) h3-CO-L 54 represents -, h3 represents an integer from 1 to 4, and * represents a bond with L 51 L 51 , L 52 , L 53 and L 54 each independently represents -O- or -S-. s1 represents an integer from 1 to 3. s1’ represents an integer from 0 to 3.

[0125] Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is preferred. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group, and a trifluoromethyl group. In formula (a1-5), R a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group. L 51 is preferably an oxygen atom. L 52 and L 53 Among them, it is preferable that one is -O- and the other is -S-. s1 is preferably 1. s1’ is preferably an integer from 0 to 2. Z a1 is preferably a single bond or *-CH2-CO-O-.

[0126] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP-A-2010-61117. Among them, the structural units represented by formula (a1-5-1) to formula (a1-5-4) are preferred, and the structural unit represented by formula (a1-5-1) or formula (a1-5-2) is more preferred. TIFF0007702818000097.tif31130

[0127] ​When the resin (A) has the structural unit (a1-5), its content is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, still more preferably 5 to 40 mol%, and even more preferably 5 to 30 mol% based on all the structural units of the resin (A).

[0128] In addition, examples of the structural unit (a1) also include the following structural units. TIFF0007702818000098.tif27161

[0129] When the resin (A) contains structural units such as (a1-3-1) to (a1-3-7) above, its content is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, still more preferably 20 to 85 mol%, even more preferably 20 to 70 mol%, and particularly preferably 20 to 60 mol% based on all the structural units of the resin (A).

[0130] 〈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.

[0131] 〈Structural unit (a2)〉 The hydroxy group of the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group. When producing a resist pattern from the resist composition of the present invention, when using a high-energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) as the exposure light source, as the structural unit (a2), a structural unit (a2) having a phenolic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-A) described later. When using an ArF excimer laser (193 nm) or the like, as the structural unit (a2), a structural unit (a2) having an alcoholic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-1) described later. As the structural unit (a2), one kind may be contained alone, or two or more kinds may be contained.

[0132] Examples of the structural unit having a phenolic hydroxy group in the structural unit (a2) include a structural unit represented by the formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)"). TIFF0007702818000099.tif3844[In the formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 represents a single bond or *-X a51 -(A a52 -X a52 ) nb -, and * represents a bond with the carbon atom to which -R a50 is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O-, or -O-CO-. nb represents 0 or 1. mb represents an integer of any one of 0 to 4. When mb is any integer of 2 or more, a plurality of Rs a51 may be the same as or different from each other.]

[0133] R a50 and R a51 Examples of the halogen atom in R include a fluorine atom, a chlorine atom, and a bromine atom, etc. R a50 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, 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 even more preferably a hydrogen atom or a methyl group. R a51 Examples of the alkyl group in R include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a51 Examples of the alkoxy group in R include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, and a tert-butoxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a51Examples of the alkoxyalkyl group include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. R a51 Examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group. R a51 Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group. R a51 Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably an acetyloxy group. R a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0134] *-X a51 -(A a52 -X a52 ) nb- includes, *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a52 -CO-O-, *-O-CO-A a52 -O-, *-O-A a52 -CO-O-, *-CO-O-A a52 -O-CO-, *-O-CO-A a52 -O-CO- is included. Among them, *-CO-O-, *-CO-O-A a52 -CO-O- or *-O-A a52 -CO-O- is preferred.

[0135] Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a52 is preferably a methylene group or an ethylene group.

[0136] A a50 is preferably a single bond, *-CO-O- or *-CO-O-A a52 -CO-O-, more preferably a single bond, *-CO-O- or *-CO-O-CH2-CO-O-, and even more preferably a single bond or *-CO-O-.

[0137] mb is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0. The hydroxy group is preferably bonded to the ortho position or the para position of the benzene ring, and more preferably bonded to the para position.

[0138] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577. Examples of the structural unit (a2-A) include structural units represented by Formula (a2-2-1) to Formula (a2-2-16) and structural units in which the methyl group corresponding to R in the structural unit (a2-A) in the structural units represented by Formula (a2-2-1) to Formula (a2-2-16) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. The structural unit (a2-A) is preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-1), the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-6), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14), and the structural unit represented by Formula (a2-2-1), the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-6), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14) is replaced with a hydrogen atom, more preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14), and the structural unit represented by Formula (a2-2-3) or the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14) is replaced with a hydrogen atom, and even more preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-8) and the structural unit represented by Formula (a2-2-8) is replaced with a hydrogen atom. a50 Examples of the structural unit (a2-A) include structural units represented by Formula (a2-2-1) to Formula (a2-2-16) and structural units in which the methyl group corresponding to R in the structural unit (a2-A) in the structural units represented by Formula (a2-2-1) to Formula (a2-2-16) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. The structural unit (a2-A) is preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-1), the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-6), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14), and the structural unit represented by Formula (a2-2-1), the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-6), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14) is replaced with a hydrogen atom, more preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14), and the structural unit represented by Formula (a2-2-3) or the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14) is replaced with a hydrogen atom, and even more preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-8) and the structural unit represented by Formula (a2-2-8) is replaced with a hydrogen atom. a50 Examples of the structural unit (a2-A) include structural units represented by Formula (a2-2-1) to Formula (a2-2-16) and structural units in which the methyl group corresponding to R in the structural unit (a2-A) in the structural units represented by Formula (a2-2-1) to Formula (a2-2-16) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. The structural unit (a2-A) is preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-1), the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-6), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14), and the structural unit represented by Formula (a2-2-1), the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-6), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14) is replaced with a hydrogen atom, more preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14), and the structural unit represented by Formula (a2-2-3) or the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14) is replaced with a hydrogen atom, and even more preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-8) and the structural unit represented by Formula (a2-2-8) is replaced with a hydrogen atom. a50 Examples of the structural unit (a2-A) include structural units represented by Formula (a2-2-1) to Formula (a2-2-16) and structural units in which the methyl group corresponding to R in the structural unit (a2-A) in the structural units represented by Formula (a2-2-1) to Formula (a2-2-16) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. The structural unit (a2-A) is preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-1), the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-6), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14), and the structural unit represented by Formula (a2-2-1), the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-6), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14) is replaced with a hydrogen atom, more preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14), and the structural unit represented by Formula (a2-2-3) or the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14) is replaced with a hydrogen atom, and even more preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-8) and the structural unit represented by Formula (a2-2-8) is replaced with a hydrogen atom. a50 Examples of the structural unit (a2-A) include structural units represented by Formula (a2-2-1) to Formula (a2-2-16) and structural units in which the methyl group corresponding to R in the structural unit (a2-A) in the structural units represented by Formula (a2-2-1) to Formula (a2-2-16) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. The structural unit (a2-A) is preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-1), the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-6), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14), and the structural unit represented by Formula (a2-2-1), the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-6), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14) is replaced with a hydrogen atom, more preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-3), the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14), and the structural unit represented by Formula (a2-2-3) or the structural unit represented by Formula (a2-2-8), the structural units represented by Formula (a2-2-12) to Formula (a2-2-14) is replaced with a hydrogen atom, and even more preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) in the structural unit represented by Formula (a2-2-8) and the structural unit represented by Formula (a2-2-8) is replaced with a hydrogen atom. TIFF0007702818000100.tif53169

[0139] When the resin (A) contains the structural unit (a2-A), the content of the structural unit (a2-A) is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, still more preferably 15 to 65 mol%, and even more preferably 20 to 65 mol% based on all the structural units. The structural unit (a2-A) can be incorporated into the resin (A) by, for example, polymerizing using the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Also, after polymerizing using acetoxystyrene or the like, the structural unit (a2-A) can be incorporated into the resin (A) by treating with an alkali such as tetramethylammonium hydroxide.

[0140] Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as "structural unit (a2-1)"). TIFF0007702818000101.tif3853In the formula (a2-1), L a3 represents -O- or *-O-(CH2) k2 -CO-O-, k2 represents an integer of any one of 1 to 7. * represents a bond with -CO-. R a14 represents a hydrogen atom or a methyl group. R a15 and R a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group. o1 represents an integer of any one of 0 to 10.

[0141] In the formula (a2-1), L a3 is preferably -O-, -O-(CH2) f1 -CO-O- (wherein f1 represents an integer of any one 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 any one of 0 to 3, and more preferably 0 or 1.

[0142] 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. TIFF0007702818000102.tif54150

[0143] 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).

[0144] <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)).

[0145] The structural unit (a3) ​​is preferably a structural unit represented by formula (a3-1), (a3-2), (a3-3) or (a3-4). One of these may be contained alone, or two or more of them may be contained. TIFF0007702818000103.tif51164 [In formula (a3-1), formula (a3-2), formula (a3-3) and formula (a3-4), L a4 , L a5 and L a6 are each independently -O- or *-O-(CH2) k3 It represents a group represented by -CO-O- (k3 represents an integer of any of 1 to 7). L a7 , -O-, *-OLa8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O- or *-O-L a8 -O-CO-L a9 represents -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * represents the bonding site with the carbonyl group. R a18 R a19 and R a20 each independently represents a hydrogen atom or a methyl group. R a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. X a3 represents -CH2- or an oxygen atom. 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 any integer from 0 to 5. q1 represents any integer from 0 to 3. r1 represents any integer from 0 to 3. w1 represents any integer from 0 to 8. When p1, q1, r1 and / or w1 is 2 or more, the plurality of R a21 R a22 R a23 and / or R a25 may be the same as or different from each other.

[0146] R a21 R a22 R a23 and R a25Examples of the aliphatic hydrocarbon group in [context] include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, and tert-butyl group. R a24 Examples of the halogen atom in [context] include fluorine atom, chlorine atom, bromine atom, and iodine atom. R a24 Examples of the alkyl group in [context] include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group, etc. Preferably, alkyl groups having 1 to 4 carbon atoms are included, and more preferably, methyl group or ethyl group is included. R a24 Examples of the alkyl group having a halogen atom in [context] include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluorohexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group, etc. L a8 and L a9 Examples of the alkanediyl group in [context] and [context] include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group, etc.

[0147] In formulas (a3-1) to (a3-3), L a4 ~L a6 are each independently preferably -O- or, *-O-(CH2) k3 -CO-O- in which k3 is an integer of 1 to 4, more preferably -O- and, *-O-CH2-CO-O-, and even more preferably an oxygen atom. R a18 ~R a21 is preferably a methyl group. R a22 and R a23 are each independently preferably a carboxy group, a cyano group or a methyl group. p1, q1 and r1 are each independently preferably any integer from 0 to 2, more preferably 0 or 1.

[0148] In formula (a3-4), R a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, still more preferably a hydrogen atom or a methyl group. R a25 is preferably a carboxy group, a cyano group or a methyl group. L a7 is preferably -O- or *-O-L a8 -CO-O-, more preferably -O-, -O-CH2-CO-O- or -O-C2H4-CO-O-. w1 is preferably any integer from 0 to 2, more preferably 0 or 1. In particular, formula (a3-4) is preferably formula (a3-4)’. TIFF0007702818000104.tif4051 (wherein R a24 , L a7 represent the same meanings as described above.)

[0149] Examples of the structural unit (a3) include structural units derived from the monomers described in JP-A-2010-204646, the monomers described in JP-A-2000-122294, and the monomers described in JP-A-2012-41274. Examples of the structural unit (a3) include structural units represented by any of formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3-1), formula (a3-3-2) and formula (a3-4-1) to formula (a3-4-12), and in the said structural units, R a18 , R a19 , R a20 and R a24A structural unit in which the methyl group corresponding thereto is replaced by a hydrogen atom is preferred.

[0150] TIFF0007702818000105.tif115165

[0151] When the resin (A) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol%, preferably 10 to 65 mol%, more preferably 10 to 60 mol% with respect to all the structural units of the resin (A). In addition, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3) or the structural unit (a3-4) is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, still more preferably 10 to 50 mol% with respect to all the structural units of the resin (A).

[0152] 〈Structural unit (a4)〉 Examples of the structural unit (a4) include the following structural units. TIFF0007702818000106.tif3066[In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having a fluorine atom with 1 to 24 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. R 42 Examples of the saturated hydrocarbon group represented by include a chain hydrocarbon group, a monocyclic or polycyclic alicyclic hydrocarbon group, and a group formed by combining these.

[0153] Examples of the chain hydrocarbon group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and octadecyl group. Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group; and polycyclic alicyclic hydrocarbon groups such as decahydronaphthyl group, adamantyl group, norbornyl group, and the following group (* represents a bond). Examples of the group formed by the combination of include a group formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, -alkanediyl group-alicyclic hydrocarbon group-alkyl group, and the like.

[0154] Examples of the structural unit (a4) include a structural unit represented by at least one selected from the group consisting of formula (a4-0), formula (a4-1), formula (a4-2), formula (a4-3), and formula (a4-4). TIFF0007702818000108.tif4652[In formula (a4-0), R 5 represents a hydrogen atom or a methyl group. L 4a represents a single bond or a divalent aliphatic saturated hydrocarbon 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 6 represents a hydrogen atom or a fluorine atom.]

[0155] L 4aExamples of the divalent aliphatic saturated hydrocarbon group in [substance] include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, etc., and branched alkanediyl groups such as ethane-1,1-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, and 2-methylpropane-1,2-diyl group. L 3a Examples of the perfluoroalkanediyl group in [substance] include difluoromethylene group, perfluoroethylene group, perfluoropropane-1,1-diyl group, perfluoropropane-1,3-diyl group, perfluoropropane-1,2-diyl group, perfluoropropane-2,2-diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane-2,2-diyl group, 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, perfluorooctane-4,4-diyl group, etc. L 3a Examples of the perfluorocycloalkanediyl group in [substance] include perfluorocyclohexanediyl group, perfluorocyclopentanediyl group, perfluorocycloheptanediyl group, perfluoroadamantanediyl group, etc.

[0156] L 4a [Substance] is preferably a single bond, a methylene group or an ethylene group, more preferably a single bond or a methylene group. L 3a [Substance] is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

[0157] As the structural unit (a4-0), there are the following structural units and the methyl group corresponding to R in the structural unit (a4-0) in the following structural units 5 in which the methyl group is replaced by a hydrogen atom. TIFF0007702818000109.tif95165

[0158] TIFF0007702818000110.tif4466[In formula (a4-1), R a41 represents a hydrogen atom or a methyl group. R a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. A a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by formula (a-g1). However, at least one of a41 A a42 and R has a halogen atom (preferably a fluorine atom) as a substituent. TIFF0007702818000111.tif1384[In formula (a-g1), s represents 0 or 1. A a42 and A a44 each independently represent a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. A a43 represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. X a41 and X a42 each independently represent -O-, -CO-, -CO-O- or -O-CO-. However, the total number of carbon atoms of a42 A a43 A a44 X a41 and X a42 is 7 or less. ] * represents a bond, and the * on the right side is -O-CO-Ra42 is a bonding hand with.]

[0159] R a42 Examples of the saturated hydrocarbon group in R include a chain saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and a group formed by combining these. 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 hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; polycyclic alicyclic saturated hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bonding hand). Examples of the group formed by combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group, etc.

[0160] R a42 Examples of the substituent that R may have include at least one selected from a halogen atom and a group represented by the formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and preferably a fluorine atom. TIFF0007702818000113.tif965[In the formula (a-g3), X a43 represents an oxygen atom, a carbonyl group, *-O-CO- or *-CO-O-. A a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. * is the bonding hand with R a42 and represents.] However, Ra42 -X a43 -A a45 In, when R a42 has no halogen atom, A a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms and having at least one halogen atom.

[0161] A a45 Examples of the aliphatic hydrocarbon group in include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group and octadecyl group; monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; and polycyclic alicyclic hydrocarbon groups such as decahydronaphthyl group, adamantyl group, norbornyl group and the following group (* represents a bond). Examples of the group formed by the combination of TIFF0007702818000114.tif11159 combination 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, -alkanediyl group-alicyclic hydrocarbon group-alkyl group and the like.

[0162] R a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and / or an aliphatic hydrocarbon group having a group represented by the formula (a-g3). R a42When it is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, still more preferably a perfluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group. R a42 When it is an aliphatic hydrocarbon group having a group represented by the formula (a-g3), including the number of carbon atoms contained in the group represented by the formula (a-g3), R a42 preferably has a total carbon number of 15 or less, and more preferably 12 or less. When having a group represented by the formula (a-g3) as a substituent, the number thereof is preferably 1.

[0163] R a42 When it is an aliphatic hydrocarbon having a group represented by the formula (a-g3), R a42 is more preferably a group represented by the formula (a-g2). TIFF0007702818000115.tif879 [In the formula (a-g2), A a46 represents a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. X a44 represents **-O-CO- or **-CO-O- (** represents a bond with A a46 ). A a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. However, the total number of carbon atoms of A a46 , A a47 and X a44 is 18 or less, and at least one of A a46 and A a47 has at least one halogen atom. * represents a bond to a carbonyl group.

[0164] A a46 The aliphatic hydrocarbon group of A preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. A a47 The aliphatic hydrocarbon group of A preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, and A a47 is more preferably a cyclohexyl group or an adamantyl group.

[0165] The preferred structure of the group represented by formula (a-g2) is the following structure (* is a bond to a carbonyl group). TIFF0007702818000116.tif13161

[0166] A a41 Examples of the alkanediyl group in A include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, and hexane-1,6-diyl group; and branched alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, and 2-methylbutane-1,4-diyl group. A a41 Examples of the substituent in the alkanediyl group of A 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 even more preferably an ethylene group.

[0167] A in the group represented by formula (a-g1) a42 A a43 and A a44Examples of the divalent saturated hydrocarbon group represented by include a linear or branched alkanediyl group, a monocyclic divalent alicyclic hydrocarbon group, and a group formed by combining an alkanediyl group and a divalent alicyclic 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.

[0168] In the group represented by formula (a-g1), X a42 In the following examples, * and ** each represent a bond, and ** represents -O-CO-R a42 It is a combination with. TIFF0007702818000117.tif54162

[0169] 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. TIFF0007702818000118.tif100142

[0170] TIFF0007702818000119.tif123141

[0171] The structural unit represented by formula (a4-1) is preferably a structural unit represented by formula (a4-2). TIFF0007702818000120.tif4365[In formula (a4-2), R f5represents a hydrogen atom or a methyl group. L 44 represents an alkanediyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. R f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and having a fluorine atom. However, L 44 and R f6 The upper limit of the total number of carbon atoms is 21.

[0172] L 44 The alkanediyl group having 1 to 6 carbon atoms of L is the same group as exemplified for the alkanediyl group in A a41 R f6 The saturated hydrocarbon group of R is the same group as exemplified for R a42 L 44 As the alkanediyl group having 1 to 6 carbon atoms in L, an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.

[0173] As the structural unit represented by the formula (a4-2), for example, the structural units represented by the formulas (a4-1-1) to (a4-1-11) can be mentioned. The structural unit in which the methyl group corresponding to R f5 in the structural unit (a4-2) is replaced by a hydrogen atom is also mentioned as the structural unit represented by the formula (a4-2).

[0174] As the structural unit (a4), the structural unit represented by the formula (a4-3) can be mentioned. TIFF0007702818000121.tif5771 [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 a bond 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.]

[0175] L 5 As the alkanediyl group in, groups similar to those exemplified as the alkanediyl group in the divalent saturated hydrocarbon group of A a41 can be mentioned. A f13 The divalent saturated hydrocarbon group which may have a fluorine atom in is preferably a divalent aliphatic 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 aliphatic hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; perfluoroalkanediyl groups such as difluoromethylene group, perfluoroethylene group, perfluoropropanediyl group, perfluorobutanediyl group and perfluoropentanediyl group. The divalent alicyclic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic group include cyclohexanediyl group and perfluorocyclohexanediyl group. Examples of the polycyclic group include adamantanediyl group, norbornanediyl group, perfluoroadamantanediyl group. A f14 The saturated hydrocarbon group and the saturated hydrocarbon group which may have a fluorine atom of are R a42Groups similar to those exemplified above can be mentioned. Among them, alkyl fluoride groups such as trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group and perfluorooctyl group, cyclopropylmethyl group, cyclopropyl group, cyclobutylmethyl group, cyclopentyl group, cyclohexyl group, perfluorocyclohexyl group, adamantyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl group, norbornylmethyl group, perfluoroadamantyl group, perfluoroadamantylmethyl group, etc. are preferred.

[0176] In formula (a4-3), L 5 is preferably an ethylene group. A f13 The divalent saturated hydrocarbon group of is preferably a group containing a divalent chain hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a divalent chain hydrocarbon group having 2 to 3 carbon atoms. A f14 The saturated hydrocarbon group of is preferably a group containing a chain hydrocarbon group having 3 to 12 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a group containing a chain hydrocarbon group having 3 to 10 carbon atoms and an alicyclic hydrocarbon group having 3 to 10 carbon atoms. Among them, A f14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, cyclopentyl group, cyclohexyl group, norbornyl group and 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), respectively. R in structural unit (a4-3)f7 A structural unit in which the methyl group corresponding to f7 is replaced by a hydrogen atom is also included as a structural unit represented by formula (a4-3).

[0178] As the structural unit (a4), a structural unit represented by formula (a4-4) is also included. TIFF0007702818000122.tif4466[In formula (a4-4), R f21 represents a hydrogen atom or a methyl group. A f21 represents -(CH2) j1 -, -(CH2) j2 -O-(CH2) j3 - or -(CH2) j4 -CO-O-(CH2) j5 -. j1 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 having a fluorine atom.]

[0179] R f22 The saturated hydrocarbon group of is the same as the saturated hydrocarbon group represented by R a42 . R f22 is preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom, and even more preferably an alkyl group having 1 to 6 carbon atoms and having a fluorine atom.

[0180] In formula (a4-4), A f21 is preferably -(CH2) j1 -, more preferably an ethylene group or a methylene group, and even more preferably a methylene group.

[0181] As the structural unit represented by formula (a4-4), for example, in the following structural unit and the structural unit represented by the following formula, a structural unit in which the methyl group corresponding to R f21 in structural unit (a4-4) is replaced by a hydrogen atom is included. TIFF0007702818000123.tif80148

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

[0183] 〈Structural unit (a5)〉 Examples of the non-detachable hydrocarbon group possessed by the structural unit (a5) include groups having a linear, branched or cyclic hydrocarbon group. Among them, the structural unit (a5) preferably has a group having an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1). TIFF0007702818000124.tif3971[In the formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atoms contained in the alicyclic hydrocarbon group may be substituted with aliphatic hydrocarbon groups having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-.]

[0184] R 52 Examples of the alicyclic hydrocarbon group in R include both monocyclic and polycyclic groups. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group. Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, and a 2-ethylhexyl group. Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group or a cyclohexyl group. L 55 Examples of the divalent saturated hydrocarbon group in L include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent chain saturated hydrocarbon group. Examples of the divalent chain saturated hydrocarbon group include alkane diyl 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 cycloalkane diyl groups such as a cyclopentanediyl group and a cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

[0185] L 55 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by L is replaced by -O- or -CO- include the groups represented by formula (L1-1) to formula (L1-4). In the following formulas, * and ** each represent a bond, and * represents a bond to an oxygen atom. In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents a bond to L x1 .). L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, the total number of carbon atoms of L x1 and L x2 is 16 or less. In formula (L1-2), Lx3 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, for 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, for 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 each represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, for L x8 L x9 and W x1 the total number of carbon atoms is 15 or less.

[0186] L x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond. L x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x5is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. L x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. W x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

[0187] Examples of the group represented by the formula (L1-1) include the following divalent groups. TIFF0007702818000126.tif52135

[0188] Examples of the group represented by the formula (L1-2) include the following divalent groups. TIFF0007702818000127.tif23130

[0189] Examples of the group represented by the formula (L1-3) include the following divalent groups. TIFF0007702818000128.tif15145

[0190] Examples of the group represented by the formula (L1-4) include the following divalent groups. TIFF0007702818000129.tif26114

[0191] L 55is preferably a single bond or a group represented by the formula (L1-1).

[0192] Examples of the structural unit (a5-1) include the structural units shown below and the structural units in the following structural units (a5-1) in which the methyl group corresponding to R 51 is replaced by a hydrogen atom. TIFF0007702818000130.tif110150 When the resin (A) has the structural unit (a5), its content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and even more preferably 3 to 15 mol% based on all the structural units of the resin (A). 〈Structural unit (a6)〉 The structural unit (a6) is a structural unit having a -SO2- group, and preferably has a -SO2- group in the side chain. The structural unit having a -SO2- group may have a linear structure having a -SO2- group, a branched structure having a -SO2- group, or a cyclic structure (monocyclic and polycyclic structures) having a -SO2- group. Preferably, it is a structural unit having a cyclic structure having a -SO2- group, and more preferably, it is a structural unit having a cyclic structure (sultone ring) containing -SO2-O-.

[0193] Examples of the sultone ring include the rings represented by the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and formula (T 1 -4). The bonding site can be at any position. The sultone ring may be monocyclic, but is preferably polycyclic. The polycyclic sultone ring means a bridged ring containing -SO2-O- as an atomic group constituting the ring, and examples include the rings represented by the formula (T 1 -1) and formula (T 1 -2). The sultone ring may further contain a hetero atom in addition to -SO2-O- as an atomic group constituting the ring, like the ring represented by the formula (T 1 -2). Examples of the hetero atom include an oxygen atom, a sulfur atom or a nitrogen atom, and preferably an oxygen atom. TIFF0007702818000131.tif3087

[0194] The sultone ring may have a substituent, and examples of the substituent include an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, and an alkylcarbonyl group having 2 to 4 carbon atoms, etc.

[0195] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group, preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group. Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, preferably a trifluoromethyl group. Examples of the alkyl group having a hydroxy group include a hydroxymethyl group and a hydroxyalkyl group such as a 2-hydroxyethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group. Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group. Examples of the alkoxycarbonyl group include a group in which an alkoxy group such as a methoxycarbonyl group or an ethoxycarbonyl group is bonded to a carbonyl group. Preferably, an alkoxycarbonyl group having 6 or less carbon atoms is mentioned, and more preferably, a methoxycarbonyl group is mentioned. Examples of the alkylcarbonyl group include acetyl group, propionyl group, and butyryl group.

[0196] From the viewpoint that the production of the monomer leading to the structural unit (a6) is easy, a sultone ring having no substituent is preferable. As the sultone ring, a ring represented by the following formula (T1') is preferable. TIFF0007702818000132.tif3072[In the formula (T1'), X 11 represents an oxygen atom, a sulfur atom, or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. The bonding site is at an arbitrary position. ] X 11 is preferably an oxygen atom or a methylene group, and more preferably a methylene group. R 41 is the same as those of the substituent of the sultone ring, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group is preferable.

[0197] As the sultone ring, a ring represented by the formula (T1) is more preferable. TIFF0007702818000133.tif3049[In formula (T1), R 8 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms or an alkylcarbonyl group having 2 to 4 carbon atoms. m represents any integer from 0 to 9. When m is 2 or more, a plurality of R 8 may be the same or different. The bonding site is at an arbitrary position.]

[0198] R 8 is the same as R 41 and the like can be mentioned. ma in formula (T1’) and m in formula (T1) are preferably 0 or 1, more preferably 0.

[0199] Examples of the ring represented by formula (T1’) and the ring represented by formula (T1) include the following rings. The bonding site is at an arbitrary position. TIFF0007702818000134.tif52161

[0200] The structural unit having a sultone ring preferably has the following group. * in the following group represents the bonding site. TIFF0007702818000135.tif50161

[0201] The structural unit having a -SO2- group preferably further has a group derived from a polymerizable group. Examples of the polymerizable group include a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, a methacryloylthio group and the like. Among them, the monomer leading to the structural unit (a6) is preferably a monomer having an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer.

[0202] The structural unit (a6) is preferably a structural unit represented by the formula (Ix). TIFF0007702818000136.tif4956[In the formula (Ix), R x represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. A xx represents an oxygen atom, -N(R c )- or a sulfur atom. A x represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -CO- or -N(R d )-. X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. R c and R d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0203] Examples of the halogen atom of R x include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R xExamples 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, etc., preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group. R x Examples of the alkyl group having a halogen atom 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, a triiodomethyl group, etc. R x is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

[0204] A x Examples of the divalent saturated hydrocarbon group of A include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and a combination of two or more of these groups may also be used. Specifically, linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, a heptadecane-1,17-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, and a propane-2,2-diyl group; Branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; Monocyclic divalent alicyclic saturated hydrocarbon groups which are cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; Polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. can be mentioned.

[0205] R 41 , X 11 And ma are the same as those in formula (T1'). Examples of the sultone ring include those described above, and among them, those with specific bonding positions are preferred.

[0206] Examples of the structural unit (a6) include the following structural units. TIFF0007702818000137.tif100159

[0207] Among them, the structural units represented by formula (a6-1), formula (a6-2), formula (a6-6), formula (a6-7), formula (a6-8) and formula (a6-12) are preferred, and the structural units represented by formula (a6-1), formula (a6-2), formula (a6-7) and (a6-8) are more preferred. When the resin (A) has the structural unit (a6), its content is preferably 1 to 50 mol%, more preferably 2 to 40 mol%, and still more preferably 3 to 30 mol% based on all the structural units of the resin (A).

[0208] <Structural unit (II)> The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as "structural unit (II)"). Specific examples of the structural unit (II) include the structural units described in JP-A-2016-79235, and it is preferably a structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain or a structural unit having a sulfonio group and an organic anion in the side chain.

[0209] The structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain is preferably a structural unit represented by the formula (II-2-A'). TIFF0007702818000138.tif35104[In the formula (II-2-A'), X III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom or a hydroxy group. A x1 represents an alkanediyl group having 1 to 8 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be replaced by a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. RA - represents a sulfonate group or a carboxylate group. R III3 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. ZA + represents an organic cation.]

[0210] R III3 Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R III3 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R include R a8Examples thereof include the same alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by A x1 Examples of the alkanediyl group having 1 to 8 carbon atoms represented by A X1 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted in X III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by Specifically, linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group; branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. can be mentioned. Examples of those in which -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- include divalent groups represented by formula (X1) to formula (X53). However, the number of carbon atoms before -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- is each 17 or less. In the following formula, * and ** represent bonding sites, and * represents a bond to A x1 and represents a bond to TIFF0007702818000139.tif145161

[0211] 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 8represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

[0212] ZA in formula (II-2-A’) + is the same as the cation Z1 in the salt represented by formula (B1) + and the like can be mentioned.

[0213] The structural unit represented by formula (II-2-A’) is preferably the structural unit represented by formula (II-2-A). TIFF0007702818000140.tif38109 [In formula (II-2-A), R III3 、X III3 and ZA + represent the same meaning as above. z2A represents any integer from 0 to 6. R III2 and R III4 each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms. When z2A is 2 or more, a plurality of R III2 and R III4 may be the same as or different from each other. Q a and Q b each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.] R III2 、R III4 、Q a and Q b Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by b1 are the same as those of the perfluoroalkyl group having 1 to 6 carbon atoms represented by the aforementioned Q

[0214] The structural unit represented by formula (II-2-A) is preferably the structural unit represented by formula (II-2-A-1). TIFF0007702818000141.tif5577 [In formula (II-2-A-1), R III2 、R III3 、R III4 、Q a 、Qb and ZA + represents the same meaning as described above. R III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms. z2A1 represents any integer from 0 to 6. X I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, wherein -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom or a hydroxy group. R III5 Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by R include linear or branched alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group. X I2 Examples of the divalent saturated hydrocarbon group represented by X include the same ones as the divalent saturated hydrocarbon group represented by X III3 represented by.

[0215] As the structural unit represented by the formula (II-2-A-1), the structural unit represented by the formula (II-2-A-2) is more preferable. TIFF0007702818000142.tif5287 [In the formula (II-2-A-2), R III3 R III5 and ZA + represent the same meaning as described above. m and nA each independently represent 1 or 2.

[0216] Examples of the structural unit represented by the formula (II-2-A') include, for example, the following structural units, R III3 a group corresponding to the methyl group of which is replaced by a hydrogen atom, a halogen atom (for example, a fluorine atom) or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (for example, a trifluoromethyl group, etc.), and the structural unit described in International Publication No. 2012 / 050015. ZA+ represents an organic cation. TIFF0007702818000143.tif86163

[0217] The structural unit having a sulfonio group and an organic anion in the side chain is preferably a structural unit represented by the formula (II-1-1). TIFF0007702818000144.tif3791[In the formula (II-1-1), A II1 represents a single bond or a divalent linking group. R II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms. R II2 and R II3 each independently represents a hydrocarbon group having 1 to 18 carbon atoms, and R II2 and R II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. R II4 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A - represents an organic anion.] R II1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R include a phenylene group and a naphthylene group. R II2 and R II3 Examples of the hydrocarbon group represented by include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. R II4 Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R II4 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R are the same as those of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R a8 A II1 ​Examples of the divalent linking group represented by include divalent saturated hydrocarbon groups having 1 to 18 carbon atoms, and the -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S- or -CO-. Specifically, X III3 include the same divalent saturated hydrocarbon groups having 1 to 18 carbon atoms as those represented by .

[0218] Examples of the structural unit containing the cation in formula (II-1-1) include the structural unit represented by the following and a structural unit in which the group corresponding to the methyl group of R II4 is replaced by a hydrogen atom, a fluorine atom, a trifluoromethyl group or the like. TIFF0007702818000145.tif84130

[0219] A - Examples of the organic anion represented by include sulfonate anions, sulfonylimide anions, sulfonylmethide anions, carboxylic acid anions and the like. A - The organic anion represented by is preferably a sulfonate anion, and more preferably an anion contained in the salt represented by the aforementioned formula (B1). The sulfonylimide anion, sulfonylmethide anion and carboxylic acid anion are more preferably anions AI - contained in the salt represented by the aforementioned formula (I).

[0220] Examples of the structural unit represented by formula (II-1-1) include the structural unit represented by the following and the like. TIFF0007702818000146.tif88149

[0221] When the resin (A) contains the structural unit (II), the content of the structural unit (II) is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and still more preferably 3 to 10 mol% based on all the structural units of the resin (A).

[0222] Resin (A) may have structural units other than the above-described structural units, and examples of such structural units include structural units well-known in the art.

[0223] Resin (A) is preferably a resin composed of structural unit (a1) and structural unit (s), that is, a copolymer of monomer (a1) and monomer (s). Structural unit (a1) is preferably at least one selected from the group consisting of structural unit (a1-0), structural unit (a1-1), and structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group), more preferably at least two kinds, and still more preferably at least two kinds selected from the group consisting of structural unit (a1-1) and structural unit (a1-2). Structural unit (s) is preferably at least one selected from the group consisting of structural unit (a2) and structural unit (a3). Structural unit (a2) is preferably structural unit (a2-1) or structural unit (a2-A). 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). Each structural unit constituting resin (A) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, radical polymerization method) using the monomers leading to these structural units. The content of each structural unit possessed by resin (A) can be adjusted by the amount of monomers used in the polymerization. The weight average molecular weight of resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, still more preferably 15,000 or less). In this specification, the weight average molecular weight is the value determined by gel permeation chromatography under the conditions described in the examples.

[0224] <Resin other than resin (A)> The resist composition of the present invention may be used in combination with a resin other than resin (A). Examples of the resin other than the resin (A) include resins containing a structural unit (a4) or a structural unit (a5) (hereinafter sometimes referred to as resin (X)). Among them, the resin containing the structural unit (a4) is preferable as the resin (X). In the resin (X), the content of the structural unit (a4) is preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 45 mol% or more based on the total of all the structural units of the resin (X). Examples of the structural unit that the resin (X) may further have include a structural unit (a1), a structural unit (a2), a structural unit (a3), and a structural unit derived from other known monomers. Among them, the resin (X) is preferably a resin composed only of the structural unit (a4) and / or the structural unit (a5). Each structural unit constituting the resin (X) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, radical polymerization method) using a monomer that induces these structural units. The content of each structural unit of the resin (X) can be adjusted by the amount of the monomer used in the polymerization. The weight average molecular weight of the resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The measuring means of the weight average molecular weight of the resin (X) is the same as that of the resin (A).

[0225] When the resist composition of the present invention contains the resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, still more preferably 1 to 40 parts by mass, even more preferably 1 to 30 parts by mass, and particularly preferably 1 to 8 parts by mass with respect to 100 parts by mass of the resin (A).

[0226] The content rate of the resin (A) in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. Further, when a resin other than the resin (A) is included, the total content rate of the resin (A) and the resin other than the resin (A) is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. In the present specification, "the solid content of the resist composition" means the total of the components excluding the solvent (E) described later from the total amount of the resist composition. The solid content of the resist composition and the content rate of the resin relative thereto can be measured by known analysis means such as liquid chromatography or gas chromatography.

[0227] <solvent (E)> The content rate of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, more preferably 94% by mass or more and 99% by mass or less. The content rate of the solvent (E) can be measured by known analysis means such as liquid chromatography or gas chromatography.

[0228] Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate, and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. One kind of the solvent (E) may be used alone, or two or more kinds may be used.

[0229] <quencher (C)> Examples of the quencher (C) include salts that generate an acid with a lower acidity than the acid generated from the basic nitrogen-containing organic compound and 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% by mass, more preferably about 0.01 to 10% by mass, further preferably about 0.1 to 5% by mass, and even more preferably about 0.1 to 3% by mass, based on the solid content of the resist composition. Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Examples of the amine include aliphatic amines and aromatic amines. Examples of the aliphatic amine include primary amines, secondary amines, and tertiary amines.

[0230] Examples of the amine include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridyl)ethane, 1,2-di(4-pyridyl)ethane, 1,2-di(2-pyridyl)ethene, 1,2-di(4-pyridyl)ethene, 1,3-di(4-pyridyl)propane, 1,2-di(4-pyridyloxy)ethane, di(2-pyridyl)ketone, 4,4'-dipyridylsulfide, 4,4'-dipyridyldisulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, bipyridine, etc. Preferably, diisopropylaniline is mentioned, and more preferably 2,6-diisopropylaniline is mentioned. 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.

[0231] The acidity of a salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is indicated by the acid dissociation constant (pKa). A salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is a salt having an acid dissociation constant of the acid generated from the salt usually of -3 < pKa, preferably -1 < pKa < 7, and more preferably 0 < pKa < 5. Examples of the salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) include salts represented by the following formula, salts represented by formula (D) described in JP-A-2015-147926 (hereinafter sometimes referred to as "weak acid inner salt (D)"), and salts described in JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502, and JP-A-2011-191745. The salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is preferably a salt that generates a carboxylic acid with a lower acidity than the acid generated from the acid generator (B) (a salt having a carboxylic acid anion), and more preferably the weak acid inner salt (D). TIFF0007702818000147.tif94163

[0232] Examples of the weak acid inner salt (D) include the following salts. TIFF0007702818000148.tif72165

[0233] 〈Other components〉 The resist composition of the present invention may contain, if necessary, components other than the above-described components (hereinafter sometimes referred to as "other components (F)"). There 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.

[0234] 〈Preparation of Resist Composition〉 The resist composition of the present invention can be prepared by mixing salt (I), resin (A) and acid generator (B), and, if necessary, a resin other than resin (A) used, solvent (E), quencher (C) and other components (F). The mixing order is arbitrary and is not particularly limited. The temperature during mixing can be selected appropriately from 10 to 40°C according to the type of resin, etc. and the solubility of the resin, etc. in solvent (E). The mixing time can be selected appropriately from 0.5 to 24 hours according to the mixing temperature. Note that the mixing means is also not particularly limited, and stirring and mixing, etc. can be used. After mixing the respective components, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

[0235] 〈Method for Producing Resist Pattern〉 The method for producing a resist pattern of the present invention (1) A step of applying the resist composition of the present invention onto a substrate, (2) A step of drying the applied composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer. To apply the resist composition onto a substrate, it can be performed by a commonly used apparatus such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers and organic substrates such as already formed resist films. Before applying the resist composition, the substrate may be cleaned, and an antireflection film or the like may be formed on the substrate. By drying the coated composition, the solvent is removed to form a composition layer. Drying is carried out, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or by using a decompression device. The heating temperature is preferably 50 to 200 °C, and the heating time is preferably 10 to 180 seconds. Also, the pressure during vacuum drying is preferably about 1 to 1.0×10 5 Pa. The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. As the exposure light source, those that emit laser light in the ultraviolet region such as a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F2 excimer laser (wavelength 157 nm), those that convert laser light from a solid laser light source (YAG or semiconductor laser, etc.) into harmonic laser light in the far ultraviolet region or vacuum ultraviolet region and emit it, those that irradiate electron beams, those that irradiate extreme ultraviolet light (EUV), etc., various ones can be used. In this specification, irradiating these radiations may be collectively referred to as "exposure". During exposure, usually, exposure is carried out through a mask corresponding to the required pattern. When the exposure light source is an electron beam, exposure may be carried out by direct drawing without using a mask. The exposed composition layer is heat-treated (so-called post-exposure bake) to promote the deprotection reaction in the acid-labile group. The heating temperature is usually about 50 to 200 °C, preferably about 70 to 150 °C. Chemical treatment (silylation) may be carried out to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the composition after heating. Also, before development, the steps of coating, drying, exposing, and heating the resist composition may be repeated on the exposed composition layer. The heated composition layer is usually developed using a developing solution with a developing device. Examples of the developing method include the dip method, the paddle method, the spray method, the dynamic dispense method, etc. The developing temperature is preferably, for example, 5 to 60 °C, and the developing time is preferably, for example, 5 to 300 seconds. By selecting the type of developing solution as follows, a positive resist pattern or a negative resist pattern can be manufactured. When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. For example, aqueous solutions of tetramethylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline), etc. may be mentioned. The alkaline developer may contain a surfactant. After development, it is preferable to wash the resist pattern with ultrapure water and then remove the water remaining on the substrate and the pattern. 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-based developer") is used as the developer. Examples of the organic solvent contained in the organic-based developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole, etc. In the organic-based developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and even more preferably substantially only the organic solvent. Among them, as the organic-based developer, a developer containing butyl acetate and / or 2-heptanone is preferable. In the organic-based developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and even more preferably substantially only butyl acetate and / or 2-heptanone. The organic-based developer may contain a surfactant. Also, the organic-based developer may contain a small amount of water. During development, the development may be stopped by substituting with a solvent of a different type from the organic-based developer. It is preferable to wash the developed resist pattern with a rinse solution. The rinse solution is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent. After washing, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

[0236] <Usage> The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, particularly as a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for semiconductor microfabrication.

Examples

[0237] The present invention will be further specifically described with reference to examples. In the examples, “%” and “parts” representing the content or the amount used are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows. Column: TSKgel Multipore HXL-M x 3 + guard column (manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Detector: RI detector Column temperature: 40 °C Injection volume: 100 μl Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC is Agilent 1100 type, MASS is Agilent LC / MSD type). In the following examples, the value of this molecular ion peak is indicated by “MASS”.

[0238] Example 1: Synthesis of the salt represented by formula (I-953) 20 parts of the compound represented by formula (I-953-a) of TIFF0007702818000149, 2.28 parts of the compound represented by formula (I-953-c), 100 parts of ethyl acetate and 15 parts of tetrahydrofuran were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 6.55 parts of the compound represented by formula (I-953-b) was added and stirred at 23 °C for 18 hours. To the resulting reaction mass, 20 parts of n-heptane and 70 parts of ion-exchanged water were added and stirred at 23 °C for 30 minutes, and then separated to take out the organic layer. 60 parts of ion-exchanged water was added to the recovered organic layer and stirred at 23 °C for 30 minutes, and then separated to take out the organic layer. This water washing operation was repeated 4 times. The resulting organic layer was concentrated, and the concentrated mass was fractionated by a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 1 / 1) to obtain 7.48 parts of the compound represented by formula (I-953-d). 0.95 part of the compound represented by formula (I-953-d) of TIFF0007702818000150 and 10 parts of tetrahydrofuran were mixed and stirred at 23 °C for 30 minutes, then cooled to 5 °C, and 0.14 part of sodium hydride was added. To the resulting mixture, 1.01 part of the salt represented by formula (I-953-e) was added and stirred at 5 °C for 3 hours. To the resulting mixture, 6.30 parts of 1N hydrochloric acid was added, then the temperature was raised to 23 °C and stirred at 23 °C for 6 hours. To the resulting mixture, 30 parts of chloroform and 15 parts of ion-exchanged water were added and stirred at 23 °C for 30 minutes, and then separated to take out the organic layer. After concentrating the resulting organic layer, 1 part of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue, stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 1.24 parts of the salt represented by formula (I-953-f). 0.62 parts of the salt represented by TIFF0007702818000151.tif25164 formula (I-953-f) and 30 parts of dimethylformamide were mixed and stirred at 23 °C for 30 minutes. Then, 0.16 parts of potassium carbonate and 0.05 parts of potassium iodide were added, and the temperature was raised to 75 °C. To the obtained mixture, 0.53 parts of the compound represented by formula (I-953-g) was added, and the mixture was stirred at 75 °C for 5 hours and then cooled to 23 °C. To the obtained mixture, 50 parts of chloroform and 20 parts of 5% aqueous oxalic acid solution were added and stirred at 23 °C for 30 minutes, and then the layers were separated to take out the organic layer. To the obtained organic layer, 20 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and then the layers were separated to take out the organic layer. This water washing operation was repeated 5 times. By concentrating the obtained organic layer, 0.91 parts of the salt represented by formula (I-953-h) was obtained. 0.74 parts of the salt represented by JPEG0007702818000152.jpg69167 formula (I-953-h), 0.34 parts of the salt represented by formula (I-953-i), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the obtained mixture, 20 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and then the layers were separated to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether was added and stirred at 23 °C for 30 minutes, and then filtered to obtain 0.91 parts of the salt represented by formula (I-953). MASS(ESI(+)Spectrum):M + 881.3 MASS(ESI(-)Spectrum):M - 323.0

[0239] Example 2: Synthesis of the salt represented by formula (I-954) 0.74 part of the salt represented by formula (I-953-h), 0.33 part of the salt represented by formula (I-954-i), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and then liquid separation was carried out to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether was added and stirred at 23 °C for 30 minutes, and then filtered to obtain 0.72 part of the salt represented by formula (I-954). MASS(ESI(+)Spectrum):M + 881.3 MASS(ESI(-)Spectrum):M - 311.0

[0240] Example 3: Synthesis of the salt represented by formula (I-958) 0.74 part of the salt represented by formula (I-953-h), 0.51 part of the salt represented by formula (I-958-i), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and then liquid separation was carried out to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether was added and stirred at 23 °C for 30 minutes, and then filtered to obtain 0.98 part of the salt represented by formula (I-958). MASS(ESI(+)Spectrum):M + 881.3 MASS(ESI(-)Spectrum):M - 517.1

[0241] Example 4: Synthesis of the salt represented by formula (I-966) 0.74 part of the salt represented by formula (I-953-h), 0.45 part of the salt represented by formula (I-966-i), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and then liquid separation was carried out to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 °C for 30 minutes, and then filtered to obtain 0.82 part of the salt represented by formula (I-966). MASS(ESI(+)Spectrum):M + 881.3 MASS(ESI(-)Spectrum):M - 467.1

[0242] Example 5: Synthesis of the salt represented by formula (I-236) 3.80 parts of the compound represented by formula (I-236-a) and 6.40 parts of Oxone® were mixed, stirred at 23 °C for 30 minutes, and then cooled to 5 °C. To the resulting mixture, 23.56 parts of sulfuric acid was added and stirred at 5 °C for 30 minutes. To the resulting mixture, a mixed solution of 3.68 parts of the compound represented by formula (I-236-b) and 18.40 parts of chloroform was added, stirred at 5 °C for 30 minutes, and further stirred at 23 °C for 2 hours. The obtained mixed solution was added to 120 parts of methanol and stirred at 23 °C for 30 minutes, and then filtered. The obtained filtrate was concentrated, 125 parts of chloroform and 25 parts of acetonitrile were added to the concentrated residue, stirred at 23 °C for 30 minutes, 60 parts of 5% hydrochloric acid was added and stirred at 23 °C for 30 minutes, and then liquid separation was carried out to take out the organic layer. 40 parts of ion-exchanged water was added to the obtained organic layer and stirred at 23 °C for 30 minutes, and then liquid separation was carried out to take out the organic layer. This water washing operation was repeated 3 times. The obtained organic layer was concentrated, 45 parts of tert-butyl methyl ether was added to the concentrated mixture, stirred at 23 °C for 30 minutes, and then filtered to obtain 2.37 parts of the salt represented by formula (I-236-c). 0.95 parts of the compound represented by formula (I-953-d) and 10 parts of tetrahydrofuran were mixed, stirred at 23 °C for 30 minutes, then cooled to 5 °C, and 0.14 parts of sodium hydride was added. To the resulting mixture, 2.32 parts of the salt represented by formula (I-236-c) was added, and the mixture was stirred at 5 °C for 3 hours. To the resulting mixture, 6.30 parts of 1N hydrochloric acid was added, then the temperature was raised to 23 °C, and the mixture was stirred at 23 °C for 6 hours. To the resulting mixture, 30 parts of chloroform and 15 parts of ion-exchanged water were added, stirred at 23 °C for 30 minutes, then separated, and the organic layer was taken out. After concentrating the obtained organic layer, 1 part of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue, stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 2.19 parts of the salt represented by formula (I-236-f). 1.37 parts of the salt represented by formula (I-236-f) and 30 parts of dimethylformamide were mixed, stirred at 23 °C for 30 minutes, then 0.16 parts of potassium carbonate and 0.05 parts of potassium iodide were added, and the temperature was raised to 75 °C. To the resulting mixture, 1.06 parts of the compound represented by formula (I-953-g) was added, stirred at 75 °C for 5 hours, then cooled to 23 °C. To the resulting mixture, 50 parts of chloroform and 20 parts of 5% aqueous oxalic acid solution were added, stirred at 23 °C for 30 minutes, then separated, and the organic layer was taken out. To the obtained organic layer, 20 parts of ion-exchanged water was added, stirred at 23 °C for 30 minutes, then separated, and the organic layer was taken out. This water washing operation was repeated 5 times. By concentrating the obtained organic layer, 1.61 parts of the salt represented by formula (I-236-h) was obtained. 0.55 parts of the salt represented by TIFF0007702818000159 (I-236-h), 0.51 parts of the salt represented by formula (I-958-i), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, then liquid-separated to take out the organic layer. This water-washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 °C for 30 minutes, and then filtered to obtain 0.73 parts of the salt represented by formula (I-236). MASS(ESI(+)Spectrum):M + 651.2 MASS(ESI(-)Spectrum):M - 517.1

[0243] Example 6: Synthesis of the salt represented by formula (I-244) 0.55 parts of the salt represented by TIFF0007702818000160 (I-236-h), 0.45 parts of the salt represented by formula (I-966-i), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, then liquid-separated to take out the organic layer. This water-washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 °C for 30 minutes, and then filtered to obtain 0.70 parts of the salt represented by formula (I-244). MASS(ESI(+)Spectrum):M + 651.2 MASS(ESI(-)Spectrum):M - 467.1

[0244] Example 7: Synthesis of the salt represented by formula (I-1308) 6.57 parts of the compound represented by formula (I-1308-a), 0.23 parts of the compound represented by formula (I-953-c), 30 parts of ethyl acetate and 15 parts of tetrahydrofuran were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 0.66 parts of the compound represented by formula (I-953-b) was added and stirred at 23 °C for 18 hours. To the resulting reaction mass, 100 parts of n-heptane and 20 parts of ion-exchanged water were added, stirred at 23 °C for 30 minutes, and then separated to obtain the organic layer. 20 parts of ion-exchanged water was added to the recovered organic layer, stirred at 23 °C for 30 minutes, and then separated to obtain the organic layer. This water washing operation was repeated 4 times. The obtained organic layer was concentrated, and the concentrated mass was fractionated by column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 1 / 1) to obtain 6.28 parts of the compound represented by formula (I-1308-d). 2.26 parts of the compound represented by formula (I-1308-d) and 10 parts of tetrahydrofuran were mixed and stirred at 23 °C for 30 minutes, then cooled to 5 °C, and 0.14 parts of sodium hydride was added. To the resulting mixture, 2.32 parts of the salt represented by formula (I-236-c) was added and stirred at 5 °C for 3 hours. To the resulting mixture, 6.30 parts of 1N hydrochloric acid was added, then the temperature was raised to 23 °C and stirred at 23 °C for 6 hours. To the resulting mixture, 30 parts of chloroform and 15 parts of ion-exchanged water were added, stirred at 23 °C for 30 minutes, and then separated to obtain the organic layer. After concentrating the obtained organic layer, 1 part of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue, stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 1.01 parts of the salt represented by formula (I-1308-f). 1.00 part of the salt represented by TIFF0007702818000163 in the form of (I-1308-f) and 30 parts of dimethylformamide were mixed and stirred at 23 °C for 30 minutes. Then, 0.08 part of potassium carbonate and 0.03 part of potassium iodide were added, and the temperature was raised to 75 °C. To the obtained mixture, 0.51 part of the compound represented by the formula (I-953-g) was added, and the mixture was stirred at 75 °C for 5 hours and then cooled to 23 °C. To the obtained mixture, 50 parts of chloroform and 20 parts of a 5% aqueous oxalic acid solution were added and stirred at 23 °C for 30 minutes, and then the layers were separated to extract the organic layer. To the obtained organic layer, 20 parts of ion-exchanged water were added and stirred at 23 °C for 30 minutes, and then the layers were separated to extract the organic layer. This water washing operation was repeated 5 times. By concentrating the obtained organic layer, 1.16 parts of the salt represented by the formula (I-1308-b) were obtained. 0.74 part of the salt represented by TIFF0007702818000164 in the form of (I-1308-b), 0.45 part of the salt represented by the formula (I-966-i), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the obtained mixture, 20 parts of ion-exchanged water were added and stirred at 23 °C for 30 minutes, and then the layers were separated to extract the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether were added and stirred at 23 °C for 30 minutes, and then the supernatant was removed and concentrated to obtain 0.96 part of the salt represented by the formula (I-1308). MASS(ESI(+)Spectrum):M + 903.0 MASS(ESI(-)Spectrum):M - 467.1

[0245] Example 8: Synthesis of the salt represented by the formula (I-1460) 2.26 parts of the compound represented by TIFF0007702818000165.tif39158 (I-1308-d), 0.78 part of the salt represented by formula (I-953-e), and 30 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes, and then the temperature was raised to 90°C. To the resulting mixture, 1.44 parts of potassium carbonate was added and stirred at 90°C for 3 hours. To the resulting mixture, 6.30 parts of 1N hydrochloric acid was added, then the temperature was raised to 23°C and stirred at 23°C for 6 hours. To the resulting mixture, 50 parts of chloroform and 30 parts of ion-exchanged water were added, stirred at 23°C for 30 minutes, and then separated to obtain the organic layer. To the obtained organic layer, 30 parts of ion-exchanged water was added, stirred at 23°C for 30 minutes, and then separated to obtain the organic layer. This water washing operation was repeated 3 times. After concentrating the obtained organic layer, 3 parts of acetonitrile and 30 parts of tert-butyl methyl ether were added to the concentrated residue, stirred at 23°C for 30 minutes, then the supernatant was removed and concentrated to obtain 1.63 parts of the salt represented by formula (I-1460-f). 1.21 parts of the salt represented by TIFF0007702818000166.tif57141 (I-1460-f) and 30 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes, then 0.16 part of potassium carbonate and 0.05 part of potassium iodide were added, and the temperature was raised to 75°C. To the resulting mixture, 1.07 parts of the compound represented by formula (I-953-g) was added and stirred at 75°C for 5 hours, and then cooled to 23°C. To the resulting mixture, 50 parts of chloroform and 20 parts of 5% oxalic acid aqueous solution were added and stirred at 23°C for 30 minutes, and then separated to obtain the organic layer. To the obtained organic layer, 20 parts of ion-exchanged water was added, stirred at 23°C for 30 minutes, and then separated to obtain the organic layer. This water washing operation was repeated 5 times. By concentrating the obtained organic layer, 1.35 parts of the salt represented by formula (I-1460-h) was obtained. 1.14 parts of the salt represented by formula (I-1460-h), 0.45 parts of the salt represented by formula (I-966-i), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and then liquid separation was carried out to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 1.35 parts of the salt represented by formula (I-1460). MASS(ESI(+)Spectrum):M + 1384.8 MASS(ESI(-)Spectrum):M - 467.1

[0246] Example 9: Synthesis of the salt represented by formula (I-1194) 0.58 parts of the salt represented by formula (I-236-f) and 30 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 0.19 parts of the compound represented by formula (I-1194-a) was added, and further stirred at 50 °C for 2 hours. To the resulting mixed solution, 0.17 parts of the compound represented by formula (I-1194-b) was added, and further stirred at 50 °C for 3 hours and then cooled to 23 °C. To the resulting mixture, 15 parts of 5% aqueous oxalic acid solution was added and stirred at 23 °C for 30 minutes, and then liquid separation was carried out to take out the organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer and stirred at 23 °C for 30 minutes, and then liquid separation was carried out to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 0.67 parts of the salt represented by formula (I-1194-h). 0.54 parts of the salt represented by TIFF0007702818000169 (I-1194-h), 0.45 parts of the salt represented by formula (I-966-i), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and then liquid separation was performed to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 0.69 parts of the salt represented by formula (I-1194). MASS(ESI(+)Spectrum):M + 637.2 MASS(ESI(-)Spectrum):M - 467.1

[0247] Synthesis of Resin The compounds (monomers) used for the synthesis of resin (A) are shown below. Hereinafter, these compounds are referred to as "monomer (a1-1-3)" etc. according to their formula numbers. TIFF0007702818000170.tif46154

[0248] Synthesis Example 1 [Synthesis of Resin A1] As monomers, monomer (a1-4-2), monomer (a1-1-3) and monomer (a1-2-6) were used and mixed so that their molar ratio [monomer (a1-4-2): monomer (a1-1-3): monomer (a1-2-6)] was 38:24:38. Further, 1.5 mass times of methyl isobutyl ketone was mixed with this monomer mixture based on the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% based on the total number of moles of all monomers, and polymerization was carried out by heating this at 85 °C for about 5 hours. Then, 2.0 mass times of an aqueous p-toluenesulfonic acid solution (2.5 wt%) was added to the polymerization reaction solution based on the total mass of all monomers, stirred for 6 hours, and then liquid separation was performed. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered and recovered, whereby the weight average molecular weight was about 5.3×103 Resin A1 (copolymer) represented by the following was obtained in a yield of 78%. This resin A1 has the following structural units. TIFF0007702818000171.tif29126

[0249] Synthesis Example 2 [Synthesis of Resin A2] As monomers, monomer (a1-4-2) and monomer (a1-2-6) were used and mixed so that the molar ratio [monomer (a1-4-2): monomer (a1-2-6)] was 38:62. Further, 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all the monomers was mixed into this monomer mixture. To the resulting mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% with respect to the total number of moles of all the monomers, and polymerization was carried out by heating this at 85 °C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) 2.0 times the mass of the total mass of all the monomers was added to the polymerization reaction solution, and after stirring for 6 hours, liquid separation was performed. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered and recovered, whereby a resin A2 (copolymer) having a weight average molecular weight of about 5.4×10 3 was obtained in a yield of 89%. This resin A2 has the following structural units. TIFF0007702818000172.tif2887

[0250] Synthesis Example 3 [Synthesis of Resin A3] As monomers, monomer (a1-1-3), monomer (a1-2-6), monomer (a2-1-3), monomer (a3-4-2) and monomer (aa1-4-2) were used and mixed so that their molar ratio [monomer (a1-1-3): monomer (a1-2-6): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-2)] was 20:35:3:15:27. Further, 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed into this monomer mixture. To the obtained mixture, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1.2 mol% and 3.6 mol%, respectively, with respect to the total monomer amount, and these were heated at 73 °C for about 5 hours. Then, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) 2.0 times the mass of the total monomers was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was obtained by filtration and recovery with a weight average molecular weight of about 5.3×10 3 Resin A3 with this value was obtained in a yield of 63%. This resin A3 has the following structural units. TIFF0007702818000173.tif37154

[0251] Synthesis Example 4 [Synthesis of Resin A4] As monomers, monomer (a1-1-3), monomer (a1-2-6), monomer (a2-1-3), monomer (a3-4-2) and monomer (a1-4-13) were used and mixed so that the molar ratio [monomer (a1-1-3): monomer (a1-2-6): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-13)] was 20:35:3:15:27. Further, 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed into this monomer mixture. To the obtained mixture, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1.2 mol% and 3.6 mol%, respectively, with respect to the total monomer amount, and these were heated at 73 °C for about 5 hours. Then, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) 2.0 times the mass of the total monomers was added to the polymerization reaction solution, and after stirring for 12 hours, liquid separation was performed. The recovered organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was obtained by filtration and recovery with a weight average molecular weight of about 5.1×10 3 Resin A4 with a yield of 61% was obtained. This resin A4 has the following structural units. TIFF0007702818000174.tif38154

[0252] <Preparation of Resist Composition> As shown in Table 2, the following components were mixed, and the obtained mixture was filtered through a fluororesin filter with a pore size of 0.2 μm to prepare a resist composition.

Table 2

[0253] (Electron beam exposure evaluation of resist composition) A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 °C for 60 seconds. The resist composition was spin-coated on this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, it was prebaked on a direct hot plate at the temperature shown in the "PB" column of Table 2 for 60 seconds to form a composition layer. A contact hole pattern (hole pitch 40 nm / hole diameter 17 nm) was directly drawn on the composition layer formed on the wafer using an electron beam lithography machine ["ELS-F125 125 keV" manufactured by Elionix, Inc.] while changing the exposure dose stepwise. After exposure, post-exposure baking was performed on a hot plate at the temperature shown in the "PEB" column of Table 2 for 60 seconds, and further paddle development was performed with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide for 60 seconds to obtain a resist pattern.

[0254] In the resist pattern obtained after development, the exposure dose at which the formed hole diameter became 17 nm was defined as the effective sensitivity.

[0255] <CD Uniformity (CDU) Evaluation> In terms of effective sensitivity, the hole diameter of the pattern formed with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was taken as the average hole diameter of one hole. Using as the population the measurement of the average hole diameter of the patterns formed with a hole diameter of 17 nm at 400 locations within the same wafer, the standard deviation was determined. The results are shown in Table 3. The numerical values in the table indicate the standard deviation (nm).

Table 3

[0256] (Electron Beam Exposure Evaluation of Resist Composition: Organic Solvent Development) A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 °C for 60 seconds. The resist composition was spin-coated on this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Thereafter, it 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. On the composition layer formed on the wafer, using an electron beam writer ["ELS-F125 125 keV" manufactured by Elionix, Inc.], a contact hole pattern (hole pitch 40 nm / hole diameter 17 nm) was directly drawn while changing the exposure dose stepwise. After exposure, post-exposure baking was performed on a hot plate at the temperature shown in the "PEB" column of Table 2 for 60 seconds. Next, the composition layer on this silicon wafer was developed at 23 °C for 20 seconds by the dynamic dispense method using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as the developer to obtain a resist pattern.

[0257] In the resist pattern obtained after development, the exposure dose at which the formed hole diameter became 17 nm was taken as the effective sensitivity.

[0258] <CD Uniformity (CDU) Evaluation> In terms of effective sensitivity, the hole diameter of the pattern formed with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was taken as the average hole diameter of one hole. The standard deviation was obtained using as the population the measurement of the average hole diameter of 400 patterns formed with a hole diameter of 17 nm within the same wafer. The results are shown in Table 4. The numerical values in the table indicate the standard deviation (nm).

Table 4

Industrial Applicability

[0259] The resist composition containing the salt of the present invention can obtain a resist pattern having good CD uniformity (CDU), and thus is suitable for semiconductor microfabrication and is extremely useful industrially.

Claims

1. A salt represented by formula (I). [In formula (I), R １ and R ２ each independently represents -O-R １０ -O-CO-R １０ -O-CO-O-R １０ -O-L １ -CO-O-R １０ respectively represent. L １ represents an alkanediyl group having 1 to 6 carbon atoms. R ４ 、 R ５ 、 R ７ and R ８ each independently represents a halogen atom, a C1-C6 perfluoroalkyl group or a C1-C18 hydrocarbon group, the hydrocarbon group may have a substituent, and the -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO ２ -. R １０ represents an acid-stable hydrocarbon group. X １ and X ２ each independently represents an oxygen atom or a sulfur atom. m1 represents an integer of any one of 1 to 5, and when m1 is 2 or more, the groups in a plurality of parentheses may be the same as or different from each other. m2 represents an integer of any one of 0 to 5, and when m2 is 2 or more, the groups in a plurality of parentheses may be the same as or different from each other. m4 represents any integer from 0 to 4, and when m4 is 2 or more, the plurality of Rs ４ may be the same as or different from each other. m5 represents any integer from 0 to 4, and when m5 is 2 or more, the plurality of Rs ５ may be the same as or different from each other. m7 represents any integer from 0 to 4, and when m7 is 2 or more, the plurality of Rs ７ may be the same as or different from each other. m8 represents any integer from 0 to 5, and when m8 is 2 or more, the plurality of Rs ８ may be the same as or different from each other. However, 1 ≤ m1 + m7 ≤ 5, 0 ≤ m2 + m8 ≤ 5. AI － represents an organic anion.]

2. X １ and X ２ The salt according to claim 1, wherein X and X are oxygen atoms.

3. R １ and R ２ is -O-CO-O-R １０ or -O-L １ -CO-O-R １０ The salt according to claim 1 or 2, wherein it is

4. R １０ The salt according to any one of claims 1 to 3, wherein the acid-stable hydrocarbon group of [In formula (3a), R １ａ and R ２ａ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms, or R １ａ and R ２ａ are bonded to each other to form a hydrocarbon ring having 3 to 36 carbon atoms which may have an alkyl group having 1 to 12 carbon atoms. R ３ａ represents a hydrogen atom, or R １ａ and R ２ａ and R ３ａ are bonded to each other to form a hydrocarbon ring having 3 to 36 carbon atoms, which may have an alkyl group having 1 to 12 carbon atoms. * represents a bond.]

5. m1 is 1, The salt according to any one of Claims 1 to 4, wherein m2 is 0 or 1.

6. m2 is 0, R ８ The salt according to any one of claims 1 to 5, wherein R is a branched alkyl group having 3 or 4 carbon atoms.

7. R １ and R ２ The bonding positions of １ and X ２ are bonded to the p-position relative to the bonding positions of X, and the salt according to any one of claims 1 to 6.

8. Either one of m4 and m5 is 1 or 2, When m4 is 1 or 2, at least one R ４ is bonded at the ortho position to the bonding position of X １ and When m5 is 1 or 2, at least one R ５ is bonded at the ortho position with respect to the bonding position of X ２ The salt according to any one of claims 1 to 7, which is bonded at the ortho position with respect to the bonding position of X

9. AI － The salt according to any one of claims 1 to 8, wherein A is a sulfonate anion, a sulfonylimide anion, a sulfonylmethide anion, or a carboxylate anion.

10. AI － is a sulfonic acid anion, and the sulfonic acid anion is an anion represented by the formula (I-A). The salt according to any one of claims 1 to 9. [In formula (I-A), Q １ and Q ２ each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L １ represents a saturated hydrocarbon group having 1 to 24 carbon atoms, and -CH ２ - in the saturated hydrocarbon group may be replaced by -O- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. Y １ represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH ２ - in the alicyclic hydrocarbon group may be replaced by -O-, -SO ２ - or -CO-.]

11. An acid generator containing the salt according to any one of Claims 1 to 10.

12. A resist composition containing the acid generator according to Claim 11 and a resin having an acid-labile group.

13. The resist composition according to Claim 12, wherein the resin having an acid-labile group contains at least one selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2). [In formula (a1-1) and formula (a1-2), L ａ１ and L ａ２ each independently represents -O- or *-O-(CH ２ ) ｋ１ -CO-O-, k1 represents any integer from 1 to 7, and * represents a bond to -CO-. R ａ４ and R ａ５ each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R 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 combining these. m1 represents an integer of any one of 0 to 14. n1 represents an integer of any one of 0 to 10. n1' represents an integer of any one of 0 to 3.]

14. The resist composition according to Claim 12 or 13, wherein the resin having an acid-labile group contains a structural unit represented by formula (a2-A). [In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group. A a50 represents a single bond or ＊ -X a51 -(A a52 -X a52 ) nｂ -, where * represents a bond with the carbon atom to which -R a50 is attached. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O- or -O-CO-. nb represents 0 or 1. mb represents an integer of any one of 0 to 4. When mb is any integer of 2 or more, a plurality of Rs a51 may be the same as or different from each other.]

15. The resist composition according to any one of Claims 12 to 14, further containing a salt that generates an acid having a lower acidity than the acid generated from the acid generator.

16. (1) A step of applying the resist composition according to any one of Claims 12 to 15 on a substrate, (2) A step of drying the applied composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer, A method for manufacturing a resist pattern including these steps.

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