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

Abstract

To provide a salt capable of producing a resist pattern having good CD uniformity (CDU), an acid generator, and a resist composition containing the same.SOLUTION: The salt represented by formula (I), the acid generator, and the resist composition are provided. [In the formula, Q1 and Q2 each represent a fluorine atom or a perfluoroalkyl group; R1 and R2 each represent a hydrogen atom, a fluorine atom or a perfluoroalkyl group; z represents an integer of 0-6; X1 represents *-CO-O-, *-O-CO- or the like; L1 represents a single bond or an optionally substituted hydrocarbon group; R3 represents a halogen atom; R4 represents a fluorinated alkyl group or an alkyl group, provided that -CH2- contained in these groups may be substituted with -O-, -CO- or the like; R5 represents an acid-labile group; m3 and m4 each represent an integer of 1-3 and m5 represents 1 or 2, provided that 3≤m3+m4+m5≤5; and Z+ represents an organic cation.]SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes a resist composition containing a salt represented by the following formula as an acid generator. TIFF0007696233000001.tif2853 Patent Document 2 describes a resist composition containing a salt represented by the following formula as an acid generator. TIFF0007696233000002.tif2754 Patent Document 3 describes a resist composition containing a salt represented by the following formula as an acid generator. TIFF0007696233000003.tif2856 Patent Document 4 describes a resist composition containing a salt represented by the following formula as an acid generator. TIFF0007696233000004.tif2872

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a salt capable of producing 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

[0005] The present invention includes the following inventions. [1] A salt represented by formula (I). TIFF0007696233000005.tif33127[In formula (I), Q 1 and Q 2 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. R 1 and R 2 each independently represents a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. z represents an integer from 0 to 6, and when z is 2 or more, a plurality of R 1 and R 2 may be the same as or different from each other. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, where * represents a bonding site with C(R 1 )(R 2 ) or C(Q 1 )(Q 2 ). L 1 represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. R 3 represents a halogen atom. R 4 represents a fluorinated alkyl group having 1 to 6 carbon atoms or an alkyl group having 1 to 12 carbon atoms, and -CH2- contained in the fluorinated alkyl group and the alkyl group may be replaced by -O- or -CO-. R 5 represents an acid-labile group. m3 represents an integer from 1 to 3. When m3 is 2 or more, a plurality of Rs 3 may be the same as or different from each other. m4 represents an integer from 1 to 3. When m4 is 2 or more, a plurality of Rs 4 may be the same as or different from each other. m5 represents 1 or 2. When m5 is 2, two Rs 5 may be the same as or different from each other. However, 3 ≤ m2 + m4 + m5 ≤ 5. Z + represents an organic cation.] [2] The salt according to [1], wherein R 3 is a fluorine atom or an iodine atom. [3] The salt according to [1] or [2], wherein m3 is 1 or 2 and m5 is 1. [4] The salt according to any one of [1] to [3], wherein m4 is 1 and R 4 is an alkoxy group having 1 to 6 carbon atoms. [5] The salt according to any one of [1] to [4], wherein m3 is 1 or 2 and the bonding position of at least one R 3 is bonded to the m-position relative to the bonding position of L 1 in the benzene ring. [6] The salt according to any one of [1] to [5], wherein the bonding position of at least one OR 5 is bonded to the o-position or p-position relative to the bonding position of L 1 in the benzene ring. [7] The salt according to any one of [1] to [6], wherein the acid-labile group of R 5 is a group represented by formula (R5-1) or a group represented by formula (R5-2). TIFF0007696233000006.tif1981[In formula (R5-1), R 14 , R 15 and R 16 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 14 and R 15are bonded to each other to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded. m represents 0 or 1. * represents a bonding site. TIFF0007696233000007.tif2181[In formula (R5-2), R 17 and R 18 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R 19 represents a hydrocarbon group having 1 to 20 carbon atoms, or R 18 and R 19 are bonded to each other to form a heterocyclic group having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded and X a and the -CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced by -O- or -S-. X a represents an oxygen atom or a sulfur atom. n represents 0 or 1. * represents a bonding site. [8]L 1 is a single bond, an alkanediyl group having 1 to 6 carbon atoms, or a group formed by combining an alkanediyl group having 1 to 6 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 18 carbon atoms (however, -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic saturated hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-). The salt according to any one of [1] to [7]. [9]L 1 is a single bond, an alkanediyl group having 1 to 6 carbon atoms or * -L 4 -CO-O- (however, L 4 represents a hydrocarbon group having 1 to 22 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-). The salt according to any one of [1] to [8].

[10] An acid generator containing the salt according to any one of [1] to [9].

[11] A resist composition containing the acid generator described in

[10] and a resin having an acid-labile group.

[12] The resist composition according to

[11] , 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). TIFF0007696233000008.tif4394[In formula (a1-1) and formula (a1-2), L a1 and L a2 each independently represents -O- or *-O-(CH2) k1 -CO-O-, k1 represents an integer of 1 to 7, and * represents a 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 0 to 14. n1 represents an integer of 0 to 10. n1’ represents an integer of 0 to 3.]

[13] The resist composition according to

[11] or

[12] , wherein the resin having an acid-labile group further contains a structural unit represented by formula (a2-A). TIFF0007696233000009.tif4551[In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 represents a single bond or* -X a51 -(A a52 -X a52 ) nb - represents, and * represents the bonding site with the carbon atom to which -R a50 is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represent -O-, -CO-O- or -O-CO-. nb represents 0 or 1. mb represents any integer from 0 to 4. When mb is any integer of 2 or more, a plurality of R a51 may be the same as or different from each other. The resist composition according to any one of

[11] to

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

[14] acid generator.

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

[11] to

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

Effects of the Invention

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

Modes for Carrying Out the Invention

[0007] In this specification, unless otherwise specified, "(meth)acrylate" means "at least one selected from the group consisting of acrylate and methacrylate". Notations such as "(meth)acrylic acid" and "(meth)acryloyl" also have the same meaning. When structural units having "CH2=C(CH3)-CO-" or "CH2=CH-CO-" are exemplified, structural units having both groups are similarly exemplified. Also, among the groups described in this specification, those that can take both a linear structure and a branched structure may be either of them. When -CH2- contained in a hydrocarbon group or the like is replaced by -O-, -S-, -CO- or -SO2-, the same examples apply to each group. "Combined group" means a group formed by bonding two or more of the exemplified groups, and the valences of these groups may be appropriately changed depending on the bonding form. "Derived from" or "derived" 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. In this specification, the "solid content of the resist composition" means the total of the components excluding the solvent (E) described later from the total amount of the resist composition.

[0008] [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)". TIFF0007696233000010.tif33130 [In formula (I), all symbols have the same meanings as described above respectively.]

[0009] In formula (I), Q 1 , Q 2 , R 1 and R 2Examples of the perfluoroalkyl group include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, and the like. Q 1 and Q 2 are each independently preferably a trifluoromethyl group or a fluorine atom, and more preferably a fluorine atom. R 1 and R 2 are each independently preferably a hydrogen atom or a fluorine atom, and more preferably a hydrogen atom. z is preferably 0 or 1. X 1 is preferably *-CO-O-, *-O-CO-O- or *-O-CO- (* represents the bonding position to C(R 1 )(R 2 ) or C(Q 1 )(Q 2 )), and more preferably *-CO-O- or *-O-CO-O-.

[0010] L 1 Examples of the divalent hydrocarbon group in L include a divalent chain hydrocarbon group such as an alkanediyl group, a monocyclic or polycyclic (including spiro ring) divalent alicyclic hydrocarbon group, and a divalent aromatic hydrocarbon group. A group formed by combining two or more of these groups (for example, a divalent hydrocarbon group formed from an alicyclic hydrocarbon group and an alkanediyl group) may also be used. Examples of the alkanediyl group include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, and heptadecane-1,17-diyl group; and branched alkanediyl groups such as ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group. The number of carbon atoms in the alkanediyl group is preferably 1 to 12, more preferably 1 to 9, still more preferably 1 to 6, and even more preferably 1 to 4. Examples of the monocyclic or polycyclic divalent alicyclic hydrocarbon group include monocyclic divalent alicyclic 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; and polycyclic divalent alicyclic hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group. 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. Specifically, examples of the alicyclic hydrocarbon group include the groups represented below. The bonding site can be at any position. As the divalent aromatic hydrocarbon group having a value of 441682, arylene groups such as phenylene group, naphthylene group, anthrylene group, biphenylene group, phenanthrylene group and other aromatic hydrocarbon groups can be mentioned. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and even more preferably 6 to 10. Among the divalent chain hydrocarbon group, monocyclic or polycyclic divalent alicyclic hydrocarbon group and divalent aromatic hydrocarbon group, examples of the group formed by combining two or more of them include a group formed by combining an alicyclic hydrocarbon group and an alkanediyl group, a group formed by combining an aromatic hydrocarbon group and an alkanediyl group, and a group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group. In the combination, the alicyclic hydrocarbon group, aromatic hydrocarbon group, and chain hydrocarbon group may each be combined with two or more. Also, any group may be X 1 bonded to. Examples of the group formed by combining an alicyclic hydrocarbon group and an alkanediyl group include, for example, -divalent alicyclic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent alicyclic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent alicyclic hydrocarbon group-, etc. Examples of the group formed by combining an aromatic hydrocarbon group and an alkanediyl group include, for example, -divalent aromatic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent aromatic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent aromatic hydrocarbon group-, etc. Examples of the group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group include -aromatic hydrocarbon group-alicyclic hydrocarbon group-, -alicyclic hydrocarbon group-aromatic hydrocarbon group-, -alicyclic hydrocarbon group-aromatic hydrocarbon group-alicyclic hydrocarbon group-, etc. L 1 The -CH2- contained in the divalent hydrocarbon group having 1 to 28 carbon atoms of L may be replaced by -O-, -S-, -SO2- or -CO-. L 1When -CH2- contained in the hydrocarbon group having 1 to 28 carbon atoms is replaced by -O-, -S-, -SO2- or -CO-, the number of carbon atoms before replacement is defined as the number of carbon atoms of the hydrocarbon group. L 1 Examples of the group in which -CH2- contained in the hydrocarbon group in 1 is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group (a group in which -CH2- contained in a methyl group is replaced by -O-), a thiol group (a group in which -CH2- contained in a methyl group is replaced by -S-), a carboxy group (a group in which -CH2-CH2- contained in an ethyl group is replaced by -O-CO-), an alkoxy group (a group in which -CH2- at any position contained in an alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in an alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which -CH2- at any position contained in an alkyl group is replaced by -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in an alkyl group is replaced by -CO-O-), an alkanedioxy group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -O-), an alkanedioxycarbonyl group (a group in which -CH2-CH2- at any position contained in an alkanediyl group is replaced by -O-CO-), an alkanediylcarbonyl group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -CO-), an alkanediylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in an alkanediyl group is replaced by -CO-O-), an alkylthio group (a group in which -CH2- at any position contained in an alkyl group is replaced by -S-), an alkylsulfonyl group (a group in which -CH2- at any position contained in an alkyl group is replaced by -SO2-), 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.

[0011] Examples of the alkoxy group include alkoxy groups having 1 to 17 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group and the like. The alkoxycarbonyl group, alkylcarbonyl group and alkylcarbonyloxy group represent groups 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. Examples of the alkanedioxy group include alkanedioxy groups having 1 to 17 carbon atoms, such as methyleneoxy group, ethyleneoxy group, propanedioxy group, butanedioxy group, pentanedioxy group and the like. Examples of the alkanedioxycarbonyl group include alkanedioxycarbonyl groups having 2 to 17 carbon atoms, such as methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propanedioxycarbonyl group, butanedioxycarbonyl group and the like. Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 18 carbon atoms, such as methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, pentanediylcarbonyl group and the like. Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 17 carbon atoms, such as methylenecarbonyloxy group, ethylenecarbonyloxy group, propanediylcarbonyloxy group, butanediylcarbonyloxy group and the like. Examples of the alkylthio group include alkylthio groups having 1 to 17 carbon atoms, such as methylthio group, ethylthio group, propylthio group and the like. Examples of the alkylsulfonyl group include 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-, -CO- or -SO2- include the following groups and the like. The bonding site can be at any position. Among the groups listed below, the position of -O- may be replaced by -S-. TIFF0007696233000012.tif47158

[0012] L 1 The substituents that may be possessed include hydroxy group, carboxy group, halogen atom, cyano group, alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, alkoxycarbonyl group having 2 to 13 carbon atoms, alkylcarbonyl group having 2 to 13 carbon atoms, alkylcarbonyloxy group having 2 to 13 carbon atoms or a group combining these and the like. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, iodine atom and the like. Examples of the alkyl group having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group, nonyl group, etc. Examples of the alkoxy group having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group, dodecyloxy group, etc. The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group having 2 to 13 carbon atoms represent groups 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 having 2 to 13 carbon atoms include methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group, etc. Examples of the alkylcarbonyl group having 2 to 13 carbon atoms include acetyl group, propionyl group, butyryl group, etc. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include acetyloxy group, propionyloxy group, butyryloxy group, etc. The substituent is preferably an alkyl group having 1 to 4 carbon atoms, a hydroxy group or a halogen atom, more preferably an alkyl group having 1 to 4 carbon atoms or a halogen atom, and even more preferably a methyl group or a fluorine atom.

[0013] L 1is preferably a single bond, an alkanediyl group having 1 to 6 carbon atoms (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), a group formed by combining an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-), or a group formed by combining an alkanediyl group having 1 to 6 carbon atoms and an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-). More preferably, it is a single bond, an alkanediyl group having 1 to 4 carbon atoms, a group formed by combining an alkanediyl group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-), or a group formed by combining an alkanediyl group having 1 to 4 carbon atoms and a phenylene group which may have a substituent (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-). Here, the combination of the alkanediyl group and the alicyclic hydrocarbon group or the aromatic hydrocarbon group includes *-alkanediyl group-alicyclic hydrocarbon group or aromatic hydrocarbon group-, *-alicyclic hydrocarbon group or aromatic hydrocarbon group-alkanediyl group-, *-alkanediyl group-alicyclic hydrocarbon group or aromatic hydrocarbon group-alkanediyl group-, etc. * represents X 1 represents a bond to For example, L 1 is * -L 4 -CO-O- (provided that L 4 represents a hydrocarbon group having 1 to 22 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-). In this case, L 4is an alkandiyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-), an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, a group formed by combining an alkandiyl group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the alkandiyl group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-), or a group formed by combining an alkandiyl group having 1 to 4 carbon atoms and an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent (provided that -CH2- contained in the alkandiyl group may be replaced by -O- or -CO-), and is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-), a phenylene group which may have a substituent, a group formed by combining an alkandiyl group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the alkandiyl group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-), or a group formed by combining an alkandiyl group having 1 to 4 carbon atoms and a phenylene group which may have a substituent (provided that -CH2- contained in the alkandiyl group may be replaced by -O- or -CO-), and is more preferably such a group.

[0014] R 3 Examples of the halogen atom represented by 3 include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like. R 3 is preferably a fluorine atom or an iodine atom. m3 is preferably 1 or 2. R 4Examples of the alkyl group having 1 to 12 carbon atoms 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 and the like. The number of carbon atoms of the alkyl group is preferably 1 to 9, more preferably 1 to 6, and still more preferably 1 to 4. R 4 When -CH2- contained in the alkyl group in 4 is replaced by -O- or -CO-, the total number of carbon atoms before replacement is defined as the total carbon atoms of the alkyl group. R 4 Examples of the group in which -CH2- contained in the alkyl group in 4 is replaced by -O- or -CO- include hydroxy group (the group in which -CH2- contained in the methyl group is replaced by -O-), carboxy group (the group in which -CH2-CH2- contained in the ethyl group is replaced by -O-CO-), alkoxy group (the group in which -CH2- at any position contained in the alkyl group is replaced by -O-), alkoxycarbonyl group (the group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -O-CO-), alkylcarbonyl group (the group in which -CH2- at any position contained in the alkyl group is replaced by -CO-), alkylcarbonyloxy group (the group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -CO-O-), and groups formed by combining two or more of these groups. R 4 Examples of the fluoroalkyl group having 1 to 6 carbon atoms include fluoroalkyl groups such as trifluoromethyl group, difluoromethyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, perfluorohexyl group and the like. The number of carbon atoms of the fluoroalkyl group is preferably 1 to 4, more preferably 1 to 3. R 4Examples of the group in which -CH2- contained in the alkyl fluoride group is replaced by -O- or -CO- include a fluoroalkoxy group (a group in which -CH2- at any position contained in the alkyl fluoride group is replaced by -O-), a fluoroalkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkyl fluoride group is replaced by -O-CO-), a fluoroalkylcarbonyl group (a group in which -CH2- at any position contained in the alkyl fluoride group is replaced by -CO-), a fluoroalkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkyl fluoride group is replaced by -CO-O-), and a group formed by combining two or more of these groups. Examples of the alkoxy group include alkoxy groups having 1 to 11 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, decyloxy group, and undecyloxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 11 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, and butoxycarbonyl group. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 12 carbon atoms, such as acetyl group, propionyl group, and butyryl group. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 11 carbon atoms, such as methylcarbonyloxy group, ethylcarbonyloxy group, propylcarbonyloxy group, and butylcarbonyloxy group. Examples of the fluoroalkoxy group, fluoroalkoxycarbonyl group, fluoroalkylcarbonyl group, and fluoroalkylcarbonyloxy group include fluoroalkoxy groups having 1 to 5 carbon atoms, fluoroalkoxycarbonyl groups having 2 to 5 carbon atoms, fluoroalkylcarbonyl groups having 2 to 6 carbon atoms, and fluoroalkylcarbonyloxy groups having 2 to 5 carbon atoms. For example, one or more hydrogen atoms of the groups exemplified above may be replaced by fluorine atoms. R 4is preferably an alkyl fluoride group having 1 to 4 carbon atoms or an alkyl group having 1 to 8 carbon atoms (wherein -CH2- contained in the alkyl fluoride group and the alkyl group may be replaced by -O- or -CO-), more preferably an alkoxy group having 1 to 6 carbon atoms, and even more preferably an alkoxy group having 1 to 3 carbon atoms. m4 is preferably 1 or 2, and more preferably 1.

[0015] R 5 The acid-labile group of R means a group that forms a hydroxy group by elimination of the acid-labile group upon contact with an acid. Examples of the acid-labile group include a group represented by the formula (R5-1) (hereinafter, sometimes referred to as "acid-labile group (R5-1)") and a group represented by the formula (R5-2) (hereinafter, sometimes referred to as "acid-labile group (R5-2)"). TIFF0007696233000013.tif1979[In the formula (R5-1), R 14 、R 15 and R 16 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, or R 14 and R 15 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. m represents 0 or 1. * represents a bonding site.] TIFF0007696233000014.tif2181[In the formula (R5-2), R 17 and R 18 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R 19 represents a hydrocarbon group having 1 to 20 carbon atoms, or R 18 and R 19 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 a and the -CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced by -O- or -S-. Xa represents an oxygen atom or a sulfur atom. n represents 0 or 1. * represents a bonding site.

[0016] R 14 R 15 and R 16 Examples of the alkyl group represented by R 14 R 15 and R 16 include a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, etc. The number of carbon atoms of the alkyl group of R R 14 R 15 and R 16 is preferably 1 to 6, more preferably 1 to 3. R 14 R 15 and R 16 Examples of the alicyclic hydrocarbon group represented by R 14 R 15 and R 16 include both monocyclic and polycyclic types. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, etc. Examples of the polycyclic alicyclic hydrocarbon group include, for example, a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bond). The number of carbon atoms of the alicyclic hydrocarbon group of R TIFF0007696233000015.tif10150R 14 R 15 and R 16 include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, a phenanthryl group, etc. Examples of the aromatic hydrocarbon group of R aa1 R aa2 and R aa3The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 14, more preferably 6 to 10.

[0017] Examples of the group combining an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, a norbornylethyl group, and the like. Examples of the group combining an alkyl group and an aromatic hydrocarbon group include a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, and the like. Examples of the group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group include a p-cyclohexylphenyl group, a p-adamantylphenyl group, and the like. m is preferably 1.

[0018] R 14 and R 15 When they are bonded to each other to form an alicyclic hydrocarbon group together with the carbon atom to which they are bonded, examples of -C(R 14 )(R 15 )(R 16 ) include the following groups. The alicyclic hydrocarbon group preferably has 3 to 16 carbon atoms, more preferably 3 to 12 carbon atoms. * represents a bond to -O-. TIFF0007696233000016.tif30138

[0019] R 17 、R 18 and R 19 Examples of the hydrocarbon groups of R include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group combining the above-described alkyl group and alicyclic hydrocarbon group (such as an alkylcycloalkyl group or cycloalkylalkyl group), an aralkyl group (such as a benzyl group), an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), an aryl-cycloalkyl group (phenylcyclohexyl group, etc.), and the like. R 18 and R 19 are bonded to each other, and together with the carbon atom to which they are bonded and X 1 form a heterocyclic ring, -C(R 17 )(R 18 )-X a -R 19 includes the following groups. * represents a bond. TIFF0007696233000017.tif18130R 17 and R 18 at least one of them is preferably a hydrogen atom. n is preferably 0.

[0020] Specific examples of the acid-labile group (R5-1) include the following groups. * represents a bond. TIFF0007696233000018.tif41147

[0021] Specific examples of the acid-labile group (R5-2) include the following groups. * represents a bond. TIFF0007696233000019.tif70162

[0022] m5 is preferably 1.

[0023] -OR 5 The bonding position of may be any of the ortho, meta, and para positions with respect to the bonding position of L 1 on the benzene ring, but the ortho or para position is preferred. R 3 The bonding position of 1 may be any of the ortho, meta, and para positions relative to the bonding position of L in the benzene ring, but the ortho and meta positions are preferred, and the meta position is more preferred. When m3 is 2, the two Rs 3 are more preferably both in the meta position relative to the bonding position of L 1 in the benzene ring. R 4 The bonding position of 1 may be any of the ortho, meta, and para positions relative to the bonding position of L in the benzene ring, but the meta position is preferred.

[0024] Examples of the anion (I) include anions represented by the following formulas (Ia-1) to (Ia-46). TIFF0007696233000020.tif231155

[0025] TIFF0007696233000021.tif236154

[0026] TIFF0007696233000022.tif125163

[0027] TIFF0007696233000023.tif95148

[0028] TIFF0007696233000024.tif154146

[0029] Z + Examples of the organic cation of

[0030] TIFF0007696233000025.tif In formulas (b2-1) to (b2-4), R b4 ~R b6 each independently represents a linear hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, and the hydrogen atom contained in the linear hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms; 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 the -CH2- contained in the ring may be replaced with -O-, -S-, or -CO-. R b7 and R b8 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. m2 and n2 each independently represent an integer of 0 to 5. When m2 is 2 or more, the plurality of R b7 may be the same or different, and when n2 is 2 or more, the plurality of R b8 may be the same or different. R b9 and R b10 each independently represents a linear hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms. R b9 and R b10 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and the -CH2- contained in the ring may be replaced with -O-, -S-, or -CO-. R b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the chain hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 may be bonded to each other to form a ring including -CH-CO- to which they are bonded, and -CH2- contained in the ring may be replaced with -O-, -S-, or -CO-. R b13 ~R b18 each independently represents a halogen atom, a hydroxy group, a fluorinated alkyl group having 1 to 12 carbon atoms, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. L b31 represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent any integer from 0 to 5. q2 and r2 each independently represent any integer from 0 to 4. u2 represents 0 or 1. When o2 is 2 or more, a plurality of R b13 are the same or different, when p2 is 2 or more, a plurality of R b14 are the same or different, when q2 is 2 or more, a plurality of R b15 are the same or different, when r2 is 2 or more, a plurality of R b16 are the same or different, when s2 is 2 or more, a plurality of R b17 are the same or different, when t2 is 2 or more, a plurality of R b18 are the same or different. When u2 is 0, any one of o2, p2, q2, and r2 is 1 or more, and R b13 ~R b16It is preferable that at least one of them is a halogen atom. When u2 is 1, any one of o2, p2, s2, t2, q2 and r2 is 1 or more, and R b13 ~R b18 It is preferable that at least one of them is a halogen atom.

[0031] The aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. In particular, the chain hydrocarbon group of R b9 ~R b12 is preferably 1 to 12 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group and the following groups. TIFF0007696233000026.tif10158 In particular, the alicyclic hydrocarbon group of R b9 ~R b12 is preferably 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.

[0032] 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, isobornyl group and the like. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The alkyl fluoride group represents an alkyl group having 1 to 12 carbon atoms with a fluorine atom, and examples thereof include fluoromethyl group, difluoromethyl group, trifluoromethyl group, perfluorobutyl, etc. The number of carbon atoms of the alkyl fluoride group is preferably 1 to 9, more preferably 1 to 6, and even more preferably 1 to 4.

[0033] Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, biphenyl group, naphthyl group, phenanthryl group, etc. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and aromatic hydrocarbon groups having a chain hydrocarbon group (such as tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and aromatic hydrocarbon groups having an alicyclic hydrocarbon group (such as p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) can be mentioned. In addition, when the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms are preferred. Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include p-methoxyphenyl group, etc. Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, naphthylethyl group, etc.

[0034] Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, dodecyloxy group, etc. Examples of the alkylcarbonyl group include acetyl group, propionyl group, butyryl group, etc. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, iodine atom, etc. Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

[0035] 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 a monocyclic, polycyclic, aromatic, non-aromatic, saturated, and unsaturated ring. Examples of this ring include rings having 3 to 18 carbon atoms, preferably rings having 4 to 18 carbon atoms. Further, examples of the ring containing a sulfur atom include 3-membered to 12-membered rings, preferably 3-membered to 7-membered rings, and examples thereof include the following rings. * represents a bonding site. TIFF0007696233000027.tif23143

[0036] R b9 and R b10 The ring formed by R and R together may be any of a monocyclic, polycyclic, aromatic, non-aromatic, saturated, and unsaturated ring. Examples of this ring include 3-membered to 12-membered rings, preferably 3-membered to 7-membered rings. Examples thereof include a thiolan-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. R b11 and R b12 The ring formed by R and R together may be any of a monocyclic, polycyclic, aromatic, non-aromatic, saturated, and unsaturated ring. Examples of this ring include 3-membered to 12-membered rings, preferably 3-membered to 7-membered rings. Examples thereof include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

[0037] Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferred. Examples of the cation (b2-1) include the following cations. TIFF0007696233000028.tif80158

[0038] TIFF0007696233000029.tif111165

[0039] Examples of the cation (b2-2) include the following cations. TIFF0007696233000030.tif18150

[0040] Examples of the cation (b2-3) include the following cations. TIFF0007696233000031.tif26140

[0041] Examples of the cation (b2-4) include the following cations. TIFF0007696233000032.tif127166

[0042] The salt (I) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the salt (I), preferably, an anion represented by any of Formula (Ia-2) to Formula (Ia-4), Formula (Ia-12) to Formula (Ia-15), Formula (Ia-17) to Formula (Ia-24), Formula (Ia-33) to Formula (Ia-36), Formula (Ia-39), Formula (Ia-40), Formula (Ia-43) to Formula (Ia-46), and a combination with the cation (b2-1), the cation (b2-2), the cation (b2-3), or the cation (b2-4) are mentioned.

[0043] Examples of the salt (I) include the salts described in Table 1. In the following table, each symbol represents the symbol attached to the structure representing the above-mentioned anion or cation. For example, the salt (I-1) means a salt composed of the anion represented by Formula (Ia-1) and the cation represented by Formula (b2-c-1), and represents the salt shown below. TIFF0007696233000033.tif3198 [Table 1] TIFF0007696233000035.tif223154 TIFF0007696233000036.tif223154 TIFF0007696233000037.tif223154 TIFF0007696233000038.tif223154 TIFF0007696233000039.tif223154 TIFF0007696233000040.tif223154 TIFF0007696233000041.tif234157 Among them, the salt (I) is preferably the salt (I-1) to salt (I-4), salt (I-9), salt (I-10), salt (I-13) to salt (I-23), salt (I-33) to salt (I-36), salt (I-41), salt (I-42), salt (I-45) to salt (I-55), salt (I-65) to salt (I-68), salt (I-73), salt (I-74), salt (I-77) to salt (I-87), salt (I-97) to salt (I-100), salt (I-105), salt (I-106), salt (I-109) to salt (I-119), salt (I-129) to salt (I-132), salt (I-137), salt (I-138), salt (I-141) to salt (I-151), salt (I-161) to salt (I-164), salt (I-169), salt (I-170), salt (I-173) to salt (I-183), salt (I-193) to salt (I-196), salt (I-201), salt (I-202), salt (I-205) to salt (I-215), salt (I-225) to salt (I-228), salt (I-231), salt (I-232), salt (I-235) to salt (I-238), salt (I-239) to salt (I-242), salt (I-245), salt (I-246), salt (I-249) to salt (I-252), salt (I-253) to salt (I-256), salt (I-259), salt (I-260), salt (I-263) to salt (I-266), salt (I-267) to salt (I-270), salt (I-273), salt (I-274), salt (I-277) to salt (I-280), salt (I-281) to salt (I-284), salt (I-287), salt (I-288), salt (I-291) to salt (I-294), salt (I-295) to salt (I-298), salt (I-301), salt (I-302), salt (I-305) to salt (I-308), salt (I-309) to salt (I-312), salt (I-315), salt (I-316), salt (I-319) to salt (I-322).

[0044] <Method for producing salt (I)> In the salt (I), X 1 The salt (represented by the formula (I1)) in which is *-CO-O- can be produced, for example, by reacting the salt represented by the formula (I1-a) with carbonyldiimidazole in a solvent and then further reacting with the compound represented by the formula (I1-b). TIFF0007696233000042.tif42164(In the formula, all the symbols represent the same meanings as described above.) Examples of the solvent in this reaction include chloroform, acetonitrile, and the like. The reaction temperature is generally 5°C to 80°C, and the reaction time is generally 0.5 hour to 24 hours.

[0045] The salts represented by formula (I1-a) include, for example, the salts represented below, and can be produced by the method described in JP-A-2008-127367. TIFF0007696233000043.tif2843Examples of the compound represented by formula (I1-b) include the compounds represented by the following formula, which can be easily obtained from the market and can also be easily produced by known production methods. TIFF0007696233000044.tif141167

[0046] In salt (I), X 1 The salt in which is *-O-CO-O- (the salt represented by formula (I2)) can be produced, for example, by reacting the salt represented by formula (I2-a) with carbonyldiimidazole in a solvent and then further reacting with the compound represented by formula (I1-b). Also, the salt represented by formula (I2) can be produced, for example, by reacting the compound represented by formula (I1-b) with carbonyldiimidazole in a solvent and then further reacting with the salt represented by formula (I2-a). TIFF0007696233000045.tif71167(In the formula, all the symbols represent the same meanings as described above.) Examples of the solvent in this reaction include chloroform, acetonitrile, and the like. The reaction temperature is generally 5°C to 80°C, and the reaction time is generally 0.5 hour to 24 hours. The salts represented by formula (I2-a) include, for example, the salts represented below, and can be produced by the method described in JP-A-2012-193170. TIFF0007696233000046.tif2843

[0047] In salt (I), X 1 where X is *-O-CO- (the salt represented by formula (I3)) can be produced, for example, by reacting a compound represented by formula (I3-b) with carbonyldiimidazole in a solvent and then further reacting with a salt represented by formula (I2-a). TIFF0007696233000047.tif43165 (wherein all the symbols have the same meanings as described above). Examples of the solvent in this reaction include chloroform and acetonitrile. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours. Examples of the compound represented by formula (I3-b) include compounds represented by the following formula and can be easily obtained from the market. TIFF0007696233000048.tif33146

[0048] In salt (I), X 1 where X is -O- (the salt represented by formula (I4)) can be obtained by reacting a salt represented by formula (I2-a) with a compound represented by formula (I1-b) in a solvent in the presence of a base. TIFF0007696233000049.tif59158 (wherein all the symbols have the same meanings as described above). Examples of the base in this reaction include potassium hydroxide. Examples of the solvent in this reaction include acetonitrile. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0049] In salt (I), L 1is a group formed by combining an alkanediyl group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-). The salt can be produced by replacing the salt represented by formula (I1-a) or the salt represented by formula (I2-a) with the salt represented by the following when synthesizing the salts represented by formula (I1) to formula (I4). TIFF0007696233000050.tif152154

[0050] TIFF0007696233000051.tif57153

[0051] [Acid generator] The acid generator of the present invention is an acid generator containing salt (I). It may contain one kind of salt (I) or two or more kinds of salt (I). In addition to salt (I), the acid generator of the present invention may contain an acid generator known in the resist field (hereinafter sometimes referred to as "acid generator (B)"). Acid generator (B) may be used alone or in combination of two or more kinds.

[0052] As acid generator (B), either nonionic or ionic type may be used. Examples of nonionic acid generators 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), etc. Representative examples of ionic acid generators include onium salts containing onium cations (e.g., diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). Examples of anions of onium salts include sulfonic acid anions, sulfonylimide anions, sulfonylmethide anions, etc.

[0053] As the acid generator (B), compounds that generate 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. Also, compounds produced by known methods may be used. The acid generator (B) may be used in combination of two or more kinds.

[0054] The acid generator (B) is preferably a fluorine-containing acid generator, and more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as "acid generator (B1)". However, salt (I) is excluded.). TIFF0007696233000052.tif2861[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, and -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 a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-. Z1 + represents an organic cation.]

[0055] Q b1 and Q b2Examples of the perfluoroalkyl group in [compound name] include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, and the like. Q b1 and Q b2 are each independently preferably a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

[0056] L b1 Examples of the divalent saturated hydrocarbon group in [compound name] 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; Monocyclic divalent alicyclic saturated hydrocarbon groups that are cycloalkanediyl groups such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, and a cyclooctane-1,5-diyl group; Examples of the polycyclic divalent alicyclic saturated hydrocarbon group such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc.

[0057] L b1 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by is replaced by -O- or -CO- include the 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 their specific examples formula (b1-4) to formula (b1-11), * and ** represent bonding sites, and * represents the bonding site with -Y.

[0058] TIFF0007696233000053.tif26117 [In formula (b1-1), L b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the 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, the 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 the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, the 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, L b4 and L b5The total number of carbon atoms with [the relevant group] is 22 or less. In formula (b1-3), L b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. L b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. However, the total number of carbon atoms of L b6 and L b7 is 23 or less. * and ** represent bonding sites, and * represents the bonding site with Y.

[0059] 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 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 b6 is 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 b7is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-.

[0060] L b1 As a group in which -CH2- contained in the divalent saturated hydrocarbon group represented by is replaced with -O- or -CO-, a group represented by the formula (b1-1) or the formula (b1-3) is preferable. Examples of the group represented by the formula (b1-1) include groups represented by the formulas (b1-4) to (b1-8), respectively. TIFF0007696233000054.tif49120[In the formula (b1-4), L b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. In 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 a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, b9 L b10 and the total carbon number of L In the formula (b1-6), L b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, b11 L b12 and the total carbon number of L 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 by -O- or -CO-. L b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. However, the total number of carbon atoms of 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 by -O- or -CO-. L b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms. L b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. However, the total number of carbon atoms of L b16 to L b18 is 19 or less. L b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. ​L b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L 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.

[0061] Examples of the group represented by formula (b1-3) include the groups represented by formulas (b1-9) to (b1-11). TIFF0007696233000055.tif23140 [In formula (b1-9), L b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group. However, b19 and b20 the total number of carbon atoms of L is 23 or less. In formula (b1-10), L b21represents 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. -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 The total number of carbon atoms is 21 or less. In formula (b1-11), L b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms. L b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms, hydroxy groups or alkylcarbonyloxy groups. -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 The total number of carbon atoms is 21 or less.]

[0062] In addition, in the group represented by formula (b1-9) to the group represented by formula (b1-11), when the hydrogen atoms contained in the saturated hydrocarbon group are substituted with alkylcarbonyloxy groups, the number of carbon atoms before replacement is taken as the number of carbon atoms of the saturated hydrocarbon group. Examples of the alkyloxycarbonyl group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, and an adamantylcarbonyloxy group.

[0063] Examples of the group represented by formula (b1-4) include the following. TIFF0007696233000056.tif16150

[0064] Examples of the group represented by formula (b1-5) include the following. TIFF0007696233000057.tif68152

[0065] Examples of the group represented by formula (b1-6) include the following. TIFF0007696233000058.tif29150

[0066] Examples of the group represented by formula (b1-7) include the following. TIFF0007696233000059.tif57146

[0067] Examples of the group represented by formula (b1-8) include the following. TIFF0007696233000060.tif23150

[0068] Examples of the group represented by formula (b1-2) include the following. TIFF0007696233000061.tif31161

[0069] Examples of the group represented by formula (b1-9) include the following. TIFF0007696233000062.tif44137

[0070] Examples of the group represented by formula (b1-10) include the following. TIFF0007696233000063.tif89157

[0071] Examples of the group represented by formula (b1-11) include the following. TIFF0007696233000064.tif82158

[0072] Examples of the alicyclic hydrocarbon group represented by Y include the groups represented by formula (Y1) to formula (Y11), formula (Y36) to formula (Y38). When -CH2- contained in the alicyclic hydrocarbon group represented by Y is replaced by -O-, -SO2- or -CO-, the number thereof may be one or two or more. Examples of such groups include the groups represented by formula (Y12) to formula (Y35), formula (Y39) to formula (Y43). * represents the bonding site to L b1 represents the bonding site to TIFF0007696233000065.tif85164 The alicyclic hydrocarbon group represented by Y 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). When the alicyclic hydrocarbon group represented by Y is a spiro ring having an oxygen atom such as formula (Y28) to formula (Y35), formula (Y39) to formula (Y40), formula (Y42) or formula (Y43), the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. Among the alkanediyl groups contained in the ketal structure, the methylene group adjacent to the oxygen atom is preferably not substituted with a fluorine atom.

[0073] Examples of the substituent of the methyl group represented by Y include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-O-R b1 group or -(CH2) ja -O-CO-R b1 group (wherein R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, and -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom. ja represents any integer from 0 to 4.) and the like. Examples of the substituent of the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 16 carbon atoms which may be substituted by a hydroxy group (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-O-R b1 group or -(CH2) ja -O-CO-R b1 group (wherein R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, and -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom. ja represents any integer from 0 to 4.) and the like.

[0074] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like. Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, an adamantyl group, and the like. The alicyclic hydrocarbon group may have a chain hydrocarbon group, and examples thereof include a methylcyclohexyl group and a dimethylcyclohexyl group. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 12, more preferably 3 to 10. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and preferred are aromatic hydrocarbon groups having a chain hydrocarbon group having 1 to 18 carbon atoms (such as a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-methylphenyl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group), and aromatic hydrocarbon groups having an alicyclic hydrocarbon group having 3 to 18 carbon atoms (such as a p-adamantylphenyl group and a p-cyclohexylphenyl group). 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 a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, and the like. The number of carbon atoms of the alkyl group is preferably 1 to 12, more preferably 1 to 6, and still more preferably 1 to 4. Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the group in which -CH2- contained in the alkyl group is replaced by -O-, -SO2-, -CO- or the like include an alkoxy group, an alkoxycarbonyl group, an alkylsulfonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group or a group combining these groups. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group and a dodecyloxy group. The number of carbon atoms in the alkoxy group is preferably 1 to 12, more preferably 1 to 6, and still more preferably 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 2 to 12, more preferably 2 to 6, and still more preferably 2 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 alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, and still more preferably 1 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 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group and a butyryloxy group. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the combined group include a group combining an alkoxy group and an alkyl group, a group combining an alkoxy group and an alkoxy group, a group combining an alkoxy group and an alkylcarbonyl group, a group combining an alkoxy group and an alkylcarbonyloxy group, and the like. Examples of the group combining an alkoxy group and an alkyl group include alkoxyalkyl groups such as methoxymethyl group, methoxyethyl group, ethoxyethyl group, ethoxy methyl group, etc. The number of carbon atoms of the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the group combining an alkoxy group and an alkoxy group include alkoxyalkoxy groups such as methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group, etc. The number of carbon atoms of the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the group combining an alkoxy group and an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as methoxyacetyl group, methoxypropionyl group, ethoxyacetyl group, ethoxypropionyl group, etc. The number of carbon atoms of the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and still more preferably 3 to 5. Examples of the group combining an alkoxy group and an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as methoxyacetyloxy group, methoxypropionyloxy group, ethoxyacetyloxy group, ethoxypropionyloxy group, etc. The number of carbon atoms of the alkoxyalkylcarbonyloxy group is preferably 3 to 13, more preferably 3 to 7, and still more preferably 3 to 5. Examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -SO2- or -CO- etc. include the groups represented by formula (Y12) to formula (Y35), formula (Y39) to formula (Y43), etc.

[0075] Examples of Y include the following. TIFF0007696233000066.tif102165

[0076] TIFF0007696233000067.tif64161

[0077] Y is preferably an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent, still more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, still more preferably an adamantyl group which may have a substituent, and -CH2- constituting the alicyclic hydrocarbon group or adamantyl group may be replaced by -CO-, -SO2- or -CO-. Specifically, Y is preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group or a group represented by formula (Y42), formula (Y100) to formula (Y114).

[0078] As the anion in the salt represented by formula (B1), anions represented by formula (B1-A-1) to formula (B1-A-59) [hereinafter may be referred to as "anion (B1-A-1)" etc. according to the formula number] are preferable, and an anion represented by any of formula (B1-A-1) to formula (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula (B1-A-24) to formula (B1-A-33), formula (B1-A-36) to formula (B1-A-40), formula (B1-A-47) to formula (B1-A-59) is more preferable. TIFF0007696233000068.tif154161

[0079] TIFF0007696233000069.tif65159

[0080] TIFF0007696233000070.tif101155

[0081] TIFF0007696233000071.tif64162

[0082] TIFF0007696233000072.tif111141

[0083] TIFF0007696233000073.tif85165

[0084] TIFF0007696233000074.tif100159 Here, R i2 ~R i7 are, independently of each other, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R i8 is, for example, a chain hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q b1 and Q b2 represent the same meaning as described above. Specific examples of the anion in the salt represented by the formula (B1) include the anions described in JP-A-2010-204646.

[0085] Preferred examples of the anion in the salt represented by the formula (B1) include the anions represented by the formulae (B1a-1) to (B1a-38), respectively. TIFF0007696233000075.tif89152

[0086] TIFF0007696233000076.tif93139

[0087] TIFF0007696233000077.tif142156

[0088] TIFF0007696233000078.tif63150

[0089] Among them, an anion represented by any one of the formulae (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38) is preferred.

[0090] Z1 +Examples of the organic cation include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Examples of the arylsulfonium cation include those similar to the cation of Z in formula (I). + include those similar to the cation of Z

[0091] The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the acid generator (B), preferably, any combination of an anion represented by any of formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-16), formula (B1a-18), formula (B1a-19), formula (B1a-22) to formula (B1a-38) and cation (b2-1), cation (b2-3) or cation (b2-4) is mentioned.

[0092] Examples of the acid generator (B) preferably 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), formula (B1-31) to formula (B1-56) are particularly preferred. TIFF0007696233000079.tif98161

[0093] TIFF0007696233000080.tif152164

[0094] TIFF0007696233000081.tif92158

[0095] TIFF0007696233000082.tif144161

[0096] TIFF0007696233000083.tif63170

[0097] TIFF0007696233000084.tif92158

[0098] When containing salt (I) and acid generator (B) as the acid generator, the ratio of the contents of salt (I) and acid generator (B) (mass ratio; salt (I): acid generator (B)) is usually 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, still more preferably 10:90 to 90:10, and particularly preferably 15:85 to 85:15. In the resist composition of the present invention, the total content rate of the acid generator is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or less, still more preferably 3 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the resin (A) described later.

[0099] 〔Resist Composition〕 The resist composition of the present invention contains an acid generator containing salt (I) and a resin having an acid-labile group (hereinafter sometimes referred to as "resin (A)"). Here, the "acid-labile group" means a group having a leaving group, and when contacted with an acid, the leaving group leaves and the structural unit is converted into a structural unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). The resist composition of the present invention preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") such as a salt that generates an acid having a lower acidity than the acid generated from the acid generator, and preferably contains a solvent (hereinafter sometimes referred to as "solvent (E)").

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

[0101] 〈Structural unit (a1)〉 Structural unit (a1) is derived from a monomer having an acid-labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid-labile group contained in resin (A) is preferably a group represented by formula (1) (hereinafter also referred to as group (1)) and / or a group represented by formula (2) (hereinafter also referred to as group (2)). TIFF0007696233000085.tif1988 [In formula (1), R a1 , R a2 and R a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, or R a1 and R a2 are bonded to each other to form a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * represents a bonding site. ] TIFF0007696233000086.tif2171 [In formula (2), R a1’ and R a2’ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R a3’ represents a hydrocarbon group having 1 to 20 carbon atoms, or R a2’ and R a3’They are bonded to each other to form a heterocyclic ring having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded and X, and the -CH2- contained in the hydrocarbon group and the heterocyclic ring may be replaced by -O- or -S-. X represents an oxygen atom or a sulfur atom. na’ represents 0 or 1. * represents a bonding site.

[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 a3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and the like. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the following group (* represents a bonding site.). The number of carbon atoms of the alicyclic hydrocarbon group of R TIFF0007696233000087.tif10150R a1 、R a2 and R a3 Examples of the aromatic hydrocarbon group in R Examples of the combined group include groups combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., alkylcycloalkyl groups or cycloalkylalkyl groups such as cyclohexylmethyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, etc. Preferably, ma is 0 and na is 1. R a1 and R a2 When they are bonded to each other to form a non-aromatic hydrocarbon ring, examples of -C(R a1 )(R a2 )(R a3 ) include the following rings. The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * represents the bonding site with -O-. TIFF0007696233000088.tif30138

[0103] R a1’ 、R a2’ and R a3’ Examples of the hydrocarbon group in R The alkyl group and alicyclic hydrocarbon group are the same as those exemplified for R a1 、R a2 and R a3 . Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, phenanthryl group, etc. As the combined group, there may be mentioned groups combining the above-described alkyl group and alicyclic hydrocarbon group (for example, alkylcycloalkyl groups or cycloalkylalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like. R a2’ and R a3’ When are bonded to each other to form a heterocyclic ring together with the carbon atom to which they are bonded and X, -C(R a1’ )(R a2’ )-X-R a3’ includes the following rings. * represents the bonding site. TIFF0007696233000089.tif18130 R 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), R a1 , R a2 and R a3 are alkyl groups, ma = 0, and na = 1. As such a group, a tert-butoxycarbonyl group is preferable. In formula (1), R a1 , R a2 together with the carbon atom to which they are bonded form an adamantyl group, R a3 is an alkyl group, ma = 0, and na = 1. In formula (1), R a1 and Ra2 are 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 the bonding site. TIFF0007696233000090.tif170163

[0105] Specific examples of the group (2) include the following groups. * represents the bonding site. TIFF0007696233000091.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 having 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), a structural unit represented by the formula (a1-0) (hereinafter sometimes referred to as the structural unit (a1-0)), a structural unit represented by the formula (a1-1) (hereinafter sometimes referred to as the structural unit (a1-1)), or a structural unit represented by the formula (a1-2) (hereinafter sometimes referred to as the structural unit (a1-2)) is mentioned. 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. TIFF0007696233000092.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 the bonding site with -CO-. R a01 R a4 and R a5 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a02 R a03 and R a04 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. 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, 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 R a04 R a6 and R a7 Examples of the alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and the group formed by combining these in R a1 Ra2 and R a3 include groups similar to the groups listed above. R a02 、R a03 、and R a04 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a6 and R a7 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group or a t-butyl group, and even more preferably an ethyl group, an isopropyl group or a t-butyl group. R a6 and R a7 The alkenyl group in is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably an ethenyl group, a propenyl group, an isopropenyl group or a butenyl group. R a02 、R a03 、R a04 、R a6 and R a7 The number of carbon atoms of the alicyclic hydrocarbon group of 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 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 a04is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. R a6 and R a7 are each independently preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, a phenyl group or a naphthyl group, and still 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 structural units represented by any of the formulas (a1-0-1) to (a1-0-18) and structural units in which the methyl group corresponding to R a01 in the structural unit (a1-0) is replaced by a hydrogen atom, a halogen atom, a haloalkyl group (an alkyl group having a halogen atom) or another alkyl group, and structural units represented by any of the formulas (a1-0-1) to (a1-0-10), (a1-0-13), (a1-0-14) are preferred. TIFF0007696233000093.tif99167

[0111] Examples of the structural unit (a1-1) include structural units derived from the monomers described in JP-A-2010-204646. Among them, structural units represented by any of the formulas (a1-1-1) to (a1-1-7) and structural units in which the methyl group corresponding to R a4 in the structural unit (a1-1) is replaced by a hydrogen atom are preferred, and structural units represented by any of the formulas (a1-1-1) to (a1-1-4) are more preferred. TIFF0007696233000094.tif40169

[0112] As the structural unit (a1-2), there are a structural unit represented by any of the formulas (a1-2-1) to (a1-2-14) and an R in the structural unit (a1-2). a5 Examples of the structural unit in which the methyl group corresponding to R is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group include structural units represented by any of the formulas (a1-2-2), (a1-2-5), (a1-2-6), and (a1-2-10) to (a1-2-14), and structural units represented by any of these are preferred. TIFF0007696233000095.tif67163

[0113] When the resin (A) contains the structural unit (a1-0), its content is usually 5 to 80 mol%, preferably 5 to 75 mol%, more preferably 10 to 70 mol% with respect to all the structural units of the resin (A). When the resin (A) contains the structural unit (a1-1) and / or the structural unit (a1-2), their total content is usually 10 to 90 mol%, preferably 15 to 85 mol%, more preferably 20 to 80 mol%, still more preferably 20 to 75 mol%, and even more preferably 20 to 70 mol% with respect to 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 the formula (a1-4) (hereinafter, may be referred to as "structural unit (a1-4)"). TIFF0007696233000096.tif3854[In the 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 a33represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group. A a30 represents a single bond or * -X a31 -(A a32 -X a32 ) nc -, where * represents the bonding site with the carbon atom to which -R a32 is bonded. A a32 represents an alkanediyl group having 1 to 6 carbon atoms. X a31 and X a32 each independently represents -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 represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -C-O- to which they are bonded, and the -CH2- contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced by -O- or -S-.

[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 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 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 include methoxymethyl group, ethoxyethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, sec-butoxymethyl group and tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and still more preferably a methoxymethyl group. R a33Examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethyl group or an ethoxyethyl group. R a33 Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group. R a33 Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably an acetyloxy group. R a33 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0116] *-X a31 -(A a32 -X a32 ) nc - includes *-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- are included. 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 preferably, 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 the bonding site). As the aromatic hydrocarbon group, aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group can be mentioned. As the combined group, groups formed by combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, alkylcycloalkyl groups or cycloalkylalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, etc. can be mentioned. Particularly, R a36 Examples include an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these.

[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, and more preferably a methyl group or an ethyl group. R a36 The hydrocarbon group of R is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and alicyclic hydrocarbon group in R are preferably unsubstituted. R a36 a36The aromatic hydrocarbon group in is preferably an aromatic ring having an aryloxy group with 6 to 10 carbon atoms. -OC(R in the structural unit (a1-4) a34 )(R a35 )-O-R a36 undergoes elimination upon contact with an acid (for example, p-toluenesulfonic acid) to form a hydroxy group. -OC(R a34 )(R a35 )-O-R a36 is preferably bonded to the o-position or p-position of the benzene ring, and more preferably bonded to the p-position.

[0121] Examples of the structural unit (a1-4) include structural units derived from the monomers described in JP-A-2010-204646. Preferably, the structural units represented by formula (a1-4-1) to formula (a1-4-18) and the structural unit (a1-4) in which the hydrogen atom corresponding to R a32 is replaced with 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), formula (a1-4-14). TIFF0007696233000098.tif100167

[0122] When the resin (A) contains the structural unit (a1-4), its content is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, still more preferably 7 to 70 mol%, still more preferably 7 to 65 mol%, and particularly preferably 10 to 60 mol% based on the total of all the structural units of the resin (A).

[0123] 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)"). TIFF0007696233000099.tif4658 In formula (a1-5), R a8represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. Z a1 represents a single bond or *-(CH2) h3 -CO-L 54 -, h3 represents an integer of any one of 1 to 4, and * represents the bonding site with 51 L. L 51 L 52 L 53 and L 54 each independently represents -O- or -S-. s1 represents an integer of any one of 1 to 3. s1’ represents an integer of any one of 0 to 3.

[0124] 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 of any one of 0 to 2. Z a1 is preferably a single bond or *-CH2-CO-O-.

[0125] 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. TIFF0007696233000100.tif33133

[0126] When the resin (A) contains the structural unit (a1-5), its content is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, still more preferably 5 to 40 mol%, and even more preferably 5 to 30 mol% based on all the structural units of the resin (A).

[0127] In addition, examples of the structural unit (a1) also include the following structural units. TIFF0007696233000101.tif31162

[0128] 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).

[0129] In addition, examples of the structural unit (a1) also include the following structural units. TIFF0007696233000102.tif5295 When the resin (A) contains structural units such as (a1-6-1) to (a1-6-3) above, its content is preferably 10 to 60 mol%, more preferably 15 to 55 mol%, still more preferably 20 to 50 mol%, even more preferably 20 to 45 mol%, and particularly preferably 20 to 40 mol% based on all the structural units of the resin (A).

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

[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)"). TIFF0007696233000103.tif4551[In the formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group. A a50 represents a single bond or *-X a51 -(A a52 -X a52 ) nb -, where * represents the bonding site with the carbon atom to which -R a50 is bonded. A a52 each independently represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O- or -O-CO-. nb represents 0 or 1. mb represents any integer from 0 to 4. When mb is any integer of 2 or more, a plurality of R a51 may be the same as or different from each other.]

[0133] R a50 and R a51 Examples of the halogen atom in R R a50 include a fluorine atom, a chlorine atom, a bromine atom and the like. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R R a50is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a51 Examples of the alkyl group in a51 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a51 Examples of the alkoxy group in a51 include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, and a tert-butoxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a51 Examples of the alkoxyalkyl group in a51 include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. R a51 Examples of the alkoxyalkoxy group in a51 include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group. R a51 Examples of the alkylcarbonyl group in a51 include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group. R a51Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0134] *-X a51 -(A a52 -X a52 ) nb Examples of - include *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a52 -CO-O-, *-O-CO-A a52 -O-, *-O-A a52 -CO-O-, *-CO-O-A a52 -O-CO-, *-O-CO-A a52 -O-CO- are 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 a50is a single bond, *-CO-O- or *-CO-OA a52 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[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 o- or p-position of the benzene ring, and more preferably to the p-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.

[0139] The structural unit (a2-A) includes structural units represented by formulae (a2-2-1) to (a2-2-16) and R in the structural unit (a2-A) in the structural units represented by formulae (a2-2-1) to (a2-2-16). a50 The structural unit (a2-A) includes a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), a structural unit represented by formula (a2-2-12) to (a2-2-14), and a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), and a structural unit represented by formula (a2-2-12) to (a2-2-14), a50It is preferable that the structural unit in which the methyl group corresponding to R is replaced by a hydrogen atom is a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-8), a structural unit represented by formulas (a2-2-12) to (a2-2-14), and a structural unit represented by formula (a2-2-3) or a structural unit represented by formula (a2-2-8), a structural unit represented by formulas (a2-2-12) to (a2-2-14). In the structural unit (a2-A), R a50 More preferably, the structural unit in which the methyl group corresponding to R is replaced by a hydrogen atom is a structural unit represented by formula (a2-2-8), and in the structural unit represented by formula (a2-2-8), R a50 Even more preferably, the structural unit in which the methyl group corresponding to R is replaced by a hydrogen atom is a structural unit represented by formula (a2-2-8). TIFF0007696233000104.tif63169

[0140] When the resin (A) contains the structural unit (a2-A), the content of the structural unit (a2-A) is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, even more preferably 15 to 65 mol%, and even more preferably 20 to 65 mol% with respect to all the structural units. The structural unit (a2-A) can be included in 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 included in the resin (A) by treating with an alkali such as tetramethylammonium hydroxide.

[0141] Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include a structural unit represented by formula (a2-1) (hereinafter sometimes referred to as "structural unit (a2-1)"). TIFF0007696233000105.tif4258 In formula (a2-1), L a3 represents -O- or *-O-(CH2) k2 -CO-O-, k2 represents any integer from 1 to 7. * represents the bonding site with -CO-. R a14 represents a hydrogen atom or a methyl group. R a15 and R a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group. o1 represents any integer from 0 to 10.

[0142] In formula (a2-1), L a3 is preferably -O-, -O-(CH2) f1 -CO-O- (wherein f1 represents any integer from 1 to 4), more preferably -O-. R a14 is preferably a methyl group. R a15 is preferably a hydrogen atom. R a16 is preferably a hydrogen atom or a hydroxy group. o1 is preferably any integer from 0 to 3, more preferably 0 or 1.

[0143] Examples of the structural unit (a2-1) include structural units derived from the monomers described in JP-A-2010-204646. The structural unit represented by any of formulas (a2-1-1) to (a2-1-6) is preferred, the structural unit represented by any of formulas (a2-1-1) to (a2-1-4) is more preferred, and the structural unit represented by formula (a2-1-1) or formula (a2-1-3) is even more preferred. TIFF0007696233000106.tif50140

[0144] When the resin (A) contains the structural unit (a2-1), the content is usually 1 to 45 mol%, preferably 1 to 40 mol%, more preferably 1 to 35 mol%, even more preferably 1 to 20 mol%, and even more preferably 1 to 10 mol% based on all the structural units of the resin (A).

[0145] 〈Structural unit (a3)〉 The lactone ring of the structural unit (a3) may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or may be a condensed ring of a monocyclic lactone ring and another ring. Preferably, a γ-butyrolactone ring, an adamantanlactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)) can be mentioned.

[0146] The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), or the formula (a3-4). These may be contained alone or in combination of two or more. TIFF0007696233000107.tif52165[In the formula (a3-1), the formula (a3-2), the formula (a3-3), and the formula (a3-4), L a4 , L a5 and L a6 each independently represents a group represented by -O- or *-O-(CH2) k3 -CO-O- (where k3 represents an integer of 1 to 7). L a7 represents -O-, *-O-L a8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O- or *-O-L a8 -O-CO-L a9 -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * represents the bonding 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. Ra21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms. R a22 、R a23 and R a25 each independently represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. p1 represents any integer from 0 to 5. q1 represents any integer from 0 to 3. r1 represents any integer from 0 to 3. w1 represents any integer from 0 to 8. When p1, q1, r1 and / or w1 is 2 or more, a plurality of R a21 、R a22 、R a23 and / or R a25 may be the same as or different from each other.

[0147] R a21 、R a22 、R a23 and R a25 Examples of the aliphatic hydrocarbon group in R a24 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group and tert-butyl group. R a24 Examples of the halogen atom in R a24 include fluorine atom, chlorine atom, bromine atom and iodine atom.

[0148] L a8 and L a9 Examples of the alkanediyl group in include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, a 2-methylbutane-1,4-diyl group, and the like.

[0149] In formulas (a3-1) to (a3-3), L a4 ~L a6 is each independently preferably -O- or, *-O-(CH2) k3 -CO-O-, where k3 is an integer from 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 an integer from 0 to 2, more preferably 0 or 1.

[0150] 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, and even more preferably a hydrogen atom or a methyl group. R a25 is preferably a carboxy group, a cyano group, or a methyl group. L a7 is preferably -O- or *-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)’. TIFF0007696233000108.tif3848 (wherein R a24 , L a7 represents the same meaning as above.)

[0151] Examples of the structural unit (a3) include structural units derived from the monomers described in JP-A-2010-204646, the monomers described in JP-A-2000-122294, and the monomers described in JP-A-2012-41274. Examples of the structural unit (a3) include structural units represented by any of formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3-1), formula (a3-3-2), and formula (a3-4-1) to formula (a3-4-12), and, in the above structural units, structural units in which the methyl groups corresponding to R a18 , R a19 , R a20 and R a24 are replaced by hydrogen atoms are preferred. TIFF0007696233000109.tif117165 When the resin (A) contains the structural unit (a3), the total content is usually 5 to 70 mol%, preferably 10 to 65 mol%, more preferably 10 to 60 mol% based on all the structural units of the resin (A). Also, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3), or the structural unit (a3-4) is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, still more preferably 10 to 50 mol% based on all the structural units of the resin (A), respectively.

[0152] 〈Structural unit (a4)〉 Examples of the structural unit (a4) include the following structural units. TIFF0007696233000110.tif2861 [In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having a halogen atom with 1 to 24 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. R 42 The saturated hydrocarbon group represented by includes a chain saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and a group formed by combining these.

[0153] Examples of the chain saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic alicyclic saturated hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; polycyclic alicyclic saturated hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents the bonding site). 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.

[0154] Examples of the structural unit (a4) include a structural unit represented by formula (a4-0), a structural unit represented by formula (a4-1), and a structural unit represented by formula (a4-4). TIFF0007696233000112.tif4247[In formula (a4-0), R 54 represents a hydrogen atom or a methyl group. L 4a represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. L 3arepresents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms. R 64 represents a hydrogen atom or a fluorine atom.

[0155] L 4a Examples of the alkanediyl group in L include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, 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.

[0156] L 3a Examples of the perfluoroalkanediyl group in L include difluoromethylene group, perfluoroethylene group, perfluoroethylfluoromethylene 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, and the like. L 3a Examples of the perfluorocycloalkanediyl group in L include perfluorocyclohexanediyl group, perfluorocyclopentanediyl group, perfluorocycloheptanediyl group, perfluoroadamantanediyl group, and the like.

[0157] L 4a is preferably a single bond, a methylene group or an ethylene group, more preferably a single bond or a methylene group. L 3a is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

[0158] As the structural unit (a4-0), there may be mentioned the structural units shown below and the structural units in the following structural units where the methyl group corresponding to R in the structural unit (a4-0) is replaced by a hydrogen atom. 54 is replaced by a hydrogen atom. TIFF0007696233000113.tif98164

[0159] TIFF0007696233000114.tif4866[In formula (a4-1), R a41 represents a hydrogen atom or a methyl group. R a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. A a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by formula (a-g1). However, at least one of A a41 and R a42 has a halogen atom (preferably a fluorine atom) as a substituent. TIFF0007696233000115.tif1488[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 saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. X a41 and X a42Each independently represents -O-, -CO-, -CO-O- or -O-CO-. However, A a42 , A a43 , A a44 , X a41 and X a42 The total number of carbon atoms of is 7 or less. ]] * is a bonding site, and the * on the right is the bonding site with -O-CO-R a42 . ]]

[0160] R a42 Examples of the saturated hydrocarbon group in include a chain hydrocarbon group, a monocyclic or polycyclic saturated alicyclic hydrocarbon group, and a group formed by combining these.

[0161] Examples of the chain hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic saturated alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; polycyclic alicyclic hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bonding site). TIFF0007696233000116.tif10160Examples of the group formed by combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, and -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group, etc.

[0162] R a42 Examples of the substituent that has include at least one selected from the group consisting of a halogen atom and a group represented by the formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and preferably a fluorine atom. TIFF0007696233000117.tif855[In formula (a-g3), X a43 represents an oxygen atom, a carbonyl group, *-O-CO- or *-CO-O-. A a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. * is the bonding site with R a42 .] However, in R a42 -X a43 -A a45 when R a42 has no halogen atom, A a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms having at least one halogen atom.

[0163] A a45 Examples of the saturated hydrocarbon group in A include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group and octadecyl group; monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; and polycyclic alicyclic hydrocarbon groups such as decahydronaphthyl group, adamantyl group, norbornyl group and the following group (* represents the bonding site). TIFF0007696233000118.tif10160Examples of the group formed by the 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.

[0164] R a42 is preferably a saturated hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and / or a saturated hydrocarbon group having a group represented by formula (a-g3). Ra42 When it is a saturated hydrocarbon group having a halogen atom, it is preferably a saturated hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, still more preferably a perfluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group. R a42 When R is a saturated hydrocarbon group having a group represented by the formula (a-g3), including the carbon atoms contained in the group represented by the formula (a-g3), the total number of carbon atoms of R a42 is preferably 15 or less, 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.

[0165] R a42 When R is a saturated hydrocarbon group having a group represented by the formula (a-g3), R a42 is more preferably a group represented by the formula (a-g2). TIFF0007696233000119.tif872 [In the formula (a-g2), A a46 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. X a44 represents **-O-CO- or **-CO-O- (** represents the bonding site with A a46 ).). A a47 represents a saturated 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 A a46 and A a47At least one of them has at least one halogen atom. * represents the bonding site with the carbonyl group.

[0166] A a46 The number of carbon atoms of the saturated hydrocarbon group of A is preferably 1 to 6, more preferably 1 to 3. A a47 The number of carbon atoms of the saturated hydrocarbon group of A is preferably 4 to 15, more preferably 5 to 12. A a47 is more preferably a cyclohexyl group or an adamantyl group.

[0167] The preferred structure of the group represented by the formula (a-g2) is the following structure (* is the bonding site with the carbonyl group). TIFF0007696233000120.tif14160

[0168] 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, 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, 2-methylbutane-1,4-diyl group. A a41 Examples of the substituent in the alkanediyl group represented by A include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. A a41 A 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.

[0169] A in the group represented by the 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 saturated hydrocarbon group, and a divalent saturated hydrocarbon group formed by combining an alkanediyl group and a divalent alicyclic saturated hydrocarbon group, etc. Specific examples include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, etc. A a42 , A a43 and A a44 Examples of the substituent of the divalent saturated hydrocarbon group represented by the formula (1) include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. It is preferred that s is 0.

[0170] In the group represented by formula (a-g1), X a42 Examples of the group in which is -O-, -CO-, -CO-O-, or -O-CO- include the following groups. In the following examples, * and ** each represent a bonding site, and ** represents -O-CO-R a42 This is the binding site for TIFF0007696233000121.tif47140

[0171] 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. TIFF0007696233000122.tif103151

[0172] TIFF0007696233000123.tif132149

[0173] Examples of the structural unit represented by formula (a4-1) include a structural unit represented by formula (a4-2) and a structural unit represented by formula (a4-3). TIFF0007696233000124.tif4356[In formula (a4-2), R f5 represents a hydrogen atom or a methyl group. L 44 represents an alkanediyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. R f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms with fluorine atoms. However, the upper limit of the total carbon number of 44 L f6 and R

[0174] L 44 The alkanediyl group having 1 to 6 carbon atoms of a41 includes the same groups as those exemplified by A R f6 The saturated hydrocarbon group of 42 includes the same groups as those exemplified by R L 44 As the alkanediyl group in

[0175] Examples of the structural unit represented by the formula (a4-2) include the structural units represented by the formulas (a4-1-1) to (a4-1-11), respectively. The structural unit in which the methyl group corresponding to R f5 in the structural unit (a4-2) is replaced by a hydrogen atom is also included as the structural unit represented by the formula (a4-2).

[0176] TIFF0007696233000125.tif5671[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- (* is A f13represents the binding site with (...). A f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom. However, A f13 and A f14 at least one of which has a fluorine atom, and the upper limit of the total carbon number of L 5 A f13 and A f14 is 20.

[0177] L 5 As the alkanediyl group in, groups similar to those exemplified as the alkanediyl group of A a41 can be mentioned.

[0178] A f13 The divalent saturated hydrocarbon group which may have a fluorine atom in is preferably a divalent chain saturated hydrocarbon group which may have a fluorine atom and a divalent alicyclic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group. Examples of the divalent chain saturated hydrocarbon group which may have a fluorine atom include alkanediyl groups such as 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 saturated 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.

[0179] 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 preferable.

[0180] 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 saturated hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a divalent chain saturated hydrocarbon group having 2 to 3 carbon atoms. A f14 The saturated hydrocarbon group of is preferably a group containing a chain saturated hydrocarbon group having 3 to 12 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a group containing a chain saturated hydrocarbon group having 3 to 10 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms. Among them, A f14 is preferably a group containing an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, cyclopentyl group, cyclohexyl group, norbornyl group and adamantyl group.

[0181] Examples of the structural unit represented by formula (a4-3) include structural units represented by formulas (a4-1'-1) to (a4-1'-11), respectively. In the structural unit (a4-3), R f7 A structural unit in which the methyl group corresponding to is replaced by a hydrogen atom is also included as a structural unit represented by formula (a4-3).

[0182] Examples of the structural unit (a4) also include a structural unit represented by formula (a4-4). TIFF0007696233000126.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.]

[0183] 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 saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom, and even more preferably an alkyl group having 1 to 6 carbon atoms and having a fluorine atom.

[0184] 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.

[0185] Examples of the structural unit represented by formula (a4-4) include the following structural units and the structural units represented by the following formulas, in which the methyl group corresponding to R in structural unit (a4-4) is replaced by a hydrogen atom. f21 Examples thereof include a structural unit in which the methyl group corresponding to R in structural unit (a4-4) is replaced by a hydrogen atom. TIFF0007696233000127.tif86160

[0186] When the resin (A) has the structural unit (a4), its content is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and even more preferably 3 to 10 mol% based on all the structural units of the resin (A).

[0187] 〈Structural unit (a5)〉 Examples of the non-leaving hydrocarbon group contained in the structural unit (a5) include a group having a linear, branched or cyclic hydrocarbon group. Among them, the structural unit (a5) preferably has a group having an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by formula (a5-1). TIFF0007696233000128.tif3351[In formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atoms contained in the alicyclic hydrocarbon group may be substituted with aliphatic hydrocarbon groups having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-.]

[0188] 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. The aliphatic hydrocarbon group having 1 to 8 carbon atoms includes, for example, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Examples of the alicyclic hydrocarbon group having a substituent include 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

[0189] L 55 Examples of the divalent saturated hydrocarbon group in L include divalent chain saturated hydrocarbon groups and divalent alicyclic saturated hydrocarbon groups, preferably divalent chain saturated hydrocarbon groups. Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl group and norbornanediyl group.

[0190] L 55 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by L is replaced by -O- or -CO- include the groups represented by formula (L1-1) to formula (L1-4). In the following formulas, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom. In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents a bonding site with L x1 .). L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, the total number of carbon atoms in L x1 and L x2 is 16 or less. In formula (L1-2), L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, the total number of carbon atoms in L x3 and L x4 is 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, the total number of carbon atoms in L x5 , L x6 and L x7 is 15 or less. In formula (L1-4), L x8 and L x9 each represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, the total number of carbon atoms in L x8 , L x9 and W x1 is 15 or less.

[0191] L x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond. L x3is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. L x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. W x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

[0192] Examples of the group represented by the formula (L1-1) include the following divalent groups. TIFF0007696233000130.tif53136

[0193] Examples of the group represented by the formula (L1-2) include the following divalent groups. TIFF0007696233000131.tif23130

[0194] Examples of the group represented by the formula (L1-3) include the following divalent groups. TIFF0007696233000132.tif15162

[0195] Examples of the group represented by the formula (L1-4) include the following divalent groups. TIFF0007696233000133.tif26114

[0196] L 55 is preferably a single bond or a group represented by the formula (L1-1).

[0197] Examples of the structural unit (a5-1) include the following structural units and the structural units (a5-1) in the following structural units in which the methyl group corresponding to R 51 is replaced by a hydrogen atom. TIFF0007696233000134.tif77158

[0198] TIFF0007696233000135.tif39159 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).

[0199] 〈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-.

[0200] Examples of the sultone ring include the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and formula (T 1Examples of the ring represented by (1-4) include. The bonding site can be at any position. The sultone ring may be monocyclic, but is preferably polycyclic. The polycyclic sultone ring means a bridged ring containing -SO2-O- as an atomic group constituting the ring, and the formula (T 1 -1) and the ring represented by the formula (T 1 -2) include. The sultone ring may, like the ring represented by the formula (T 1 -2), contain, in addition to -SO2-O-, a hetero atom as an atomic group constituting the ring. Examples of the hetero atom include an oxygen atom, a sulfur atom, or a nitrogen atom, preferably an oxygen atom. TIFF0007696233000136.tif3187

[0201] The sultone ring may have a substituent. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, and an alkylcarbonyl group having 2 to 4 carbon atoms, etc.

[0202] 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, more preferably a methyl group. Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, preferably a trifluoromethyl group. Examples of the alkyl group having a hydroxy group include hydroxyalkyl groups such as hydroxymethyl group and 2-hydroxyethyl group. 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. Examples of the aryl group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl group. Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group and naphthylethyl group. Examples of the alkoxycarbonyl group include groups in which an alkoxy group such as methoxycarbonyl group and ethoxycarbonyl group is bonded to a carbonyl group, preferably an alkoxycarbonyl group having 6 or less carbon atoms, more preferably methoxycarbonyl group. Examples of the alkylcarbonyl group include acetyl group, propionyl group and butyryl group.

[0203] From the viewpoint of easy production of the monomer leading to the structural unit (a6), a sultone ring having no substituent is preferred. As the sultone ring, a ring represented by the following formula (T1') is preferred. TIFF0007696233000137.tif3171[In the formula (T1'), X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 represents a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents an integer from 0 to 9. When ma is 2 or more, a plurality of Rs 41 may be the same or different. The bonding site is at an arbitrary position.] X 11 is preferably an oxygen atom or a methylene group, more preferably a methylene group. R 41 Examples of R include the same as the substituents of the sultone ring, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group is preferred.

[0204] As the sultone ring, a ring represented by the formula (T1) is more preferred. TIFF0007696233000138.tif3149[In the formula (T1), R 8 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms or an alkylcarbonyl group having 2 to 4 carbon atoms. m represents an integer from 0 to 9. When m is 2 or more, a plurality of Rs 8 may be the same or different. The bonding site is at an arbitrary position.]

[0205] R 8 is, R 41 Examples of which are the same as those of. ma in the formula (T1') and m in the formula (T1) are preferably 0 or 1, more preferably 0.

[0206] Examples of the ring represented by the formula (T1') and the ring represented by the formula (T1) include the following rings. The bonding site is at an arbitrary position. TIFF0007696233000139.tif57165

[0207] The structural unit having a sultone ring preferably has the following group. * in the following group represents a bonding site. TIFF0007696233000140.tif51165

[0208] The structural unit having a -SO2- group preferably further has a group derived from a polymerizable group. Examples of the polymerizable group include a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, a methacryloylthio group, and the like. Among them, the monomer that leads to the structural unit (a6) is preferably a monomer having an ethylenically unsaturated bond, and more preferably a (meth)acrylic monomer.

[0209] The structural unit (a6) is preferably a structural unit represented by the formula (Ix). TIFF0007696233000141.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 R41 may be the same or different. R c and R d each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0210] R x Examples of the halogen atom of R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R x Examples of the alkyl group of R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group, etc. Preferably, it is an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group. R x Examples of the alkyl group having a halogen atom of R include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, etc. R x 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.

[0211] 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 methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1,17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group; Branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; Monocyclic divalent alicyclic saturated hydrocarbon groups which are cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; Polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. may be mentioned.

[0212] 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 a specific bonding position are preferred.

[0213] Examples of the structural unit (a6) include the following structural units. TIFF0007696233000142.tif104168

[0214] 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 preferable, and the structural units represented by formula (a6-1), formula (a6-2), formula (a6-7) and (a6-8) are more preferable. 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% with respect to all the structural units of the resin (A).

[0215] <Structural unit (II)> The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as "structural unit (II)"). Specific examples of the structural unit (II) include the structural units described in JP-A-2016-79235, and a structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain or a structural unit having a sulfonio group and an organic anion in the side chain is preferable.

[0216] The structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain is preferably a structural unit represented by formula (II-2-A'). TIFF0007696233000143.tif3089[In formula (II-2-A'), X III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom or a hydroxy group. A x1 represents an alkanediyl group having 1 to 8 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted by a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. RA - represents a sulfonate group or a carboxylate group. R III3represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. ZA + represents an organic cation.

[0217] R III3 Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R III3 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R include the same ones as the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R. a8 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R include the same ones as the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R. A x1 Examples of the alkanediyl group having 1 to 8 carbon atoms represented by A include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-2,2-diyl group, a pentane-2,4-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, a 2-methylbutane-1,4-diyl group, and the like. A x1 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted on A include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, and the like.

[0218] X III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and combinations thereof may also be possible. Specifically, linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group; branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; divalent monocyclic alicyclic saturated hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; Examples thereof include divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group.

[0219] Examples of those in which -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- include divalent groups represented by formula (X1) to formula (X53). However, the number of carbon atoms before -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- is 17 or less, respectively. In the following formula, * and ** represent bonding sites, and * represents the bonding site with A x1 and represents the bonding site with A. TIFF0007696233000144.tif145161

[0220] X 3 represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms. X 4 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. X 5 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. X 6 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 7 represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 8 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

[0221] ZA + Examples of the organic cation represented by ZA include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, cations represented by any of the above-described formulas (b2-1) to (b2-4) (hereinafter, may be referred to as "cation (b2-1)" etc. according to the formula number) can be mentioned.

[0222] The structural unit represented by the formula (II-2-A') is preferably the structural unit represented by the formula (II-2-A). JPEG0007696233000145.jpg37109[In the formula (II-2-A), R III3 、X III3 and ZA + represent the same meaning as described above. z represents any integer from 0 to 6. R III2 and R III4 each independently represent a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms. When z is 2 or more, a plurality of R III2 and R III4 may be the same as or different from each other. Q a and Q b each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.]

[0223] R III2 、R III4 、Q a and Q bExamples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by include the same groups as the perfluoroalkyl group having 1 to 6 carbon atoms represented by Q described below. b1 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by include the same groups as the perfluoroalkyl group having 1 to 6 carbon atoms represented by Q described below.

[0224] The structural unit represented by formula (II-2-A) is preferably the structural unit represented by formula (II-2-A-1). TIFF0007696233000146.tif5676 [In formula (II-2-A-1), R III2 、R III3 、R III4 、Q a 、Q b 、z and ZA + have the same meanings as described above. R III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms. X I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, 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.

[0225] R III5 Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by include linear or branched alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group. X I2 Examples of the divalent saturated hydrocarbon group represented by include the same groups as the divalent saturated hydrocarbon group represented by X III3 described below.

[0226] As the structural unit represented by formula (II-2-A-1), the structural unit represented by formula (II-2-A-2) is preferable. TIFF0007696233000147.tif5287 [In formula (II-2-A-2), R III3 、RIII5 and ZA + represents the same meaning as described above. m and nA each independently represent 1 or 2.

[0227] Examples of the structural unit represented by the formula (II-2-A') include the following structural units, R III3 a group corresponding to the methyl group of, a hydrogen atom, a halogen atom (for example, a fluorine atom), or a C1-C6 alkyl group which may have a halogen atom (for example, a trifluoromethyl group, etc.) and the structural units described in WO 2012 / 050015. ZA + represents an organic cation. TIFF0007696233000148.tif86163

[0228] 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). TIFF0007696233000149.tif3381[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 represent a hydrocarbon group having 1 to 18 carbon atoms, and R II2 and R II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. R II4 represents a hydrogen atom, a halogen atom, or a C1-C6 alkyl group which may have a halogen atom. A - represents an organic anion. R II1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R include a phenylene group and a naphthylene group. R II2 and R II3Examples of the hydrocarbon group represented by include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Examples of the alkyl group and the alicyclic hydrocarbon group are the same as those described above. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group formed by combining the above-described alkyl group and alicyclic hydrocarbon group, an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. R II4 Examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R II4 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by are the same as those of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by . a8 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by are the same as those of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by . A II1 Examples of the divalent linking group represented by include, for example, a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S- or -CO-. Specifically, examples are the same as those of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by . III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by are the same as those described above.

[0229] Examples of the structural unit containing the cation in formula (II-1-1) include the structural units represented below,, R II4Examples of the structural unit in which the group corresponding to the methyl group is replaced with a hydrogen atom, a halogen atom (e.g., fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., trifluoromethyl group) etc. are given below. TIFF0007696233000150.tif84130

[0230] A - Examples of the organic anion represented by A include sulfonate anion, sulfonylimide anion, sulfonylmethide anion, and carboxylate anion etc. A - The organic anion represented by A is preferably a sulfonate anion, and examples of the sulfonate anion include the same ones as the anion represented by the aforementioned formula (B1).

[0231] A - Examples of the sulfonylimide anion represented by A include the following. TIFF0007696233000151.tif33136

[0232] Examples of the sulfonylmethide anion include the following. TIFF0007696233000152.tif29123

[0233] Examples of the carboxylate anion include the following. TIFF0007696233000153.tif42154

[0234] Examples of the structural unit represented by the formula (II-1-1) include the structural units represented by the following etc. TIFF0007696233000154.tif88149

[0235] When the resin (A) contains the structural unit (II), the content of the structural unit (II) is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and still more preferably 3 to 10 mol% with respect to all the structural units of the resin (A).

[0236] 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.

[0237] 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, and even more preferably at least two 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 a structural unit represented by formula (a2-1) or a structural unit represented by formula (a2-A). Structural unit (a3) is preferably at least one selected from the group consisting of a structural unit represented by formula (a3-1), a structural unit represented by formula (a3-2), and a structural unit represented by formula (a3-4).

[0238] 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 monomers that lead to these structural units. The content of each structural unit of resin (A) can be adjusted by the amount of monomers used in the polymerization. The weight average molecular weight of resin (A) is preferably 2,000 or more (more preferably 2,500 or more, even more preferably 3,000 or more), and 50,000 or less (more preferably 30,000 or less, even more preferably 15,000 or less). In this specification, the weight average molecular weight is a value determined by gel permeation chromatography under the conditions described in the examples.

[0239] <Resin other than resin (A)> The resist composition of the present invention may contain a resin other than resin (A). Examples of the resin other than resin (A) include resins containing structural unit (a4) or structural unit (a5) (hereinafter sometimes referred to as resin (X)).

[0240] Among them, a resin containing structural unit (a4) is preferable as resin (X). In resin (X), the content of structural unit (a4) is preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more with respect to the total of all structural units of resin (X). Examples of the structural units that resin (X) may further have include structural unit (a2), structural unit (a3), and structural units derived from other known monomers. Among them, resin (X) is preferably a resin composed of only structural unit (a4) and / or structural unit (a5), and more preferably a resin composed of only structural unit (a4). Each structural unit constituting 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 the monomers that induce these structural units. The content of each structural unit of resin (X) can be adjusted by the amount of monomers used in the polymerization. The weight average molecular weight of resin (X) is preferably 6,000 or more (more preferably 7,000 or more), and 80,000 or less (more preferably 60,000 or less). The measuring means of the weight average molecular weight of resin (X) is the same as that of resin (A). When the resist composition contains resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, even more preferably 1 to 40 parts by mass, 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 resin (A).

[0241] 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. The solid content of the resist composition and the content rate of the resin with respect thereto can be measured by known analysis means such as liquid chromatography or gas chromatography.

[0242] <Solvent (E)> The content rate of the solvent (E) in the resist composition is generally 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. 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.

[0243] <Quencher (C)> Examples of the quencher (C) include basic nitrogen-containing organic compounds and salts that generate an acid having a lower acidity than the acid generated from the acid generator (B). When the resist composition contains the quencher (C), the content of the quencher (C) is preferably about 0.01 to 15% by mass, more preferably about 0.01 to 10% by mass, still more 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. Examples of the amine include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridyl)ethane, 1,2-di(4-pyridyl)ethane, 1,2-di(2-pyridyl)ethene, 1,2-di(4-pyridyl)ethene, 1,3-di(4-pyridyl)propane, 1,2-di(4-pyridyloxy)ethane, di(2-pyridyl)ketone, 4,4'-dipyridylsulfide, 4,4'-dipyridyldisulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, bipyridine and the like. 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.

[0244] 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. As the salt that generates an acid with a lower acidity than the acid generated from the acid generator (B), preferably, it is a salt that generates a carboxylic acid with a lower acidity than the acid generated from the acid generator (B) (a salt having a carboxylic acid anion), and more preferably, it is the weak acid inner salt (D). TIFF0007696233000155.tif94163

[0245] Examples of the weak acid inner salt (D) include the following salts. TIFF0007696233000156.tif72165

[0246] 〈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.

[0247] 〈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 not particularly limited. The temperature during mixing can be appropriately selected from 10 to 40°C according to the type of resin, etc. and the solubility of the resin, etc. in solvent (E). The mixing time can be appropriately selected from 0.5 to 24 hours according to the mixing temperature. Note that the mixing means is also not particularly limited, and stirring and mixing, etc. can be used. After mixing the components, it is preferable to filter using a filter with a pore size of about 0.003 to 0.2 μm.

[0248] 〈Method for Manufacturing Resist Pattern〉 The method for manufacturing 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 carried out by a commonly used apparatus such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers. Before applying the resist composition, the substrate may be cleaned, or 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 performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-bake), or by using a decompression device. The heating temperature is preferably 50 to 200 °C, and the heating time is preferably 10 to 180 seconds. Also, the pressure during 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 the laser light from a solid laser light source (such as YAG or semiconductor laser) into harmonic laser light in the far ultraviolet region or vacuum ultraviolet region and emit it, those that irradiate electron beams, 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 performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask. The 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. 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. can 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 trace amount of water. During development, 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.

[0249] <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

[0250] The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing content or usage amount are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows. Column: TSKgel Multipore HXL-M x 3 + guard column (manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Detector: RI detector Column temperature: 40 °C Injection volume: 100 μl Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC 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”.

[0251] Example 1: Synthesis of the salt represented by formula (I-1) 4.38 parts of the salt represented by formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by formula (I-1-b) was added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 2.66 parts of the compound represented by formula (I-1-c) was added, and further stirred at 50°C for 3 hours, then cooled to 23°C. To the resulting mixture, 15 parts of a 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. To the resulting organic layer, 15 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. This water washing operation was repeated 5 times. The resulting organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether was added and stirred at 23°C for 30 minutes, then the supernatant was removed and concentrated to obtain 4.02 parts of the salt represented by formula (I-1-d). 1.26 parts of the salt represented by formula (I-1-d), 0.05 part of the compound represented by formula (I-1-f) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.20 part of the compound represented by formula (I-1-e) was added and stirred at 23°C for 2 hours. To the resulting reaction mixture, 10 parts of chloroform and 10 parts of a 10% aqueous potassium carbonate solution were added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. To the resulting organic layer, 10 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. This water washing operation was repeated 4 times. The resulting 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, then the supernatant was removed and concentrated to obtain 0.83 part of the salt represented by formula (I-1). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 494.9

[0252] Example 2: Synthesis of the salt represented by formula (I-3) 5.36 parts of the compound represented by formula (I-3-a), 0.46 part of the compound represented by formula (I-1-f) and 30 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 2.00 parts of the compound represented by formula (I-1-e) was added and stirred at 23 °C for 2 hours. To the resulting reaction mixture, 20 parts of chloroform and 20 parts of a 10% aqueous potassium carbonate solution were added and stirred at 23 °C for 30 minutes, followed by liquid separation to take out the organic layer. 60 parts of ion-exchanged water was added to the obtained organic layer and stirred at 23 °C for 30 minutes, followed by liquid separation to take out the organic layer. This water washing operation was repeated 4 times. The obtained organic layer was concentrated, and the concentrated mixture was fractionated on a column (silica gel 60N (spherical, neutral) 100 - 210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 5 / 1) to obtain 6.89 parts of the compound represented by formula (I-3-d). 6.80 parts of the compound represented by formula (I-3-d) and 30 parts of acetonitrile were mixed and stirred at 23 °C for 30 minutes, and then cooled to 5 °C. To the resulting mixed solution, a mixed solution of 0.35 part of sodium borohydride and 5.30 parts of ion-exchanged water was added and stirred at 23 °C for 18 hours. After concentrating the resulting reaction mixture, 80 parts of tert-butyl methyl ether and 40 parts of ion-exchanged water were added to the concentrated residue and stirred at 23 °C for 30 minutes, followed by liquid separation to take out the organic layer. 90 parts of ion-exchanged water was added to the obtained organic layer and stirred at 23 °C for 30 minutes, followed by liquid separation to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was fractionated on a column (silica gel 60N (spherical, neutral) 100 - 210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 2 / 1) to obtain 6.43 parts of the compound represented by formula (I-3-e). 4.38 parts of the salt represented by TIFF0007696233000161.tif56168 formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by formula (I-1-b) were added, and further stirred at 50 °C for 2 hours. To the resulting mixed solution, 3.66 parts of the compound represented by formula (I-3-e) were added, and further stirred at 50 °C for 3 hours and then cooled to 23 °C. To the resulting mixture, 15 parts of a 5% aqueous oxalic acid solution were added and stirred at 23 °C for 30 minutes, then separated and the organic layer was taken out. To the obtained organic layer, 15 parts of ion-exchanged water were added and stirred at 23 °C for 30 minutes, then separated and the organic layer was taken out. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 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 4.47 parts of the salt represented by formula (I-3). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 523.0

[0253] Example 3: Synthesis of the salt represented by formula (I-225) 4.38 parts of the salt represented by TIFF0007696233000162.tif42155 formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by formula (I-1-b) were added, and further stirred at 50 °C for 2 hours. To the resulting mixed solution, 2.66 parts of the compound represented by formula (I-225-c) were added, and further stirred at 50 °C for 3 hours and then cooled to 23 °C. To the resulting mixture, 15 parts of a 5% aqueous oxalic acid solution were added and stirred at 23 °C for 30 minutes, then separated and the organic layer was taken out. To the obtained organic layer, 15 parts of ion-exchanged water were added and stirred at 23 °C for 30 minutes, then separated and the organic layer was taken out. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 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 3.28 parts of the salt represented by formula (I-225-d). 1.26 parts of the salt represented by TIFF0007696233000163 (I-225-d), 0.05 part of the compound represented by formula (I-1-f), and 30 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 0.20 part of the compound represented by formula (I-1-e) was added, and the mixture was stirred at 23 °C for 2 hours. To the resulting reaction mixture, 10 parts of chloroform and 10 parts of a 10% aqueous potassium carbonate solution were added, and the mixture was stirred at 23 °C for 30 minutes. Then, the layers were separated and the organic layer was taken out. To the obtained organic layer, 10 parts of ion-exchanged water was added, and the mixture was stirred at 23 °C for 30 minutes. Then, the layers were separated and the organic layer was taken out. This water washing operation was repeated 4 times. The obtained organic layer was concentrated. To the concentrated residue, 30 parts of tert-butyl methyl ether was added, and the mixture was stirred at 23 °C for 30 minutes. Then, the supernatant was removed and the residue was concentrated to obtain 0.66 part of the salt represented by formula (I-225). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 494.9

[0254] Example 4: Synthesis of the salt represented by formula (I-227) 5.36 parts of the compound represented by TIFF0007696233000164 (I-227-a), 0.46 part of the compound represented by formula (I-1-f), and 30 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 2.00 parts of the compound represented by formula (I-1-e) was added, and the mixture was stirred at 23 °C for 2 hours. To the resulting reaction mixture, 20 parts of chloroform and 20 parts of a 10% aqueous potassium carbonate solution were added, and the mixture was stirred at 23 °C for 30 minutes. Then, the layers were separated and the organic layer was taken out. To the obtained organic layer, 60 parts of ion-exchanged water was added, and the mixture was stirred at 23 °C for 30 minutes. Then, the layers were separated and the organic layer was taken out. This water washing operation was repeated 4 times. The obtained organic layer was concentrated. The concentrated mixture was separated by column (silica gel 60N (spherical, neutral), 100 - 210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 5 / 1) to obtain 6.95 parts of the compound represented by formula (I-227-d). 6.80 parts of the compound represented by TIFF0007696233000165.tif4994 (I-227-d) and 30 parts of acetonitrile were mixed and stirred at 23 °C for 30 minutes, and then cooled to 5 °C. To the resulting mixed solution, a mixed solution of 0.35 part of sodium borohydride and 5.30 parts of ion-exchanged water was added, and the mixture was stirred at 23 °C for 18 hours. After concentrating the resulting reaction mixture, 80 parts of tert-butyl methyl ether and 40 parts of ion-exchanged water were added to the concentrate residue, and the mixture was stirred at 23 °C for 30 minutes, and then separated to extract the organic layer. 90 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 °C for 30 minutes, and then separated to extract the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was fractionated by column (silica gel 60N (spherical, neutral) 100 - 210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 2 / 1) to obtain 5.38 parts of the compound represented by formula (I-227-e). 4.38 parts of the salt represented by TIFF0007696233000166.tif56168 (I-1-a) and 30 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by formula (I-1-b) was added, and the mixture was further stirred at 50 °C for 2 hours. To the obtained mixed solution, 3.66 parts of the compound represented by formula (I-227-e) was added, and the mixture was 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 the mixture was stirred at 23 °C for 30 minutes, and then separated to extract the organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23 °C for 30 minutes, and then separated to extract the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 °C for 30 minutes, and then the supernatant was removed and concentrated to obtain 3.12 parts of the salt represented by formula (I-227). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 523.0

[0255] Example 5: Synthesis of the salt represented by formula (I-236) 7.67 parts of the compound represented by formula (I-236-a), 0.46 part of the compound represented by formula (I-1-f), and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 2.00 parts of the compound represented by formula (I-1-e) were added, and the mixture was stirred at 23°C for 2 hours. To the resulting reaction mixture, 20 parts of chloroform and 20 parts of a 10% aqueous potassium carbonate solution were added, and the mixture was stirred at 23°C for 30 minutes. Then, liquid separation was performed to take out the organic layer. To the obtained organic layer, 60 parts of ion-exchanged water were added, and the mixture was stirred at 23°C for 30 minutes. Then, liquid separation was performed to take out the organic layer. This water washing operation was repeated 4 times. The obtained organic layer was concentrated, and the concentrated mixture 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 = 5 / 1) to obtain 7.11 parts of the compound represented by formula (I-236-d). 6.41 parts of the compound represented by formula (I-236-d) and 30 parts of acetonitrile were mixed and stirred at 23°C for 30 minutes, and then cooled to 5°C. To the resulting mixed solution, a mixed solution of 0.25 part of sodium borohydride and 3.75 parts of ion-exchanged water was added, and the mixture was stirred at 23°C for 18 hours. After concentrating the resulting reaction mixture, 80 parts of tert-butyl methyl ether and 40 parts of ion-exchanged water were added to the concentrated residue, and the mixture was stirred at 23°C for 30 minutes. Then, liquid separation was performed to take out the organic layer. To the obtained organic layer, 90 parts of ion-exchanged water were added, and the mixture was stirred at 23°C for 30 minutes. 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, and the concentrated mixture 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 = 2 / 1) to obtain 4.97 parts of the compound represented by formula (I-236-e). 4.38 parts of the salt represented by TIFF0007696233000169.tif46156 (I-1-a) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by the formula (I-1-b) was added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 4.92 parts of the compound represented by the formula (I-236-e) was added, and further stirred at 50°C for 3 hours, then cooled to 23°C. To the resulting mixture, 15 parts of a 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. To the resulting organic layer, 15 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. This water washing operation was repeated 5 times. The resulting organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23°C for 30 minutes, then the supernatant was removed and concentrated to obtain 5.92 parts of the salt represented by the formula (I-236). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 648.9

[0256] Example 6: Synthesis of the salt represented by the formula (I-238) 7.51 parts of the compound represented by formula (I-238-a), 3.13 parts of pyridine, 0.44 part of dimethylaminopyridine and 40 parts of tetrahydrofuran were mixed and stirred at 23 °C for 30 minutes, and then cooled to 5 °C. To the resulting mixture, 4.70 parts of the compound represented by formula (I-238-b) was added, and the mixture was stirred at 5 °C for 30 minutes and then further stirred at 23 °C for 2 hours. To the resulting mixture, 60 parts of chloroform and 15 parts of a 10% aqueous potassium carbonate solution were added and stirred at 23 °C for 30 minutes, and then the layers were separated to obtain the organic layer. To the obtained organic layer, 15 parts of a 5% aqueous oxalic acid solution was added and stirred at 23 °C for 30 minutes, and then the layers were separated to obtain the organic layer. This washing operation was repeated 3 times. To the obtained organic layer, 15 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and then the layers were separated to obtain the organic layer. This water washing operation was repeated 3 times. The obtained organic layer was concentrated, and the concentrated mixture was fractionated using 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 8.12 parts of the compound represented by formula (I-238-d). 6.78 parts of the compound represented by formula (I-238-d) and 30 parts of acetonitrile were mixed and stirred at 23 °C for 30 minutes, and then cooled to 5 °C. To the resulting mixed solution, a mixed solution of 0.25 part of sodium borohydride and 3.75 parts of ion-exchanged water was added, and the mixture was stirred at 23 °C for 18 hours. After the resulting reaction mixture was concentrated, 80 parts of tert-butyl methyl ether and 40 parts of ion-exchanged water were added to the concentrated residue and stirred at 23 °C for 30 minutes, and then the layers were separated to obtain the organic layer. 90 parts of ion-exchanged water was added to the obtained organic layer and stirred at 23 °C for 30 minutes, and then the layers were separated to obtain the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and the concentrated mixture was fractionated using a column (silica gel 60N (spherical, neutral) 100 - 210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 2 / 1) to obtain 5.27 parts of the compound represented by formula (I-238-e). 4.38 parts of the salt represented by TIFF0007696233000172.tif54156 (I-1-a) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by the formula (I-1-b) were added, and the mixture was further stirred at 50°C for 2 hours. To the resulting mixed solution, 5.20 parts of the compound represented by the formula (I-238-e) were added, and the mixture was further stirred at 50°C for 3 hours and then cooled to 23°C. To the resulting mixture, 15 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 obtain the organic layer. To the obtained organic layer, 15 parts of ion-exchanged water were added and stirred at 23°C for 30 minutes, and then the layers were separated to obtain the organic layer. This washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether were added to the concentrated residue, and the mixture was stirred at 23°C for 30 minutes. Then, the supernatant was removed and concentrated to obtain 5.88 parts of the salt represented by the formula (I-238). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 676.9

[0257] Synthesis Example 1: Synthesis of the salt represented by the formula (B1-X5) 1.11 parts of the compound represented by TIFF0007696233000173.tif72157 (B1-X5-d), 0.05 part of the compound represented by the formula (I-1-f) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.20 part of the compound represented by the formula (I-1-e) was added, and the mixture was stirred at 23°C for 2 hours. To the resulting reaction mixture, 10 parts of chloroform and 10 parts of a 10% aqueous potassium carbonate solution were added and stirred at 23°C for 30 minutes, and then the layers were separated to obtain the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water were added and stirred at 23°C for 30 minutes, and then the layers were separated to obtain the organic layer. This washing operation was repeated 4 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether were added to the concentrated residue, and the mixture was stirred at 23°C for 30 minutes. Then, the supernatant was removed and concentrated to obtain 0.77 part of the salt represented by the formula (B1-X5). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 411.0

[0258] Synthesis Example 2: Synthesis of the salt represented by formula (B1-X6) 4.38 parts of the salt represented by formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by formula (I-1-b) were added, and the mixture was further stirred at 50°C for 2 hours. To the resulting mixed solution, 2.36 parts of the compound represented by formula (B1-X6-c) were added, and the mixture was further stirred at 50°C for 3 hours and then cooled to 23°C. To the resulting mixture, 15 parts of a 5% aqueous oxalic acid solution were added and the mixture was stirred at 23°C for 30 minutes, followed by liquid separation to extract the organic layer. To the resulting organic layer, 15 parts of ion-exchanged water were added and the mixture was stirred at 23°C for 30 minutes, followed by liquid separation to extract the organic layer. This water washing operation was repeated 5 times. The resulting organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether were added and the mixture was stirred at 23°C for 30 minutes. Then, the supernatant was removed and the residue was concentrated to obtain 2.44 parts of the salt represented by formula (B1-X6-d). 1.20 parts of the salt represented by formula (B1-X6-d), 0.05 part of the compound represented by formula (I-1-f) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 0.20 part of the compound represented by formula (I-1-e) was added and the mixture was stirred at 23°C for 2 hours. To the resulting reaction mixture, 10 parts of chloroform and 10 parts of a 10% aqueous potassium carbonate solution were added and the mixture was stirred at 23°C for 30 minutes, followed by liquid separation to extract the organic layer. To the resulting organic layer, 10 parts of ion-exchanged water were added and the mixture was stirred at 23°C for 30 minutes, followed by liquid separation to extract the organic layer. This water washing operation was repeated 4 times. The resulting organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether were added and the mixture was stirred at 23°C for 30 minutes. Then, the supernatant was removed and the residue was concentrated to obtain 0.93 part of the salt represented by formula (B1-X6). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 464.9

[0259] Synthesis of Resin The compounds (monomers) used in the synthesis of resin (A) are shown below. Hereinafter, these compounds are referred to as "monomer (a1-1-3)" etc. according to their formula numbers. TIFF0007696233000176.tif4081

[0260] Synthesis Example 3 [Synthesis of Resin A1] As monomers, monomer (a1-4-2), monomer (a1-1-3) and monomer (a1-2-6) were used, and they were mixed so that the 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, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, and after stirring for 6 hours, liquid separation was carried out. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was obtained by filtration and recovery. Resin A1 (copolymer) having a weight average molecular weight of about 5.3×10 3 was obtained in a yield of 78%. This resin A1 has the following structural units. TIFF0007696233000177.tif29126

[0261] Synthesis Example 4 [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 mass times of methyl isobutyl ketone was mixed with this monomer mixture based on the total mass of all monomers. Azobisisobutyronitrile was added to the obtained mixture as an initiator so that it was 7 mol% based on the total number of moles of all monomers, and polymerization was carried out by heating this at 85 °C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was obtained by filtration and recovery. The 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. TIFF0007696233000178.tif2886

[0262] <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

[0263] <Resin> A1, A2: Resin A1, Resin A2 <Salt (I)> I-1: Salt represented by formula (I-1) I-3: Salt represented by formula (I-3) I-225: Salt represented by formula (I-225) I-227: Salt represented by formula (I-227) I-236: Salt represented by formula (I-236) I-238: Salt represented by formula (I-238) <Acid generator (IX)> B1-X1 B1-X2 B1-X3 B1-X4 TIFF0007696233000180.tif64132B1-X5: Salt represented by formula (B1-X5) B1-X6: Salt represented by formula (B1-X6) <Quencher (C)> C1: Synthesized by the method described in JP-A-2011-39502 TIFF0007696233000181.tif3646<Solvent> 400 parts of propylene glycol monomethyl ether acetate 100 parts of propylene glycol monomethyl ether 5 parts of γ-butyrolactone

[0264] (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.

[0265] 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.

[0266] <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 average hole diameters of 400 patterns formed with a hole diameter of 17 nm within the same wafer. The results are shown in Table 3. The numerical values in the table indicate the standard deviation (nm).

Table 3

Industrial Applicability

[0267] The resist composition containing the salt of the present invention is suitable for fine processing of semiconductors because a resist pattern having good CD uniformity (CDU) can be obtained, and is extremely useful industrially.

Claims

1. A salt represented by formula (I). [In formula (I), Q １ and Q ２ each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. R １ and R ２ each independently represents a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. z represents any integer from 0 to 6. When z is 2 or more, a plurality of R １ and R ２ may be the same as or different from each other. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, where * represents a bonding site with C(R １ )(R ２ ), or C(Q １ )(Q ２ ). L 1 represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH 2 - contained in the hydrocarbon group may be replaced by -O-, -S-, -SO ２ -, or -CO-. R ３ represents a halogen atom. R ４ represents an alkoxy group having 1 to 6 carbon atoms. R ５ represents a group represented by formula (R5-1) or a group represented by formula (R5-2). m3 represents any integer from 1 to 3. When m3 is 2 or more, a plurality of R ３ may be the same as or different from each other. m4 represents any integer from 1 to 3. When m4 is 2 or more, a plurality of R ４ may be the same as or different from each other. m5 represents 1 or 2. When m5 is 2, two R ５ may be the same as or different from each other. However, 3 ≤ m3 + m4 + m5 ≤ 5. Z ＋ represents an organic cation. ] [In formula (R5-1), R14, R15, and R16 each independently represent 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 R14 and R15 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. m represents 0 or 1. * represents a bonding site. ] [In formula (R5-2), R17 and R18 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R19 represents a hydrocarbon group having 1 to 20 carbon atoms, or R18 and R19 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 Xa, and -CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced by -O- or -S-. Xa represents an oxygen atom or a sulfur atom. n represents 0 or 1. * represents a bonding site. ]

2. R ３ The salt according to claim 1, wherein R is a fluorine atom or an iodine atom.

3. The salt according to claim 1 or 2, wherein m3 is 1 or 2 and m5 is 1.

4. The salt according to any one of claims 1 to 3, wherein m4 is 1 and R ４ is an alkoxy group having 1 to 6 carbon atoms.

5. m3 is 1 or 2, and the bonding position of at least one R ３ is bonded to the m-position relative to the bonding position of L １ in the benzene ring. The salt according to any one of claims 1 to 4.

6. At least one OR ５ is bonded to the o-position or p-position with respect to the bonding position of L in the benzene ring １ The salt according to any one of claims 1 to 5.

7. L 1 is a single bond, an alkanediyl group having 1 to 6 carbon atoms, or a group formed by combining an alkanediyl group having 1 to 6 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 18 carbon atoms (however, -CH 2 - contained in the alkanediyl group may be replaced by -O- or -CO-, and -CH 2 - contained in the alicyclic saturated hydrocarbon group may be replaced by -O-, -S-, -SO ２ - or -CO-). The salt according to any one of claims 1 to 6.

8. L 1 is a single bond, an alkanediyl group having 1 to 6 carbon atoms, or *-L ４ -CO-O- (however, L ４ represents a hydrocarbon group having 1 to 22 carbon atoms which may have a substituent, and -CH 2 - contained in the hydrocarbon group may be replaced by -O-, -S-, -SO ２ - or -CO-. * represents a bond with X1). The salt according to any one of claims 1 to 7.

9. An acid generator containing the salt according to any one of claims 1 to 8.

10. A resist composition containing the acid generator according to claim 9 and a resin having an acid-labile group.

11. The resist composition according to claim 10, 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 are each independently -O- or *-O-(CH ２ ) k1represents -CO-O-, k1 represents any integer from 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 any integer from 0 to 14. n1 represents any integer from 0 to 10. n1' represents any integer from 0 to 3. ]

12. The resist composition according to claim 10 or 11, wherein the resin having an acid-labile group further 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 -, * represents a bonding site with the carbon atom to which -R a50 is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O-, or -O-CO-. nb represents 0 or 1. mb represents any integer from 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. ]

13. The resist composition according to any one of claims 10 to 12, further containing a salt that generates an acid having a lower acidity than the acid generated from the acid generator.

14. (1) A step of applying the resist composition according to any one of claims 10 to 13 onto a substrate, (2) A step of drying the applied composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer, A method for manufacturing a resist pattern including these steps.

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