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

Abstract

To provide a salt, an acid generator, and a resist composition capable of producing a resist pattern having good CD uniformity (CDU).SOLUTION: The salt represented by formula (I), the acid generator, and the resist composition are provided. [In the formula, R1 represents -O-L1-CO-O-R5; L1 represents an alkanediyl group; R5 represents an acid-labile group; R2, R3 and R4 each represent a halogen atom or the like; m2 represents 0-4; m3 and m4 each represent an integer of 0-5; Q1 and Q2 each represent a fluorine atom or the like; R11 and R12 each represent a hydrogen atom or the like; z represents an integer of 0-6; X0 represents -CO-O- or the like; A1 represents a single bond or the like; Xa and Xb each represent O or S; X1 represents an alicyclic hydrocarbon group; and ring W represents an alicyclic hydrocarbon group.]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. TIFF0007702813000001.tif3880 Patent Document 2 describes a resist composition containing a salt represented by the following formula as an acid generator. TIFF0007702813000002.tif2784 Patent Document 3 describes a resist composition containing a salt represented by the following formula as an acid generator. TIFF0007702813000003.tif3591

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a salt that forms a resist pattern having better 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). TIFF0007702813000004.tif48148[In formula (I), R 1 represents -O-L 1 -CO-O-R 5 -O-R 5 or -O-CO-O-R 5 respectively. L 1 represents an alkanediyl group having 1 to 6 carbon atoms. R 5 represents an acid-labile group. R 2 R 3 and R 4 each independently represents a halogen atom, a fluorinated alkyl group having 1 to 12 carbon atoms, a hydrocarbon group having 1 to 18 carbon atoms, -O-L 1 -CO-O-R 5 -O-R 5 or -O-CO-O-R 5 respectively, and the hydrocarbon group may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O- or -CO-. m2 represents any integer from 0 to 4, and when m2 is 2 or more, a plurality of R 2 may be the same as or different from each other. m3 represents any integer from 0 to 5, and 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 0 to 5, and when m4 is 2 or more, a plurality of R 4 may be the same as or different from each other. Q 1 and Q 2 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. R 11 and R 12 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, 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 0 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, and * represents a bonding site with C(R 11 )(R 12 ) or C(Q 1 )(Q 2 ). A 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-. X a and X b each independently represent an oxygen atom or a sulfur atom. X 1 represents a divalent group having 1 to 18 carbon atoms and having an alicyclic hydrocarbon group having 3 to 24 carbon atoms, -CH2- contained in the divalent group having the alicyclic hydrocarbon group may be replaced by -O- or -CO-, and the divalent group having the alicyclic hydrocarbon group may have a hydroxy group or a fluorine atom. Ring W represents an alicyclic hydrocarbon group having 3 to 36 carbon atoms which may have a substituent, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-.] [2] Any one of m2, m3 and m4 is an integer of 1 or more, R 2 , R 3 and R 4 Among them, any one is -O-L 1 -CO-O-R 5 , -O-R 5 or -O-CO-O-R 5 The salt according to [1].[[]END]] [3] Any one of m3 and m4 is an integer of 1 or more, R 3 and R 4 Among them, any one is a halogen atom or a fluorinated alkyl group having 1 to 12 carbon atoms. The salt according to [1] or [2].[[]END]] [4] The acid-labile group of R 5 is a group represented by the formula (1a) or a group represented by the formula (2a). The salt according to any one of [1] to [3].[[]END]] TIFF0007702813000005.tif2058[In formula (1a), R aa1 , R aa2 and R aa3 each independently represents an optionally substituted alkyl group having 1 to 8 carbon atoms, an optionally substituted alkenyl group having 2 to 8 carbon atoms, an optionally substituted alicyclic hydrocarbon group having 3 to 20 carbon atoms, or an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or R aa1 and R aa2 are bonded to each other to form, together with the carbon atom to which they are bonded, an alicyclic hydrocarbon group having 3 to 20 carbon atoms. * represents a bond.] TIFF0007702813000006.tif2163[In formula (2a), R aa1’ and R aa2’ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R aa3’ represents a hydrocarbon group having 1 to 20 carbon atoms, or R aa2’ and R aa3’ are bonded to each other to form, together with the -C-X a - to which they are bonded, a heterocyclic group having 3 to 20 carbon atoms, 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. * represents a bond.] [5] The salt according to any one of [1] to [4], wherein A 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 (provided that the -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-, and the -CH2- contained in the alicyclic saturated hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-). [6] The salt according to any one of [1] to [5], wherein ring W is a ring represented by formula (w1-1), a ring represented by formula (w1-2), or a ring represented by formula (w1-3). TIFF0007702813000007.tif2766[In formulas (w1-1), (w1-2), and (w1-3), the -CH2- contained in the ring may be replaced by -O-, -S-, -SO2-, or -CO-, and the ring may have a substituent. The bond is at an arbitrary position.] [7] X 1 is a divalent group represented by formula (X 1 -1), a divalent group represented by formula (X 1 -2), a divalent group represented by formula (X 1 -3), or a divalent group represented by formula (X 1 -4), and is the salt according to any one of [1] to [6]. TIFF0007702813000008.tif35155[In the formula, R 21 , R 22 , R 23 , R 24 , R 25 and R 26 represent an alicyclic hydrocarbon group having 3 to 18 carbon atoms, the -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-, and the alicyclic hydrocarbon group may have a hydroxy group or a fluorine atom. * represents the bond with X a and X b .] [8] R 21 , R 22 , R 23 , R 24 , R 25 and R 26 are the ring represented by formula (w0-1), the ring represented by formula (w0-2), the ring represented by formula (w0-3), or the ring represented by formula (w0-12), and is the salt according to [7]. TIFF0007702813000009.tif2683[In formulas (w0-1), (w0-2), (w0-3), and (w0-12), the -CH2- contained in the ring may be replaced by -O- or -CO-, and the ring may have a hydroxy group or a fluorine atom. The bond is at an arbitrary position.] An acid generator containing a salt according to any one of [1] to [8].

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

[11] The resist composition according to

[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). TIFF0007702813000010.tif49108 [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 any one 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 any one of 0 to 14. n1 represents an integer of any one of 0 to 10. n1’ represents an integer of any one of 0 to 3.]

[12] The resist composition according to

[10] or

[11] , wherein the resin having an acid-labile group contains a structural unit represented by formula (a2-A). TIFF0007702813000011.tif5259 [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 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 - and * represents a bond to the carbon atom to which -R a50 is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O- or -O-CO-. nb represents 0 or 1. mb represents any integer from 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same as or different from each other. The resist composition according to any one of

[10] to

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

[13] acid generator.

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

[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, which is a method for manufacturing a resist pattern.

Advantages 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, the term "(meth)acrylic monomer" means "at least one of acrylic monomers and methacrylic monomers". Expressions such as "(meth)acrylate" and "(meth)acrylic acid" also represent the same meaning. For groups described in this specification that can take both linear and branched structures, either one is acceptable. When -CH2- contained in a hydrocarbon group or the like is replaced by -O-, -S-, -CO- or -SO2-, the same examples are applicable to each group. The term "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. The terms "derived from" or "derived" refer 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.

[0008] The present invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)"). Among salts (I), the negatively charged side may be referred to as "anion (I)", and the positively charged side may be referred to as "cation (I)". TIFF0007702813000012.tif48146[wherein all the symbols have the same meanings as described above respectively.]

[0009] In formula (I), R 1 such as the L that constitutes 1 Examples of the alkanediyl group in include a linear alkanediyl group 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, and a branched alkanediyl group 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, a 2-methylbutane-1,4-diyl group. L 1is preferably an alkanediyl group having 1 to 3 carbon atoms, more preferably a methylene group.

[0010] R 1 R that constitutes etc. 5 The acid-labile group of is a group that, when contacted with an acid (for example, trifluoromethanesulfonic acid), the group represented by R 5 is eliminated to form a carboxy group or a hydroxy group. As the acid-labile group, a group represented by formula (1a) (hereinafter, sometimes referred to as "acid-labile group (1a)"), a group represented by formula (2a) (hereinafter, sometimes referred to as "acid-labile group (2a)") are preferable. TIFF0007702813000013.tif2058 [In formula (1a), R aa1 R aa2 and R aa3 each independently represents an alkyl group having 1 to 8 carbon atoms which may have a substituent, an alkenyl group having 2 to 8 carbon atoms which may have a substituent, an alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, or R aa1 and R aa2 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. * represents a bond. ] TIFF0007702813000014.tif2059 [In formula (2a), R aa1’ and R aa2’ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R aa3’ represents a hydrocarbon group having 1 to 20 carbon atoms, or R aa2’ and R aa3’ are bonded to each other to form a heterocyclic group having 3 to 20 carbon atoms together with the -C-X a - to which they are bonded, 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. * represents a bond. ]

[0011] R aa1 、R aa2 and R aa3 Examples of the alkyl group of R aa1 、R aa2 and R aa3 include methyl group, ethyl group, propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, etc. The carbon number of the alkyl group of R R aa1 、R aa2 and R aa3 is preferably 1 to 6, more preferably 1 to 3. R aa1 、R aa2 and R aa3 Examples of the alkenyl group of R aa1 、R aa2 and R aa3 include ethenyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, tert-butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, isooctenyl group, nonenyl group. TIFF0007702813000015.tif9159R aa1 、R aa2 and R aa3 Examples of the alicyclic hydrocarbon group of R aa1 、R aa2 and R aa3 include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, phenanthryl group. The carbon number of the alicyclic hydrocarbon group of R

[0012] Examples of substituents of an alkyl group having 1 to 8 carbon atoms which may have a substituent include an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, and an aromatic hydrocarbon group having 6 to 18 carbon atoms. Examples of substituents of an alkenyl group having 2 to 8 carbon atoms which may have a substituent include an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, and an aromatic hydrocarbon group having 6 to 18 carbon atoms. Examples of substituents of an alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent include an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, and an aromatic hydrocarbon group having 6 to 18 carbon atoms. Examples of substituents of an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent include an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, and an alicyclic hydrocarbon group having 3 to 20 carbon atoms. More specifically, a group obtained by combining the above-described alkyl group and alicyclic hydrocarbon group (for example, an alkylcycloalkyl group or cycloalkylalkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), an aralkyl group such as benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), an aryl-cycloalkyl group such as phenylcyclohexyl group, etc. are mentioned.

[0013] R aa1 and R aa2 When they are bonded to each other to form an alicyclic hydrocarbon group together with a carbon atom, examples of -C(R aa1 )(R aa2 )(R aa3 ) include the following groups. The alicyclic hydrocarbon group is preferably 3 to 16, more preferably 3 to 12 carbon atoms. * represents a bond to -O-. TIFF0007702813000016.tif30140

[0014] Examples of the group represented by formula (1a) include a 1,1,1-trialkyl group (wherein in formula (1a), R aa1 , R aa2 and R aa3 are alkyl groups, preferably a tert-butoxycarbonyl group), a 2-alkyladamantan-2-yl group (in formula (1a), R aa1 , R aa2 and the carbon atom to which they are attached form an adamantyl group, and R aa3 is an alkyl group), and a 1-(adamantan-1-yl)-1,1-dialkyl group (in formula (1a), R aa1 and R aa2 are alkyl groups, and R aa3 is an adamantyl group), etc.

[0015] Examples of the hydrocarbon groups for R aa1' , R aa2' and R aa3' include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these, etc. Examples of the alkyl group and the alicyclic hydrocarbon group are the same as those exemplified for R aa1 , R aa2 and R aa3 . Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, a phenanthryl group, etc. Examples of the combined group include a group combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., cycloalkylalkyl group or alkylcycloalkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), aralkyl group such as benzyl group, aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl group such as phenylcyclohexyl group, etc. R aa2' and R aa3' are bonded to each other and, together with the carbon atom to which they are bonded and X a form a heterocyclic group, -C(R aa1' )(R aa2' )-X a -(R aa3' ) includes the following groups. * represents a bond. TIFF0007702813000017.tif20143R aa1' and R aa2' Among them, at least one is preferably a hydrogen atom.

[0016] Specific examples of the acid-labile group (1a) include the following groups. * represents a bond. TIFF0007702813000018.tif44153

[0017] Specific examples of the acid-labile group (2a) include the following groups. * represents a bond. TIFF0007702813000019.tif77159R 1 In the benzene ring, S + may be bonded to any of the ortho, meta, and para positions with respect to the position to which it is bonded, and among them, the meta or para position is preferable, and the para position is more preferable.

[0018] R 2 、R 3 and R 4 Examples of the halogen atoms of R, R, and R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 2 、R 3 and R 4 The fluorinated alkyl group having 1 to 12 carbon atoms of R, R, and R represents an alkyl group having 1 to 4 carbon atoms having a fluorine atom, and a perfluoroalkyl group having 1 to 4 carbon atoms (trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group), and 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, and 3,3,4,4,4-pentafluorobutyl group, etc. are mentioned. The number of carbon atoms of the fluorinated alkyl group is preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3. R 2 、R 3 and R 4 Examples of the hydrocarbon group having 1 to 18 carbon atoms of R, R, and R include chain hydrocarbon groups such as alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. The number of carbon atoms of the alkyl group is preferably 1 to 12, more preferably 1 to 9, still more preferably 1 to 6, and even more preferably 1 to 4. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Specifically, examples of the alicyclic hydrocarbon group include the groups represented below. The bonding site can be at any position. As the monocyclic alicyclic hydrocarbon group, examples include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group and the like. As the polycyclic alicyclic hydrocarbon group, examples include decahydronaphthyl group, adamantyl group, norbornyl group and the like. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, and still more preferably 3 to 12. As the aromatic hydrocarbon group, examples include phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, binaphthyl group and the like. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and still more preferably 6 to 10. Examples of the group formed by combination include a group formed by combining an aromatic hydrocarbon group and a chain hydrocarbon group (for example, aromatic hydrocarbon group - alkane diyl group - *, alkyl group - aromatic hydrocarbon group - *, and -CH2- contained in the alkane diyl group and the alkyl group may be replaced by -O-, -CO-, -S- or -SO2-), a group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group (for example, alicyclic hydrocarbon group - alkane diyl group - *, alkyl group - alicyclic hydrocarbon group - *, and -CH2- contained in the alkane diyl group and the alkyl group may be replaced by -O-, -CO-, -S- or -SO2-), and a group formed by combining an aromatic hydrocarbon group and an alicyclic hydrocarbon group (for example, aromatic hydrocarbon group - alicyclic hydrocarbon group - *, alicyclic hydrocarbon group - aromatic hydrocarbon group - *). * represents a bonding site. Examples of the aromatic hydrocarbon group - alkane diyl group - * include aralkyl groups such as benzyl group and phenethyl group. Examples of the alkyl group - aromatic hydrocarbon group - * include tolyl group, xylyl group, cumenyl group and the like. Examples of the alicyclic hydrocarbon group - alkane diyl group - * include cycloalkylalkyl groups such as cyclohexylmethyl group, cyclohexylethyl group, 1-(adamantan-1-yl)methyl group, 1-(adamantan-1-yl)-1-methylethyl and the like. Examples of the alkyl group - alicyclic hydrocarbon group - * include cycloalkyl groups having an alkyl group such as a methylcyclohexyl group, a dimethylcyclohexyl group, and a 2-alkyladamantan-2-yl group. Examples of the aromatic hydrocarbon group - alicyclic hydrocarbon group - * include a phenylcyclohexyl group. Examples of the alicyclic hydrocarbon group - aromatic hydrocarbon group - * include a cyclohexylphenyl group. In the combination, two or more alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined with each other. Also, any of these groups may be bonded to the benzene ring. Examples of the group in which -CH2- contained in the hydrocarbon group is replaced by -O-, -CO-, -S-, or -SO2- include a hydroxy group (a group in which -CH2- contained in the methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- contained in the ethyl group is replaced by -O-CO-), a thiol group (a group in which -CH2- contained in the methyl group is replaced by -S-), an alkoxy group (a group in which -CH2- at any position contained in the alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which -CH2- at any position contained in the alkyl group is replaced by -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -CO-O-), a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, an aromatic hydrocarbon group - carbonyloxy group, an alkylthio group (a group in which -CH2- at any position contained in the alkyl group is replaced by -S-), an alkylsulfonyl group (a group in which -CH2- at any position contained in the alkyl group is replaced by -SO2-), and groups formed by combining two or more of these groups. Examples of the alkoxy group include alkoxy groups having 1 to 17 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group and the like. The number of carbon atoms of the alkoxy group is preferably 1 to 11, more preferably 1 to 6, and still more preferably 1 to 4. The alkoxycarbonyl group, alkylcarbonyl group and alkylcarbonyloxy group represent groups in which a carbonyl group or carbonyloxy group is bonded to the above-described alkyl group or alkoxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group and the like. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 18 carbon atoms, such as acetyl group, propionyl group and butyryl group and the like. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as acetyloxy group, propionyloxy group, butyryloxy group and the like. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, and still more preferably 2 to 4. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 17 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 17 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as a butoxycarbonyloxy group. Examples of the aromatic hydrocarbon group-carbonyloxy group include aromatic hydrocarbon group-carbonyloxy groups having 7 to 17 carbon atoms, such as a benzoyloxy group. The alkylthio group includes an alkylthio group having 1 to 17 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, etc. The number of carbon atoms in the alkylthio group is preferably 2 to 11, more preferably 2 to 6, and further preferably 2 to 4. The alkylsulfonyl group includes alkylsulfonyl groups having 1 to 17 carbon atoms, such as a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, etc. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, and further preferably 1 to 4. Examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced with -O- or -CO- include the groups shown below. The -O- and -CO- positions in the groups shown below may be replaced with -O- and -SO2-, respectively. The bonding site may be any position. TIFF0007702813000021.tif46161When -CH2- contained in a hydrocarbon group is replaced by -O- or -CO-, the number of carbon atoms before the replacement is regarded as the total number of carbon atoms of the hydrocarbon group. In addition, the number may be 1 or 2 or more. R 2 , R 3 and R 4Examples of the substituent that the hydrocarbon group may have include a halogen atom, a cyano group, and an alkyl group having 1 to 12 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O-, -CO-, -S- or -SO2-). Examples of the halogen atom include the same groups as those described above. Examples of the alkyl group having 1 to 12 carbon atoms include the same groups as those described above. When -CH2- contained in the alkyl group is replaced by -O- or -CO- as the substituent, the total number of carbon atoms before replacement is defined as the total number of carbon atoms of the alkyl group. Examples of the replaced group include a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group and the like. Examples of the alkoxy group, the alkoxycarbonyl group, the alkylcarbonyl group and the alkylcarbonyloxy group include the same groups as those described above. The hydrocarbon group may have one substituent or a plurality of substituents.

[0019] m2 is preferably any integer from 0 to 2, more preferably 0 or 2. m3 and m4 are each independently preferably any integer from 0 to 2, more preferably 0 or 1. It is even more preferable that both m3 and m4 are 1. R 2 is preferably a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 6 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), -O-L 1 -CO-O-R 5 , -O-R 5 or -O-CO-O-R 5 more preferably an alkyl group having 1 to 4 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), and even more preferably an alkyl group having 1 to 4 carbon atoms. R 3 and R 4is, independently of one another, a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 6 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), -O-L 1 -CO-O-R 5 , -O-R 5 or -O-CO-O-R 5 is preferably, a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), -O-L 1 -CO-O-R 5 , -O-R 5 or -O-CO-O-R 5 is more preferably, a fluorine atom, a perfluoroalkyl group having 1 to 4 carbon atoms or -O-CH2-CO-O-R 5 is even more preferably, a fluorine atom, a trifluoromethyl group or -O-CH2-CO-O-R 5 is even more preferably. In addition, when any one of m2, m3 and m4 is an integer of 1 or more, R 2 , R 3 and R 4 Among them, any one of them is preferably -O-L 1 -CO-O-R 5 , -O-R 5 or -O-CO-O-R 5 is preferable. Further, when any one of m3 and m4 is an integer of 1 or more, R 3 and R 4 Among them, any one of them is preferably a halogen atom or a fluorinated alkyl group having 1 to 12 carbon atoms. The bonding position of R 2 in the benzene ring may be any of the ortho, meta, and para positions with respect to the position where S + is bonded, and among them, the meta position and / or the para position are preferable. The bonding position of R 3 and R 4 in the benzene ring is S +With respect to the position where it binds, it may be any of the ortho, meta, and para positions, and among them, the meta or para position is preferable.

[0020] Examples of the cation of salt (I) include cations represented by the following formulas (I-c-1) to (I-c-35). TIFF0007702813000022.tif79164

[0021] TIFF0007702813000023.tif115164

[0022] TIFF0007702813000024.tif243165

[0023] TIFF0007702813000025.tif229163

[0024] Among them, cations represented by formulas (I-c-1) to (I-c-9), formula (I-c-16), formula (I-c-7), formula (I-c-22), formula (I-c-24), formula (I-c-27), and formulas (I-c-32) to (I-c-34) are preferable, cations represented by formulas (I-c-1) to (I-c-6), formula (I-c-7), formula (I-c-16), formula (I-c-7), formula (I-c-22), formula (I-c-24), formula (I-c-27), and formulas (I-c-32) to (I-c-34) are more preferable, cations represented by formulas (I-c-1) to (I-c-4), formula (I-c-7), formula (I-c-16), formula (I-c-7), formula (I-c-22), formula (I-c-24), formula (I-c-27), and formulas (I-c-32) to (I-c-34) are further preferable, and cations represented by formula (I-c-1), formula (I-c-3), formula (I-c-4), formula (I-c-7), formula (I-c-16), formula (I-c-7), formula (I-c-22), formula (I-c-24), formula (I-c-27), and formulas (I-c-32) to (I-c-34) are even more preferable.

[0025] In formula (I), Q 1 、Q 2 、R 11 and R 12Examples of the perfluoroalkyl group include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, 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 11 and R 12 are each independently preferably a hydrogen atom or a fluorine atom, and more preferably a hydrogen atom. z is preferably 0 or 1. X 0 is preferably *-CO-O-, *-O-CO-O- or *-O-CO- (* represents the bonding position to C(R 11 )(R 12 ) or C(Q 1 )(Q 2 )). More preferably, it is *-CO-O- or *-O-CO-O-.

[0026] A 1 Examples of the hydrocarbon group in A include a divalent chain hydrocarbon group such as an alkanediyl group, a divalent alicyclic hydrocarbon group which is monocyclic or polycyclic (including a spiro ring), 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, and 2-methylbutane-1,4-diyl group. Examples of the monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group include the following alicyclic saturated hydrocarbon groups. The bonding positions can be arbitrary. TIFF0007702813000026.tif44168Specifically, monocyclic divalent alicyclic saturated hydrocarbon groups that are cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group, and polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group. Examples of the divalent aromatic hydrocarbon group include aromatic hydrocarbon groups such as arylene groups such as phenylene group, naphthylene group, anthrylene group, biphenylene group, and phenanthrylene group. Examples of the group formed by combining two or more groups include a group formed by combining an alicyclic saturated 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 saturated hydrocarbon group and an aromatic hydrocarbon group. In the combination, two or more alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined with each other. Also, any group may be bonded to X 0 . Examples of the group formed by combining an alicyclic saturated hydrocarbon group and an alkanediyl group include, for example, -divalent alicyclic saturated hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent alicyclic saturated hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent alicyclic saturated 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 saturated 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. A 1 The -CH2- contained in the hydrocarbon group having 1 to 28 carbon atoms of A may be replaced by -O-, -S-, -SO2- or -CO-. A 1 When the -CH2- contained in the hydrocarbon group having 1 to 28 carbon atoms of A 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. Examples of groups in which -CH2- contained in a hydrocarbon group is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group; a carboxy group; an alkoxy group such as a methoxy group, an ethoxy group, a butoxy group; a cycloalkoxy group such as a cyclohexyloxy group; a cycloalkylalkoxy group such as a cyclohexylmethoxy group; an alkylcarbonyl group such as an acetyl group; an alkoxycarbonyl group such as a methoxycarbonyl group; an alkylcarbonyloxy group such as an acetyloxy group; an alkoxycarbonyloxy group such as a butoxycarbonyloxy group; an aromatic hydrocarbon group-carbonyl-oxy group such as a benzoyloxy group; an alkanedioxy group; an alkanedioxycarbonyl group; an alkanediylcarbonyl group; an alkanediylcarbonyloxy group and the like. In particular, examples of groups in which -CH2- contained in an alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include the following groups. The positions of -O- and -CO- in the groups represented below may be replaced by -O- and -SO2-, respectively. TIFF0007702813000027.tif46166

[0027] A 1 Examples of substituents that may be possessed include a hydroxy group, a carboxy group, a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyloxy group having 2 to 13 carbon atoms or a group combining these and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a nonyl group and the like. Examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, a dodecyloxy group and the like. The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms and the alkylcarbonyloxy group having 2 to 13 carbon atoms represent a group in which a carbonyl group or a 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 a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group and the like. Examples of the alkylcarbonyl group having 2 to 13 carbon atoms include an acetyl group, a propionyl group, a butyryl group and the like. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, a butyryloxy group and the like. The substituent is preferably an alkyl group having 1 to 4 carbon atoms, a hydroxy group or a halogen atom, more preferably an alkyl group having 1 to 4 carbon atoms or a halogen atom, and still more preferably a methyl group or a fluorine atom.

[0028] A 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, for example, *-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 0 represents a bond with For example, A 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 preferably an alkanediyl 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 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-), or a group formed by combining an alkanediyl 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 alkanediyl group may be replaced by -O- or -CO-); more preferably, it is 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 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-).

[0029] X a and X b are preferably the same atom, and more preferably both are oxygen atoms.

[0030] X 1Examples of the divalent group having an alicyclic hydrocarbon group include monocyclic or polycyclic alicyclic hydrocarbon groups, groups in which a chain hydrocarbon group such as an alkanediyl group is combined with the alicyclic hydrocarbon group, groups in which three or more kinds of alicyclic hydrocarbon groups and chain hydrocarbon groups such as alkanediyl groups are combined, and the like. Among them, the alicyclic hydrocarbon group may be one or more, and it is preferably one or two. Examples of the alicyclic saturated hydrocarbon group include monocyclic alicyclic saturated hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group; and polycyclic alicyclic saturated hydrocarbon groups such as norbornyl group, adamantyl group, decahydronaphthyl group, and the like. For example, examples of the alicyclic hydrocarbon group and the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O- or -CO- include the groups exemplified by A 1 and the like.

[0031] Specifically, examples of the alicyclic hydrocarbon group in X 1 include groups derived from the rings represented by formula (w0-1) to formula (w0-13), and alicyclic hydrocarbon groups having 3 to 18 carbon atoms are preferred. Among them, the ring represented by formula (w0-1), the ring represented by formula (w0-2), the ring represented by formula (w0-3), or the ring represented by formula (w0-12) is preferred. TIFF0007702813000028.tif56142[In formula (w0-1) to formula (w0-13), -CH2- contained in the ring may be replaced by -O- or -CO-, and the ring may have a hydroxy group or a fluorine atom. The bonding position is arbitrary.] Among them, the number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 5 to 18, and still more preferably 5 to 16. In particular, as the alicyclic hydrocarbon group, those having an adamantane ring are preferable, and (w0-1) and (w0-12) are more preferable. The -CH2- contained in the adamantane ring may be replaced by -O- or -CO-, and the adamantane ring may have a hydroxy group or a fluorine atom. In the case of the ring represented by (w0-12), the -CH2- contained in cycloheptane may be replaced by -O- or -CO-, and may have a hydroxy group or a fluorine atom. 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, and octane-1,8-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, and 2-methylbutane-1,4-diyl group. The number of carbon atoms of the alkanediyl group is preferably 1 to 14, more preferably 1 to 12, and still more preferably 1 to 10. As the divalent group having an alicyclic hydrocarbon group, an alkanediyl group having 1 to 14 carbon atoms and having an alicyclic hydrocarbon group is preferable, an alkanediyl group having 1 to 12 carbon atoms and having an alicyclic hydrocarbon group is more preferable, and an alkanediyl group having 1 to 10 carbon atoms and having an alicyclic hydrocarbon group is still more preferable. In particular, those in which 1 to 3 sets of methylene groups contained in the alkanediyl group are replaced by oxygen atoms and carbonyl groups are preferable, and those replaced by 1 or 2 sets of oxygen atoms and carbonyl groups are more preferable. That is, as the divalent group having an alicyclic hydrocarbon group, it is more preferable to further have one or more, one or two oxycarbonyl groups or carbonyloxy groups.

[0032] X 1The divalent group having an alicyclic hydrocarbon group in the formula (X) is preferably a divalent saturated hydrocarbon group having an alicyclic hydrocarbon group having 3 to 18 carbon atoms, for example, a divalent saturated hydrocarbon group having an alicyclic hydrocarbon group having 3 to 18 carbon atoms and an oxycarbonyl group or a carbonyloxy group is preferable, a divalent alkanediyl group having an alicyclic hydrocarbon group having 3 to 18 carbon atoms is more preferable, for example, a divalent alkanediyl group having an alicyclic hydrocarbon group having 3 to 18 carbon atoms and an oxycarbonyl group or a carbonyloxy group is more preferable, 1 a divalent group represented by the formula (X 1 a divalent group represented by the formula (X 1 -3), or a divalent group represented by the formula (X 1 -4) is more preferable. TIFF0007702813000029.tif35155[In the formula, R 21 , R 22 , R 23 , R 24 , R 25 and R 26 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, in which -CH2- may be replaced by -O- or -CO-, and the alicyclic hydrocarbon group may have a hydroxy group or a fluorine atom. * is X a and X b It represents a bond with . R 21 , R 22 , R 23 , R 24 , R 25 and R 26 Examples of the alicyclic hydrocarbon group in R include the same groups as those described above. 21 , R 22 , R 23 , R 24 , R 25 and R 26 is preferably a ring represented by the above formula (w0-1), a ring represented by formula (w0-2), a ring represented by formula (w0-3) or a ring represented by formula (w0-12).

[0033] As the alicyclic hydrocarbon group having 3 to 36 carbon atoms in the ring W, it may be a monocyclic or polycyclic group. Specifically, groups derived from the rings represented by formula (w1-1) to formula (w1-13) are exemplified, and an alicyclic hydrocarbon group having 3 to 18 carbon atoms is preferable. Among them, the ring represented by formula (w1-1), the ring represented by formula (w1-2), or the ring represented by formula (w1-3) is preferable. The bonding hands in these rings can be at any position. TIFF0007702813000030.tif54142[In formula (w1-1) to formula (w1-13), -CH2- contained in the ring may be replaced by -O-, -S-, -SO2- or -CO-, and the ring may have a substituent. The bonding hand is at an arbitrary position.] Which carbon atom in the rings represented by formula (w1-1) to formula (w1-13) may be bonded to X a and X b and may be bonded. Examples of the substituent that the ring W may have include a hydroxy group, an alkyl group having 1 to 12 carbon atoms, 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 10 carbon atoms, etc. Examples of the alkyl group having 1 to 12 carbon atoms that is a substituent of the ring W include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. Examples of the alkoxy group having 1 to 12 carbon atoms that is a substituent of the ring W include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, a dodecyloxy group, etc. Examples of the alicyclic hydrocarbon group having 3 to 12 carbon atoms that is a substituent of the ring W include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, etc., and for example, the groups shown below are exemplified. * is the bonding hand with W. As the aromatic hydrocarbon group having 6 to 10 carbon atoms which is a substituent of the 14153-ring W, a phenyl group and a naphthyl group can be mentioned.

[0034] Examples of the anion (I) include anions represented by the following formulas (Ia-1) to (Ia-32). Among them, anions represented by formulas (Ia-1) to (Ia-16) are preferable, and anions represented by formulas (Ia-5) to (Ia-8) are more preferable. TIFF0007702813000032.tif192136

[0035] TIFF0007702813000033.tif208150

[0036] TIFF0007702813000034.tif215144

[0037] TIFF0007702813000035.tif204151

[0038] Examples of the salt (I) include the salts described in Table 1. For example, in Table 1, the salt (I-1) is a salt composed of an anion represented by the formula (Ia-1) and a cation represented by the formula (I-c-1), and means the following salts. TIFF0007702813000036.tif30136

Table 1

[0039] <Method for producing salt (I)> The salt (I) can be produced by reacting the salt represented by the formula (I-a) and the salt represented by the formula (I-b) in a solvent. TIFF0007702813000065.tif86152[Wherein, all the symbols have the same meanings as described above.] Examples of the solvent include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, water and the like. The reaction temperature is usually 15°C to 80°C, and the reaction time is usually 0.5 to 24 hours.

[0040] Examples of the salt represented by the formula (I-a) include salts represented by the following formula, etc., which can be easily obtained from the market and can also be easily produced by known production methods. TIFF0007702813000066.tif123160

[0041] Examples of the salt represented by the formula (I-b) include salts represented by the following, etc., which can be easily obtained from the market and can also be easily produced by known production methods. TIFF0007702813000067.tif77150

[0042] <Acid generator> The acid generator of the present invention is an acid generator containing salt (I). It may contain one kind of salt (I) or 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.

[0043] Either nonionic or ionic acid generator (B) 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 are 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.

[0044] 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, US Patent No. 3,779,778, US Patent No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. can be used. Further, compounds produced by known methods may also be used. The acid generator (B) may be used in combination of two or more kinds.

[0045] 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.). TIFF0007702813000068.tif2863[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.]

[0046] Q b1 and Q b2Examples of the perfluoroalkyl group represented by [group 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.

[0047] L b1 Examples of the divalent saturated hydrocarbon group in [group 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 may also be used. 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 thereof include polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.

[0048] 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 groups represented by any of formula (b1-1) to formula (b1-3). In the groups represented by formula (b1-1) to formula (b1-3) and the groups represented by formula (b1-4) to formula (b1-11) which are specific examples thereof, * and ** represent a bond, and * represents a bond to -Y.

[0049] TIFF0007702813000069.tif26118[In formula (b1-1), L b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. However, b2 the total number of carbon atoms of L b3 and L is 22 or less. In formula (b1-2), b4 L represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. b4 However, b5The total number of carbon atoms with [it] is 22 or less. In formula (b1-3), L b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. L b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. However, the total number of carbon atoms of L b6 and L b7 is 23 or less.

[0050] In the groups represented by formula (b1-1) to formula (b1-3), when -CH2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the number of carbon atoms before replacement is taken as the number of carbon atoms of the saturated hydrocarbon group. Examples of the divalent saturated hydrocarbon group include the same ones as the divalent saturated hydrocarbon group of L b1 .

[0051] L b2 is preferably a single bond. L b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and 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-.

[0052] L b1 As the 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. TIFF0007702813000070.tif48120[In the formula (b1-4), L b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and 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 and b10 the total number of carbon atoms of is 20 or less. 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 and b12 the total number of carbon atoms of is 21 or less. In formula (b1-7), L b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms. L b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced 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 b13is 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.

[0053] Examples of the group represented by formula (b1-3) include the groups represented by formulas (b1-9) to (b1-11). TIFF0007702813000071.tif23140[In formula (b1-9), L b19 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. L b20 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, hydroxy groups or alkylcarbonyloxy groups. The -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atoms contained in the alkylcarbonyloxy group may be substituted with hydroxy groups. However, the total number of carbon atoms of L b19 and L b20 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.]

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

[0055] Examples of the group represented by formula (b1-4) include the following. TIFF0007702813000072.tif16150

[0056] Examples of the group represented by formula (b1-5) include the following. TIFF0007702813000073.tif72149

[0057] Examples of the group represented by formula (b1-6) include the following. TIFF0007702813000074.tif29150

[0058] Examples of the group represented by formula (b1-7) include the following. TIFF0007702813000075.tif63151

[0059] Examples of the group represented by formula (b1-8) include the following. TIFF0007702813000076.tif23150

[0060] Examples of the group represented by formula (b1-2) include the following. TIFF0007702813000077.tif31160

[0061] Examples of the group represented by formula (b1-9) include the following. TIFF0007702813000078.tif44137

[0062] Examples of the group represented by formula (b1-10) include the following. TIFF0007702813000079.tif89158

[0063] Examples of the group represented by formula (b1-11) include the following. TIFF0007702813000080.tif81158

[0064] Examples of the alicyclic hydrocarbon group represented by Y include the groups represented by formula (Y1) to formula (Y11) and 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) and formula (Y39) to formula (Y43). TIFF0007702813000081.tif83165Examples of the alicyclic hydrocarbon group represented by Y are preferably groups represented by any of formula (Y1) to formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39) to formula (Y43), more preferably groups 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 even more preferably groups 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), formula (Y40), formula (Y42), formula (Y43), etc., the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. Further, among the alkanediyl groups contained in the ketal structure, the methylene group adjacent to the oxygen atom is preferably not substituted with a fluorine atom.

[0065] Examples of the substituent of the methyl group represented by Y include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-O-Rb1 a group or -(CH2) ja -O-CO-R b1 group (wherein, R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these. ja represents any integer from 0 to 4. The -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and the hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom.) and the like can be mentioned. As the substituent of the alicyclic hydrocarbon group represented by Y, a halogen atom, a hydroxy group, an alkyl group having 1 to 16 carbon atoms which may be substituted by a hydroxy group (the -CH2- contained in the alkyl group may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-O-R b1 group or -(CH2) ja -O-CO-R b1 group (wherein, R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these. ja represents any integer from 0 to 4. The -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and the hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom.) and the like can be mentioned.

[0066] 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, etc. 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 in 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. Examples of the aromatic hydrocarbon group having a chain hydrocarbon group include a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group. Examples of the aromatic hydrocarbon group having an alicyclic hydrocarbon group include a p-cyclohexylphenyl group and a p-adamantylphenyl group. The number of carbon atoms in 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, etc. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4. Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as 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- or -CO- etc. include an alkoxy group, an alkylsulfonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group or a group combining these etc. 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 etc. The number of carbon atoms of the alkoxy group is preferably 1 to 12, more preferably 1 to 6, still more preferably 1 to 4. Examples of the alkylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group etc. The number of carbon atoms of the alkylsulfonyl group is preferably 1 to 12, more preferably 1 to 6, still more preferably 1 to 4. Examples of the alkoxycarbonyl group include, for example, a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group etc. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4. Examples of the alkylcarbonyl group include, for example, an acetyl group, a propionyl group and a butyryl group etc. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4. Examples of the alkylcarbonyloxy group include, for example, an acetyloxy group, a propionyloxy group, a butyryloxy group etc. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4. Examples of the combined group include, for example, 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 etc. 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 and the like. The number of carbon atoms of the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the group combining an alkoxy group and an alkoxy group include alkoxyalkoxy groups such as methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group and the like. The number of carbon atoms of the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the group combining an alkoxy group and an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as methoxyacetyl group, methoxypropionyl group, ethoxyacetyl group, ethoxypropionyl group and the like. The number of carbon atoms of the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and still more preferably 3 to 5. Examples of the group combining an alkoxy group and an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as methoxyacetyloxy group, methoxypropionyloxy group, ethoxyacetyloxy group, ethoxypropionyloxy group and the like. 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).

[0067] Examples of Y include the following. TIFF0007702813000082.tif103165

[0068] TIFF0007702813000083.tif66163

[0069] Y is preferably an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent, still more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and even more preferably an adamantyl group which may have a substituent. The -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).

[0070] 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. TIFF0007702813000084.tif87159

[0071] TIFF0007702813000085.tif117158

[0072] TIFF0007702813000086.tif125157

[0073] TIFF0007702813000087.tif129140

[0074] TIFF0007702813000088.tif111158

[0075] TIFF0007702813000089.tif67139

[0076] Here, R i2 ~Ri7 is, 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.

[0077] Preferred examples of the anion in the salt represented by the formula (B1) include the anions represented by the formulas (B1a-1) to (B1a-38), respectively. TIFF0007702813000090.tif89152

[0078] TIFF0007702813000091.tif93139

[0079] TIFF0007702813000092.tif142156

[0080] TIFF0007702813000093.tif63150

[0081] Among them, an anion represented by any of the formulas (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38) is preferred.

[0082] Z1 +Examples of the organic cation include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, organic phosphonium cations, and the like. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, cations represented by any of Formula (b2-1) to Formula (b2-4) (hereinafter, may be referred to as "cation (b2-1)" etc. according to the formula number) can be mentioned.

[0083] In Formula (b2-1) to Formula (b2-4), TIFF0007702813000094.tif47167 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, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R b4 and R b5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH2- contained in the ring may be replaced with -O-, -S-, or -CO-. R b7 and R b8 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. m2 and n2 each independently represent an integer of 0 to 5. When m2 is 2 or more, a plurality of R b7may be the same or different, and when n2 is 2 or more, a plurality of R b8 may be the same or different. R b9 and R b10 each independently represents a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms. R b9 and R b10 may combine with each other to form a ring together with the sulfur atom to which they are attached, and the -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the chain hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the 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 combine with each other to form a ring including -CH-CO- to which they are attached, and the -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b13 ~R b18 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. L b31 represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent any integer from 0 to 5. q2 and r2 each independently represent any integer from 0 to 4. u2 represents 0 or 1. When o2 is 2 or more, a plurality of R b13are the same or different, and when p2 is 2 or more, a plurality of Rs b14 are the same or different, and when q2 is 2 or more, a plurality of Rs b15 are the same or different, and when r2 is 2 or more, a plurality of Rs b16 are the same or different, and when s2 is 2 or more, a plurality of Rs b17 are the same or different, and when t2 is 2 or more, a plurality of Rs b18 are the same or different. An aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, and 2-ethylhexyl group. In particular, R b9 ~R b12 The chain hydrocarbon group of 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. TIFF0007702813000095.tif10158 In particular, R b9 ~R b12 The alicyclic hydrocarbon group of is preferably 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms. Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include methylcyclohexyl group, dimethylcyclohexyl group, 2-methyladamantan-2-yl group, 2-ethyladamantan-2-yl group, 2-isopropyladamantan-2-yl group, methylnorbornyl group, and isobornyl group. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The alkyl fluoride group represents an alkyl group having 1 to 12 carbon atoms with a fluorine atom, and examples thereof include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, and a perfluorobutyl group. The number of carbon atoms in the alkyl fluoride group is preferably 1 to 9, more preferably 1 to 6, and still more preferably 1 to 4.

[0084] Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a biphenyl group, a naphthyl group, and a phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples of the aromatic hydrocarbon group having a chain hydrocarbon group with 1 to 18 carbon atoms include a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group, and examples of the aromatic hydrocarbon group having an alicyclic hydrocarbon group with 3 to 18 carbon atoms include a p-cyclohexylphenyl group and a p-adamantylphenyl group. When the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group with 1 to 18 carbon atoms and an alicyclic hydrocarbon group with 3 to 18 carbon atoms are preferred. Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group. Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group. R b4 and R b5 The ring formed by 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. Examples thereof include the following rings. * represents a bond. TIFF0007702813000096.tif23143R 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.

[0085] Among cations (b2-1) to (b2-4), preferably, it is cation (b2-1). Examples of cation (b2-1) include the following cations. TIFF0007702813000097.tif79158

[0086] TIFF0007702813000098.tif110165

[0087] Examples of the cation (b2-2) include the following cations. TIFF0007702813000099.tif18150

[0088] Examples of the cation (b2-3) include the following cations. TIFF0007702813000100.tif26140

[0089] Examples of the cation (b2-4) include the following cations. TIFF0007702813000101.tif127165

[0090] The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. Preferred examples of the acid generator (B) include a combination of an anion represented by any of Formula (B1a-1) to Formula (B1a-3), Formula (B1a-7) to Formula (B1a-16), Formula (B1a-18), Formula (B1a-19), and Formula (B1a-22) to Formula (B1a-38), and the cation (b2-1), the cation (b2-3), or the cation (b2-4). Preferred examples of the acid generator (B) include those represented by Formula (B1-1) to Formula (B1-56), and 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. TIFF0007702813000102.tif98161

[0091] TIFF0007702813000103.tif152165

[0092] TIFF0007702813000104.tif92158

[0093] TIFF0007702813000105.tif144161

[0094] TIFF0007702813000106.tif99130

[0095] TIFF0007702813000107.tif92158

[0096] When containing salt (I) and acid generator (B) as an acid generator, the ratio of the content of salt (I) to the content of acid generator (B) (mass ratio; salt (I): acid generator (B)) is usually from 1:99 to 99:1, preferably from 2:98 to 98:2, more preferably from 5:95 to 95:5, still more preferably from 10:90 to 90:10, and particularly preferably from 15:85 to 85:15.

[0097] 〔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 is eliminated and the constitutional unit is converted into a constitutional unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). The resist composition of the present invention preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") such as a salt that generates an acid having a lower acidity than the acid generated from the acid generator, and preferably contains a solvent (hereinafter sometimes referred to as "solvent (E)").

[0098] <Acid generator> In the resist composition of the present invention, the total content ratio of the acid generator is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or less, still more preferably 3 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the resin (A) described later.

[0099] <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.).

[0100] 〈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)). TIFF0007702813000108.tif2298[In formula (1), R a1 , R a2 and R a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, or R a1 and R a2 are bonded to each other to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * represents a bond.] TIFF0007702813000109.tif2378[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 Ra3’ are bonded to each other to form, together with the carbon atoms to which they are bonded and X, a heterocyclic group having 3 to 20 carbon atoms, and the -CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced by -O- or -S-. X represents an oxygen atom or a sulfur atom. na’ represents 0 or 1. * represents a bond.]

[0101] R a1 、R a2 and R a3 Examples of the alkyl group in include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and the like. R a1 、R a2 and R a3 Examples of the alkenyl group in include ethenyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, tert-butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, isooctenyl group, nonenyl group. R a1 、R a2 and R a3 The alicyclic hydrocarbon group in may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents a bond.). R a1 、R a2 and R a3 The alicyclic hydrocarbon group of preferably has 3 to 16 carbon atoms. TIFF0007702813000110.tif10159R a1 、R a2 and R a3 Examples of the aromatic hydrocarbon group in include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, phenanthryl group and the like. As the combined group, there may be mentioned groups combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., alkylcycloalkyl group or cycloalkylalkyl group), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like. Preferably, ma is 0 and na is 1. R a1 and R a2 When they are bonded to each other to form an alicyclic hydrocarbon group, examples of -C(R a1 )(R a2 )(R a3 ) include the following groups. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * represents a bond to -O-. TIFF0007702813000111.tif35157

[0102] 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 mentioned 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, and the like. Examples of the combined group include a group combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., alkylcycloalkyl group or cycloalkylalkyl group), aralkyl group such as benzyl group, aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl group such as phenylcyclohexyl group, and the like. R a2’ and R a3’ When R and R are bonded to each other to form a heterocyclic group together with the carbon atom to which they are bonded and X, -C(R a1’ )(R a2’ )-X-R a3’ includes the following groups. * represents a bond. TIFF0007702813000112.tif18124R a1’ and R a2’ Among them, at least one is preferably a hydrogen atom. na’ is preferably 0.

[0103] Examples of the group (1) include the following groups. In formula (1), a group in which R a1 , R a2 and R a3 are alkyl groups, ma = 0, and na = 1. As the group, a tert-butoxycarbonyl group is preferable. In formula (1), a group in which R a1 , R a2 together with the carbon atom to which they are bonded form an adamantyl group, R a3 is an alkyl group, ma = 0, and na = 1. In formula (1), a group in which R a1 and R a2 are each independently an alkyl group, R a3 is an adamantyl group, ma = 0, and na = 1. Examples of the group (1) specifically include the following groups. * represents a bond. TIFF0007702813000113.tif129163

[0104] TIFF0007702813000114.tif40155

[0105] Specific examples of the group (2) include the following groups. * represents a bond. TIFF0007702813000115.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, those having an alicyclic hydrocarbon group with 5 to 20 carbon atoms are preferably mentioned. If a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

[0108] As the structural unit derived from the (meth)acrylic monomer having the group (1), preferably, the structural unit represented by the formula (a1-0) (hereinafter, may be referred to as the structural unit (a1-0)), the structural unit represented by the formula (a1-1) (hereinafter, may be referred to as the structural unit (a1-1)) or the structural unit represented by the formula (a1-2) (hereinafter, may be referred to as the structural unit (a1-2)) is mentioned. More preferably, it is at least one structural unit selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). These may be used alone or in combination of two or more. TIFF0007702813000116.tif46149[In the formula (a1-0), the formula (a1-1) and the formula (a1-2), L a01 、L a1 and L a2Each independently represents -O- or *-O-(CH2) k1 -CO-O-, k1 represents an integer from 1 to 7, and * represents a bond with -CO-. R a01 R a4 and R a5 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a02 R a03 and R a04 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. R a6 and R a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. m1 represents an integer from 0 to 14. n1 represents an integer from 0 to 10. n1’ represents an integer from 0 to 3.]

[0109] R a01 R a4 and R a5 are preferably a hydrogen atom or a methyl group, 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), more preferably an oxygen atom. R a02 R a03 R a04 R a6 and R a7 As the alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and a 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 still 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 still 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 is preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, a phenyl group or a naphthyl group, and even more preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group or a phenyl group. m1 is preferably any integer from 0 to 3, more preferably 0 or 1. n1 is preferably any integer from 0 to 3, more preferably 0 or 1. n1' is preferably 0 or 1.

[0110] Examples of the structural unit (a1-0) include 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 with a hydrogen atom, a halogen atom, a haloalkyl (alkyl group having a halogen atom) group or another alkyl group. Structural units represented by any of the formulas (a1-0-1) to (a1-0-10), (a1-0-13), and (a1-0-14) are preferred. TIFF0007702813000117.tif98166

[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 with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group are preferred, and structural units represented by any of the formulas (a1-1-1) to (a1-1-4) are more preferred. TIFF0007702813000118.tif39167

[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 a structural unit in which the methyl group corresponding to R in the structural unit (a1-2) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. Among them, the 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) are preferred. a5 Examples of the structural unit in which the methyl group corresponding to R in the structural unit (a1-2) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group include a structural unit represented by any of the formulas (a1-2-2), (a1-2-5), (a1-2-6), and (a1-2-10) to (a1-2-14). The 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) are preferred. TIFF0007702813000119.tif67163

[0113] When the resin (A) contains the structural unit (a1-0), its content is usually 5 to 60 mol%, preferably 5 to 50 mol%, more preferably 10 to 40 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), the total content thereof is usually 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, still more preferably 25 to 75 mol%, and even more preferably 30 to 75 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 sometimes referred to as "structural unit (a1-4)"). TIFF0007702813000120.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 -, and * 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 -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 and R include a fluorine atom, a chlorine atom, a bromine atom and the like. 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 even more preferably a hydrogen atom or a methyl group. R a33 Examples of the alkyl group in include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group. R a33 Examples of the alkoxy group in include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group and hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a33 Examples of the alkoxyalkyl group in include methoxymethyl group, ethoxyethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, sec-butoxymethyl group and tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even 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 Examples of *- include *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a32 -CO-O-, *-O-CO-A a32 -O-, *-O-A a32 -CO-O-, *-CO-O-A a32 -O-CO-, *-O-CO-A a32 -O-CO-. Among them, *-CO-O-, *-CO-O-A a32 -CO-O- or *-O-A a32-CO-O- is preferred.

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

[0118] A a30 is a single bond, *-CO-O- or *-CO-O-A a32 -CO-O- is 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). TIFF0007702813000121.tifExamples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group. Examples of the combined group include a group formed by combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., cycloalkylalkyl group), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like. In particular, R a36 Examples of R 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 the alicyclic hydrocarbon group in R a36 are preferably unsubstituted. The aromatic hydrocarbon group in R a36 preferably has an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

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

[0122] Examples of the structural unit (a1-4) include structural units derived from 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 hydrogen atom corresponding to R in the structural unit (a1-4) a32 are replaced by a halogen atom, a haloalkyl group or an alkyl group, and more preferably, the structural units represented by Formula (a1-4-1) to Formula (a1-4-5), Formula (a1-4-10), Formula (a1-4-13), and Formula (a1-4-14). TIFF0007702813000122.tif99165

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

[0124] Examples of the structural unit derived from the (meth)acrylic monomer having the group (2) also include the structural unit represented by Formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)"). TIFF0007702813000123.tif4253In Formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. Z a1 is a single bond or *-(CH2) h3-CO-L 54 represents -, h3 represents an integer from 1 to 4, and * represents a bond with L 51 L 51 , L 52 , L 53 and L 54 each independently represents -O- or -S-. s1 represents an integer from 1 to 3. s1’ represents an integer from 0 to 3.

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

[0126] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP-A-2010-61117. Among them, the structural units represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and the structural unit represented by formula (a1-5-1) or formula (a1-5-2) is more preferable. TIFF0007702813000124.tif31129

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

[0128] Examples of the structural unit (a1) also include the following structural units. TIFF0007702813000125.tif27161

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

[0130] 〈Structural unit (s)〉 The structural unit (s) is derived from a monomer having no acid-labile group (hereinafter sometimes referred to as "monomer (s)"). As the monomer that leads to the structural unit (s), a monomer having no acid-labile group known in the resist field can be used. The structural unit (s) preferably has a hydroxy group or a lactone ring. By using a resin having a structural unit having a hydroxy group and no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit having a lactone ring and no acid-labile group (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

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

[0132] Examples of the structural unit having a phenolic hydroxy group in the structural unit (a2) include a structural unit represented by the formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)"). TIFF0007702813000126.tif4552[In the formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 represents a single bond or *-X a51 -(A a52 -X a52 ) nb -, where * represents a bond to 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 an integer of any one of 0 to 4. When mb is an integer of 2 or more, a plurality of Rs a51 may be the same as or different from each other.]

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

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

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

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

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

[0138] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577. As the structural unit (a2-A), there are structural units represented by formula (a2-2-1) to formula (a2-2-16) and structural units represented by formula (a2-2-1) to formula (a2-2-16) in which the methyl group corresponding to R in the structural unit (a2-A) a50 is replaced by a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. The structural unit (a2-A) is preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) is replaced by a hydrogen atom in the structural unit represented by formula (a2-2-1), the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-6), the structural unit represented by formula (a2-2-8), the structural units represented by formula (a2-2-12) to formula (a2-2-14) and the structural unit represented by formula (a2-2-1), the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-6), the structural unit represented by formula (a2-2-8), the structural units represented by formula (a2-2-12) to formula (a2-2-14). a50 More preferably, it is a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) is replaced by a hydrogen atom in the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-8), the structural units represented by formula (a2-2-12) to formula (a2-2-14) and the structural unit represented by formula (a2-2-3) or the structural unit represented by formula (a2-2-8), the structural units represented by formula (a2-2-12) to formula (a2-2-14). a50 Even more preferably, it is a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) is replaced by a hydrogen atom in the structural unit represented by formula (a2-2-8) and the structural unit represented by formula (a2-2-8). a50 Even more preferably, it is a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) is replaced by a hydrogen atom. TIFF0007702813000127.tif64168

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

[0140] Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as "structural unit (a2-1)"). TIFF0007702813000128.tif4258In the formula (a2-1), L a3 represents -O- or *-O-(CH2) k2 -CO-O-, k2 represents an integer of any one of 1 to 7. * represents a bond to -CO-. R a14 represents a hydrogen atom or a methyl group. R a15 and R a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group. o1 represents an integer of any one of 0 to 10.

[0141] In the formula (a2-1), L a3 is preferably -O-, -O-(CH2) f1 -CO-O- (wherein f1 represents an integer of any one of 1 to 4), more preferably -O-. R a14 is preferably a methyl group. R a15 is preferably a hydrogen atom. R a16 is preferably a hydrogen atom or a hydroxy group. o1 is preferably an integer of any one of 0 to 3, more preferably 0 or 1.

[0142] 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 formula (a2-1-1) to formula (a2-1-6) is preferable, the structural unit represented by any of formula (a2-1-1) to formula (a2-1-4) is more preferable, and the structural unit represented by formula (a2-1-1) or formula (a2-1-3) is even more preferable. TIFF0007702813000129.tif54151

[0143] When the resin (A) contains the structural unit (a2-1), the content thereof is usually 1 to 45 mol%, preferably 1 to 40 mol%, more preferably 1 to 35 mol%, even more preferably 1 to 20 mol%, and even more preferably 1 to 10 mol% based on all the structural units of the resin (A).

[0144] 〈Structural unit (a3)〉 The lactone ring contained in 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 adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)) can be mentioned.

[0145] The structural unit (a3) is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3), or formula (a3-4). These may be contained alone or in combination of two or more. TIFF0007702813000130.tif52167[In formula (a3-1), formula (a3-2), formula (a3-3), and 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 is -O-, *-O-La8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O- or *-O-L a8 -O-CO-L a9 represents -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * represents the bonding site with the carbonyl group. R a18 , R a19 and R a20 each independently represents a hydrogen atom or a methyl group. R a24 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. X a3 represents -CH2- or an oxygen atom. R a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms. R a22 , R a23 and R a25 each independently represents a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. p1 represents any integer from 0 to 5. q1 represents any integer from 0 to 3. r1 represents any integer from 0 to 3. w1 represents any integer from 0 to 8. When p1, q1, r1 and / or w1 is 2 or more, a plurality of R a21 , R a22 , R a23 and / or R a25 may be the same as or different from each other.

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

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

[0148] In formula (a3-4), R a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, still more preferably a hydrogen atom or a methyl group. R a25 is preferably a carboxy group, a cyano group or a methyl group. L a7 is preferably -O- or *-O-L a8 -CO-O-, more preferably -O-, -O-CH2-CO-O- or -O-C2H4-CO-O-. w1 is preferably any integer from 0 to 2, more preferably 0 or 1. In particular, formula (a3-4) is preferably formula (a3-4)'. TIFF0007702813000131.tif4051 (wherein R a24 , L a7 represent the same meanings as described above.)

[0149] Examples of the structural unit (a3) include structural units derived from the monomers described in JP-A-2010-204646, the monomers described in JP-A-2000-122294, and the monomers described in JP-A-2012-41274. Examples of the structural unit (a3) include structural units represented by any of formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3-1), formula (a3-3-2) and formula (a3-4-1) to formula (a3-4-12), and in the above structural units, R a18 , R a19 , R a20 and R a24A structural unit in which a methyl group corresponding to the following is replaced by a hydrogen atom is preferred. TIFF0007702813000132.tif117165

[0150] When the resin (A) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol%, preferably 10 to 65 mol%, more preferably 10 to 60 mol% with respect to all the structural units of the resin (A). In addition, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3) or the structural unit (a3-4) is preferably 5 to 60 mol%, more preferably 5 to 50 mol%, still more preferably 10 to 50 mol% with respect to all the structural units of the resin (A).

[0151] 〈Structural unit (a4)〉 Examples of the structural unit (a4) include the following structural units. TIFF0007702813000133.tif3066[In the formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having a fluorine atom with 1 to 24 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. R 42 Examples of the saturated hydrocarbon group represented by include a chain hydrocarbon group, a monocyclic or polycyclic alicyclic hydrocarbon group, and a group formed by combining these.

[0152] 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 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 bond). As the group formed by the combination of TIFF0007702813000134.tif11159, groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups can be mentioned, such as -alkanediyl group - alicyclic hydrocarbon group, -alicyclic hydrocarbon group - alkyl group, -alkanediyl group - alicyclic hydrocarbon group - alkyl group, etc.

[0153] Examples of the structural unit (a4) include structural units represented by at least one selected from the group consisting of formula (a4-0), formula (a4-1), formula (a4-2), formula (a4-3), and formula (a4-4). TIFF0007702813000135.tif4652[In formula (a4-0), R 5 represents a hydrogen atom or a methyl group. L 4a represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms. L 3a represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms. R 6 represents a hydrogen atom or a fluorine atom.]

[0154] L 4a Examples of the divalent aliphatic saturated hydrocarbon 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. L 3aExamples of the perfluoroalkanediyl group in [description] include a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, a perfluoropropane-2,2-diyl group, a perfluorobutane-1,4-diyl group, a perfluorobutane-2,2-diyl group, a perfluorobutane-1,2-diyl group, a perfluoropentane-1,5-diyl group, a perfluoropentane-2,2-diyl group, a perfluoropentane-3,3-diyl group, a perfluorohexane-1,6-diyl group, a perfluorohexane-2,2-diyl group, a perfluorohexane-3,3-diyl group, a perfluoroheptane-1,7-diyl group, a perfluoroheptane-2,2-diyl group, a perfluoroheptane-3,4-diyl group, a perfluoroheptane-4,4-diyl group, a perfluorooctane-1,8-diyl group, a perfluorooctane-2,2-diyl group, a perfluorooctane-3,3-diyl group, a perfluorooctane-4,4-diyl group, and the like. L 3a Examples of the perfluorocycloalkanediyl group in [description] include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantanediyl group, and the like.

[0155] 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.

[0156] Examples of the structural unit (a4-0) include 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. 5 include the structural units where the methyl group corresponding to R in the structural unit (a4-0) is replaced by a hydrogen atom. TIFF0007702813000136.tif98164

[0157] TIFF0007702813000137.tif4466[In formula (a4-1), R a41 represents a hydrogen atom or a methyl group. R a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. A a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by formula (a-g1). However, at least one of a41 A a42 and R has a halogen atom (preferably a fluorine atom) as a substituent. TIFF0007702813000138.tif1384[In formula (a-g1), s represents 0 or 1. A a42 and A a44 each independently represent a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. A a43 represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. X a41 and X a42 each independently represent -O-, -CO-, -CO-O- or -O-CO-. However, the total number of carbon atoms of a42 A a43 A a44 A a41 X a42 and X is 7 or less. ] * represents a bond, and the * on the right side is a bond with -O-CO-R a42 . ]

[0158] R a42 Examples of the saturated hydrocarbon group in R include a chain saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and a group formed by combining these. Examples of the chain saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic saturated hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bond). Examples of the group formed by the combination of TIFF0007702813000139.tif11159 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, and the like.

[0159] R a42 Examples of the substituent that R may have include at least one selected from a halogen atom and a group represented by the formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and preferably a fluorine atom. TIFF0007702813000140.tif965[In the formula (a-g3), X a43 represents an oxygen atom, a carbonyl group, *-O-CO- or *-CO-O-. A a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. * represents a bond with R a42 .] However, in R a42 -X a43 -A a45 , when R a42 does not have a halogen atom, A a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which has at least one halogen atom.

[0160] A a45 Examples of the aliphatic hydrocarbon group in include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group and octadecyl group; monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; and polycyclic alicyclic hydrocarbon groups such as decahydronaphthyl group, adamantyl group, norbornyl group and the following group (* represents a bond). Examples of the group formed by the combination of TIFF0007702813000141.tif11159 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, etc.

[0161] R a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and / or an aliphatic hydrocarbon group having a group represented by formula (a-g3). R a42 When is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, still more preferably a perfluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include perfluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, perfluoroheptyl group and perfluorooctyl group. Examples of the perfluorocycloalkyl group include perfluorocyclohexyl group. R a42When R is an aliphatic hydrocarbon group having a group represented by the formula (a-g3), including the number of carbon atoms contained in the group represented by the formula (a-g3), a42 the total number of carbon atoms is preferably 15 or less, more preferably 12 or less. When having a group represented by the formula (a-g3) as a substituent, the number thereof is preferably 1.

[0162] R a42 When R is an aliphatic hydrocarbon having a group represented by the formula (a-g3), a42 R is more preferably a group represented by the formula (a-g2). TIFF0007702813000142.tif879[In the formula (a-g2), A a46 represents a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. X a44 represents **-O-CO- or **-CO-O- (** represents a bond to A a46 ). A a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. However, the total number of carbon atoms of A a46 A a47 and X a44 is 18 or less, and at least one of A a46 and A a47 has at least one halogen atom. * represents a bond to a carbonyl group.]

[0163] A a46 The number of carbon atoms of the aliphatic hydrocarbon group is preferably 1 to 6, more preferably 1 to 3. A a47 The number of carbon atoms of the aliphatic hydrocarbon group is preferably 4 to 15, more preferably 5 to 12, and A a47 is more preferably a cyclohexyl group or an adamantyl group.

[0164] A preferred structure of the group represented by the formula (a-g2) is the following structure (* is a bond to a carbonyl group). TIFF0007702813000143.tif13161

[0165] A a41 Examples of the alkanediyl group in the formula (I) include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group; and branched alkanediyl groups such as a propane-1,2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a 1-methylbutane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a41 Examples of the substituent in the alkanediyl group include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. A a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and further preferably an ethylene group.

[0166] A in the group represented by formula (a-g1) a42 , A a43 and A a44 Examples of the divalent saturated hydrocarbon group represented by include a linear or branched alkanediyl group, a monocyclic divalent alicyclic hydrocarbon group, and a group formed by combining an alkanediyl group and a divalent alicyclic hydrocarbon group, etc. Specific examples include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, etc. A a42 , A a43 and A a44 Examples of the substituent of the divalent saturated hydrocarbon group represented by the formula (1) include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. It is preferred that s is 0.

[0167] In the group represented by formula (a-g1), X a42Examples of the group being -O-, -CO-, -CO-O- or -O-CO- include the following groups and the like. In the following examples, * and ** each represent a bond, and ** is a bond with -O-CO-R a42 is the bond with. TIFF0007702813000144.tif54162

[0168] Examples of the structural unit represented by formula (a4-1) include the following structural units and the structural units in the following structural units where the methyl group corresponding to R in the structural unit represented by formula (a4-1) is replaced by a hydrogen atom. a41 TIFF0007702813000145.tif167144

[0169] TIFF0007702813000146.tif66133

[0170] As the structural unit represented by formula (a4-1), the structural unit represented by formula (a4-2) is preferred. TIFF0007702813000147.tif4365[In formula (a4-2), R f5 represents a hydrogen atom or a methyl group. L 44 represents an alkanediyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. R f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and having a fluorine atom. However, the upper limit of the total carbon number of L 44 and R f6 is 21.]

[0171] L 44 The alkanediyl group having 1 to 6 carbon atoms of is the same as the groups exemplified for the alkanediyl group in A a41 . R f6 The saturated hydrocarbon group of is the same as the groups exemplified for R a42 . L​44 As the C1-C6 alkanediyl group in [reference], a C2-C4 alkanediyl group is preferred, and an ethylene group is more preferred.

[0172] Examples of the structural unit represented by formula (a4-2) include structural units represented by formulas (a4-1-1) to (a4-1-11), respectively. The methyl group corresponding to R in structural unit (a4-2) f5 The structural unit in which the methyl group is replaced by a hydrogen atom is also included as the structural unit represented by formula (a4-2).

[0173] Examples of the structural unit (a4) include the structural unit represented by formula (a4-3). TIFF0007702813000148.tif5771[In formula (a4-3), R f7 represents a hydrogen atom or a methyl group. L 5 represents a C1-C6 alkanediyl group. A f13 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms which may have a fluorine atom. X f12 represents *-O-CO- or *-CO-O- (* represents the bond with A f13 .). A f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom. However, at least one of A f13 and A f14 has a fluorine atom, and the upper limit of the total number of carbon atoms of L 5 , A f13 and A f14 is 20.]

[0174] L 5 Examples of the alkanediyl group in [reference] include the same groups as those exemplified for the alkanediyl group in the divalent saturated hydrocarbon group of A a41 . A f13The divalent saturated hydrocarbon group which may have a fluorine atom is preferably a divalent aliphatic saturated hydrocarbon group which may have a fluorine atom and a divalent alicyclic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group. Examples of the divalent aliphatic hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; perfluoroalkanediyl groups such as difluoromethylene group, perfluoroethylene group, perfluoropropanediyl group, perfluorobutanediyl group and perfluoropentanediyl group. The divalent alicyclic hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic group include cyclohexanediyl group and perfluorocyclohexanediyl group. Examples of the polycyclic group include adamantandiyl group, norbornanediyl group, perfluoroadamantandiyl group. A f14 The saturated hydrocarbon group and the saturated hydrocarbon group which may have a fluorine atom of a42 include the same groups as those exemplified by R. Among them, fluorinated alkyl 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 are preferred.

[0175] In formula (a4-3), L 5 is preferably an ethylene group. A f13 The divalent saturated hydrocarbon group of is preferably a group containing a divalent chain hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a divalent chain hydrocarbon group having 2 to 3 carbon atoms. A f14 The saturated hydrocarbon group of is preferably a group containing a chain hydrocarbon group having 3 to 12 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a group containing a chain hydrocarbon group having 3 to 10 carbon atoms and an alicyclic hydrocarbon group having 3 to 10 carbon atoms. Among them, A f14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group.

[0176] Examples of the structural unit represented by formula (a4-3) include structural units represented by formulas (a4-1'-1) to (a4-1'-11), respectively. The structural unit in which the methyl group corresponding to R f7 in structural unit (a4-3) is replaced by a hydrogen atom is also included as a structural unit represented by formula (a4-3).

[0177] Examples of structural unit (a4) also include a structural unit represented by formula (a4-4). TIFF0007702813000149.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 f22represents a saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom.

[0178] R f22 The saturated hydrocarbon group of is the same as the saturated hydrocarbon group represented by R a42 Examples thereof include. R f22 is preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom, and even more preferably an alkyl group having 1 to 6 carbon atoms and having a fluorine atom.

[0179] 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.

[0180] 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 f21 in structural unit (a4-4) is replaced by a hydrogen atom. TIFF0007702813000150.tif80148

[0181] When resin (A) has 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 resin (A).

[0182] 〈Structural unit (a5)〉 Examples of the non-leaving hydrocarbon group of structural unit (a5) include groups having a linear, branched or cyclic hydrocarbon group. Among them, structural unit (a5) preferably has a group having an alicyclic hydrocarbon group. Examples of structural unit (a5) include the structural unit represented by formula (a5-1). TIFF0007702813000151.tif3971[In formula (a5-1), R 51represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atoms contained in the alicyclic hydrocarbon group may be substituted with aliphatic hydrocarbon groups having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.

[0183] R 52 The alicyclic hydrocarbon group in R may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group. Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, and a 2-ethylhexyl group. Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group, or a cyclohexyl group. L 55 Examples of the divalent saturated hydrocarbon group in L include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and preferably a divalent chain saturated hydrocarbon group. Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkane diyl groups such as cyclopentane diyl group and cyclohexane diyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantane diyl group and norbornane diyl group.

[0184] L 55 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by L is replaced by -O- or -CO- include the groups represented by formula (L1-1) to formula (L1-4). In the following formulas, * and ** each represent a bond, and * represents a bond with an oxygen atom. TIFF0007702813000152.tif18166In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents a bond 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 of 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 of 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, Lx5 , L x6 and L x7 The total carbon number of is 15 or less. In formula (L1-4), L x8 and L x9 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 carbon number of L x8 , L x9 and W x1 is 15 or less.

[0185] L x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond. L x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L 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. Wx1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

[0186] Examples of the group represented by formula (L1-1) include the following divalent groups. TIFF0007702813000153.tif54134

[0187] Examples of the group represented by formula (L1-2) include the following divalent groups. TIFF0007702813000154.tif23130

[0188] Examples of the group represented by formula (L1-3) include the following divalent groups. TIFF0007702813000155.tif15145

[0189] Examples of the group represented by formula (L1-4) include the following divalent groups. TIFF0007702813000156.tif26114

[0190] L 55 is preferably a single bond or a group represented by formula (L1-1).

[0191] Examples of the structural unit (a5-1) include the following structural units and the structural units in which the methyl group corresponding to R in the structural unit (a5-1) below is replaced by a hydrogen atom. 51 are mentioned. TIFF0007702813000157.tif75150

[0192] TIFF0007702813000158.tif36150 When the resin (A) has the structural unit (a5), its content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and still more preferably 3 to 15 mol% based on all the structural units of the resin (A). 〈Structural unit (a6)〉 The structural unit (a6) is a structural unit having a -SO2- group, and preferably has a -SO2- group in the side chain. The structural unit having a -SO2- group may have a linear structure having a -SO2- group, a branched structure having a -SO2- group, or a cyclic structure (monocyclic and polycyclic structures) having a -SO2- group. Preferably, it is a structural unit having a cyclic structure having a -SO2- group, and more preferably, it is a structural unit having a cyclic structure (sultone ring) containing -SO2-O-.

[0193] Examples of the sultone ring include the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and formula (T 1 -4). The bonding site can be at any position. The sultone ring may be monocyclic, but is preferably polycyclic. The polycyclic sultone ring means a bridged ring containing -SO2-O- as an atomic group constituting the ring, and examples include the rings represented by formula (T 1 -1) and formula (T 1 -2). The sultone ring may further contain a heteroatom in addition to -SO2-O- as an atomic group constituting the ring, like the ring represented by formula (T 1 -2). Examples of the heteroatom include an oxygen atom, a sulfur atom or a nitrogen atom, and preferably an oxygen atom. TIFF0007702813000159.tif3187

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

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

[0196] 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 preferable. TIFF0007702813000160.tif3172[In formula (T1’), X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. The bonding site is at an arbitrary position.] X 11 is preferably an oxygen atom or a methylene group, more preferably a methylene group. R 41 is exemplified by the same groups as the substituents of the sultone ring, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group is preferable.

[0197] As the sultone ring, a ring represented by formula (T1) is more preferable. TIFF0007702813000161.tif3149[In formula (T1), R 8 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms or an alkylcarbonyl group having 2 to 4 carbon atoms. m represents any integer from 0 to 9. When m is 2 or more, a plurality of R 8 may be the same or different. The bonding site is at an arbitrary position.]

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

[0199] Examples of the ring represented by formula (T1’) and the ring represented by formula (T1) include the following rings. The bonding site can be at any position. TIFF0007702813000162.tif53160

[0200] The structural unit having a sultone ring preferably has the following group. * in the following group represents the bonding site. TIFF0007702813000163.tif50161

[0201] The structural unit having a -SO2- group preferably further has a group derived from a polymerizable group. Examples of the polymerizable group include a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, a methacryloylthio group, etc. 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.

[0202] The structural unit (a6) is preferably a structural unit represented by formula (Ix). TIFF0007702813000164.tif4956[In 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 is -O-, -CO- or -N(Rd )- may be replaced. X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 is an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. R c and R d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0203] 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.

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

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

[0206] Examples of the structural unit (a6) include the following structural units. TIFF0007702813000165.tif100159

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

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

[0209] The structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain is preferably a structural unit represented by formula (II-2-A'). TIFF0007702813000166.tif35104[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 III3 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. ZA + represents an organic cation.

[0210] R III3 Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R III3 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R include the same as those of 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 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 in 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. 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; cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. can be mentioned. Examples of those in which -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- include divalent groups represented by formula (X1) to formula (X53). However, the number of carbon atoms before -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- is 17 or less, respectively. In the following formulae, * and ** represent bonding sites, and * represents a bond to A x1 and represents a bond to A. TIFF0007702813000167.tif145161

[0211] X 3 represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms. X 4 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. X 5 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. X 6 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 7 represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 8represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

[0212] ZA in formula (II-2-A’) + is the same as the cation Z1 in the salt represented by formula (B1). + Examples thereof include the same ones.

[0213] The structural unit represented by formula (II-2-A’) is preferably the structural unit represented by formula (II-2-A). TIFF0007702813000168.tif38109 [In formula (II-2-A), R III3 , X III3 and ZA + represent the same meanings as described above. z2A represents any integer from 0 to 6. R III2 and R III4 each independently represent a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. When z2A is 2 or more, a plurality of R III2 and R III4 may be the same as or different from each other. Q a and Q b each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.] R III2 , R III4 , Q a and Q b Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by b1 are the same as those of the perfluoroalkyl group having 1 to 6 carbon atoms represented by the aforementioned Q

[0214] The structural unit represented by formula (II-2-A) is preferably the structural unit represented by formula (II-2-A-1). TIFF0007702813000169.tif5577 [In formula (II-2-A-1), R III2 , R III3 , R III4 , Q a , Qb and ZA + represents the same meaning as described above. R III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms. z2A1 represents any integer from 0 to 6. X I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, wherein -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom or a hydroxy group. R III5 Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by R include linear or branched alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group. X I2 Examples of the divalent saturated hydrocarbon group represented by X include those similar to the divalent saturated hydrocarbon group represented by X III3 represented by.

[0215] As the structural unit represented by formula (II-2-A-1), the structural unit represented by formula (II-2-A-2) is more preferable. TIFF0007702813000170.tif5287 [In formula (II-2-A-2), R III3 R III5 and ZA + represent the same meaning as described above. m and nA each independently represent 1 or 2.

[0216] Examples of the structural unit represented by formula (II-2-A') include, for example, the following structural units, R III3 a group corresponding to the methyl group of which is replaced by a hydrogen atom, a halogen atom (for example, a fluorine atom) or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (for example, a trifluoromethyl group, etc.), and the structural units described in International Publication No. 2012 / 050015. ZA+ represents an organic cation. TIFF0007702813000171.tif86163

[0217] The structural unit having a sulfonio group and an organic anion in the side chain is preferably a structural unit represented by the formula (II-1-1). TIFF0007702813000172.tif3791[In the formula (II-1-1), A II1 represents a single bond or a divalent linking group. R II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms. R II2 and R II3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and R II2 and R II3 may combine with each other to form a ring together with the sulfur atom to which they are attached. R II4 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A - represents an organic anion.] R II1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by include a phenylene group and a naphthylene group. R II2 and R II3 Examples of the hydrocarbon group represented by include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. R II4 Examples of the halogen atom represented by 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 R a8 A II1 ​Examples of the divalent linking group represented by include divalent saturated hydrocarbon groups having 1 to 18 carbon atoms, and the -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S- or -CO-. Specifically, X III3 include the same as the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by .

[0218] Examples of the structural unit containing the cation in formula (II-1-1) include the structural unit represented by the following and a structural unit in which the group corresponding to the methyl group of R II4 is replaced by a hydrogen atom, a fluorine atom, a trifluoromethyl group or the like. TIFF0007702813000173.tif84130

[0219] A - Examples of the organic anion represented by include sulfonate anions, sulfonylimide anions, sulfonylmethide anions, carboxylic acid anions and the like. A - The organic anion represented by is preferably a sulfonate anion, and more preferably an anion contained in the salt represented by the aforementioned formula (B1). A - Examples of the sulfonylimide anion represented by include the following. TIFF0007702813000174.tif32135 Examples of the sulfonylmethide anion include the following. TIFF0007702813000175.tif29123 Examples of the carboxylic acid anion include the following. TIFF0007702813000176.tif42154

[0220] Examples of the structural unit represented by formula (II-1-1) include the structural unit represented by the following and the like. TIFF0007702813000177.tif88149

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

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

[0223] The resin (A) is preferably a resin composed of the structural unit (a1) and the structural unit (s), that is, a copolymer of the monomer (a1) and the monomer (s). The structural unit (a1) is preferably at least one selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1), and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group), more preferably at least two, and still more preferably at least two selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). The structural unit (s) is preferably at least one selected from the group consisting of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably the structural unit (a2-1) or the structural unit (a2-A). The structural unit (a3) is preferably at least one selected from the group consisting of the structural unit represented by the formula (a3-1), the structural unit represented by the formula (a3-2), and the structural unit represented by the formula (a3-4). Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, a radical polymerization method) using the monomers that lead to these structural units. The content of each structural unit of the resin (A) can be adjusted by the amount of the monomers used in the polymerization. The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, still more preferably 15,000 or less). In this specification, the weight average molecular weight is a value determined by gel permeation chromatography under the conditions described in the examples.

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

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

[0226] The content rate of resin (A) in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less with respect to the solid content of the resist composition. When containing a resin other than resin (A), the total content rate of resin (A) and the resin other than resin (A) is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less with respect to the solid content of the resist composition. 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. 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.

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

[0228] <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 still 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 compounds include amines and ammonium salts. Examples of the amines include aliphatic amines and aromatic amines. Examples of the aliphatic amines include primary amines, secondary amines, and tertiary amines.

[0229] Examples of the amine include 1-naphthylamine, 2-naphthylamine, aniline, diisopropyl aniline, 2-, 3- or 4-methyl aniline, 4-nitroaniline, N-methyl aniline, N,N-dimethyl aniline, 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'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, bipyridine, etc. Preferably, diisopropyl aniline is mentioned, and more preferably 2,6-diisopropyl aniline is mentioned.

[0230] Examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate, choline, and the like.

[0231] The acidity of a salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is indicated by the acid dissociation constant (pKa). A salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is a salt having an acid dissociation constant of the acid generated from the salt usually of -3 < pKa, preferably -1 < pKa < 7, and more preferably 0 < pKa < 5. Examples of the salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) include salts represented by the following formula, salts represented by formula (D) described in JP-A-2015-147926 (hereinafter sometimes referred to as "weak acid inner salt (D)"), and salts described in JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502, and JP-A-2011-191745. The salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is preferably a salt that generates a carboxylic acid with a lower acidity than the acid generated from the acid generator (B) (a salt having a carboxylic acid anion), and more preferably the weak acid inner salt (D). TIFF0007702813000178.tif96166

[0232] Examples of the weak acid inner salt (D) include the following salts. TIFF0007702813000179.tif72164

[0233] 〈Other components〉 The resist composition of the present invention may contain, if necessary, components other than the above-described components (hereinafter sometimes referred to as "other components (F)"). There is no particular limitation on the other components (F), and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, etc. can be used.

[0234] 〈Preparation of Resist Composition〉 The resist composition of the present invention can be prepared by mixing salt (I), resin (A), acid generator (B), and, if necessary, a resin other than resin (A) used, solvent (E), quencher (C), and other components (F). The mixing order is arbitrary and is not particularly limited. The temperature during mixing can be 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 mixing, etc. can be used. After mixing the respective components, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

[0235] 〈Method for 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 performed by a commonly used apparatus such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers and already formed resist films. Before applying the resist composition, the substrate may be cleaned, or an antireflection film, etc. may be formed on the substrate. By drying the applied composition, the solvent is removed to form a composition layer. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-bake), or by using a decompression device. The heating temperature is preferably 50 to 200 °C, and the heating time is preferably 10 to 180 seconds. Also, the pressure during 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 KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F2 excimer laser (wavelength 157 nm), those that convert laser light from a solid laser light source (YAG or semiconductor laser, etc.) into harmonic laser light in the far ultraviolet region or vacuum ultraviolet region and emit it, those that irradiate electron beams, 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. Chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the composition after heating. Also, before development, the steps of coating, drying, exposing, and heating the resist composition may be repeatedly performed on the exposed composition layer. The heated composition layer is usually developed using a developing solution with a developing device. Examples of the developing method include the dip method, paddle method, spray method, dynamic dispense method, etc. The developing temperature is preferably, for example, 5 to 60 °C, and the developing time is preferably, for example, 5 to 300 seconds. By selecting the type of developing solution as follows, a positive resist pattern or a negative resist pattern can be manufactured. When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. For example, aqueous solutions of tetramethylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline), etc. may be mentioned. The alkaline developer may contain a surfactant. After development, it is preferable to wash the resist pattern with ultrapure water and then remove the water remaining on the substrate and the pattern. When producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as an "organic-based developer") is used as the developer. Examples of the organic solvent contained in the organic-based developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole, etc. In the organic-based developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and even more preferably substantially only the organic solvent. Among them, as the organic-based developer, a developer containing butyl acetate and / or 2-heptanone is preferable. In the organic-based developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and even more preferably substantially only butyl acetate and / or 2-heptanone. The organic-based developer may contain a surfactant. Also, the organic-based developer may contain a small amount of water. During development, development may be stopped by substituting with a solvent of a different type from the organic-based developer. It is preferable to wash the developed resist pattern with a rinse solution. The rinse solution is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent. After washing, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

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

Examples

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

[0238] Example 1: Synthesis of the salt represented by formula (I-5) 10 parts of the salt represented by formula (I-5-a) and 50 parts of dimethylformamide were mixed and stirred at 23 °C for 30 minutes. Then, 1.60 parts of potassium carbonate and 0.48 parts of potassium iodide were added, and the temperature was raised to 75 °C. To the resulting mixture, 11.27 parts of the compound represented by formula (I-5-b) were added, and the mixture was stirred at 75 °C for 5 hours and then cooled to 23 °C. To the resulting mixture, 100 parts of chloroform and 45 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, 50 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 water washing operation was repeated 5 times. By concentrating the obtained organic layer, 13.94 parts of the salt represented by formula (I-5-c) were obtained. 3.04 parts of the salt represented by formula (I-5-c), 4.25 parts of the salt represented by formula (I-5-d), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water were 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 5 times. The obtained organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether were added and stirred at 23 °C for 30 minutes, and then filtered to obtain 5.37 parts of the salt represented by formula (I-5). MASS(ESI(+)Spectrum):M + 485.2 MASS(ESI(-)Spectrum):M - 765.3

[0239] Example 2: Synthesis of the salt represented by formula (I-6) 3.04 parts of the salt represented by formula (I-5-c), 4.38 parts of the salt represented by formula (I-6-d), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, then liquid separation was carried out to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 °C for 30 minutes, and then filtered to obtain 5.22 parts of the salt represented by formula (I-6). MASS(ESI(+)Spectrum):M + 485.2 MASS(ESI(-)Spectrum):M - 793.3

[0240] Example 3: Synthesis of the salt represented by formula (I-8) 3.04 parts of the salt represented by formula (I-5-c), 5.76 parts of the salt represented by formula (I-8-d), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, then liquid separation was carried out to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 °C for 30 minutes, and then filtered to obtain 6.01 parts of the salt represented by formula (I-8). MASS(ESI(+)Spectrum):M + 485.2 MASS(ESI(-)Spectrum):M - 1081.3

[0241] Example 4: Synthesis of the salt represented by formula (I-486) 5.19 parts of the salt represented by TIFF0007702813000184 in the form of (I - 486 - a) and 50 parts of dimethylformamide were mixed and stirred at 23°C for 30 minutes. Then, 1.60 parts of potassium carbonate and 0.48 parts of potassium iodide were added, and the temperature was raised to 75°C. To the resulting mixture, 11.27 parts of the compound represented by the formula (I - 5 - b) were added, and the mixture was stirred at 75°C for 5 hours and then cooled to 23°C. To the resulting mixture, 100 parts of chloroform and 45 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, 50 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 water - washing operation was repeated 5 times. By concentrating the obtained organic layer, 8.24 parts of the salt represented by the formula (I - 486 - c) were obtained. 4.10 parts of the salt represented by TIFF0007702813000185 in the form of (I - 486 - c), 4.38 parts of the salt represented by the formula (I - 6 - d), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23°C for 2 hours. To the resulting mixture, 20 parts of ion - exchanged water were 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 5 times. The obtained organic layer was concentrated, and to the concentrated residue, 30 parts of tert - butyl methyl ether were added and stirred at 23°C for 30 minutes, and then filtered to obtain 6.12 parts of the salt represented by the formula (I - 486). MASS(ESI(+)Spectrum):M + 707.3 MASS(ESI(-)Spectrum):M - 793.3

[0242] Example 5: Synthesis of the salt represented by the formula (I - 102) 6.59 parts of the salt represented by TIFF0007702813000186.tif44141 formula (I-102-a) and 30 parts of dimethylformamide were mixed and stirred at 23 °C for 30 minutes. Then, 0.80 part of potassium carbonate and 0.24 part of potassium iodide were added, and the temperature was raised to 75 °C. To the resulting mixture, 5.64 parts of the compound represented by formula (I-5-b) were added, and the mixture was stirred at 75 °C for 5 hours and then cooled to 23 °C. To the resulting mixture, 50 parts of chloroform and 30 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, 30 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 water washing operation was repeated 5 times. By concentrating the obtained organic layer, 7.94 parts of the salt represented by formula (I-102-c) were obtained. 3.69 parts of the salt represented by TIFF0007702813000187.tif38167 formula (I-102-c), 4.38 parts of the salt represented by formula (I-6-d), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water were 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 5 times. The obtained organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether were added and stirred at 23 °C for 30 minutes, and then filtered to obtain 5.98 parts of the salt represented by formula (I-102). MASS(ESI(+)Spectrum):M + 621.2 MASS(ESI(-)Spectrum):M - 793.3

[0243] Example 6: Synthesis of the salt represented by formula (I-742) 7.78 parts of the compound represented by TIFF0007702813000188.tif52154 formula (I-742-a), 0.23 parts of the compound represented by formula (I-742-c), and 30 parts of acetonitrile were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 0.66 parts of the compound represented by formula (I-742-b) was added, and the mixture was stirred at 23 °C for 18 hours. To the resulting reaction mass, 60 parts of chloroform and 30 parts of ion-exchanged water were added, and the mixture was stirred at 23 °C for 30 minutes, followed by liquid separation to take out the organic layer. 30 parts of ion-exchanged water was added to the recovered organic layer, and the mixture was stirred at 23 °C for 30 minutes, followed by liquid separation to take out the organic layer. This water washing operation was repeated 4 times. By concentrating the obtained organic layer, 7.92 parts of the salt represented by formula (I-742-d) was obtained. 2.40 parts of the salt represented by TIFF0007702813000189.tif39159 formula (I-742-d), 4.38 parts of the salt represented by formula (I-6-d), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23 °C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water was added, and the mixture was stirred at 23 °C for 30 minutes, followed by liquid separation to take out the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23 °C for 30 minutes, followed by filtration to obtain 3.68 parts of the salt represented by formula (I-742). MASS(ESI(+)Spectrum):M + 351.1 MASS(ESI(-)Spectrum):M - 793.3

[0244] Example 7: Synthesis of the salt represented by formula (I-1094) 3.00 parts of the salt represented by formula (I-5-a) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 1.14 parts of the compound represented by formula (I-1094-a) were added, and the mixture was further stirred at 50°C for 2 hours. To the resulting mixed solution, 1.14 parts of the compound represented by formula (I-1094-b) 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 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, and the mixture was stirred at 23°C for 30 minutes. Then, the supernatant was removed and concentrated to obtain 3.24 parts of the salt represented by formula (I-1094-c). 2.98 parts of the salt represented by formula (I-1094-c), 4.38 parts of the salt represented by formula (I-6-d), 30 parts of chloroform and 15 parts of ethyl acetate were mixed and stirred at 23°C for 2 hours. To the resulting mixture, 20 parts of ion-exchanged water were 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 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 and then filtered to obtain 4.69 parts of the salt represented by formula (I-1094). MASS(ESI(+)Spectrum):M + 471.2 MASS(ESI(-)Spectrum):M - 793.3

[0245] Synthesis of Resin The compounds (monomers) used for the synthesis of resin (A) are shown below. Hereinafter, these compounds are referred to as "monomer (a1-1-3)" etc. according to their formula numbers. TIFF0007702813000192.tif46154

[0246] Synthesis Example 1 [Synthesis of Resin A1] As monomers, monomer (a1-4-2), monomer (a1-1-3), and monomer (a1-2-6) were used, and 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 (2.5 wt%) 2.0 mass times the total mass of all monomers 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 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. TIFF0007702813000193.tif29126

[0247] Synthesis Example 2 [Synthesis of Resin A2] As monomers, monomer (a1-4-2) and monomer (a1-2-6) were used, and they were 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. 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 (2.5 wt%) 2.0 mass times the total mass of all monomers 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 having a weight average molecular weight of about 5.4×10 3Resin A2 (copolymer) was obtained in a yield of 89%. This resin A2 has the following structural units. TIFF0007702813000194.tif2887

[0248] Synthesis Example 3 [Synthesis of Resin A3] As monomers, monomer (a1-1-3), monomer (a1-2-6), monomer (a2-1-3), monomer (a3-4-2) and monomer (aa1-4-2) were used, and their molar ratio [monomer (a1-1-3): monomer (a1-2-6): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-2)] was mixed so as to be in a ratio of 20:35:3:15:27. Further, 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed into this monomer mixture. To the obtained mixture, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in amounts of 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were heated at 73 °C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) 2.0 times the mass of the total monomer amount was added to the polymerization reaction solution, and after stirring for 12 hours, liquid separation was performed. The recovered organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered and recovered, whereby a resin A3 having a weight average molecular weight of about 5.3×10 3 was obtained in a yield of 63%. This resin A3 has the following structural units. TIFF0007702813000195.tif38154

[0249] Synthesis Example 4 [Synthesis of Resin A4] As monomers, monomer (a1-1-3), monomer (a1-2-6), monomer (a2-1-3), monomer (a3-4-2) and monomer (a1-4-13) were used, and their molar ratio [monomer (a1-1-3): monomer (a1-2-6): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-13)] was mixed at a ratio of 20:35:3:15:27. Further, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture based on the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were heated at 73 °C for about 5 hours. Then, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) 2.0 times the mass of the total monomer amount was added to the polymerization reaction solution, and after stirring for 12 hours, liquid separation was performed. The recovered organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was obtained by filtration and recovery, and resin A4 having a weight average molecular weight of about 5.1×10 3 was obtained at a yield of 61%. This resin A4 has the following structural units. TIFF0007702813000196.tif38154

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

Table 2

[0251] <Resin> A1~A4: Resin A1~Resin A <Salt (I)> I-5: Salt represented by formula (I-5) I-6: Salt represented by formula (I-6) I-8: Salt represented by formula (I-8) I-102: Salt represented by formula (I-102) I-486: Salt represented by formula (I-486) I-742: Salt represented by formula (I-742) I-1094: Salt represented by formula (I-1094) <Acid generator> IX-1 IX-2 IX-3 TIFF0007702813000198.tif76157 <Quencher (C)> C1: Synthesized by the method described in JP-A-2011-39502 TIFF0007702813000199.tif4355 <Solvent> 400 parts of propylene glycol monomethyl ether acetate 100 parts of propylene glycol monomethyl ether 5 parts of γ-butyrolactone

[0252] (Electron beam exposure evaluation of resist composition) A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 °C for 60 seconds. The resist composition was spin-coated on this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, it was prebaked on a direct hot plate at the temperature shown in the "PB" column of Table 2 for 60 seconds to form a composition layer. 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.

[0253] 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.

[0254] <CD uniformity (CDU) evaluation> In terms of the 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

[0255] (Electron beam exposure evaluation of resist composition: organic solvent development) A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 °C for 60 seconds. The resist composition was spin-coated onto this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, it was pre-baked on a direct hot plate at the temperature shown in the "PB" column of Table 2 for 60 seconds to form the 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. Next, the composition layer on this silicon wafer was developed using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as the developer at 23 °C for 20 seconds by the dynamic dispense method to obtain a resist pattern.

[0256] In the resist pattern obtained after development, the exposure dose at which the formed hole diameter became 17 nm was taken as the effective sensitivity.

[0257] <CD uniformity (CDU) evaluation> In terms of the effective sensitivity, the hole diameter of the pattern formed with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was taken as the average hole diameter of one hole. The standard deviation was obtained using as the population the measurement of the average hole diameter of 400 patterns formed with a hole diameter of 17 nm within the same wafer. The results are shown in Table 4. The numerical values in the table indicate the standard deviation (nm).

Table 4

Industrial Applicability

[0258] The resist composition containing the salt of the present invention can obtain a resist pattern having good CD uniformity (CDU), and thus is suitable for fine processing of semiconductors and is extremely useful industrially.

Claims

1. A salt represented by formula (I). [In formula (I), R １ represents -O-L １ -CO-O-R ５ -O-R ５ or -O-CO-O-R ５ and is represented by L １ represents an alkanediyl group having 1 to 6 carbon atoms. R ５ represents an acid-labile group represented by the formula (1a) or the formula (2a). R ２ 、R ３ and R ４ each independently represents a halogen atom, a fluorinated alkyl group having 1 to 12 carbon atoms, a hydrocarbon group having 1 to 18 carbon atoms, -O-L １ -CO-O-R ５ 、-O-R ５ or -O-CO-O-R ５ ; the hydrocarbon group may have a substituent, and -CH 2 - contained in the hydrocarbon group may be replaced by -O- or -CO-. m2 represents any integer from 0 to 4, and when m2 is 2 or more, the plurality of Rs ２ may be the same as or different from each other. m3 represents any integer from 0 to 5, and when m3 is 2 or more, the plurality of Rs ３ may be the same as or different from each other. m4 represents any integer from 0 to 5, and when m4 is 2 or more, the plurality of Rs ４ may be the same as or different from each other. Q １ and Q ２ each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. R １１ and R １２ each independently represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms. z represents an integer of any one of 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 ０ represents *-CO-O-, *-O-CO-, or *-O-CO-O-, where * represents a bonding site with C(R １１ )(R １２ ), or C(Q １ )(Q ２ ). A 1 represents a single bond. X a and X b each independently represents an oxygen atom or a sulfur atom. X １ represents a divalent group represented by formula (X1-1), a divalent group represented by formula (X1-2), a divalent group represented by formula (X1-3), or a divalent group represented by formula (X1-4). ring W represents a ring represented by formula (w1-1), a ring represented by formula (w1-2), or a ring represented by formula (w1-3).] [In formula (1a), Raa1, Raa2, and Raa3 are each independently an optionally substituted alkyl group having 1 to 8 carbon atoms, an optionally substituted alkenyl group having 2 to 8 carbon atoms, an optionally substituted alicyclic hydrocarbon group having 3 to 20 carbon atoms, or an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms, or Raa1 and Raa2 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, and Raa3 is each independently an optionally substituted alkyl group having 1 to 8 carbon atoms, an optionally substituted alkenyl group having 2 to 8 carbon atoms, an optionally substituted alicyclic hydrocarbon group having 3 to 20 carbon atoms, or an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms.] * represents a bond.] [In formula (2a), Raa1’ and Raa2’ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and Raa3’ represents a hydrocarbon group having 1 to 20 carbon atoms, or Raa1’ represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and Raa2’ and Raa3’ are bonded to each other to form a heterocyclic group having 3 to 20 carbon atoms together with the -C-Xa- to which they are bonded, 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.] * represents a bond.] [In the formula, R21, R22, R23, R24, R25, and R26 represent an alicyclic hydrocarbon group having 3 to 18 carbon atoms, the -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-, and the alicyclic hydrocarbon group may have a hydroxy group or a fluorine atom.] * represents a bond to Xa and Xb.] [In formula (w1-1), formula (w1-2), and formula (w1-3), the -CH2- contained in the ring may be replaced by -O-, -S-, -SO2-, or -CO-, and the ring may have a substituent. The bond is at an arbitrary position.]

2. Any one of m2, m3, and m4 is an integer of 1 or more, Existing R ２ , R ３ and R ４ Among them, any one of them is -O-L １ -CO-O-R ５ , -O-R ５ or -O-CO-O-R ５ The salt according to claim 1, wherein it is

3. Either m3 or m4 is an integer of 1 or more, Existing R ３ and R ４ The salt according to claim 1 or 2, wherein any one of them is a halogen atom or a fluorinated alkyl group having 1 to 12 carbon atoms.

4. R 21 、R 22 、R 23 、R 24 、R 25 and R 26 is the salt according to claim 1, wherein R 21 , R 22 , R 23 , R 24 , R 25 and R 26 are a ring represented by formula (w0-1), a ring represented by formula (w0-2), a ring represented by formula (w0-3) or a ring represented by formula (w0-12). In formula (w0-1), formula (w0-2), formula (w0-3) and formula (w0-12), -CH contained in the ring 2 - may be replaced by -O- or -CO-, and the ring may have a hydroxy group or a fluorine atom. The bond is at an arbitrary position.]

5. An acid generator containing the salt according to any one of Claims 1 to 4.

6. A resist composition containing the acid generator according to Claim 5 and a resin having an acid-labile group.

7. The resist composition according to Claim 6, wherein the resin having an acid-labile group contains at least one selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2). [In formula (a1-1) and formula (a1-2), L ａ１ and L ａ２ each independently represents -O- or *-O-(CH ２ ) ｋ１ -CO-O-, k1 represents an 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. ]

8. The resist composition according to Claim 6 or 7, wherein the resin having an acid-labile group contains a structural unit represented by formula (a2-A). [In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group. A a50 represents a single bond or *-X a51 -(A a52 -X a52 ) nｂ -, where * represents a bond with the carbon atom to which -R a50 is attached. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O- or -O-CO-. nb represents 0 or 1. mb represents 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.]

9. The resist composition according to any one of Claims 6 to 8, further containing a salt that generates an acid having a lower acidity than the acid generated from the acid generator.

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

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