Inhibitor composition, inhibitor pattern formation method, compound and acid generating agent

Abstract

An inhibitor composition comprising a base component (A) and a compound (B0) represented by general formula (b0). In the formula, Rpg is an acid-degrading group. Rl0 is a cyclic organic group that may have substituents. L02 is a divalent linker. L01 is a divalent linker or a single bond. Rm1 is a substituent other than an iodine atom. Vb0 is a single bond, etc. R0 is a hydrogen atom, etc. nb1 is an integer from 1 to 4, nb2 is an integer from 1 to 4, and nb3 is an integer from 0 to 3. Mm+ represents an m-valent organic cation. m is an integer greater than or equal to 1.

Description

Technical Field

[0001] The present invention relates to a resist composition, a resist pattern forming method, a compound and an acid generator. This case claims priority based on Japanese Special Application No. 2022-040827 filed in Japan on March 15, 2022, the contents of which are incorporated herein. Prior Art

[0002] In recent years, advancements in lithography have led to a rapid increase in the miniaturization of patterns in the manufacture of semiconductor devices and liquid crystal displays. This miniaturization is typically achieved by shortening the wavelength (or increasing the energy) of the exposure light source.

[0003] Resist materials are required to have lithographic properties such as sensitivity to the exposure light source and resolution to reproduce fine-sized patterns. As a resist material that meets such requirements, a chemically amplified resist composition containing a base component whose solubility in a developer changes due to the action of an acid and an acid generator component that generates an acid due to exposure has been used in the past.

[0004] For example, Patent Document 1 discloses a resist composition containing a resin component having specific three structural units and a known onium salt acid generator. It also discloses that this resist composition can control acid diffusion, increase affinity for developer solutions, and improve sensitivity, roughness reduction, and resolution. [Prior Art Literature] [Patent Document]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2020-085916 Summary of the Invention

[0006] [Problems to be solved by the invention]

[0007] With the advancement of lithography technology and the expansion of its application areas, the miniaturization of patterns is progressing rapidly. Consequently, technologies that can form fine patterns with good shapes are required in the manufacture of semiconductor devices and other devices. However, the conventional resist composition described in Patent Document 1 does not necessarily meet this requirement by achieving both the in-plane uniformity (CDU) of pattern dimensions and the resolution, and a higher level of balance is required. Furthermore, from the perspective of further improving the in-plane uniformity (CDU) of pattern size and resolution, there is room for further research on the acid generator component.

[0008] The present invention is made in view of the above circumstances, and its object is to provide a resist composition capable of forming a resist pattern with good CDU and resolution, a resist pattern forming method using the resist composition, a novel compound useful as an acid generator for the resist composition, and an acid generator using the compound. [Methods used to solve the problem]

[0009] In order to solve the above-mentioned problems, the present invention adopts the following structure. That is, the first aspect of the present invention is a resist composition that generates acid upon exposure and changes its solubility in a developer by the action of the acid. The resist composition comprises a base component (A) whose solubility in a developer changes by the action of the acid, and an acid generator component (B) that generates acid upon exposure, wherein the acid generator component (B) comprises a compound (B0) represented by the following general formula (b0).

[0010] [In the formula, Rpg is an acid-decomposable group. Rl0 is a cyclic organic group which may have a substituent. L02 is a divalent linking group. L01 is a divalent linking group or a single bond. Rm1 is a substituent other than an iodine atom. Vb0 is a single bond, an alkylene group, or a fluorinated alkylene group. R0 is a hydrogen atom, a fluorinated alkylene group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 1 to 4, nb2 is an integer of 1 to 4, and nb3 is an integer of 0 to 3. Mm+ represents an m-valent organic cation. m is an integer of 1 or greater].

[0011] The second aspect of the present invention is a method for forming a resist pattern, comprising the steps of forming a resist film on a support using the resist composition of the first aspect, exposing the resist film, and developing the exposed resist film to form a resist pattern.

[0012] The third aspect of the present invention is the compound represented by the above-mentioned general formula (b0).

[0013] A fourth aspect of the present invention is an acid generator comprising the compound of the third aspect of the present invention. [Effects of the Invention]

[0014] According to the present invention, a resist composition capable of forming a resist pattern with good CDU and resolution, a resist pattern forming method using the resist composition, a novel compound useful as an acid generator for the resist composition, and an acid generator using the compound can be provided. Implementation Method

[0015] In this specification and the scope of the patent application of this case, "aliphatic" is a concept relative to aromatic and is defined to mean groups, compounds, etc. that do not have aromatic properties. Unless otherwise specified, "alkyl" refers to a linear, branched, or cyclic monovalent saturated hydrocarbon group. The same applies to the alkyl group in an alkoxy group. Unless otherwise specified, "alkylene" refers to a divalent saturated hydrocarbon group including linear, branched, and cyclic groups. Examples of the "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The term "constituent unit" refers to a monomer unit (monomer unit) constituting a high molecular compound (resin, polymer, copolymer). When it is described as "may have a substituent", both the case where a hydrogen atom (-H) is substituted with a monovalent group and the case where a methylene group (-CH 2-) is substituted with a divalent group are included. “Exposure” is a concept that includes all radiation exposure.

[0016] The "acid-decomposable group" is an acid-decomposable group that can cleave at least a portion of the bonds in the structure of the acid-decomposable group by the action of an acid. Examples of the acid-decomposable group whose polarity increases with the action of an acid include groups that decompose with the action of an acid to generate polar groups. Examples of the polar group include a carboxyl group, a hydroxyl group, an amino group, and a sulfo group (—SO 3H). More specifically, examples of the acid-decomposable group include groups in which the aforementioned polar groups are protected by an acid-dissociable group (for example, groups in which the hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

[0017] "Acid-dissociable group" means (i) a group having acid-dissociable properties that can cleave the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid, or (ii) a group that can further cleave the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by causing a decarbonation reaction after a portion of the bond is cleaved by the action of an acid. The acid-dissociable group that constitutes the acid-decomposable group must be a group with a lower polarity than the polar group generated by the dissociation of the acid-dissociable group. Therefore, when the acid-dissociable group dissociates under the action of the acid, a polar group with a higher polarity than the acid-dissociable group is generated, thereby increasing the polarity. As a result, the polarity of the entire component (A1) increases. With this increase in polarity, the solubility in the developer changes accordingly, increasing with alkaline developers and decreasing with organic developers.

[0018] "Base component" refers to an organic compound capable of forming a membrane. Organic compounds used as base components are broadly divided into non-polymers and polymers. Non-polymers generally have a molecular weight of 500 to less than 4000. "Low molecular weight compounds" are generally non-polymers with a molecular weight of 500 to less than 4000. Polymers generally have a molecular weight of 1000 or greater. "Resins," "high molecular weight compounds," or "polymers" are generally polymers with a molecular weight of 1000 or greater. The molecular weight of polymers is the weight average molecular weight calculated in terms of polystyrene as determined by GPC (gel permeation chromatography).

[0019] The "derived constitutional unit" refers to a constitutional unit formed by cleavage of multiple bonds between carbon atoms, such as ethylenic double bonds. "Acrylic esters" may have a substituent replacing the hydrogen atom bonded to the α-carbon atom. The substituent (R αx) replacing the hydrogen atom bonded to the α-carbon atom is an atom or group other than a hydrogen atom. Furthermore, this term also includes itaconic acid diesters in which the substituent (R αx) is substituted with an ester-containing substituent, or α-hydroxy acrylates in which the substituent (R αx) is substituted with a hydroxyalkyl group or a group modified with the hydroxyl group. Furthermore, unless otherwise specified, the carbon atom at the α-position of an acrylate refers to the carbon atom bonded to the carbonyl group of the acrylic acid. Hereinafter, acrylates in which the hydrogen atom bonded to the α-position carbon atom is substituted with a substituent are sometimes referred to as α-substituted acrylates.

[0020] The term "derivative" encompasses compounds in which the α-position hydrogen atom of the target compound is replaced with an alkyl group, alkyl halide, or other substituent, as well as derivatives thereof. Examples of such derivatives include compounds in which the α-position hydrogen atom is substituted with an organic group, compounds in which the α-position hydrogen atom is substituted with a substituent, and compounds in which a substituent other than a hydroxyl group is bonded to the α-position hydrogen atom. Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same substituents as those for R αx .

[0021] Throughout this specification and the patent application, depending on the structure represented by the chemical formula, enantiomers or diastereomers may exist due to the presence of asymmetric carbon atoms. In such cases, a single chemical formula is used to represent these isomers. These isomers may be used individually or as a mixture.

[0022] (Resistant composition) The resist composition of this embodiment generates acid upon exposure, and its solubility in a developer changes due to the action of the acid. The resist composition comprises a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer solution changes due to the action of an acid, and an acid generator component (B) which generates an acid due to exposure.

[0023] When a resist film is formed using the resist composition of this embodiment and selectively exposed, acid is generated from component (B) in the exposed portions of the resist film. This acid changes the solubility of component (A) in the developer. On the other hand, the solubility of component (A) in the developer remains unchanged in the unexposed portions of the resist film, resulting in a difference in solubility in the developer between the exposed and unexposed portions. Consequently, when the resist film is developed, if the resist composition is positive-working, the exposed portions of the resist film are dissolved and removed, forming a positive-working resist pattern. If the resist composition is negative-working, the unexposed portions of the resist film are dissolved and removed, forming a negative-working resist pattern.

[0024] The resist composition of this embodiment can be either a positive-tone resist composition or a negative-tone resist composition. Furthermore, the resist composition of this embodiment can be used in an alkali development process using an alkali developer during the development process for resist pattern formation, or in a solvent development process using a developer containing an organic solvent (organic developer).

[0025] <(A)Component> In the resist composition of this embodiment, the component (A) preferably includes a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer solution changes due to the action of an acid. By using component (A1), the polarity of the substrate components changes before and after exposure, so that good development contrast can be obtained not only in an alkali development process but also in a solvent development process. As the component (A), the component (A1) and other high molecular weight compounds and / or low molecular weight compounds may be used in combination. Component (A) may be a "base component that generates an acid upon exposure and changes its solubility in a developer solution due to the action of the acid." If component (A) is a base component that generates an acid upon exposure and changes its solubility in a developer solution due to the action of the acid, component (A1) is preferably a resin that generates an acid upon exposure and changes its solubility in a developer solution due to the action of the acid. Such a resin can be a polymer compound having a structural unit that generates an acid upon exposure. Known structural units that generate an acid upon exposure can be used.

[0026] In the resist composition of this embodiment, the component (A) may be used alone or in combination of two or more.

[0027] ･About (A1) ingredients The component (A1) is a resin component whose solubility in a developer changes due to the action of an acid. The component (A1) is preferably one having a structural unit (a1) containing an acid-decomposable group whose polarity increases due to the action of an acid. The component (A1) may have other structural units in addition to the structural unit (a1) as needed.

[0028] Constituent unit (a1) The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases due to the action of an acid.

[0029] Examples of the acid-dissociable group include those that have been proposed as base resins for chemically amplified resist compositions. Specifically, the acid-dissociable groups proposed as the base resin for the chemically amplified resist composition include the "acetal-type acid-dissociable group", "tertiary alkyl ester-type acid-dissociable group", and "tertiary alkoxycarbonyl acid-dissociable group" described below.

[0030] Acetal type acid dissociative group: Among the aforementioned polar groups, examples of acid-dissociable groups that protect carboxyl groups or hydroxyl groups include acid-dissociable groups represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as "acetal-type acid-dissociable groups").

[0031] [In the formula, Ra'1 and Ra'2 are hydrogen atoms or alkyl groups. Ra'3 is a hydrocarbon group, and Ra'3 may also be bonded to either Ra'1 or Ra'2 to form a ring].

[0032] In formula (a1-r-1), it is preferred that at least one of Ra'1 and Ra'2 is a hydrogen atom, and it is more preferred that both are hydrogen atoms. When Ra'1 or Ra'2 is an alkyl group, examples of the alkyl group include the same alkyl groups listed as substituents that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylates above, preferably an alkyl group having 1 to 5 carbon atoms. Specifically, preferred examples include linear or branched alkyl groups. More specifically, examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. More preferred are methyl and ethyl groups, and particularly preferred is methyl.

[0033] In formula (a1-r-1), the hydrocarbon group of Ra'3 can be a linear or branched alkyl group, or a cyclic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include methyl, ethyl, n-propyl, n-butyl, and n-pentyl. Among these, methyl, ethyl, and n-butyl are particularly preferred; methyl or ethyl are even more preferred.

[0034] The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specific examples include isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, and 2,2-dimethylbutyl, with isopropyl being preferred.

[0035] When Ra'3 is a cyclic hydrocarbon group, the hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The alicyclic hydrocarbon group of the monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The alicyclic hydrocarbon group of the polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms. Specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0036] When the cyclic hydrocarbon group of Ra' 3 is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system with 4n+2 π electrons and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some of the carbon atoms constituting these aromatic hydrocarbon rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocyclic rings include oxygen, sulfur, and nitrogen atoms. Specific examples of aromatic heterocyclic rings include pyridine and thiophene rings. Specific examples of the aromatic hydrocarbon group in Ra'3 include groups derived from the aforementioned aromatic hydrocarbon ring or aromatic heterocycle by removing a single hydrogen atom (aryl or heteroaryl); groups derived from aromatic compounds containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.) by removing a single hydrogen atom; and groups derived from the aforementioned aromatic hydrocarbon ring or aromatic heterocycle by replacing a single hydrogen atom with an alkylene group (e.g., arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, and 2-naphthylethyl). The alkylene group bonded to the aforementioned aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0037] The cyclic hydrocarbon group in Ra'3 may also have a substituent. Examples of such substituents include -RP1, -RP2-ORP1, -RP2-CO-RP1, -RP2-CO-ORP1, -RP2-O-CO-RP1, -RP2-OH, -RP2-CN, and -RP2-COOH (hereinafter, these substituents are collectively referred to as "Rax5"). Here, R P1 represents a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Furthermore, R P2 represents a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, some or all of the hydrogen atoms in the chain saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group represented by R P1 and R P2 may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the above-mentioned substituents, or may have one or more of each of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl. The monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms includes, for example, monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octyl, tricyclo[5.2.1.02,6]decyl, tricyclo[3.3.1.13,7]decyl, tetracyclo[6.2.1.13,6.02,7]dodecyl, and adamantyl. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0038] When Ra'3 is bonded to either Ra'1 or Ra'2 to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include tetrahydropyranyl and tetrahydrofuranyl.

[0039] Tertiary alkyl ester type acid dissociative group: Among the polar groups, examples of acid-dissociable groups for protecting carboxyl groups include acid-dissociable groups represented by the following general formula (a1-r-2). Furthermore, among the acid-dissociable groups represented by the following formula (a1-r-2), those composed of an alkyl group are sometimes referred to as "tertiary alkyl ester-type acid-dissociable groups" for convenience.

[0040] [In the formula, Ra'4~Ra'6 are hydrocarbon groups respectively, and Ra'5 and Ra'6 can also be bonded to each other to form a ring].

[0041] The hydrocarbon group of Ra'4 may be a linear or branched alkyl group, a chain or cyclic alkenyl group, a chain alkynyl group, or a cyclic hydrocarbon group. Examples of the linear or branched alkyl group and cyclic hydrocarbon group (monocyclic alicyclic hydrocarbon group, polycyclic alicyclic hydrocarbon group, aromatic hydrocarbon group) in Ra'4 include the same ones as those in Ra'3 above. The chain or cyclic alkenyl group in Ra' 4 is preferably an alkenyl group having 2 to 10 carbon atoms. The hydrocarbon groups of Ra'5 and Ra'6 can be the same as those mentioned above for Ra'3.

[0042] When Ra'5 and Ra'6 are bonded to each other to form a ring, suitable examples include a group represented by the following general formula (a1-r2-1), a group represented by the following general formula (a1-r2-2), and a group represented by the following general formula (a1-r2-3). On the other hand, when Ra'4 to Ra'6 are not bonded to each other but are independent hydrocarbon groups, suitable examples include groups represented by the following general formula (a1-r2-4).

[0043] [In formula (a1-r2-1), Ra'10 represents a linear or branched alkyl group having 1 to 12 carbon atoms, a portion of which may be substituted with a halogen atom or a heteroatom-containing group. Ra'11 represents a group that forms an aliphatic cyclic group together with the carbon atom to which Ra'10 is bonded. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in the cyclic hydrocarbon group may be substituted. Ra101 to Ra103 are each independently a hydrogen atom, a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the chain saturated hydrocarbon group and the aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Ra101 to Ra103 may be bonded to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra 104 is an aromatic hydrocarbon group that may have a substituent. In formula (a1-r2-4), Ra' 12 and Ra' 13 are each independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in the chain-like saturated hydrocarbon group may be substituted. Ra' 14 is a hydrocarbon group that may have a substituent. * indicates a bonding site (the same applies hereinafter).

[0044] In the above formula (a1-r2-1), Ra' 10 is a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with a halogen atom or a heteroatom-containing group.

[0045] The linear alkyl group in Ra'10 has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Examples of the branched chain alkyl group in Ra'10 include the same ones as those in Ra'3 described above.

[0046] The alkyl group in Ra' 10 may be partially substituted with a halogen atom or a heteroatom-containing group. For example, a portion of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Furthermore, a portion of the carbon atoms (such as a methylene group) constituting the alkyl group may be substituted with a heteroatom-containing group. The heteroatoms referred to herein include oxygen, sulfur, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0047] In formula (a1-r2-1), Ra'11 (the aliphatic cyclic group formed together with the carbon atom to which Ra'10 is bonded) is preferably a group listed as the monocyclic or polycyclic alicyclic hydrocarbon group (alicyclic hydrocarbon group) of Ra'3 in formula (a1-r-1). Among them, a monocyclic alicyclic hydrocarbon group is particularly preferred, and more specifically, a cyclopentyl group and a cyclohexyl group are more preferred.

[0048] In formula (a1-r2-2), the cyclic hydrocarbon group formed together with Xa and Ya can be a group obtained by further removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (alicyclic hydrocarbon group) in Ra' 3 in the aforementioned formula (a1-r-1). The cyclic hydrocarbon group formed together with Xa and Ya may also have a substituent. Examples of such substituents include the same substituents as those that may be possessed by the cyclic hydrocarbon group in Ra' 3 described above. In formula (a1-r2-2), the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra 101 to Ra 103 can be exemplified by a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. The monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in Ra 101 to Ra 103 includes, for example, monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octyl, tricyclo[5.2.1.02,6]decyl, tricyclo[3.3.1.13,7]decyl, tetracyclo[6.2.1.13,6.02,7]dodecyl and adamantyl. Among Ra 101 to Ra 103, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is particularly preferred; a hydrogen atom, a methyl group, and an ethyl group are more preferred; and a hydrogen atom is particularly preferred.

[0049] Examples of the substituents possessed by the chain saturated hydrocarbon group or aliphatic cyclic saturated hydrocarbon group represented by Ra 101 to Ra 103 include the same substituents as those for Ra x5 above.

[0050] Examples of groups containing a carbon-carbon double bond, where two or more of Ra 101 to Ra 103 are bonded to form a cyclic structure, include cyclopentenyl, cyclohexenyl, methylcyclopentenyl, methylcyclohexenyl, cyclopentylidenevinyl, and cyclohexylidenevinyl. Among these, cyclopentenyl, cyclohexenyl, and cyclopentylidenevinyl are particularly preferred from the perspective of ease of synthesis.

[0051] In formula (a1-r2-3), the aliphatic cyclic group formed together with Xaa and Yaa is preferably a group listed as the alicyclic hydrocarbon group of the monocyclic group or polycyclic group of Ra'3 in formula (a1-r-1). In formula (a1-r2-3), the aromatic hydrocarbon group in Ra 104 can be a group derived from an aromatic hydrocarbon ring having 5 to 30 carbon atoms by removing one or more hydrogen atoms. Among them, Ra 104 is particularly preferably a group derived from an aromatic hydrocarbon ring having 6 to 15 carbon atoms by removing one or more hydrogen atoms; more preferably, a group derived from benzene, naphthalene, anthracene, or phenanthrene by removing one or more hydrogen atoms; still more preferably, a group derived from benzene, naphthalene, or anthracene by removing one or more hydrogen atoms; particularly preferably, a group derived from benzene or naphthalene by removing one or more hydrogen atoms; and most preferably, a group derived from benzene by removing one or more hydrogen atoms.

[0052] Examples of substituents that Ra 104 in formula (a1-r2-3) may have include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group), and an alkoxycarbonyl group.

[0053] In formula (a1-r2-4), Ra'12 and Ra'13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Ra'12 and Ra'13 include the same monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms as those described above for Ra'101 to Ra'103. Some or all of the hydrogen atoms in the chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 are particularly preferably an alkyl group having 1 to 5 carbon atoms; more preferably a methyl group or an ethyl group; and even more preferably a methyl group. When the chain saturated hydrocarbon group represented by Ra' 12 and Ra' 13 is substituted, the substituent may be the same as that of Ra x5.

[0054] In formula (a1-r2-4), Ra' 14 is a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group in Ra' 14 include a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0055] The linear alkyl group in Ra'14 preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include methyl, ethyl, n-propyl, n-butyl, and n-pentyl. Among these, methyl, ethyl, and n-butyl are particularly preferred; methyl or ethyl are even more preferred.

[0056] The branched chain alkyl group in Ra'14 preferably has 3 to 10 carbon atoms, more preferably 3 to 5. Specific examples include isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, and 2,2-dimethylbutyl, with isopropyl being preferred.

[0057] When Ra' 14 is a cyclic hydrocarbon group, the hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The alicyclic hydrocarbon group of the monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The alicyclic hydrocarbon group of the polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms. Specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0058] The aromatic hydrocarbon group in Ra'14 may be the same as the aromatic hydrocarbon group in Ra'104. Among them, Ra'14 is particularly preferably a group derived from an aromatic hydrocarbon ring having 6 to 15 carbon atoms by removing one or more hydrogen atoms; more preferably, a group derived from benzene, naphthalene, anthracene, or phenanthrene by removing one or more hydrogen atoms; still more preferably, a group derived from benzene, naphthalene, or anthracene by removing one or more hydrogen atoms; particularly preferably, a group derived from naphthalene or anthracene by removing one or more hydrogen atoms; and most preferably, a group derived from naphthalene by removing one or more hydrogen atoms. Examples of the substituent that Ra' 14 may have include the same substituents as those that Ra 104 may have.

[0059] When Ra' 14 in formula (a1-r2-4) is a naphthyl group, the position where it is bonded to the tertiary carbon atom in the aforementioned formula (a1-r2-4) can be either the 1-position or the 2-position of the naphthyl group. When Ra'14 in formula (a1-r2-4) is an anthracene group, the position at which it is bonded to the tertiary carbon atom in formula (a1-r2-4) can be any of the 1-position, 2-position, or 9-position of the anthracene group.

[0060] Specific examples of the group represented by the aforementioned formula (a1-r2-1) are listed below.

[0061]

[0062]

[0063]

[0064] Specific examples of the group represented by the aforementioned formula (a1-r2-2) are listed below.

[0065]

[0066]

[0067]

[0068] Specific examples of the group represented by the aforementioned formula (a1-r2-3) are listed below.

[0069]

[0070] Specific examples of the group represented by the aforementioned formula (a1-r2-4) are listed below.

[0071]

[0072] Tertiary alkoxycarbonyl acid dissociative group: Among the aforementioned polar groups, examples of acid-dissociable groups that protect hydroxyl groups include acid-dissociable groups represented by the following general formula (a1-r-3) (hereinafter sometimes referred to as "tertiary alkoxycarbonyl acid-dissociable groups" for convenience).

[0073] [Wherein, Ra' 7 to Ra' 9 are alkyl groups respectively].

[0074] In formula (a1-r-3), Ra'7 to Ra'9 are preferably alkyl groups having 1 to 5 carbon atoms, more preferably alkyl groups having 1 to 3 carbon atoms. Furthermore, the total number of carbon atoms of the alkyl groups is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0075] Secondary alkyl ester type acid dissociative group: Among the polar groups, examples of acid-dissociable groups for protecting carboxyl groups include acid-dissociable groups represented by the following general formula (a1-r-4).

[0076] [In the formula, Ra'10 is a hydrocarbon group. Ra'11a and Ra'11b are each independently a hydrogen atom, a halogen atom, or an alkyl group. Ra'12 is a hydrogen atom or a hydrocarbon group. Ra'10 and Ra'11a or Ra'11b may also be bonded to form a ring. Ra'11a or Ra'11b and Ra'12 may also be bonded to form a ring].

[0077] In the formula, the hydrocarbon groups in Ra'10 and Ra'12 can be the same as those mentioned above for Ra'3. In the formula, the alkyl groups in Ra' 11a and Ra' 11b can be the same as the alkyl groups in Ra' 1 described above. In the formula, the hydrocarbon groups in Ra'10 and Ra'12, and the alkyl groups in Ra'11a and Ra'11b, may also have substituents. Examples of such substituents include the aforementioned Ra x5.

[0078] Ra'10 and Ra'11a or Ra'11b may also be bonded to each other to form a ring. The ring may be polycyclic or monocyclic, alicyclic or aromatic. The alicyclic and aromatic rings may also contain heteroatoms.

[0079] The ring formed by Ra'10 and Ra'11a or Ra'11b bonding to each other is preferably a monocyclic alkene, a ring in which some of the carbon atoms of the monocyclic alkene are substituted with heteroatoms (oxygen atoms, sulfur atoms, etc.), or a monocyclic diene among the above; more preferably, it is a cycloalkene having 3 to 6 carbon atoms, and more preferably, cyclopentene or cyclohexene.

[0080] The ring formed by Ra'10 and Ra'11a or Ra'11b bonding to each other may also be a condensed ring. Specific examples of such condensed rings include indane and the like.

[0081] The ring formed by bonding Ra'10 and Ra'11a or Ra'11b may also have a substituent. Examples of such substituents include the aforementioned Ra x5.

[0082] Ra'11a or Ra'11b and Ra'12 may also be bonded to each other to form a ring, and the ring may be the same as the ring formed by bonding Ra'10 and Ra'11a or Ra'11b.

[0083] Specific examples of the group represented by the aforementioned formula (a1-r-4) are listed below.

[0084]

[0085] Examples of the structural unit (a1) include a structural unit derived from an acrylate in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, a structural unit derived from an acrylamide, a structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least a portion of the hydrogen atoms in the hydroxyl group is protected by a substituent containing the aforementioned acid-decomposable group, and a structural unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative in which at least a portion of the hydrogen atoms in the -C(=O)-OH group is protected by a substituent containing the aforementioned acid-decomposable group.

[0086] Specific examples of the structural unit (a1) are shown below. In the following formulae, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095] The structural unit (a1) contained in the component (A1) may be one type or two or more types. The constituent unit (a1) is preferably a constituent unit represented by the aforementioned formula (a1-1) because it can more easily improve the characteristics (sensitivity, shape, etc.) of lithography performed using an electron beam or EUV. Among them, the structural unit (a1) is particularly preferably a structural unit represented by the following general formula (a1-1-1).

[0096] [Wherein, Ra 1″ is an acid-dissociable group represented by the general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4). * indicates a bonding site].

[0097] In the aforementioned formula (a1-1-1), R, Va1 and n a1 are the same as R, Va1 and n a1 in the aforementioned formula (a1-1). The acid-dissociable groups represented by the general formula (a1-r2-1), (a1-r2-3), or (a1-r2-4) are described above. Of these, cyclic groups are particularly preferred, and acid-dissociable groups represented by the general formula (a1-r2-1) are even more preferred, as they enhance reactivity for EB or EUV applications.

[0098] The proportion of the structural units (a1) in the component (A1) is preferably 5 to 95 mol%, more preferably 10 to 90 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total of all the structural units constituting the component (A1) (100 mol%). When the ratio of the constituent unit (a1) is above the lower limit of the preferred range, lithographic characteristics such as sensitivity, CDU, resolution, and roughness improvement are improved. On the other hand, when the ratio is below the upper limit of the preferred range, a balance is achieved with other constituent units, resulting in various favorable lithographic characteristics.

[0099] Other components The component (A1) may have other structural units in addition to the above-mentioned structural unit (a1) as needed. Other structural units include, for example, the structural unit (a10) represented by the general formula (a10-1) described below; the structural unit (a2) containing a lactone-containing cyclic group; and the structural unit (a8) derived from the compound represented by the general formula (a8-1) described below.

[0100] Regarding the constituent unit (a10): The structural unit (a10) is a structural unit represented by the following general formula (a10-1) (except for those corresponding to the structural unit (a1)).

[0101] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Yax1 is a single bond or a divalent linking group. Wax1 is an aromatic hydrocarbon group which may have a substituent. Nax1 is an integer greater than or equal to 1].

[0102] In the aforementioned formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. In view of industrial availability, it is more preferably a hydrogen atom, a methyl group, or a trifluoromethyl group; further preferably a hydrogen atom or a methyl group; particularly preferably a hydrogen atom.

[0103] In the aforementioned formula (a10-1), Yax1 is a single bond or a divalent linking group. In the above chemical formula, the divalent linking group in Yax1 is not particularly limited, and suitable examples include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a heteroatom.

[0104] Ya x1 is preferably a single bond, an ester bond [—C(═O)—O—, —OC(═O)—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof; more preferably a single bond, an ester bond [—C(═O)—O—, —OC(═O)—].

[0105] In the aforementioned formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. The aromatic hydrocarbon group in Wa x1 can be a group derived from an aromatic ring that may have a substituent by removing (n ax1 + 1) hydrogen atoms. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system with 4n + 2 π electrons. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, even more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which a portion of the carbon atoms constituting the aforementioned aromatic hydrocarbon rings are substituted with heteroatoms. Heteroatoms in the aromatic heterocyclic ring include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocyclic ring include pyridine rings and thiophene rings. The aromatic hydrocarbon group in Wax1 may also be a group obtained by removing (nax1+1) hydrogen atoms from an aromatic compound containing two or more aromatic rings which may have substituents (e.g., biphenyl, fluorene, etc.). Among the above, Wax1 is particularly preferably a group derived from benzene, naphthalene, anthracene or biphenyl by removing (nax1+1) hydrogen atoms; more preferably a group derived from benzene or naphthalene by removing (nax1+1) hydrogen atoms; and even more preferably a group derived from benzene by removing (nax1+1) hydrogen atoms.

[0106] The aromatic hydrocarbon group in Wax1 may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent include the same substituents as those listed for the cyclic alicyclic hydrocarbon group in Yax1. The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, even more preferably an ethyl group or a methyl group, and particularly preferably a methyl group. The aromatic hydrocarbon group in Wax1 preferably has no substituent.

[0107] In the aforementioned formula (a10-1), n ​​ax1 is an integer greater than 1, preferably an integer from 1 to 10, more preferably an integer from 1 to 5, further preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0108] Specific examples of the structural unit (a10) represented by the above formula (a10-1) are shown below. In the following formulae, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0109]

[0110]

[0111]

[0112] The structural unit (a10) contained in the component (A1) may be one type or two or more types. When the component (A1) has the structural unit (a10), the ratio of the structural unit (a10) in the component (A1) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 30 to 60 mol% relative to the total of all the structural units constituting the component (A1) (100 mol%). When the ratio of the constituent unit (a10) is above the lower limit, the sensitivity can be increased more easily. On the other hand, when the ratio is below the upper limit, the balance with other constituent units can be achieved more easily.

[0113] Regarding constituent unit (a2): The component (A1) may further have a structural unit (a2) containing a lactone-containing cyclic group (except for those corresponding to the structural unit (a1)). The lactone-containing cyclic group in the structural unit (a2) is effective in improving the adhesion of the resist film to the substrate when the component (A1) is used to form a resist film. Furthermore, the presence of the structural unit (a2) improves lithographic properties by, for example, appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0114] A "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -OC(=O)- in its ring backbone. A group consisting solely of the lactone ring is referred to as a monocyclic group, with the lactone ring being counted as the first ring. A group containing other ring structures is referred to as a polycyclic group, regardless of their structure. A lactone-containing cyclic group may be either monocyclic or polycyclic. The lactone-containing cyclic group in the structural unit (a2) is not particularly limited, and any group can be used. Specifically, groups represented by the following general formulas (a2-r-1) to (a2-r-7) can be mentioned.

[0115] [In the formula, Ra' and Ra' are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group; A" is an alkylene group having 1 to 5 carbon atoms, an oxygen atom, or a sulfur atom which may contain an oxygen atom (-O-) or a sulfur atom (-S-); n' is an integer from 0 to 2; and m' is 0 or 1. * represents a bonding site (the same applies hereinafter)].

[0116] In the aforementioned general formulas (a2-r-1) to (a2-r-7), the alkyl group in R ' is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, and hexyl. Among these, methyl or ethyl are particularly preferred, and methyl is particularly preferred. The alkoxy group in Ra'21 is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, it can be a group formed by linking the alkyl groups listed above as the alkyl group in Ra'21 with an oxygen atom (-O-). The halogen atom in Ra' 21 is preferably a fluorine atom. The halogenated alkyl group in Ra'21 includes a group in which a part or all of the hydrogen atoms of the alkyl group in Ra'21 are substituted with the aforementioned halogen atoms. The halogenated alkyl group is preferably a fluorinated alkyl group, particularly preferably a perfluoroalkyl group.

[0117] In -COOR" and -OC(=O)R" in Ra' 21, R" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R" may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R" is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably is a methyl group or an ethyl group. When R″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, examples include groups obtained by removing one or more hydrogen atoms from a monocycloalkane that may or may not be substituted with a fluorine atom or a fluorinated alkyl group; groups obtained by removing one or more hydrogen atoms from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane; and more specifically, groups obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane; and groups obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The lactone-containing cyclic group in R" may be the same as the groups represented by the aforementioned general formulas (a2-r-1) to (a2-r-7). The hydroxyalkyl group in Ra' 21 preferably has 1 to 6 carbon atoms. Specifically, it includes a group in which at least one hydrogen atom of the alkyl group in Ra' 21 is substituted with a hydroxyl group.

[0118] As Ra' 21, among the above, it is particularly preferred that each independently represents a hydrogen atom or a cyano group.

[0119] In the aforementioned general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A" is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups having -O- or -S- at the end of the aforementioned alkylene group or between carbon atoms, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, and -CH2-S-CH2-. A" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0120] Specific examples of the groups represented by general formulae (a2-r-1) to (a2-r-7) are listed below.

[0121]

[0122]

[0123] Among the structural units (a2), particularly preferred are structural units derived from acrylic acid esters in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0124] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya 21 is a single bond or a divalent linking group. La 21 is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. However, when La 21 is -O-, Ya 21 is not -CO-. Ra 21 is a cyclic group containing a lactone.

[0125] In the aforementioned formula (a2-1), R is the same as described above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. In view of industrial availability, a hydrogen atom or a methyl group is particularly preferred.

[0126] In the aforementioned formula (a2-1), the divalent linking group in Ya 21 is not particularly limited, and suitable examples thereof include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a heteroatom.

[0127] Ya 21 is preferably a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof.

[0128] In the aforementioned formula (a2-1), preferably Ya 21 is a single bond, and La 21 is -COO- or -OCO-.

[0129] In the aforementioned formula (a2-1), Ra 21 is a lactone-containing cyclic group. Suitable examples of the lactone-containing cyclic group in Ra 21 include the groups represented by the aforementioned general formulae (a2-r-1) to (a2-r-7).

[0130] The structural unit (a2) contained in the component (A1) may be one type or two or more types. When the component (A1) has the structural unit (a2), the ratio of the structural unit (a2) relative to the total of all the structural units constituting the component (A1) (100 mol%) is preferably 1 to 20 mol%, more preferably 1 to 15 mol%, and even more preferably 1 to 10 mol%. If the ratio of the constituent unit (a2) is above the preferred lower limit, the effect of containing the constituent unit (a2) can be fully obtained through the aforementioned effect. If it is below the upper limit, a balance with other constituent units can be achieved, and various micro-photographic properties become good.

[0131] Regarding the constituent unit (a8): The structural unit (a8) is a structural unit derived from a compound represented by the following general formula (a8-1). However, those corresponding to the constituent unit (a0) are excluded.

[0132] [In the formula, W2 is a group containing a polymerizable group. Yax2 is a single bond or a (nax2+1)-valent linking group. Yax2 and W2 may also form a condensed ring. R1 is a fluorinated alkyl group having 1 to 12 carbon atoms. R2 is an organic group having 1 to 12 carbon atoms which may have a fluorine atom, or a hydrogen atom. R2 and Yax2 may also be bonded to each other to form a ring structure. nax2 is an integer from 1 to 3].

[0133] The "polymerizable group" in the polymerizable group-containing group of W2 refers to a group that allows the compound having the polymerizable group to be polymerized by free radical polymerization, for example, a group containing multiple bonds between carbon atoms such as ethylenic double bonds.

[0134] The group containing a polymerizable group may be composed solely of the polymerizable group or may be composed of the polymerizable group and a group other than the polymerizable group. Examples of the group other than the polymerizable group include a divalent hydrocarbon group that may have a substituent and a divalent linking group containing a heteroatom. The group containing a polymerizable group may be suitably exemplified by the chemical formula: A group represented by C(R X11)(R X12)=C(R X13)-Ya x0-. In the chemical formula, R X11, R X12, and R X13 are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya x0 is a single bond or a divalent linking group.

[0135] Examples of the condensed ring formed by Yax2 and W2 include a condensed ring formed by a polymerizable group at the W2 site and Yax2, and a condensed ring formed by a group other than a polymerizable group at the W2 site and Yax2. The condensed ring formed by Yax2 and W2 may also have a substituent.

[0136] Specific examples of the constituent unit (a8) are shown below. In the following formula, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0137]

[0138] Among the above examples, the constituent unit (a8) is preferably at least one selected from the group consisting of constituent units represented by chemical formulas (a8-1-01) to (a8-1-04), (a8-1-06), (a8-1-08), (a8-1-09), and (a8-1-10); and more preferably at least one selected from the group consisting of constituent units represented by chemical formulas (a8-1-01) to (a8-1-04) and (a8-1-09).

[0139] The structural unit (a8) contained in the component (A1) may be one type or two or more types. The ratio of the structural unit (a8) in the component (A1) is preferably 50 mol% or less, more preferably 0 to 30 mol%, relative to the total of all the structural units constituting the component (A1) (100 mol%).

[0140] The component (A1) contained in the resist composition may be used alone or in combination of two or more. In the resist composition of this embodiment, the component (A1) may be a polymer compound having a repeating structure of the structural unit (a1). Among the above-mentioned components, particularly suitable examples of the component (A1) include polymer compounds having a repeating structure of the structural unit (a1) and the structural unit (a10).

[0141] In the polymer compound having a repeating structure of the constituent unit (a1) and the constituent unit (a10), the ratio of the constituent unit (a1) relative to the total of all the constituent units constituting the polymer compound (100 mol %) is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, even more preferably 30 to 70 mol %, and particularly preferably 40 to 60 mol %. Furthermore, the ratio of the structural unit (a10) in the polymer compound is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total of all structural units constituting the polymer compound (100 mol%).

[0142] The component (A1) can be produced by dissolving monomers derived from the constituent units in a polymerization solvent, adding a free radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (such as V-601), and performing polymerization. Alternatively, the component (A1) can be produced by dissolving a monomer derived from the structural unit (a1) and a monomer of a structural unit other than the structural unit (a1) as required (e.g., the structural unit (a10)) in a polymerization solvent, adding a free radical polymerization initiator as described above, and carrying out polymerization, followed by a deprotection reaction. Furthermore, during polymerization, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH can be used to introduce a -C(CF3)2-OH group at the terminal. In this way, copolymers containing hydroxyalkyl groups in which some of the alkyl group's hydrogen atoms are replaced with fluorine atoms are effective in reducing development defects and LER (line edge roughness: unevenness of line sidewalls).

[0143] The weight average molecular weight (Mw) of the component (A1) (measured by gel permeation chromatography (GPC) in terms of polystyrene) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 20,000. If the Mw of component (A1) is below the preferred upper limit of the range, it has sufficient solubility in the resist solvent for use as a resist. If it is above the preferred lower limit of the range, the dry etching resistance or the cross-sectional shape of the resist pattern is good. The dispersion degree (Mw / Mn) of component (A1) is not particularly limited, but is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Mn represents the number average molecular weight.

[0144] ･About ingredient (A2) The resist composition of this embodiment may also be combined with a base component (hereinafter referred to as "(A2) component"), which is different from the aforementioned (A1) component and whose solubility in the developer solution changes due to the action of an acid, as the (A) component. The component (A2) is not particularly limited and may be arbitrarily selected from a plurality of conventionally known base components for chemically amplified resist compositions. As the component (A2), a high molecular weight compound or a low molecular weight compound may be used alone or in combination of two or more.

[0145] The proportion of component (A1) in component (A) relative to the total mass of component (A) is preferably 25% by mass or greater, more preferably 50% by mass or greater, even more preferably 75% by mass or greater, and may be 100% by mass. When this proportion is 25% by mass or greater, it is easy to form a resist pattern having excellent lithographic properties such as high sensitivity, improved resolution, and improved roughness.

[0146] In the resist composition of this embodiment, the content of component (A) can be adjusted according to the desired resist film thickness.

[0147] <Acid Generator Component (B)> The component (B) in the resist composition of this embodiment includes a compound (B0) represented by the following general formula (b0) (hereinafter also referred to as "component (B0)").

[0148] Compound (B0) The component (B0) is a compound represented by the following general formula (b0).

[0149] [In the formula, Rpg is an acid-decomposable group. Rl0 is a cyclic organic group which may have a substituent. L02 is a divalent linking group. L01 is a divalent linking group or a single bond. Rm1 is a substituent other than an iodine atom. Vb0 is a single bond, an alkylene group, or a fluorinated alkylene group. R0 is a hydrogen atom, a fluorinated alkylene group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 1 to 4, nb2 is an integer of 1 to 4, and nb3 is an integer of 0 to 3. Mm+ represents an m-valent organic cation. m is an integer of 1 or greater].

[0150] {Anion portion of component (B0)} In the general formula (b0), Rpg is an acid-degradable group. An acid-degradable group is a group that decomposes upon the action of an acid to produce a polar group. Examples of such polar groups include carboxyl, hydroxyl, amino, and sulfo groups (-SO 3H). Rpg is preferably an acid-decomposable group represented by any one of the following general formulas (r-pg-1) to (r-pg-4).

[0151] Acid-decomposable group represented by the general formula (r-pg-1) The acid-decomposable group represented by the general formula (r-pg-1) is a group obtained by protecting the hydroxyl group with the "acetal-type acid-decomposable group" described in the structural unit (a1) of the component (A).

[0152] [In the formula, Rp01 and Rp02 are each independently a hydrogen atom or an alkyl group. Rp03 is a hydrocarbon group, and Rp03 may be bonded to either Rp01 or Rp02 to form a ring. * indicates a bonding site].

[0153] Acid-decomposable group represented by the general formula (r-pg-2) The acid-decomposable group represented by the general formula (r-pg-2) is a group obtained by protecting the carboxyl group with the "acetal-type acid-decomposable group" described in the structural unit (a1) of the component (A).

[0154] [In the formula, Rp04 and Rp05 are each independently a hydrogen atom or an alkyl group. Rp06 is a hydrocarbon group, and Rp06 may be bonded to either Rp04 or Rp05 to form a ring. * indicates a bonding site].

[0155] Acid-decomposable group represented by the general formula (r-pg-3) The acid-decomposable group represented by the general formula (r-pg-3) is a group obtained by protecting the carboxyl group with the "tertiary alkyl ester type acid-decomposable group" described in the structural unit (a1) of the component (A).

[0156] [In the formula, Rp07 to Rp09 are each independently a hydrocarbon group. Rp08 and Rp09 may be bonded to each other to form a ring. * indicates a bonding site].

[0157] Acid-decomposable group represented by the general formula (r-pg-4) The acid-decomposable group represented by the general formula (r-pg-4) is a group obtained by protecting the carboxyl group with the "secondary alkyl ester type acid-decomposable group" described in the structural unit (a1) of the component (A).

[0158] [In the formula, Rp10 is a hydrocarbon group. Rp11a and Rp11b are each independently a hydrogen atom, a halogen atom, or an alkyl group. Rp12 is a hydrogen atom or a hydrocarbon group. Rp10 and Rp11a or Rp11b may be bonded to form a ring. Rp11a or Rp11b and Rp12 may be bonded to form a ring. * indicates a bonding site].

[0159] In the above formula (b0), Rpg is preferably an acid-decomposable group represented by the above general formula (r-pg-3), and more preferably an acid-decomposable group represented by any one of the following general formulas (r-pg-3-01) to (r-pg-3-04).

[0160] [In formula (r-pg-3-01), Rb001 represents a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with a halogen atom or a heteroatom-containing group. Rb002 represents a group that forms an aliphatic cyclic group together with the carbon atom to which Rb001 is bonded. In formula (R-PG-3-02), Yb is a carbon atom. Xb is a group that forms a cyclic organic group together with Yb. Some or all of the hydrogen atoms in the cyclic organic group may be substituted. Rb003 through Rb005 are each independently a hydrogen atom, a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the chain saturated hydrocarbon group and the aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Rb003 through Rb005 may bond to each other to form a cyclic structure. In formula (r-pg-3-03), Ybb is a carbon atom. Xbb is a group that forms an aliphatic cyclic group together with Ybb. Rb006 is an aromatic hydrocarbon group that may have a substituent. In formula (R-PG-3-04), Rb007 and Rb008 are each independently a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms in the chain hydrocarbon group may be substituted. Rb009 is an optionally substituted hydrocarbon group. * indicates a bonding site (the same applies hereinafter).

[0161] ･Acid-decomposable group represented by the general formula (r-pg-3-01) In the above formula (r-pg-3-01), Rb001 is a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with a halogen atom or a heteroatom-containing group.

[0162] The linear alkyl group in Rb001 has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Examples of the branched chain alkyl group in Rb 001 include isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, 1,1-diethylpropyl, and 2,2-dimethylbutyl.

[0163] The alkyl group in Rb001 may be partially substituted with a halogen atom or a group containing a heteroatom. For example, a portion of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a group containing a heteroatom. Furthermore, a portion of the carbon atoms (such as a methylene group) constituting the alkyl group may be substituted with a group containing a heteroatom. The heteroatoms referred to herein include oxygen, sulfur, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0164] In the above formula (r-pg-3-01), Rb001 is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 5 carbon atoms, and even more preferably a methyl group or an ethyl group.

[0165] In the above formula (r-pg-3-01), Rb002 (the aliphatic cyclic group formed together with the carbon atom to which Rb001 is bonded) can be a monocyclic group or a polycyclic alicyclic hydrocarbon group. The alicyclic hydrocarbon group of the monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The alicyclic hydrocarbon group of the polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms. Specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0166] In the above formula (r-pg-3-01), Rb002 (the aliphatic cyclic group formed together with the carbon atom to which Rb001 is bonded) is preferably a cyclopentyl group, a cyclohexyl group, an adamantyl group, or a norbornyl group among the above groups; more preferably a cyclopentyl group or an adamantyl group.

[0167] Preferred specific examples of the acid-decomposable group represented by the general formula (r-pg-3-01) are shown below.

[0168]

[0169] ･Acid-decomposable group represented by the general formula (r-pg-3-02) In the above formula (r-pg-3-02), the cyclic organic group formed by Xb and Yb together may be a monocyclic group or a polycyclic alicyclic hydrocarbon group. The alicyclic hydrocarbon group of the monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The alicyclic hydrocarbon group of the polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms. Specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0170] Furthermore, the cyclic organic group formed by Xb and Yb together may contain a heteroatom, such as a heterocycle. Examples of heteroatoms include oxygen, sulfur, and nitrogen atoms. Specific examples of heterocycles include aliphatic heterocycles such as tetrahydrofuran, tetrahydropyran, and tetrahydrothiophene.

[0171] The cyclic organic group formed together with Xb and Yb may have a substituent. Examples of the substituent include the above-mentioned Ra x5.

[0172] In the above formula (r-pg-3-02), the cyclic organic group formed together with Xb and Yb is preferably a monocyclic alicyclic hydrocarbon group or a monocyclic aliphatic heterocyclic hydrocarbon group; more preferably, it is a cyclopentyl group, a cyclohexyl group, or a tetrahydrofuranyl group.

[0173] In the above formula (R-PG-3-02), the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in Rb003 to Rb005 can be exemplified by methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl. The monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in Rb003 to Rb005 includes, for example, monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octyl, tricyclo[5.2.1.02,6]decyl, tricyclo[3.3.1.13,7]decyl, tetracyclo[6.2.1.13,6.02,7]dodecyl and adamantyl.

[0174] Examples of the substituents possessed by the chain saturated hydrocarbon group or aliphatic cyclic saturated hydrocarbon group represented by Rb003 to Rb005 include the same substituents as those for Ra x5 above.

[0175] Examples of groups containing a carbon-carbon double bond, where two or more of Rb003 to Rb005 are bonded to form a cyclic structure, include cyclopentenyl, cyclohexenyl, methylcyclopentenyl, methylcyclohexenyl, cyclopentylidenevinyl, and cyclohexylidenevinyl. Among these, cyclopentenyl, cyclohexenyl, and cyclopentylidenevinyl are particularly preferred from the perspective of ease of synthesis.

[0176] In the above formula (R-PG-3-02), among the above, Rb003 to Rb005 are preferably a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms from the viewpoint of ease of synthesis; more preferably a hydrogen atom, a methyl group, or an ethyl group. More specifically, it is preferred that all of Rb003 to Rb005 are hydrogen atoms, or Rb003 and Rb004 are hydrogen atoms and Rb005 is a methyl group or an ethyl group.

[0177] Preferred specific examples of the acid-decomposable group represented by the general formula (r-pg-3-02) are shown below.

[0178]

[0179] ･Acid-decomposable group represented by the general formula (r-pg-3-03) In the above formula (r-pg-3-03), the aliphatic cyclic group formed together with Xbb and Ybb may be a monocyclic group or a polycyclic group. The alicyclic hydrocarbon group of the monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The alicyclic hydrocarbon group of the polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms. Specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0180] Furthermore, the aliphatic cyclic group formed together with Xbb and Ybb may also contain a heteroatom, such as a heterocycle. Examples of heteroatoms include oxygen, sulfur, and nitrogen atoms. Specific examples of such heterocycles include aliphatic heterocycles such as tetrahydrofuran, tetrahydropyran, and tetrahydrothiophene.

[0181] The cyclic hydrocarbon group formed together with Xbb and Ybb may have a substituent. Examples of the substituent include the above-mentioned Ra x5.

[0182] In the above formula (r-pg-3-03), the aliphatic cyclic group formed by Xbb and Ybb together is preferably a monocyclic alicyclic hydrocarbon group or a monocyclic aliphatic heterocyclic hydrocarbon group; more preferably, it is a cyclopentyl group, a cyclohexyl group, or a tetrahydrofuranyl group.

[0183] In the above formula (R-PG-3-03), the aromatic hydrocarbon group in Rb006 can be a group derived from an aromatic hydrocarbon ring having 5 to 30 carbon atoms by removing one or more hydrogen atoms. Among them, Rb006 is particularly preferably a group derived from an aromatic hydrocarbon ring having 6 to 15 carbon atoms by removing one or more hydrogen atoms; more preferably, a group derived from benzene, naphthalene, anthracene, or phenanthrene by removing one or more hydrogen atoms; still more preferably, a group derived from benzene, naphthalene, or anthracene by removing one or more hydrogen atoms; particularly preferably, a group derived from benzene or naphthalene by removing one or more hydrogen atoms; and most preferably, a group derived from benzene by removing one or more hydrogen atoms. Furthermore, the aromatic hydrocarbon ring may contain heteroatoms like a heterocycle. Examples of heteroatoms include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of heterocycles include pyridine rings and thiophene rings.

[0184] Examples of the substituent that Rb006 may have include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group), and an alkoxycarbonyl group.

[0185] In the above formula (r-pg-3-03), the aromatic hydrocarbon group in Rb006 is preferably a phenyl group or a thiophenyl group among the above.

[0186] Preferred specific examples of the acid-decomposable group represented by the general formula (r-pg-3-03) are shown below.

[0187]

[0188] ･Acid-decomposable group represented by the general formula (r-pg-3-04) In the above formula (R-PG-3-04), Rb007 and Rb008 are each independently a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms in the monovalent chain hydrocarbon group may be substituted with a substituent. Examples of such substituents include Ra x5 described above.

[0189] The monovalent chain hydrocarbon group may be a straight-chain or branched saturated hydrocarbon group (alkyl group), or a straight-chain or branched unsaturated hydrocarbon group.

[0190] Specific examples of the linear or branched alkyl group include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl.

[0191] More specifically, the linear or branched unsaturated hydrocarbon group includes unsaturated hydrocarbon groups having double bonds such as alkenyl, dienyl, and trialenyl; and unsaturated hydrocarbon groups having triple bonds such as alkynyl, a group obtained by removing one hydrogen atom from a diene, and a group obtained by removing one hydrogen atom from a triyne.

[0192] Specific examples of the straight-chain or branched alkenyl group include straight-chain alkenyl groups such as vinyl, propenyl (allyl), and 2-butenyl; and branched alkenyl groups such as 1-methylvinyl, 2-methylvinyl, 1-methylpropenyl, and 2-methylpropenyl.

[0193] Specific examples of the diene group include allene and butene. Specific examples of the trienyl group include butatrienyl and the like.

[0194] Specific examples of the straight-chain or branched-chain alkynyl group include straight-chain alkynyl groups such as ethynyl, propargyl, 3-pentynyl, and methylethynyl (-C≡C-CH 3); and branched-chain alkynyl groups such as 1-methylpropargyl.

[0195] Specific examples of the group obtained by removing one hydrogen atom from a diyne include a group obtained by removing one hydrogen atom from diacetylene. Specific examples of the group obtained by removing one hydrogen atom from a triyne include a group obtained by removing one hydrogen atom from hexamethylene-1,3,5-triyne. In the above formula (R-PG-3-04), Rb007 and Rb008 are each independently preferably a linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a linear unsaturated hydrocarbon group; more preferably a linear saturated hydrocarbon group having 1 to 5 carbon atoms, or a linear unsaturated hydrocarbon group.

[0196] In the above formula (R-PG-3-04), Rb009 is a hydrocarbon group that may have a substituent. Examples of the hydrocarbon group in Rb009 include a linear or branched saturated hydrocarbon group (alkyl group), a linear or branched unsaturated hydrocarbon group, or a cyclic hydrocarbon group.

[0197] When Rb009 is a cyclic hydrocarbon group, the hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The alicyclic hydrocarbon group of the monocyclic group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The alicyclic hydrocarbon group of the polycyclic group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms. Specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0198] The aromatic hydrocarbon group for Rb009 may be the same as the aromatic hydrocarbon group for Rb006. Among them, Rb009 is particularly preferably a group derived from an aromatic hydrocarbon ring having 6 to 15 carbon atoms by removing one or more hydrogen atoms; more preferably, a group derived from benzene, naphthalene, anthracene, or phenanthrene by removing one or more hydrogen atoms; still more preferably, a group derived from benzene, naphthalene, or anthracene by removing one or more hydrogen atoms; particularly preferably, a group derived from naphthalene or anthracene by removing one or more hydrogen atoms; and most preferably, a group derived from naphthalene by removing one or more hydrogen atoms. Examples of the substituent that Rb009 may have include the same substituents as those that Rb006 may have.

[0199] In the above formula (R-PG-3-04), Rb009 is preferably a linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a linear unsaturated hydrocarbon group, and more preferably a linear saturated hydrocarbon group having 1 to 5 carbon atoms, or a linear unsaturated hydrocarbon group.

[0200] Preferred specific examples of the acid-decomposable group represented by the above general formula (r-pg-3-04) are shown below.

[0201]

[0202] In the above formula (b0), Rpg is preferably an acid-decomposable group represented by the above general formula (r-pg-3-01) or (r-pg-3-04), and more preferably an acid-decomposable group represented by the above general formula (r-pg-3-01).

[0203] In the above general formula (b0), R10 is a cyclic organic group which may have a substituent. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.

[0204] The monocyclic alicyclic group is preferably a group derived from a monocyclic alkane or monocyclic alkene by removing two or more hydrogen atoms. The monocyclic alkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The monocyclic alkene preferably has 3 to 6 carbon atoms, and specific examples include cyclopentene and cyclohexene. The polycyclic alicyclic group is preferably a group derived from a polycyclic alkane or polycyclic alkene by removing two or more hydrogen atoms. The polycyclic alkane preferably has 7 to 12 carbon atoms, and specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Furthermore, the polycyclic alkene preferably has 7 to 12 carbon atoms, and specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0205] The aromatic hydrocarbon group is preferably a group derived from benzene, naphthalene, anthracene or phenanthrene by removing two or more hydrogen atoms; more preferably a group derived from benzene, naphthalene or anthracene by removing two or more hydrogen atoms; and even more preferably a group derived from benzene by removing two or more hydrogen atoms.

[0206] Examples of the substituents that the cyclic organic group may have include the same substituents as those mentioned above for Ra x5. Furthermore, with respect to the organic group, a portion of the carbon atoms (methylene group, etc.) constituting the organic group may be substituted by a group containing a heteroatom. The heteroatoms referred to herein include oxygen, sulfur, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, and -S(=O)2-O-. That is, the cyclic organic group in R10 which may have a substituent may be a group derived from an aromatic heterocyclic ring such as a pyridine ring or a thiophene ring by removing two or more hydrogen atoms; or a group derived from an aliphatic heterocyclic ring such as tetrahydrofuran, tetrahydropyran, or tetrahydrothiophene by removing two or more hydrogen atoms.

[0207] The cyclic organic group which may have a substituent in R10 may be a lactone-containing cyclic group such as those represented by the following general formulas (Lr-1) to (Lr-7).

[0208] [wherein, Ra' and O21 are independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR O", -OC(=O)R O", a hydroxyalkyl group, or a cyano group; R O" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group; A O" is an alkylene group having 1 to 5 carbon atoms, an oxygen atom, or a sulfur atom which may contain an oxygen atom (-O-) or a sulfur atom (-S-); n0' is an integer from 0 to 2; and m0' is 0 or 1].

[0209] In the aforementioned general formulas (Lr-1) to (Lr-7), the alkyl group in Ra'021 is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. The alkoxy group in Ra'021 is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, it can be a group formed by linking the alkyl groups listed above as the alkyl group in Ra'021 with an oxygen atom (-O-). The halogen atom in Ra'021 is preferably a fluorine atom. Examples of the halogenated alkyl group in Ra'021 include groups in which some or all of the hydrogen atoms of the alkyl group in Ra'021 are substituted with the aforementioned halogen atoms. The halogenated alkyl group is preferably a fluorinated alkyl group, particularly preferably a perfluoroalkyl group.

[0210] In -COOR 0" and -OC(=O)R 0" in Ra' 021, R 0" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R0" may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R 0" is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably is a methyl group or an ethyl group. When R 0" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Examples of the lactone-containing cyclic group in R 0" include the same groups as those represented by the aforementioned general formulas (Lr-1) to (Lr-7). The hydroxyalkyl group in Ra'021 preferably has 1 to 6 carbon atoms. Specifically, it includes a group in which at least one hydrogen atom of the alkyl group in Ra'021 is replaced by a hydroxyl group.

[0211] In the aforementioned general formulas (Lr-2), (Lr-3), and (Lr-5), the alkylene group having 1 to 5 carbon atoms in A0" is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups having -O- or -S- at the end of the alkylene group or between carbon atoms, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, and -CH2-S-CH2-. A0" is preferably an alkylene group having 1 to 5 carbon atoms or -O-.

[0212] The cyclic organic group in R10 may be a condensed ring group comprising a condensed ring formed by condensing an aliphatic hydrocarbon ring and an aromatic ring. Examples of the condensed ring group include polycycloalkanes having a cross-linked polycyclic skeleton with one or more aromatic rings condensed therein. Specific examples of the cross-linked polycycloalkanes include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The condensed ring group preferably comprises a condensed ring formed by condensing two or three aromatic rings therein.

[0213] In the above general formula (b0), from the viewpoint of improving the uniformity within the resist film, R10 among the above is preferably an aromatic hydrocarbon group which may have a substituent, or a polycyclic alicyclic hydrocarbon group which may have a substituent; more preferably, it is an aromatic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycyclic alkane or a polycyclic alkene, a lactone-containing cyclic group represented by the above general formula (Lr-3), or a condensed cyclic group comprising a condensed ring obtained by condensing an aliphatic hydrocarbon ring and an aromatic ring.

[0214] Specifically, R10 is preferably a group represented by any one of the following chemical formulas (R10-1) to (R10-5); more preferably, a group represented by the following chemical formula (R10-1), (R10-2), or (R10-5); and even more preferably, a group represented by the following chemical formula (R10-2) or (R10-5). Furthermore, the hydrogen atoms of the groups represented by the following chemical formulas (R10-1) to (R10-5) may each be independently substituted with a substituent. Examples of such substituents include the same substituents as those for Ra x5 above.

[0215]

[0216] In the above general formula (b0), L 01 is a divalent linking group or a single bond, and L 02 is a divalent linking group. Suitable examples of the divalent linking group in L 01 and L 02 include divalent linking groups containing an oxygen atom. When L01 and L02 are divalent linking groups containing oxygen atoms, L01 and L02 may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of divalent linking groups containing oxygen atoms include non-hydrocarbon oxygen-containing linking groups such as oxygen atoms (ether bonds: -O-), ester bonds (-C(=O)-O-), oxycarbonyl groups (-OC(=O)-), amide bonds (-C(=O)-NH-), carbonyl groups (-C(=O)-), and carbonate bonds (-OC(=O)-O-); and combinations of these non-hydrocarbon oxygen-containing linking groups with alkylene groups. These combinations may further include sulfonyl groups (-SO2-).

[0217] More specifically, the divalent linking group in L01 and L02 includes -O-, -CO-, -OCO-, -COO-, -SO2-, -N(Ra)-C(=O)-, -N(Ra)-, -C(Ra)(Ra)-N(Ra)-, -C(Ra)(N(Ra)(Ra))-, or -C(=O)-N(Ra)-, etc. Ra is independently a hydrogen atom or an alkyl group.

[0218] In the above general formula (b0), L 01 is preferably a divalent linking group among the above; more preferably a divalent linking group containing an oxygen atom; and even more preferably -OCO-, -COO-, or -C(=O)-N(Ra)-; particularly preferably -OCO-, or -COO-.

[0219] In the above general formula (b0), L 02 is preferably a divalent linking group among the above; more preferably a divalent linking group containing an oxygen atom; and even more preferably -OCO-, -COO-, or -C(=O)-N(Ra)-; particularly preferably -OCO-, or -COO-.

[0220] In the above general formula (b0), Rm1 is a substituent other than an iodine atom. Examples of such substituents include a hydroxyl group, an alkyl group, a fluorinated alkyl group, a fluorine atom, and a chlorine atom. The alkyl group, and the alkyl group in the fluorinated alkyl group, is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group.

[0221] In the above general formula (b0), Vb0 is a single bond, an alkylene group or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group in Vb0 preferably have 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms. Examples of the fluorinated alkylene group in Vb0 include groups in which a part or all of the hydrogen atoms of the alkylene group are substituted with fluorine atoms.

[0222] In the above general formula (b0), Vb0 is preferably an alkylene group or a fluorinated alkylene group among the above; more preferably an alkylene group having 1 to 4 carbon atoms or a fluorinated alkylene group having 1 to 4 carbon atoms; and more preferably a methylene group, -CH(CF3)-, -CH 2CH 2CF 2-, or -CH 2CH 2CHF-.

[0223] In the above general formula (b0), R 0 is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. R 0 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom.

[0224] In the above general formula (b0), nb1 represents the number of iodine atoms (I). nb1 is an integer of 1-4, preferably an integer of 1-3, and more preferably 2 or 3.

[0225] In the above general formula (b0), nb2 is an integer of 1 to 4, preferably 1 or 2, and more preferably 1.

[0226] In the above general formula (b0), nb3 is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.

[0227] Preferred specific examples of the anion portion of the component (B0) are shown below.

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234]

[0235]

[0236]

[0237]

[0238]

[0239]

[0240] The anion portion of the component (B0) is preferably any one of the chemical formulas (b0-an-001) to (b0-an-003), (b0-an-009), (b0-an-013), (b0-an-025) to (b0-an-027), (b0-an-078) to (b0-an-080), (b0-an-084), and (b0-an-097) to (b0-an-107). An anion; more preferably, an anion represented by any one of (b0-an-025) to (b0-an-027), (b0-an-078) to (b0-an-080), (b0-an-084), (b0-an-102) to (b0-an-107); and still more preferably, an anion represented by any one of (b0-an-084), (b0-an-103), (b0-an-104), and (b0-an-107).

[0241] {Cation portion of component (B0)} In the above general formula (b0), M m+ represents an organic cation with a valence of m, particularly preferably a cation of iodonium or iodonium. m is an integer greater than or equal to 1.

[0242] Preferred cationic moieties ((M m+) 1 / m) include organic cations represented by the following general formulas (ca-1) to (ca-3).

[0243] [In the formula, R 201 to R 207 each independently represents an aryl group, an alkyl group, or an alkenyl group which may have a substituent. R 201 to R 203 and R 206 to R 207 may also be bonded to each other and form a ring together with the sulfur atom in the formula. R 208 to R 209 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a cyclic group containing -SO 2- which may have a substituent. L 201 represents -C(=O)- or -C(=O)-O-].

[0244] In the above-mentioned general formulas (ca-1) to (ca-3), the aryl group in R 201 to R 207 can be an unsubstituted aryl group having 6 to 20 carbon atoms, preferably a phenyl group or a naphthyl group. The alkyl group in R 201 to R 207 is a chain or cyclic alkyl group, preferably one having 1 to 30 carbon atoms. The alkenyl group in R 201 to R 207 preferably has 2 to 10 carbon atoms. Examples of substituents that R 201 to R 207 and R 210 may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulas (ca-r-1) to (ca-r-7).

[0245] [wherein, R'201 is independently a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent].

[0246] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, which may be either an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group refers to a hydrocarbon group that is not aromatic. Furthermore, an aliphatic hydrocarbon group may be saturated or unsaturated, but is generally preferably saturated.

[0247] The aromatic hydrocarbon group in R'201 is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in R'201 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which a portion of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen, sulfur, and nitrogen atoms. Specific examples of the aromatic hydrocarbon group in R'201 include groups obtained by removing one hydrogen atom from the aforementioned aromatic ring (aryl groups: for example, phenyl, naphthyl, etc.), and groups obtained by replacing one hydrogen atom of the aforementioned aromatic ring with an alkylene group (for example, arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, and 2-naphthylethyl). The number of carbon atoms in the aforementioned alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0248] Examples of the cyclic aliphatic hydrocarbon group in R'201 include aliphatic hydrocarbon groups containing a ring in the structure. The aliphatic hydrocarbon group containing a ring in the structure includes an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group exists in the middle of a straight-chain or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The aforementioned alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. A monocyclic alicyclic hydrocarbon group is preferably a group derived from a monocycloalkane by removing one or more hydrogen atoms. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. A polycyclic alicyclic hydrocarbon group is preferably a group derived from a polycycloalkane by removing one or more hydrogen atoms, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a cross-linked polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; or a polycycloalkane having a condensed polycyclic skeleton, such as a cyclic group having a steroid skeleton.

[0249] The cyclic aliphatic hydrocarbon group in R'201 is preferably a group derived from a monocycloalkane or polycycloalkane by removing one or more hydrogen atoms; more preferably a group derived from a polycycloalkane by removing one hydrogen atom; particularly preferably an adamantyl group or a norbornyl group; and most preferably an adamantyl group.

[0250] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. The straight-chain aliphatic hydrocarbon group is preferably a straight-chain alkylene group, and specific examples thereof include methylene [—CH 2—], ethylene [—(CH 2) 2—], trimethylene [—(CH 2) 3—], tetramethylene [—(CH 2) 4—], and pentamethylene [—(CH 2) 5—]. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specifically, -CH(CH 3)-, -CH(CH 2CH 3)-, -C(CH 3) 2-, -C(CH 3)(CH 2CH 3)-, -C(CH 3)(CH 2CH 2CH 3)-, -C(CH 2CH 3) 2- and other alkylmethylene groups; -CH(CH 3)CH 2-, -CH(CH 3)CH(CH 3)-, -C(CH 3) 2CH 2-, -CH(CH 2CH 3)CH 2-, -C(CH 2CH 3) 2-CH 2- and other alkyl ethylidene groups; -CH(CH 3)CH 2CH 2-, -CH 2CH(CH 3)CH 2- and other alkyl trimethylene groups; Alkyl groups such as -CH(CH 3)CH 2CH 2CH 2-, -CH 2CH(CH 3)CH 2CH 2-, and alkyl tetramethylene groups, and alkyl alkylene groups. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0251] Furthermore, the cyclic hydrocarbon group in R'201 may also contain heteroatoms, such as heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the aforementioned general formulas (a2-r-1) to (a2-r-7), -SO2--containing cyclic groups represented by the aforementioned general formulas (b5-r-1) to (b5-r-4), and heterocyclic groups represented by other aforementioned chemical formulas (r-hr-1) to (r-hr-16).

[0252] Examples of the substituent in the cyclic group of R'201 include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and the most preferred are methyl, ethyl, propyl, n-butyl, and tert-butyl. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms; more preferably, it is methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, tert-butoxy; and most preferably, it is methoxy and ethoxy. The halogen atom as a substituent is preferably a fluorine atom. Examples of the halogenated alkyl substituent include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl, in which some or all of the hydrogen atoms are substituted with the aforementioned halogen atoms. The carbonyl group as a substituent is a group that replaces the methylene group (-CH2-) constituting the cyclic hydrocarbon group.

[0253] A chain alkyl group which may have a substituent: The chain alkyl group represented by R'201 may be straight chain or branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl.

[0254] Chain alkenyl groups which may have substituents: The chain alkenyl group represented by R'201 may be linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of linear alkenyl groups include vinyl, propenyl (allyl), and butenyl. Examples of branched alkenyl groups include 1-methylvinyl, 2-methylvinyl, 1-methylpropenyl, and 2-methylpropenyl. As the chain alkenyl group, among the above, a straight-chain alkenyl group is particularly preferred; vinyl and propenyl are more preferred; and vinyl is particularly preferred.

[0255] Examples of substituents in the chain alkyl or alkenyl group of R'201 include alkoxy groups, halogen atoms, halogenated alkyl groups, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the cyclic groups mentioned above for R'201.

[0256] In addition to the above-mentioned cyclic group which may have a substituent, chain alkyl group which may have a substituent, or chain alkenyl group which may have a substituent, examples of the cyclic group which may have a substituent or chain alkyl group which may have a substituent include the same acid-dissociable groups as those represented by the above-mentioned formula (a1-r-2).

[0257] Among them, R'201 is particularly preferably a cyclic group that may have a substituent, and more preferably a cyclic hydrocarbon group that may have a substituent. More specifically, preferred examples include phenyl, naphthyl, a group derived from a polycycloalkane by removing one or more hydrogen atoms, a lactone-containing cyclic group represented by the aforementioned general formulas (a2-r-1) to (a2-r-7), and a -SO2- containing cyclic group represented by the aforementioned general formulas (b5-r-1) to (b5-r-4).

[0258] In the general formulas (ca-1) to (ca-3) above, when R 201 to R 203 and R 206 to R 207 are bonded to form a ring together with the sulfur atom in the formula, they may be bonded via a heteroatom such as a sulfur atom, an oxygen atom, a nitrogen atom, or a functional group such as a carbonyl group, -SO-, -SO 2-, -SO 3-, -COO-, -CONH-, or -N(RN)- (where RN is an alkyl group having 1 to 5 carbon atoms). The ring thus formed has a ring skeleton containing one of the sulfur atoms in the formula. The sulfur atom-containing ring is preferably a 3- to 10-membered ring, particularly a 5- to 7-membered ring. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thienyl ring, a phenoxathiol ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0259] R 208 to R 209 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. When they are alkyl groups, they may be bonded to form a ring.

[0260] R 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a cyclic group containing -SO 2 - which may have a substituent. The aryl group in R 210 includes unsubstituted aryl groups having 6 to 20 carbon atoms, preferably phenyl or naphthyl. The alkyl group in R 210 is a chain or cyclic alkyl group, preferably one with 1 to 30 carbon atoms. The alkenyl group in R 210 preferably has 2 to 10 carbon atoms. The cyclic group containing -SO 2- which may have a substituent in R 210 is preferably a "polycyclic group containing -SO 2-", and more preferably a group represented by the above general formula (b5-r-1).

[0261] Suitable cations represented by the aforementioned formula (ca-1) include, specifically, cations represented by the following chemical formulas (ca-1-1) to (ca-1-70).

[0262]

[0263]

[0264] [In the formula, g1, g2, and g3 represent the number of repetitions, g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 0 to 20].

[0265]

[0266]

[0267] [In the formula, R"201 is a hydrogen atom or a substituent. The substituent is the same as those listed as the substituents that R201 to R207 and R210 to R212 may have.]

[0268]

[0269] Specific examples of suitable cations represented by the above formula (ca-2) include diphenyliodonium cations and bis(4-tert-butylphenyl)iodonium cations.

[0270] Suitable cations represented by the aforementioned formula (ca-3) include, specifically, cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0271]

[0272] The cationic portion of the component (B01) is preferably a cation represented by the above-mentioned general formula (ca-1) among the above-mentioned ones. Among them, any one of R 201 to R 203 in the above general formula (ca-1) is particularly preferably an aryl group having a fluorine atom. Specifically, the cationic portion of the component (B01) is preferably a cation represented by any one of the above chemical formulas (ca-1-44), (ca-1-55) to (ca-1-57), and (ca-1-71) to (ca-1-83).

[0273] Preferred specific examples of the component (B0) are shown below.

[0274]

[0275]

[0276]

[0277]

[0278] Among the above, component (B0) is preferably a compound represented by any one of the chemical formulas (B0-14) to (B0-30); more preferably, a compound represented by any one of the chemical formulas (B0-18), (B0-19), (B0-28) to (B0-30).

[0279] In the resist composition of this embodiment, the component (B0) may be used alone or in combination of two or more.

[0280] In the resist composition of this embodiment, the component (B0) may be used alone or in combination of two or more. In the resist composition of this embodiment, the content of component (B0) is preferably 15 to 40 parts by mass, more preferably 20 to 40 parts by mass, and even more preferably 20 to 35 parts by mass, relative to 100 parts by mass of component (A). If the content of component (B0) is above the lower limit of the preferred range, lithographic properties such as sensitivity, CDU, and resolution during resist pattern formation are further improved. On the other hand, if the content is below the upper limit of the preferred range, a uniform solution is easily obtained when the components of the resist composition are dissolved in an organic solvent, thereby further improving the storage stability of the resist composition.

[0281] The proportion of the component (B0) in the entire component (B) in the resist composition of this embodiment is, for example, 50% by mass or more, preferably 70% by mass or more, more preferably 95% by mass or more, and may also be 100% by mass.

[0282] The component (B) in the resist composition of this embodiment may also contain an acid generator component (B1) (hereinafter also referred to as "component (B1)") other than the above-mentioned component (B0).

[0283] (B1) Ingredients Component (B1) includes onium salt acid generators such as iodonium salts or coronium salts, oxime sulfonate acid generators; diazomethane acid generators such as dialkyl or diaryl sulfonyl diazomethanes and poly (bissulfonyl) diazomethanes; nitrobenzyl sulfonate acid generators, iminosulfonate acid generators, disulfonium acid generators, and the like.

[0284] Examples of onium salt acid generators include compounds represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), compounds represented by the following general formula (b-2) (hereinafter also referred to as "component (b-2)"), and compounds represented by the following general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0285] Examples of onium salt acid generators include compounds represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), compounds represented by the following general formula (b-2) (hereinafter also referred to as "component (b-2)"), and compounds represented by the following general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0286] [In the formula, R 101 and R 104 to R 108 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. R 104 and R 105 may also be bonded to each other to form a ring structure. R 102 is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 to V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group. L 101 to L 102 are each independently a single bond or an oxygen atom. L 103 to L 105 are each independently a single bond, -CO-, or -SO 2-. m is an integer greater than 1, and M'm+ is an m-valent onium cation].

[0287] {Anion Section} ･Anions in (b-1) component In formula (b-1), R 101 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

[0288] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, which may be either an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group refers to a hydrocarbon group that is not aromatic. Furthermore, an aliphatic hydrocarbon group may be saturated or unsaturated, but is generally preferably saturated.

[0289] The aromatic hydrocarbon group in R 101 is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3-30, more preferably 5-30, even more preferably 5-20, particularly preferably 6-15, and most preferably 6-10. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring contained in the aromatic hydrocarbon group in R 101 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocyclic rings in which a portion of the carbon atoms constituting the aromatic rings are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocyclic ring include oxygen, sulfur, and nitrogen atoms. Specific examples of the aromatic hydrocarbon group in R 101 include groups derived from the aforementioned aromatic ring by removing one hydrogen atom (aryl groups: for example, phenyl, naphthyl, etc.), and groups derived from the aforementioned aromatic ring by replacing one hydrogen atom with an alkylene group (for example, arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, and 2-naphthylethyl). The number of carbon atoms in the aforementioned alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0290] Examples of the cyclic aliphatic hydrocarbon group in R 101 include aliphatic hydrocarbon groups containing a ring in the structure. The aliphatic hydrocarbon group containing a ring in the structure includes an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group exists in the middle of a straight-chain or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The aforementioned alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. A monocyclic alicyclic hydrocarbon group is preferably a group derived from a monocycloalkane by removing one or more hydrogen atoms. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. A polycyclic alicyclic hydrocarbon group is preferably a group derived from a polycycloalkane by removing one or more hydrogen atoms, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is more preferably a polycycloalkane having a cross-linked polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; or a polycycloalkane having a condensed polycyclic skeleton, such as a cyclic group having a steroid skeleton.

[0291] Among them, the cyclic aliphatic hydrocarbon group in R 101 is preferably a group derived from a monocycloalkane or polycycloalkane by removing one or more hydrogen atoms; more preferably a group derived from a polycycloalkane by removing one hydrogen atom; still more preferably an adamantyl group or a norbornyl group; and particularly preferably an adamantyl group.

[0292] The linear aliphatic hydrocarbon group that may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof include methylene [-CH2-], ethylene [-(CH2)2-], trimethylene [-(CH2)3-], tetramethylene [-(CH2)4-], and pentamethylene [-(CH2)5-]. The branched aliphatic hydrocarbon group that may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6, even more preferably 3 or 4, and most preferably 3. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include -CH(CH 3)-, -CH(CH 2CH 3)-, -C(CH 3) 2-, -C(CH 3)(CH 2CH 3)-, -C(CH 3)(CH 2CH 2CH 3)-, -C(CH 2CH 3) 2-, etc. alkylmethylene; -CH(CH 3)CH 2-, -CH(CH 3)CH(CH 3)-, -C(CH 3) 2CH 2-, -CH(CH 2CH 3)CH 2-, -C(CH 2CH 3) 2-CH 2- and the like alkyl ethylidene groups; -CH(CH 3)CH 2CH 2-, -CH 2CH(CH 3)CH 2- and the like alkyl trimethylene groups; -CH(CH 3)CH 2CH 2-, -CH 2CH(CH 3)CH 2- and the like alkyltrimethylene groups; The alkyl group in the alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0293] Furthermore, the cyclic hydrocarbon group in R 101 may also contain heteroatoms, such as heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the aforementioned general formulas (a2-r-1) to (a2-r-7), -SO 2--containing cyclic groups represented by the following general formulas (b5-r-1) to (b5-r-4), and heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16). In the formula, * indicates the bonding site of Y 101 in formula (b-1).

[0294] [In the formula, Rb' and Rb' are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or a -SO2- containing cyclic group; B" is an alkylene group having 1 to 5 carbon atoms, an oxygen atom, or a sulfur atom, which may contain an oxygen atom or a sulfur atom; and n' is an integer from 0 to 2. * indicates a bonding site].

[0295] In the aforementioned general formulas (b5-r-1) to (b5-r-2), B″ is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom. B" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and even more preferably a methylene group.

[0296] In the aforementioned general formulas (b5-r-1) to (b5-r-4), Rb' and Rb' are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group, preferably each independently a hydrogen atom or a cyano group.

[0297] Specific examples of the groups represented by general formulae (b5-r-1) to (b5-r-4) are listed below: "Ac" in the formula represents an acetyl group.

[0298]

[0299]

[0300]

[0301]

[0302] Examples of the substituent in the cyclic group of R 101 include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and the most preferred are methyl, ethyl, propyl, n-butyl, and tert-butyl. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms; more preferably, it is methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, tert-butoxy; and most preferably, it is methoxy and ethoxy. Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. Examples of the halogenated alkyl substituent include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl, in which some or all of the hydrogen atoms are substituted with the aforementioned halogen atoms. The carbonyl group as a substituent is a group that replaces the methylene group (-CH2-) constituting the cyclic hydrocarbon group.

[0303] The cyclic hydrocarbon group in R 101 may be a condensed ring group comprising a condensed ring formed by condensing an aliphatic hydrocarbon ring and an aromatic ring. Examples of such condensed rings include polycycloalkanes having a cross-linked polycyclic skeleton with one or more aromatic rings condensed therein. Specific examples of such cross-linked polycycloalkanes include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The condensed ring group is preferably a group comprising a condensed ring formed by condensing two or three aromatic rings therein, more preferably a group comprising a condensed ring formed by condensing two or three aromatic rings therein. Specific examples of the condensed ring group in R 101 include those represented by the following formulas (R-br-1) to (R-br-2). In the formula, * represents the bonding site to Y 101 in formula (b-1).

[0304]

[0305] Examples of the substituent that the condensed cyclic group in R 101 may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group. Examples of the alkyl group, alkoxy group, halogen atom, and alkyl halide as the substituent of the condensed cyclic group include the same substituents as those exemplified as the substituents of the cyclic group in R 101 . Examples of the aromatic hydrocarbon group as a substituent of the aforementioned condensed cyclic group include groups obtained by removing one hydrogen atom from an aromatic ring (aryl groups: for example, phenyl, naphthyl, etc.), groups obtained by replacing one hydrogen atom of the aforementioned aromatic ring with an alkylene group (for example, arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.), and heterocyclic groups represented by the above formulas (R-HR-1) to (R-HR-6). The alicyclic hydrocarbon group as a substituent of the aforementioned condensed cyclic group includes a group obtained by removing one hydrogen atom from a monocyclic alkane such as cyclopentane and cyclohexane; a group obtained by removing one hydrogen atom from a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane; a lactone-containing cyclic group represented by the aforementioned general formulas (a2-r-1) to (a2-r-7); a -SO2- containing cyclic group represented by the aforementioned general formulas (b5-r-1) to (b5-r-4); a heterocyclic group represented by the aforementioned formulas (r-hr-7) to (r-hr-16); and the like.

[0306] A chain alkyl group which may have a substituent: The chain alkyl group of R 101 may be straight chain or branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl.

[0307] Chain alkenyl groups which may have substituents: The chain alkenyl group represented by R 101 may be linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of linear alkenyl groups include vinyl, propenyl (allyl), and butenyl. Examples of branched alkenyl groups include 1-methylvinyl, 2-methylvinyl, 1-methylpropenyl, and 2-methylpropenyl. As the chain alkenyl group, among the above, a straight-chain alkenyl group is particularly preferred; vinyl and propenyl are more preferred; and vinyl is particularly preferred.

[0308] Examples of the substituent in the chain alkyl or alkenyl group of R 101 include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the cyclic group of R 101 mentioned above.

[0309] Among the above, R 101 is particularly preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, the cyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, or a polycycloalkane; a lactone-containing cyclic group represented by the aforementioned general formulas (a2-r-1) to (a2-r-7); a -SO2- containing cyclic group represented by the aforementioned general formulas (b5-r-1) to (b5-r-4); more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane; and even more preferably an adamantyl group.

[0310] In formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. When Y 101 is a divalent linking group containing an oxygen atom, Y 101 may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of divalent oxygen-containing linking groups include non-hydrocarbon oxygen-containing linking groups such as oxygen atoms (ether bonds: -O-), ester bonds (-C(=O)-O-), oxycarbonyl groups (-OC(=O)-), amide bonds (-C(=O)-NH-), carbonyl groups (-C(=O)-), and carbonate bonds (-OC(=O)-O-); and combinations of these non-hydrocarbon oxygen-containing linking groups with alkylene groups. These combinations may further be linked to sulfonyl groups (-SO2-). Examples of divalent oxygen-containing linking groups include those represented by the following general formulas (y-a1-1) to (y-a1-7). Furthermore, in the following general formulas (y-al-1) to (y-al-7), the group bonded to R 101 in the above formula (b-1) is V' 101 in the following general formulas (y-al-1) to (y-al-7).

[0311] [In the formula, V'101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and V'102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms].

[0312] The divalent saturated hydrocarbon group in V'102 is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0313] The alkylene group in V'101 and V'102 may be a linear alkylene group or a branched alkylene group, and is preferably a linear alkylene group. Specifically, the alkylene groups in V'101 and V'102 include methylene groups. [-CH 2-];-CH(CH 3)-, -CH(CH 2CH 3)-, -C(CH 3) 2-, -C(CH 3)(CH2CH 3)-, -C(CH 3)(CH 2CH 2CH 3)-, -C(CH 2CH 3) 2- and other alkylmethylene groups; ethylenyl [-CH 2CH 2-]; -CH(CH 3)CH 2-, -CH(CH 3)CH(CH 3)-, -C(CH 3) 2CH 2-, -CH(CH 2CH 3)CH 2- and other alkyl ethylidene groups; trimethylene (n-propylidene) [-CH 2CH 2CH 2-]; alkyl trimethylene such as -CH(CH 3)CH 2CH 2-, -CH 2CH(CH 3)CH 2-; tetramethylene [-CH 2CH 2CH 2CH 2-]; Alkyl tetramethylene such as -CH(CH 3)CH 2CH 2CH 2-, -CH 2CH(CH 3)CH 2CH 2-; pentamethylene [-CH 2CH 2CH 2CH 2CH 2-], etc. Furthermore, a portion of the methylene groups in the aforementioned alkylene groups in V'101 or V'102 may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a divalent group derived from the cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group or polycyclic aliphatic hydrocarbon group) of Ra'3 in the aforementioned formula (a1-r-1) by further removing one hydrogen atom; more preferably, it is a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group.

[0314] Y101 is preferably a divalent linking group containing an ester bond, or a divalent linking group containing an ether bond; more preferably, it is a linking group represented by the above formulas (y-a1-1) to (y-a1-5), respectively.

[0315] In formula (b-1), V101 is a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group or fluorinated alkylene group in V101 preferably has 1 to 4 carbon atoms. Examples of the fluorinated alkylene group in V101 include groups in which some or all of the hydrogen atoms in the alkylene group in V101 are substituted with fluorine atoms. V101 is particularly preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms; more preferably, a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

[0316] In formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0317] Specific examples of the anion moiety represented by the aforementioned formula (b-1) include, for example, when Y 101 is a single bond, fluorinated alkylsulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; and when Y 101 is a divalent linking group containing an oxygen atom, an anion represented by any of the following formulas (an-1) to (an-3) can be mentioned.

[0318] [In the formula, R"101 is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by the aforementioned chemical formulas (R-HR-1) to (R-HR-6), a condensed cyclic group represented by the aforementioned formula (R-Br-1) or (R-Br-2), or a chain alkyl group which may have a substituent. R"102 is an aliphatic cyclic group which may have a substituent, a condensed cyclic group represented by the aforementioned formula (R-Br-1) or (R-Br-2), a lactone-containing cyclic group represented by the aforementioned general formulas (A2-R-1), (A2-R-3) to (A2-R-7), or a -SO2- containing cyclic group represented by the aforementioned general formulas (B5-R-1) to (B5-R-4). R"103 is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. V"101 is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. R102 is a fluorine atom or a fluorinated alkylene group having 1 to 5 carbon atoms. v" is each independently an integer from 0 to 3, q" is each independently an integer from 0 to 20, and n" is 0 or 1.

[0319] The aliphatic cyclic group which may have a substituent, R'101, R'102, and R'103, is preferably the group exemplified as the cyclic aliphatic hydrocarbon group in R'101 in the aforementioned formula (b-1). The aforementioned substituent may be the same as the substituent which may be substituted for the cyclic aliphatic hydrocarbon group in R'101 in the aforementioned formula (b-1).

[0320] The aromatic cyclic group in R"103 which may have a substituent is preferably the group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in R101 in the aforementioned formula (b-1). The aforementioned substituent may be the same as the substituent that may be substituted for the aromatic hydrocarbon group in R101 in the aforementioned formula (b-1).

[0321] The optionally substituted chain alkyl group in R101 is preferably the group exemplified as the chain alkyl group in R101 in the aforementioned formula (b-1). The optionally substituted chain alkenyl group in R103 is preferably the group exemplified as the chain alkenyl group in R101 in the aforementioned formula (b-1).

[0322] ･Anions in component (b-2) In formula (b-2), R104 and R105 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the same as for R101 in formula (b-1). However, R104 and R105 may also be bonded to form a ring. R 104 and R 105 are preferably chain alkyl groups which may have a substituent; more preferably, they are linear or branched alkyl groups, or linear or branched fluorinated alkyl groups. The number of carbon atoms in the chain alkyl group is preferably 1-10, more preferably 1-7, and even more preferably 1-3. Within the aforementioned range, the number of carbon atoms in the chain alkyl group represented by R104 and R105 is preferably as small as possible for reasons such as improved solubility in resist solvents. Furthermore, the greater the number of hydrogen atoms substituted with fluorine atoms in the chain alkyl group represented by R104 and R105, the stronger the acid strength and the improved transparency to high-energy light or electron beams below 250 nm. The ratio of fluorine atoms in the chain alkyl group, or the fluorination rate, is preferably 70-100%, more preferably 90-100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 and V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and examples thereof include the same as those for V 101 in formula (b-1). In formula (b-2), L 101 and L 102 are each independently a single bond or an oxygen atom.

[0323] ･Anions in (b-3) component In formula (b-3), R 106 to R 108 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof are the same as those for R 101 in formula (b-1). In formula (b-3), L103 to L105 are each independently a single bond, -CO- or -SO 2-.

[0324] {Cation Department} In the aforementioned formulas (b-1), (b-2), and (b-3), M'm+ represents an m-valent onium cation. Among them, a coronium cation and an iodonium cation are particularly preferred. m is an integer greater than or equal to 1.

[0325] Preferred cationic moieties ((M'm+) 1 / m) include organic cations represented by the above-mentioned general formulas (ca-1) to (ca-3).

[0326] In the resist composition of this embodiment, the component (B1) may be used alone or in combination of two or more. The content of the component (B1) is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less, based on 100 parts by mass of the component (A). The resist composition of this embodiment preferably contains only the component (B0) as the acid generator.

[0327] <Other ingredients> The resist composition of this embodiment may further contain other components in addition to the above-mentioned components (A) and (B). Examples of such other components include the following components (D), (E), (F), and (S).

[0328] Alkali component (D) The resist composition of this embodiment preferably further contains an alkaline component (hereinafter also referred to as "component (D)") that traps (i.e., controls the diffusion of) the acid generated by exposure. Component (D) acts as a quencher (acid diffusion controller) in the resist composition, trapping the acid generated by exposure. Examples of the component (D) include a photodisintegrating base (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure and loses its acid diffusion control properties, and a nitrogen-containing organic compound (D2) (hereinafter referred to as "component (D2)") that does not correspond to component (D1). Of these, a photodisintegrating base (component (D1)) is preferred because it can easily improve roughness reduction properties. Furthermore, the inclusion of component (D1) can easily enhance both high sensitivity and the suppression of coating defects.

[0329] ･About the (D1) ingredient By forming a resist composition containing the component (D1), the contrast between the exposed portion and the unexposed portion of the resist film can be further improved when forming a resist pattern. The (D1) component is not particularly limited as long as it decomposes by exposure and loses the acid diffusion control property. It is preferably one or more compounds selected from the group consisting of a compound represented by the following general formula (d1-1) (hereinafter referred to as the "(d1-1) component"), a compound represented by the following general formula (d1-2) (hereinafter referred to as the "(d1-2) component"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as the "(d1-3) component"). Components (d1-1) to (d1-3) decompose in the exposed portion of the resist film and lose their acid diffusion control properties (alkalinity), so they do not act as a quencher, but act as a quencher in the unexposed portion of the resist film.

[0330] [In the formula, Rd1-Rd4 are cyclic groups that may have substituents, chain alkyl groups that may have substituents, or chain alkenyl groups that may have substituents. However, in Rd2 in formula (d1-2), no fluorine atom is bonded to the carbon atom adjacent to the sulfur atom. Yd1 is a single bond or a divalent linking group. m is an integer greater than 1, and Mm+ are each independently an m-valent organic cation.]

[0331] {(d1-1)Component} ･･Anion part In formula (d1-1), Rd1 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples of each of them are the same as those for R'201 described above. Among these, Rd1 is particularly preferably an aromatic hydrocarbon group that may have a substituent, an aliphatic cyclic group that may have a substituent, or an alkyl chain that may have a substituent. Examples of substituents that these groups may have include hydroxyl groups, pendant oxygen groups, alkyl groups, aryl groups, fluorine atoms, fluorinated alkyl groups, lactone-containing cyclic groups represented by the above-mentioned general formulas (a2-r-1) to (a2-r-7), ether bonds, ester bonds, or combinations thereof. When an ether bond or ester bond is included as a substituent, it may be separated by an alkylene group. In such cases, the substituent is preferably a linking group represented by the above-mentioned formulas (y-a1-1) to (y-a1-5). Furthermore, when the aromatic hydrocarbon group, aliphatic cyclic group, or chain alkyl group in Rd1 has a linking group represented by the above-mentioned general formulas (y-al-1) to (y-al-7) as a substituent, the carbon atom in the above-mentioned general formulas (y-al-1) to (y-al-7) that is bonded to the aromatic hydrocarbon group, aliphatic cyclic group, or chain alkyl group in Rd1 in formula (d3-1) is V'101 in the above-mentioned general formulas (y-al-1) to (y-al-7). Preferred examples of the aromatic hydrocarbon group include phenyl, naphthyl, and a polycyclic structure including a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and other ring structures). The aforementioned aliphatic cyclic group is more preferably a group derived from a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane by removing one or more hydrogen atoms. The aforementioned chain alkyl group preferably has 1 to 10 carbon atoms. Specifically, examples include straight-chain alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl; and branched-chain alkyl groups such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl.

[0332] When the aforementioned chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may also contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include oxygen atoms, sulfur atoms, and nitrogen atoms.

[0333] Preferred specific examples of the anion portion of the component (d1-1) are shown below.

[0334]

[0335] ･･Cationic Department In formula (d1-1), M m+ is an organic cation with a valence of m. The organic cation of M m+ can be suitably the same as the cations represented by the aforementioned general formulas (ca-1) to (ca-3), more preferably the cation represented by the aforementioned general formula (ca-1), and even more preferably the cations represented by the aforementioned formulas (ca-1-1) to (ca-1-113). The component (d1-1) may be used alone or in combination of two or more.

[0336] {(d1-2)Component} ･･Anion part In formula (d1-2), Rd2 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the same as those for R'201 described above. However, in Rd2, the carbon atom adjacent to the S atom has no fluorine atom bonded to it (it is not fluorine-substituted). This makes the anion of the (d1-2) component a moderately weak acid anion, enhancing its quenching ability as the (D) component. Rd 2 is preferably a chain alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent; more preferably an aliphatic cyclic group which may have a substituent.

[0337] The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may also have a substituent); or a group obtained by removing one or more hydrogen atoms from camphor.

[0338] The hydrocarbon group of Rd2 may also have a substituent, and examples of the substituent include the same substituents as the substituents that the hydrocarbon group in Rd1 in the aforementioned formula (d1-1) (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) may have.

[0339] Preferred specific examples of the anion portion of the component (d1-2) are shown below.

[0340]

[0341] ･･Cationic Department In formula (d1-2), M m+ is an organic cation with a valence of m, which is the same as M m+ in the aforementioned formula (d1-1). The component (d1-2) may be used alone or in combination of two or more.

[0342] {(d1-3)Component} ･･Anion part In formula (d1-3), Rd3 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. Examples of such groups include the same as those for R'201 described above. Preferred are cyclic groups containing fluorine atoms, chain alkyl groups, or chain alkenyl groups. Fluorinated alkyl groups are particularly preferred, and the same fluorinated alkyl groups as those for Rd1 described above are even more preferred.

[0343] In formula (d1-3), Rd4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the same as those for R'201 described above. Among them, an alkyl group, an alkoxy group, an alkenyl group, and a cyclic group which may have a substituent are particularly preferred. The alkyl group in Rd4 is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl. Some of the hydrogen atoms in the alkyl group in Rd4 may be substituted with a hydroxyl group, a cyano group, or the like. The alkoxy group in Rd4 is preferably an alkoxy group having 1 to 5 carbon atoms. Specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, and tert-butoxy. Among them, methoxy and ethoxy are particularly preferred.

[0344] Examples of the alkenyl group in Rd4 include the same alkenyl groups as those in R'201, preferably vinyl, propenyl (allyl), 1-methylpropenyl, and 2-methylpropenyl. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

[0345] The cyclic group in Rd4 can be the same as the cyclic group in R'201 described above. Preferred are alicyclic groups derived from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane by removing one or more hydrogen atoms, or aromatic groups such as phenyl and naphthyl. When Rd4 is an alicyclic group, the resist composition dissolves well in organic solvents, resulting in excellent lithographic properties. Furthermore, when Rd4 is an aromatic group, the resist composition exhibits excellent light absorption efficiency in lithography using EUV or other light sources, resulting in excellent sensitivity and lithographic properties.

[0346] In formula (d1-3), Yd1 is a single bond or a divalent linking group. The divalent linking group in Yd1 is not particularly limited, and examples thereof include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a divalent linking group containing a heteroatom, and the like. These examples include the same divalent hydrocarbon group which may have a substituent and the divalent linking group containing a heteroatom as those listed in the description of the divalent linking group in Ya21 in the above formula (a2-1). Yd1 is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

[0347] Preferred specific examples of the anion portion of the component (d1-3) are shown below.

[0348]

[0349]

[0350] ･･Cationic Department In formula (d1-3), M m+ is an organic cation with a valence of m, which is the same as M m+ in the aforementioned formula (d1-1). The component (d1-3) may be used alone or in combination of two or more.

[0351] As the component (D1), any one of the components (d1-1) to (d1-3) may be used alone, or two or more thereof may be used in combination. When the resist composition contains component (D1), the content of component (D1) in the resist composition is preferably 0.5 to 15 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 8 parts by mass, relative to 100 parts by mass of component (A). If the content of component (D1) is above the preferred lower limit, particularly good lithographic characteristics and resist pattern shapes are easily obtained. On the other hand, if it is below the upper limit, good sensitivity can be maintained and excellent flux is also achieved.

[0352] In the resist composition of this embodiment, the component (D1) preferably includes the above-mentioned component (d1-1). The content of the component (d1-1) in the total amount of the component (D) contained in the resist composition of this embodiment is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The component (D) may also be composed solely of the compound (d1-1).

[0353] (D1) Method of manufacturing ingredients: The production method of the aforementioned components (d1-1) and (d1-2) is not particularly limited and they can be produced by known methods. The method for producing the component (d1-3) is not particularly limited, and it can be produced, for example, in the same manner as described in US Pat. No. 2012-0149916.

[0354] ･About the (D2) ingredient The component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") which does not correspond to the component (D1) described above. Component (D2) is not particularly limited as long as it functions as an acid diffusion controller and does not correspond to component (D1), and any known component can be used. Among them, aliphatic amines are particularly preferred, and secondary or tertiary aliphatic amines are particularly preferred. Aliphatic amine refers to an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. Examples of the aliphatic amine include amines (alkylamines or alkanolamines) or cyclic amines in which at least one hydrogen atom of ammonia NH 3 is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms. Specific examples of alkylamines and alkanolamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkanolamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0355] Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine). Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0356] Other aliphatic amines include tris-(2-methoxymethoxyethyl)amine, tris-{2-(2-methoxyethoxy)ethyl}amine, tris-{2-(2-methoxyethoxymethoxy)ethyl}amine, tris-{2-(1-methoxyethoxy)ethyl}amine, tris-{2-(1-ethoxyethoxy)ethyl}amine, tris-{2-(1-ethoxypropoxy)ethyl}amine, tris-[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, and triethanolamine triacetate, with triethanolamine triacetate being preferred.

[0357] Furthermore, aromatic amines can also be used as the component (D2). Examples of the aromatic amine include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole, or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, and 2,6-di-tert-butylpyridine.

[0358] Among the above, component (D2) is preferably an alkylamine, more preferably a trialkylamine having 6 to 30 carbon atoms.

[0359] The component (D2) may be used alone or in combination of two or more. When the resist composition contains component (D2), the content of component (D2) in the resist composition is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of component (A). If the content of component (D2) is above the preferred lower limit, particularly good lithographic characteristics and resist pattern shapes are easily obtained. On the other hand, if it is below the upper limit, good sensitivity can be maintained and excellent flux is also achieved.

[0360] At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxoacids, and their derivatives The resist composition of this embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxyacids, and their derivatives (hereinafter referred to as "component (E)") for the purpose of preventing sensitivity degradation or improving the resist pattern shape and stability over time after exposure. Specific examples of the organic carboxylic acid include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, among which salicylic acid is particularly preferred. Examples of phosphorus oxygen acids include phosphoric acid, phosphonic acid, hypophosphorous acid, and the like, with phosphonic acid being particularly preferred.

[0361] In the resist composition of this embodiment, the component (E) may be used alone or in combination of two or more. When the resist composition contains component (E), the content of component (E) is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, relative to 100 parts by mass of component (A). By falling within this range, lithography properties are further improved.

[0362] Fluorine additive ingredients (F) The resist composition of this embodiment may also contain a fluorine additive component (hereinafter referred to as "component (F)") as a hydrophobic resin. Component (F) is used to impart water repellency to the resist film. By using it as a different resin from component (A), it can improve lithography properties. As the component (F), for example, fluorine-containing polymer compounds described in JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226 can be used. More specifically, component (F) includes a polymer having a structural unit (f1) represented by the following general formula (f1-1). The polymer is preferably a polymer (homopolymer) composed solely of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the aforementioned structural unit (a1); a copolymer of the structural unit (f1) and a structural unit derived from acrylic acid or methacrylic acid, and the aforementioned structural unit (a1); and more preferably a copolymer of the structural unit (f1) and the aforementioned structural unit (a1). The structural unit (a1) copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate or a structural unit derived from 1-methyl-1-adamantyl (meth)acrylate; more preferably, a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate.

[0363] [In the formula, R is the same as described above, Rf102 and Rf103 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf102 and Rf103 may be the same or different. nf1 is an integer from 0 to 5, and Rf101 is an organic group containing a fluorine atom].

[0364] In formula (f1-1), R bonded to the carbon atom at the α position is the same as described above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), the halogen atom represented by Rf102 and Rf103 is preferably a fluorine atom. The alkyl group having 1 to 5 carbon atoms represented by Rf102 and Rf103 can be the same as the alkyl group having 1 to 5 carbon atoms represented by R, and is preferably a methyl group or an ethyl group. Specifically, the halogenated alkyl group having 1 to 5 carbon atoms represented by Rf102 and Rf103 can be a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. The halogen atom is preferably a fluorine atom. Rf102 and Rf103 are particularly preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms; more preferably, a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group; and even more preferably, a hydrogen atom. In formula (f1-1), nf1 is an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0365] In formula (f1-1), Rf101 is an organic group containing a fluorine atom, preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing a fluorine atom may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. In addition, for a hydrocarbon group containing fluorine atoms, it is preferred that more than 25% of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably more than 50% are fluorinated, and since the hydrophobicity of the resist film during immersion exposure is improved, it is particularly preferred that more than 60% are fluorinated. Among them, Rf101 is more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms; particularly preferably a trifluoromethyl group, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH 2-CH 2-CF 3, -CH 2-CH 2-CF 2-CF 2-CF 2-CF 3.

[0366] The weight-average molecular weight (Mw) of component (F) (measured by gel permeation chromatography, based on polystyrene) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. If the Mw is below the upper limit of this range, the component will have sufficient solubility in resist solvents for use as a resist. If the Mw is above the lower limit of this range, the resist film will have excellent water repellency. The dispersion degree (Mw / Mn) of the (F) component is preferably 1.0-5.0, more preferably 1.0-3.0, and most preferably 1.0-2.5.

[0367] In the resist composition of this embodiment, the component (F) may be used alone or in combination of two or more. When the resist composition contains component (F), the content of component (F) is preferably 0.5 to 10 parts by mass, more preferably 1 to 10 parts by mass, relative to 100 parts by mass of component (A).

[0368] Organic solvent component (S) The resist composition of this embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter referred to as "(S) component"). The component (S) may be any one that can dissolve the components to be used to form a uniform solution, and any one that is conventionally known as a solvent for a chemically amplified resist composition may be appropriately selected and used. (S) component includes, for example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-amyl ketone, methyl isoamyl ketone, 2-heptanone; polyols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; derivatives of polyols such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or monophenyl ether of the aforementioned polyols or compounds having an ester bond. Examples include propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME); cyclic ethers such as dioxane, or esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenethyl ether, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, isopropyltoluene, and mesitylene; and dimethyl sulfoxide (DMSO). In the resist composition of this embodiment, the component (S) may be used alone or as a mixture of two or more components. Among them, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are particularly preferred.

[0369] Component (S) is also preferably a mixed solvent of PGMEA and a polar solvent. The blending ratio (mass ratio) can be appropriately determined by taking into account factors such as the compatibility of PGMEA and the polar solvent, and is preferably within a range of 1:9 to 9:1, and more preferably 2:8 to 8:2. More specifically, when EL or cyclohexanone is added as a polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. Furthermore, when PGME is added as a polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred. Furthermore, component (S) is preferably a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone. In this case, the mixing ratio of the former to the latter is preferably 70:30 to 95:5 by weight. The amount of component (S) used is not particularly limited and is appropriately set based on the coating thickness, allowing for application to a substrate. Generally, component (S) is used to achieve a solids concentration within the range of 0.1-20% by mass, preferably 0.2-15% by mass, of the resist composition.

[0370] The resist composition of this embodiment can also be filtered using a polyimide porous membrane, a polyamide-imide porous membrane, or the like after dissolving the resist material in component (S). For example, the resist composition can be filtered using a filter composed of a polyimide porous membrane, a filter composed of a polyamide-imide porous membrane, or a filter composed of a polyimide porous membrane and a polyamide-imide porous membrane. Examples of the polyimide porous membrane and the polyamide-imide porous membrane include those described in Japanese Patent Application Laid-Open No. 2016-155121.

[0371] The resist composition of the present embodiment described above contains a base component (A) and an acid generator component (B), wherein the acid generator component (B) includes a compound (B0) represented by the general formula (b0). Compound (B0), because it contains multiple iodine atoms, has high absorption efficiency for EUV (extreme ultraviolet) and EB (electron beam). On the other hand, the presence of iodine atoms tends to reduce solubility in developer. However, since compound (B0) contains acid-degradable groups (Rpg), the acid-dissociable groups of the acid-degradable groups dissociate in the exposed areas of the resist film, transforming the acid-dissociable groups into polar groups, thereby improving solubility in developer. In other words, compound (B0), by containing iodine atoms and acid-degradable groups, dissolves the exposed areas of the resist film more readily in developer, while the unexposed areas of the resist film dissolve less readily in developer. Furthermore, since compound (B0) contains a cyclic organic group (R10) having an acid-decomposable group having a relatively bulky structure, the diffusion length of the acid is moderately suppressed. Therefore, the resist composition of this embodiment containing compound (B0) is presumably capable of forming a CDU and a resist pattern with good resolution by controlling the diffusion length of the acid or improving the balance between hydrophilicity and hydrophobicity.

[0372] (Resist Pattern Formation Method) The second aspect of the present invention is a method for forming a resist pattern, comprising the steps of forming a resist film on a support using the resist composition of the first aspect of the present invention, exposing the resist film, and developing the exposed resist film to form a resist pattern. As one embodiment of the resist pattern forming method, for example, the resist pattern forming method performed as follows can be cited.

[0373] First, the resist composition of the above embodiment is coated on a support using a spinner or the like, and then baked (post-apply bake (PAB)) at a temperature of, for example, 80-150° C. for 40-120 seconds, preferably 60-90 seconds, to form a resist film. Next, the resist film is selectively exposed using an exposure device such as an electron beam lithography device or an ArF exposure device, by exposing through a mask having a specific pattern (mask pattern) or by lithography without irradiating the mask pattern with an electron beam, and then baked (post-exposure bake (PEB)) at a temperature of 80-150°C for 40-120 seconds, preferably 60-90 seconds. Next, the resist film is developed. In terms of development, an alkali developer is used in an alkali development process, and an organic developer (organic developer) is used in a solvent development process.

[0374] After the development process, a rinse process is preferably performed. As for the rinse process, pure water is preferably used for alkali development, and a rinse solution containing an organic solvent is preferably used for solvent development. In the case of a solvent development process, after the aforementioned development or rinsing process, a process of removing the developer or rinse solution attached to the pattern by using a supercritical fluid may be performed. After the development process or the rinse process, drying is performed. In addition, a baking process (post-baking) may also be performed after the development process, depending on the situation. In this way, a resist pattern can be formed.

[0375] The support is not particularly limited; conventionally known materials may be used. Examples include substrates for electronic components or substrates on which a specific wiring pattern is formed. More specifically, examples include silicon wafers, substrates made of metals such as copper, chromium, iron, and aluminum, and glass substrates. Materials for the wiring pattern include copper, aluminum, nickel, and gold.

[0376] The wavelength used for exposure is not particularly limited, and exposure can be performed using radiation such as ArF excimer lasers, KrF excimer lasers, F2 excimer lasers, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays. The resist composition is highly useful for use with KrF excimer lasers, ArF excimer lasers, EB, or EUV; even more useful for use with ArF excimer lasers, EB, or EUV; and particularly useful for use with EB or EUV. In other words, the resist patterning method of this embodiment is particularly useful when the step of exposing the resist film includes exposing the resist film to EUV (extreme ultraviolet) or EB (electron beam).

[0377] The exposure method of the resist film can be conventional exposure (dry exposure) performed in air or an inert gas such as nitrogen, or liquid immersion lithography. Liquid immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure device is pre-filled with a solvent (liquid immersion medium) having a refractive index greater than that of air, and exposure is performed in this state (immersion exposure). As the immersion medium, a solvent having a refractive index larger than that of air and smaller than that of the exposed resist film is preferred, and examples thereof include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents. As the immersion medium, water is preferably used.

[0378] The alkaline developer used in the development process in the alkaline development process may be, for example, a 0.1-10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution. The organic solvent contained in the organic developer used in the solvent development process can be any solvent that dissolves component (A) (component (A) before exposure) and can be appropriately selected from known organic solvents. Specifically, examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0379] Examples of the ester solvent include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxy propionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butyrate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0380] Examples of the nitrile solvent include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0381] The organic developer may contain known additives as needed. Examples of such additives include surfactants. The surfactant is not particularly limited; for example, ionic or nonionic fluorine-based and / or silicon-based surfactants may be used. The surfactant is preferably a nonionic surfactant, more preferably a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant. When a surfactant is added, its amount is generally 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total amount of the organic developer.

[0382] The development process can be carried out by a known development method, for example, a method of immersing the support in a developer for a certain period of time (immersion method), a method of allowing the developer to swell on the surface of the support due to surface tension and then remain stationary for a certain period of time (liquid coating method), a method of spraying the developer onto the surface of the support (spraying method), a method of continuously coating the developer on a support rotating at a certain speed while scanning the developer coating nozzle at a certain speed (dynamic coating method), etc.

[0383] The organic solvent contained in the rinse solution used in the post-development rinse process during the solvent development process can be appropriately selected from the organic solvents listed above for the organic developer, for example, one that does not readily dissolve the resist pattern. Typically, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and amide solvents is preferred; at least one selected from alcohol solvents and ester solvents is more preferred; and alcohol solvents are particularly preferred. The alcohol solvent used in the rinse solution is preferably a monohydric alcohol having 6 to 8 carbon atoms. The monohydric alcohol may be linear, branched, or cyclic. Specifically, examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 4-octanol, and benzyl alcohol. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are particularly preferred, with 1-hexanol and 2-hexanol being even more preferred. These organic solvents may be used alone or in combination. Furthermore, they may be mixed with organic solvents other than those listed above or with water. However, considering development characteristics, the amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3% by mass or less, relative to the total amount of the rinse solution. The rinse solution may contain known additives as needed. Examples of such additives include surfactants. Examples of surfactants include the same surfactants as described above, preferably nonionic surfactants, more preferably nonionic fluorine-based surfactants or nonionic silicone-based surfactants. When a surfactant is added, its amount is generally 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass relative to the total amount of the rinse solution.

[0384] Rinse treatment (cleaning treatment) using a rinse solution can be performed using known rinsing methods. Examples of such rinsing methods include continuously applying the rinse solution to a support rotating at a constant speed (spin coating), immersing the support in the rinse solution for a predetermined period of time (immersion), and spraying the rinse solution onto the support surface (spraying).

[0385] According to the resist pattern forming method of the present embodiment described above, since the resist composition described above is used, a CDU and a resist pattern with good resolution can be formed.

[0386] The resist composition of the above-described embodiment and the various materials used in the patterning method of the above-described embodiment (e.g., resist solvent, developer, rinse solution, antireflective film-forming composition, surface coating layer-forming composition, etc.) preferably contain no impurities such as metals, halogen-containing metal salts, acids, bases, or components containing sulfur or phosphorus atoms. Examples of metal atom-containing impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The impurity content in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device).

[0387] (Compound) The third aspect of the compound of the present invention is a compound represented by the following general formula (b0).

[0388] [In the formula, Rpg is an acid-decomposable group. Rl0 is a cyclic organic group which may have a substituent. L02 is a divalent linking group. L01 is a divalent linking group or a single bond. Rm1 is a substituent other than an iodine atom. Vb0 is a single bond, an alkylene group, or a fluorinated alkylene group. R0 is a hydrogen atom, a fluorinated alkylene group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 1 to 4, nb2 is an integer of 1 to 4, and nb3 is an integer of 0 to 3. Mm+ represents an m-valent organic cation. m is an integer of 1 or greater].

[0389] The compound represented by the general formula (b0) is the same as the component (B0) in the resist composition of the first aspect of the present invention.

[0390] [Method for producing the compound represented by general formula (b0)] The component (B0) can be produced using a known method. For example, a precursor Bpre represented by the following general formula (Bpre) can be subjected to a salt exchange reaction with a compound S0 represented by the following general formula (S-0) to obtain component (B0).

[0391] [In the formula, Rpg is an acid-decomposable group. Rl0 is a cyclic organic group which may have a substituent. L02 is a divalent linking group. L01 is a divalent linking group or a single bond. Rm1 is a substituent other than an iodine atom. Vb0 is a single bond, an alkylene group, or a fluorinated alkylene group. R0 is a hydrogen atom, a fluorinated alkylene group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 1 to 4, nb2 is an integer of 1 to 4, and nb3 is an integer of 0 to 3. (M1″m+)1 / m is an ammonium cation. Z- is a non-nucleophilic ion. Mm+ represents an m-valent organic cation. m is an integer greater than 1].

[0392] More specifically, the salt exchange reaction is a step of reacting the precursor Bpre with the salt exchange compound S0 in a solvent such as water, dichloromethane, acetonitrile, or chloroform to exchange the cation of the precursor Bpre with the cation of the compound S0 to obtain the component (B0).

[0393] In the above formula, (M1″m+)1 / m is an ammonium cation, which may be an ammonium cation derived from an aliphatic amine or an ammonium cation derived from an aromatic amine.

[0394] In the above formula, Z- can be an ion that can become an acid with lower acidity than the precursor Bpre, specifically, halogen ions such as bromide ion and chloride ion, BF4-, AsF6-, SbF6-, PF6-, ClO4-, etc.

[0395] The reaction temperature is, for example, 0 to 100° C., and the reaction time is, for example, 10 minutes to 24 hours.

[0396] After the salt exchange reaction is completed, the compound in the reaction solution can be isolated and purified. Isolation and purification can be performed using conventionally known methods, such as concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc., which can be appropriately combined. The structure of the compound obtained as described above can be identified by general organic analytical methods such as 1H-nuclear magnetic resonance (NMR) spectroscopy, 13C-NMR spectroscopy, 19F-NMR spectroscopy, infrared absorption (IR) spectroscopy, mass spectrometry (MS), elemental analysis, and X-ray crystallography.

[0397] For example, the method for producing the precursor Bpre may include the following methods: method 1 for producing the precursor Bpre and method 2 for producing the precursor Bpre.

[0398] [Method 1 for producing precursor Bpre] Method 1 for producing a precursor Bpre comprises a step (step A) of reacting a compound represented by the following general formula (CA-00) (hereinafter referred to as "compound (CA00)") with a compound represented by the following general formula (X-00) (hereinafter referred to as "compound (X00)") to obtain a compound represented by the following general formula (Y-00) (hereinafter referred to as "compound (Y00)"), and a step (step B) of reacting the compound represented by the following general formula (Y-00) with a compound represented by the following general formula (Al-00) (hereinafter referred to as "compound (Al00)") to obtain a precursor Bpre' represented by the following general formula (Bpre'). The precursor Bpre' is a compound used to obtain the compound (B0), which is a compound in which L01 and L02 in the general formula (b0) are defined as ester bonds.

[0399] [In the formula, Rpg is an acid-decomposable group. R10 is a cyclic organic group which may have a substituent. Rm1 is a substituent other than an iodine atom. Vb0 is a single bond, an alkylene group, or a fluorinated alkylene group. R0 is a hydrogen atom, a fluorinated alkylene group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer from 1 to 4, and nb3 is an integer from 0 to 3. (M1″m+)1 / m is an ammonium cation].

[0400] Step A: Step A is, for example, a step of reacting compound (CA00) with compound (X00) in an organic solvent (THF, hexane, etc.) to obtain compound (Y00).

[0401] In the reaction in step A, a condensation agent, an alkaline catalyst, etc. may also be used. Specific examples of the condensing agent include N,N′-dicyclohexylcarbodiimide, N,N′-diisopropylcarbodiimide (DIC), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and carbonyldiimidazole (CDI). Specifically, the alkaline catalyst includes tertiary amines such as trimethylamine, triethylamine, and tributylamine; aromatic amines such as pyridine, dimethylaminopyridine (DMAP), and pyrrolidinylpyridine; and diazabicyclononene (DBN) and diazabicycloundecene (DBU).

[0402] The reaction temperature is, for example, 0 to 80° C., and the reaction time is, for example, 10 minutes to 24 hours.

[0403] Step B: Step B is, for example, a step of reacting compound (Y00) with compound (Al00) in an organic solvent (such as dichloromethane) to obtain a precursor Bpre'.

[0404] In step B, similarly to step A, a condensing agent, an alkaline catalyst, etc. may be used. The reaction temperature of step B is, for example, 0-50° C., and the reaction time is, for example, 10 minutes or more and 24 hours or less.

[0405] [Method 2 for producing precursor Bpre] Method 2 for producing a precursor Bpre comprises a step (step A') of reacting a compound represented by the following general formula (CA-00') (hereinafter referred to as "compound (CA00')") with a compound represented by the following general formula (X-00') (hereinafter referred to as "compound (X00')") to obtain a compound represented by the following general formula (Y-00') (hereinafter referred to as "compound (Y00')"), and a step (step B') of reacting a compound represented by the following general formula (Y-00') with a compound represented by the following general formula (Al-00') (hereinafter referred to as "compound (Al00')") to obtain a precursor Bpre'' represented by the following general formula (Bpre''). The precursor Bpre'' is a compound used to obtain the compound (B0), which is a compound in which the acid-decomposable group in Rpg in the general formula (b0) is limited to -(C=O)-O-Rpg 00, L 02 is limited to an ester bond, and the cyclic organic group in Rl 0 is limited to a specific condensed cyclic group.

[0406] [In the formula, Rpg 00 is an acid-dissociable group. R m1 is a substituent other than an iodine atom. L 01 is a divalent linking group or a single bond. Vb 0 is a single bond, an alkylene group, or a fluorinated alkylene group. R 0 is a hydrogen atom, a fluorinated alkylene group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer from 1 to 4, and nb3 is an integer from 0 to 3. (M1″ m+) 1 / m is an ammonium cation].

[0407] Step A': Step A' is, for example, a step of reacting compound (CA00') with compound (X00') in an organic solvent (THF, hexane, etc.) in the presence of a base to obtain compound (Y00').

[0408] Specific examples of the base include sodium hydride, K 2 CO 3 , Cs 2 CO 3 , lithium diisopropylamide (LDA), triethylamine, and 4-dimethylaminopyridine. The reaction temperature is, for example, 0 to 50° C., and the reaction time is, for example, 10 minutes to 24 hours.

[0409] Step B': Step B' is, for example, a step of reacting compound (Y00') with compound (Al00') in an organic solvent (such as dichloromethane) to obtain a precursor Bpre''.

[0410] In step B', similarly to step B, a condensing agent, an alkaline catalyst, etc. may be used. The reaction temperature of step B is, for example, 0-50° C., and the reaction time is, for example, 10 minutes or more and 24 hours or less.

[0411] The compound of the third aspect of the present invention described above is a compound useful as an acid generator in the resist composition of the first aspect of the present invention.

[0412] (Acid Generator) The acid generator of the fourth aspect of the present invention comprises the compound of the third aspect. This acid generator is useful as an acid generator component in a chemically amplified resist composition. By using this acid generator component in a chemically amplified resist composition, CDU and resolution are further improved during resist patterning. This acid generator component further enhances CDU and resolution, particularly during resist patterning using EB or EUV light sources. [Example]

[0413] The present invention will be described in more detail below with reference to the following examples, but the present invention is not limited to these examples.

[0414] <Synthesis Example of Compound> [Synthesis Example of Intermediate] ･Synthesis of intermediate P1 1,1'-Carbonyldiimidazole (CDI) (4.60 g, 28.4 mmol) and acetonitrile (20 g) were placed in a 300 mL three-necked flask. A solution of 3-hydroxy-4-iodobenzoic acid (CA1) (6.74 g, 25.5 mmol) in acetonitrile (20 g) was then added dropwise over 30 minutes, followed by one hour of reaction. Compound (I-1) (9.5 g, 30.6 mmol) was then added, and the mixture was allowed to react at 65°C for 3 hours. After cooling, ultrapure water (250 g) was added, and the mixture was stirred for 30 minutes. The precipitated solid was filtered. The filtrate was redissolved in methanol (100 g), added dropwise to MTBE (500 g), and the precipitated solid was filtered. The filtrate was dried under reduced pressure to obtain Intermediate P1.

[0415]

[0416] ･Synthesis of intermediates 2~6 Intermediates P2 to P5 were synthesized in the same manner as in the synthesis example of intermediate P1, except that 3-hydroxy-4-iodobenzoic acid (CA1) (6.74 g, 25.5 mmol) was replaced with an equal mole of any of the following carboxylic acids CA2 to CA5.

[0417]

[0418]

[0419] ･Synthesis of intermediate P6 Intermediate P6 was obtained in the same manner as in the preparation example of intermediate P1, except that CA1 (6.74 g, 25.5 mmol) was changed to CA2 (10.0 g, 25.5 mmol) and compound I-1 (9.5 g, 30.6 mmol) was changed to compound I-2 (11.6 g, 30.6 mmol).

[0420]

[0421] ･Synthesis of intermediate P7 Intermediate P7 was obtained in the same manner as in the preparation example of intermediate P1, except that CA1 (6.74 g, 25.5 mmol) was changed to CA2 (10.0 g, 25.5 mmol) and compound I-1 (9.5 g, 30.6 mmol) was changed to compound I-3 (11.0 g, 30.6 mmol).

[0422]

[0423] ･Synthesis of intermediate P8 Intermediate P8 was obtained in the same manner as in the preparation example of intermediate P1, except that CA1 (6.74 g, 25.5 mmol) was changed to CA2 (10.0 g, 25.5 mmol) and compound I-1 (9.5 g, 30.6 mmol) was changed to compound I-4 (11.5 g, 30.6 mmol).

[0424]

[0425] ･Synthesis of intermediate AA1 A 1.06M solution of lithium diisopropylamide (LDA) in THF / hexane (87 mL, 92.3 mmol) was placed in a 500 mL three-necked flask. After cooling to 5°C, a solution of t-butanol (8.0 g, 108.6 mmol) in THF (30 g) was added and the mixture was allowed to react at or below 5°C for 2 hours. Compound M-1 (15.0 g, 54.3 mmol) in THF (225 g) was then added and the mixture was allowed to react at or below 5°C for 2 hours. The reaction mixture was poured into ultrapure water (205 g) over 30 minutes, followed by the addition of heptane (205 g). After stirring for 30 minutes, the organic layer was removed. The aqueous layer was washed three times with heptane (100 g), followed by the addition of MTBE (150 g) and a 10% aqueous citric acid solution (205 g, 106.1 mmol). After stirring for 30 minutes, the aqueous layer was removed. The recovered organic layer was washed three times with ultrapure water (150 g), concentrated using a rotary evaporator, and recrystallized from ethyl acetate to obtain intermediate AA1.

[0426]

[0427] ･Synthesis of intermediate AA2 Intermediate AA2 was obtained in the same manner as in the Preparation Example of Intermediate AA1 except that t-butanol (8.0 g, 108.6 mmol) was changed to 1-methylcyclopentanol (10.9 g, 108.6 mmol).

[0428]

[0429] [Synthesis Examples of Intermediates BA1-BA3 and NA1-NA3] Compound M-1 was converted to compounds M-2 and M-3 in equal moles, and reacted with t-butanol, 1-methylcyclopentanol, and 1-methyladamantanol, respectively, to obtain intermediates BA1-BA3 and NA1-NA3 in the same manner as in the preparation of intermediate AA1.

[0430]

[0431] [Synthesis Example of Precursor] ･Synthesis of precursor (Bpre-01) In a 200 mL three-necked flask, intermediate BA1 (3.6 g, 16.1 mmol), intermediate P1 (8.1 g, 14.5 mmol), and dichloromethane (180 g) were placed and stirred at room temperature to dissolve. Next, diisopropylcarbodiimide (DIC) (3.1 g, 24.2 mmol) and dimethylaminopyridine (0.2 g, 1.6 mmol) were added and reacted at room temperature for 5 hours. The reaction solution was filtered, and the filtrate was concentrated using a rotary evaporator. The concentrate was dissolved in acetonitrile (30 g) and added dropwise to MTBE (180 g), and the precipitated solid was filtered. The filtrate was again dissolved in acetonitrile (60 g), added dropwise to MTBE (400 g), and the precipitated solid was filtered. This process was repeated twice, and the filtrate was dried under reduced pressure to obtain the precursor (Bpre-01).

[0432]

[0433] ･Synthesis of precursors (Bpre-02)~(Bpre-29) Using the carboxylic acid group (16.1 mmol) of the intermediates BA1-BA3, NA1-NA3, AA1, and AA2 and the phenol group (14.5 mmol) of the intermediates P1-P8, the precursors (Bpre-02-10, 14-21, 25-29) were synthesized in the same manner as in the preparation of the precursor (Bpre-01). The combinations of carboxylic acids and intermediates used to obtain various precursors are shown in Table 1.

[0434]

[0435]

[0436]

[0437]

[0438]

[0439] [Synthesis Example of Compound (B0)] ･Synthesis of compound (B0-1) The precursor (Bpre-01) (8.0 g, 10.5 mmol) and salt-exchange compound A (3.8 g, 11.0 mmol) were dissolved in dichloromethane (120 g). Ultrapure water (120 g) was added and the mixture was reacted at room temperature for 30 minutes. After the reaction, the aqueous phase was removed, and the organic phase was washed four times with ultrapure water (120 g). The organic phase was concentrated to dryness using a rotary evaporator to obtain compound (B0-1).

[0440]

[0441] ･Synthesis of compounds (B0-2)~(B0-30) Compounds (B0-2) to (B0-30) were obtained in the same manner as in the "Synthesis Example of Compound (B0-1)" except that the combination of the above-mentioned precursors (Bpre-02-10, 14-21, 25-29) and the following salt-exchange compounds A-D was changed. The obtained compounds were subjected to NMR analysis and their structures were identified based on the following analysis results.

[0442]

[0443]

[0444]

[0445]

[0446]

[0447] Compound (B0-1): Combination of precursor (Bpre-01) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.67-7.90(m, ArH+Ar-I, 17H), 7.53-7.63(d, ArH, 4H), 6.94(d, Ar-I, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 1.54(s, CH 3, 9H)

[0448] Compound (B0-2): Combination of precursor (Bpre-02) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.99(d, Ar-I, 1H), 7.74-7.90(m, ArH+Ar-I, 16H), 7.53-7.63(d, ArH, 4H), 4.51-4.68(m, CF 2CH 2, 2H), 1.54(s, CH 3, 9H)

[0449] Compound (B0-3): Combination of precursor (Bpre-03) and salt exchange compound A 1H-NMR (DMSO, 400MHz): δ(ppm)=8.12(d, Ar-I, 1H), 7.74-7.90(m, ArH, 15H), 7.53-7.63(d, ArH, 4H), 6.94(d, Ar-I, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 1.54(s, CH 3, 9H)

[0450] Compound (B0-4): Combination of precursor (Bpre-04) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=9.48(s, NH, 1H), 8.12(d, Ar-I, 1H), 8.01(d, Ar-I, 1H), 7.74-7.90(m, ArH, 15H), 7.53-7.63(d, ArH, 4H), 4.51-4.68(m, CF 2CH 2, 2H), 1.54(s, CH 3, 9H)

[0451] Compound (B0-5): Combination of precursor (Bpre-05) and salt exchange compound A 1H-NMR (DMSO, 400MHz): δ(ppm)=8.12(d, Ar-I, 1H), 7.74-7.90(m, ArH, 15H), 7.53-7.63(d, ArH, 4H), 4.51-4.68(m, CF 2CH 2, 2H), 1.54(s, CH 3, 9H)

[0452] Compound (B0-6): Combination of precursor (Bpre-06) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.99(d, Ar-I, 1H), 7.74-7.90(m, ArH+Ar-I, 16H), 7.53-7.63(d, ArH, 4H), 4.51-4.68(m, CF2CH2, 2H), 1.50-2.05(m, cyclopentyl, 8H), 1.40(s, CH 3, 3H)

[0453] Compound (B0-7): Combination of precursor (Bpre-07) and salt exchange compound A 1H-NMR (DMSO, 400MHz): δ(ppm)=8.12(d, Ar-I, 1H), 7.74-7.90(m, ArH, 15H), 7.53-7.63(d, ArH, 4H), 6.94(d, Ar-I, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 1.50-2.00(m, methyladamantyl, 17H)

[0454] Compound (B0-8): Combination of precursor (Bpre-08) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.99(d, Ar-I, 1H), 7.74-7.90(m, ArH+Ar-I, 16H), 7.53-7.63(d, ArH, 4H), 5.90(m, CF 3CH, 1H), 1.50-2.05(m, cyclopentyl, 8H), 1.40(s, CH 3, 3H)

[0455] Compound (B0-9): Combination of precursor (Bpre-09) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.99(d, Ar-I, 1H), 7.74-7.90(m, ArH+Ar-I, 16H), 7.53-7.63(d, ArH, 4H), 4.91-5.20(m, CFCH, 1H), 3.95-4.20(m, COOCH 2CH 2-, 2H), 2.30-2.45(m, COOCH 2CH 2, 1H), 1.50-2.05(m, cyclopentyl+ COOCH 2CH 2, 9H), 1.40(s, CH 3, 3H)

[0456] Compound (B0-10): Combination of precursor (Bpre-10) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.99(d, Ar-I, 1H), 7.74-7.90(m, ArH+Ar-I, 16H), 7.53-7.63(d, ArH, 4H), 4.05-4.25(m, COOCH 2CH 2-, 2H), 2.63-2.73(m, COOCH 2CH 2, 2H), 1.50-2.05(m, cyclopentyl, 8H), 1.40(s, CH 3, 3H)

[0457] Compound (B0-11): Combination of precursor (Bpre-02) and salt exchange compound B 1H-NMR (DMSO, 400MHz): δ(ppm)=7.70-8.22(m, ArH+Ar-I, 16H), 7.53-7.63(d, ArH, 4H), 4.51-4.68(m, CF 2CH 2, 2H), 3.30-3.45(m, SO 2CH, 1H), 1.09-1.90(m, cyclohexyl+CH 3, 19H)

[0458] Compound (B0-12): Combination of precursor (Bpre-02) and salt exchange compound C 1H-NMR (DMSO, 400MHz): δ(ppm)=7.77-7.99(m, ArH+Ar-I, 13H), 7.53-7.63(d, ArH, 4H), 4.51-4.68(m, CF 2CH 2, 2H), 1.54(s, CH 3, 9H)

[0459] Compound (B0-13): Combination of Precursor (Bpre-02) and Salt Exchange Compound D 1H-NMR (DMSO, 400MHz): δ(ppm)=8.50(d, ArH, 2H), 8.37(d, ArH, 2H), 7.99(d, Ar-I, 1H), 7.93(t, ArH, 2H), 7.84(d, Ar-I, 1H), 7.53-7.75(d, ArH, 11H), 4.51-4.68(m, CF 2CH 2, 2H), 1.54(s, CH 3, 9H)

[0460] Compound (B0-14): Combination of precursor (Bpre-14) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.67-7.90(m, ArH+Ar-I, 17H), 6.94(d, Ar-I, 1H), 6.30(d, CH, 1H), 6.10(d, CH, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15(m, CH, 2H), 3.00(m, CH, 1H), 2.38(m, CH, 1H), 1.30-1.50(m, CH 3+CH 2, 11H)

[0461] Compound (B0-15): Combination of precursor (Bpre-15) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.74-7.99(m, ArH+Ar-I, 17H), 6.30(d, CH, 1H), 6.10(d, CH, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15(m, CH, 2H), 3.00(m, CH, 1H), 2.38(m, CH, 1H), 1.30-1.50(m, CH 3+CH 2, 11H)

[0462] Compound (B0-16): Combination of precursor (Bpre-16) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=8.12(d, Ar-I, 1H), 7.74-7.90(m, ArH, 15H), 6.94(d, Ar-I, 1H), 6.30(d, CH, 1H), 6.10(d, CH, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15(m, CH, 2H), 3.00(m, CH, 1H), 2.38(m, CH, 1H), 1.30-1.50(m, CH 3+CH 2, 11H)

[0463] Compound (B0-17): Combination of precursor (Bpre-17) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=8.12(d, Ar-I, 1H), 7.74-7.90(m, ArH, 15H), 6.30(d, CH, 1H), 6.10(d, CH, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15(m, CH, 2H), 3.00(m, CH, 1H), 2.38(m, CH, 1H), 1.30-1.50(m, CH 3+CH 2, 11H)

[0464] Compound (B0-18): Combination of precursor (Bpre-18) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=8.12(d, Ar-I, 1H), 7.74-7.90(m, ArH, 15H), 6.94(d, Ar-I, 1H), 6.30(d, CH, 1H), 6.10(d, CH, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15(m, CH, 2H), 3.00(m, CH, 1H), 2.38(m, CH, 1H), 1.30-2.00(m, methyladamantyl+CH 2, 19H)

[0465] Compound (B0-19): Combination of precursor (Bpre-19) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=8.12(d, Ar-I, 1H), 7.74-7.90(m, ArH, 15H), 6.94(d, Ar-I, 1H), 6.30(d, CH, 1H), 6.10(d, CH, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15(m, CH, 2H), 3.00(m, CH, 1H), 2.38(m, CH, 1H), 1.30-2.05(m, methylcyclopentyl+CH 2, 13H)

[0466] Compound (B0-20): Combination of precursor (Bpre-20) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.74-7.99(m, ArH+Ar-I, 17H), 6.30(d, CH, 1H), 6.10(d, CH, 1H), 5.90(m, CF 3CH, 1H), 3.15(m, CH, 2H), 3.00(m, CH, 1H), 2.38(m, CH, 1H), 1.30-1.50(m, CH 3+CH 2, 11H)

[0467] Compound (B0-21): Combination of precursor (Bpre-21) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.74-7.99(m, ArH+Ar-I, 17H), 6.30(d, CH, 1H), 6.10(d, CH, 1H), 4.05-4.25(m, COOCH 2CH 2-, 2H), 3.15(m, CH, 2H), 3.00(m, CH, 1H), 2.63-2.73(m, COOCH 2CH 2, 2H), 2.38(m, CH, 1H), 1.30-1.50(m, CH 3+CH 2, 11H)

[0468] Compound (B0-22): Combination of Precursor (Bpre-15) and Salt Exchange Compound B 1H-NMR (DMSO, 400MHz): δ(ppm)=7.70-8.22(m, ArH+Ar-I, 16H), 6.30(d, CH, 1H), 6.10(d, CH, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 3.30-3.45(m, SO 2CH, 1H), 3.15(m, CH, 2H), 3.00(m, CH, 1H), 2.38(m, CH, 1H), 1.09-1.90(m, cyclohexyl+ CH 3+CH 2, 21H)

[0469] Compound (B0-23): Combination of Precursor (Bpre-15) and Salt Exchange Compound C 1H-NMR (DMSO, 400MHz): δ(ppm)=7.77-7.99(m, ArH+Ar-I, 13H), 6.30(d, CH, 1H), 6.10(d, CH, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15(m, CH, 2H), 3.00(m, CH, 1H), 2.38(m, CH, 1H), 1.30-1.50(m, CH 3+CH 2, 11H)

[0470] Compound (B0-24): Combination of Precursor (Bpre-15) and Salt Exchange Compound D 1H-NMR (DMSO, 400MHz): δ(ppm)=8.50(d, ArH, 2H), 8.37(d, ArH, 2H), 7.99(d, Ar-I, 1H), 7.93(t, ArH, 2H), 7.84(d, Ar-I, 1H), 7.55-7.75(m, ArH, 7H), 6.30(d, CH, 1H), 6.10(d, CH, 1H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15(m, CH, 2H), 3.00(m, CH, 1H), 2.38(m, CH, 1H), 1.30-1.50(m, CH 3+CH 2, 11H)

[0471] Compound (B0-25): Combination of precursor (Bpre-25) and salt exchange compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.67-7.90(m, ArH+Ar-I, 17H), 7.01-7.47(m, ArH, 8H), 6.94(d, Ar-I, 1H), 4.70-4.85(m, -OCO-CH-CH-COO-, 2H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15-3.40(m, CH, 2H), 1.54(s, CH 3, 9H)

[0472] Compound (B0-26): Combination of Precursor (Bpre-26) and Salt Exchange Compound A 1H-NMR (DMSO, 400MHz): δ(ppm)=7.74-7.99(m, ArH+Ar-I, 17H), 7.01-7.47(m, ArH, 8H), 4.70-4.85(m, -OCO-CH-CH-COO-, 2H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15-3.40(m, CH, 2H), 1.54(s, CH 3, 9H)

[0473] Compound (B0-27): Combination of Precursor (Bpre-27) and Salt Exchange Compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=8.12(m, Ar-I, 1H), 7.74-7.90(m, ArH, 15H), 7.01-7.47(m, ArH, 8H), 4.70-4.85(m, -OCO-CH-CH-COO-, 2H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15-3.40(m, CH, 2H), 1.54(s, CH 3, 9H)

[0474] Compound (B0-28): Combination of precursor (Bpre-28) and salt exchange compound A 1H-NMR (DMSO, 400MHz): δ(ppm)=7.74-7.99(m, ArH+Ar-I, 17H), 7.01-7.47(m, ArH, 8H), 4.70-4.85(m, -OCO-CH-CH-COO-, 2H), 4.51-4.68(m, CF 2CH 2, 2H), 3.15-3.40(m, CH, 2H), 1.50-2.05(m, cyclopentyl, 8H), 1.40(s, CH 3, 3H)

[0475] Compound (B0-29): Combination of Precursor (Bpre-29) and Salt Exchange Compound A 1H-NMR(DMSO, 400MHz): δ(ppm)=7.74-7.99(m, ArH+Ar-I, 17H), 7.01-7.47(m, ArH, 8H), 5.90(m, CF 3CH, 1H), 4.70-4.85(m, -OCO-CH-CH-COO-, 2H), 3.15-3.40(m, CH, 2H), 1.50-2.05(m, cyclopentyl, 8H), 1.40(s, CH 3, 3H)

[0476] Compound (B0-30): Combination of Precursor (Bpre-29) and Salt Exchange Compound D 1H-NMR (DMSO, 400MHz): δ(ppm)=8.50(d, ArH, 2H), 8.37(d, ArH, 2H), 7.99(m, Ar-I, 1H), 7.93(t, ArH, 2H), 7.84(d, Ar-I, 1H), 7.55-7.75(m, ArH, 7H), 7.01-7.47(m, ArH, 8H), 5.90(m, CF 3CH, 1H), 4.70-4.85(m, -OCO-CH-CH-COO-, 2H), 3.15-3.40(m, CH, 2H), 1.50-2.05(m, cyclopentyl, 8H), 1.40(s, CH 3, 3H)

[0477] <Preparation of Resist Composition> (Examples 1 to 31, Comparative Examples 1 to 5) The components shown in Tables 2 to 5 were mixed and dissolved to prepare the resist compositions of each example.

[0478]

[0479]

[0480]

[0481]

[0482] In Tables 2 to 5, the abbreviations have the following meanings. The values ​​in [ ] are the blending amounts (parts by mass).

[0483] (A)-1: A polymer compound represented by the following chemical formula (A-1). The weight average molecular weight (Mw) of polymer compound (A-1) measured by GPC, in terms of standard polystyrene, was 7100, and the molecular weight dispersion (Mw / Mn) was 1.69. The copolymer composition ratio (the ratio (molar ratio) of the constituent units in the structural formula) determined by 13C-NMR was l / m = 50 / 50.

[0484] (A)-2: A polymer compound represented by the following chemical formula (A-2). The weight average molecular weight (Mw) of polymer compound (A-2) measured by GPC, in terms of standard polystyrene, was 7000, and the molecular weight dispersion (Mw / Mn) was 1.72. The copolymer composition ratio (the ratio (molar ratio) of the constituent units in the structural formula) determined by 13C-NMR was l / m = 50 / 50.

[0485]

[0486] (B0)-1 to (B0)-30: Acid generators composed of the above compounds (B0-1) to (B0-30), respectively.

[0487] (B1)-1: An acid generator composed of the following compound (B-1). (B1)-2: An acid generator composed of the following compound (B-2). (B1)-3: An acid generator composed of the following compound (B-3). (D)-1: An acid diffusion controller composed of the following compound (D-1). (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60 / 40 (mass ratio).

[0488]

[0489] <Formation of Resist Pattern> The resist compositions of each example were coated on an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS) using a spinner, and then dried by pre-baking (PAB) on a hot plate at 110°C for 60 seconds to form a 50 nm thick resist film. Next, the resist film was exposed using a JEOL-JBX-9300FS electron beam lithography system (manufactured by JEOL Ltd.) at an accelerating voltage of 100 kV to create a contact hole pattern (hereinafter referred to as the "CH pattern") with holes of 32 nm in diameter arranged at equal intervals (pitch of 64 nm). This was followed by a post-exposure bake (PEB) treatment at 110°C for 60 seconds. Next, alkali development was performed at 23° C. for 60 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Afterwards, rinse with pure water for 15 seconds. As a result, a CH pattern was formed in which holes with a diameter of 32 nm were arranged at equal intervals (spacing 64 nm).

[0490] [Evaluation of pattern size uniformity (CDU)] The CH pattern formed by the "Resist Pattern Formation" described above was observed from above using a scanning electron microscope (SEM, accelerating voltage 500V, trade name: CG5000, manufactured by Hitachi Advanced Technologies, Ltd.) to measure the pore diameter (nm) of each pore. The value (3σ) of the triple standard deviation (σ) calculated from these measurement results was then calculated. The results are shown as "CDU (nm)" in Tables 6 and 7. The smaller the value of 3σ obtained in this manner, the higher the uniformity of the size (CD) of the plurality of holes formed in the resist film.

[0491] [Evaluation of Ultimate Resolution] A scanning electron microscope (S-9380, manufactured by Hitachi Advanced Technologies) was used to determine the limiting resolution at the optimal exposure (Eop) for forming the CH pattern. Specifically, the diameter (nm) of the holes in the pattern that could be resolved when the exposure was gradually reduced from the optimal Eop. The results are shown in Tables 6 and 7 as "Limiting Resolution (nm)."

[0492]

[0493]

[0494] As shown in Tables 6 and 7, it can be confirmed that the resist composition of the embodiment has better CDU and limiting resolution than the resist composition of the comparative example.

[0495] The compounds (B-1) to (B-3) contained in the resist compositions of Comparative Examples 1 to 5, respectively, all have a phenylene group having an iodine atom directly bonded to an acid-degradable group. In other words, compounds (B-1) to (B-3) do not have R10 (a cyclic organic group optionally having a substituent) in the general formula (b0). It is speculated that the compound (B0) contained in the resist composition of the embodiment has R10 (a cyclic organic group which may have a substituent) between the phenyl group having an iodine atom and the acid-decomposable group, thereby controlling the diffusion length of the acid and improving the balance of hydrophilicity and hydrophobicity, thereby achieving good CDU and resolution.

[0496] While the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications may be made without departing from the spirit of the present invention. The present invention is not limited by the foregoing description but only by the scope of the appended claims.

Claims

1. A resist composition comprising a substrate component (A) whose solubility in a developer changes under the action of an acid, and an acid-generating agent component (B) that generates acid upon exposure, wherein the acid-generating agent component (B) comprises a compound (B0) represented by the following general formula (b0); [wherein, Rpg is an acid-degrading group represented by any of the following general formulas (r-pg-1) to (r-pg-4); Rl0 is a cyclic organic group that may have substituents; L02 is a divalent linker; L01 is a divalent linker or a single bond; Rm1 is a substituent other than an iodine atom; Vb0 is a single bond, an alkyl group, or a fluorinated alkyl group; R0 is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom; nb1 is an integer from 1 to 4; nb2 is an integer from 1 to 4; nb3 is an integer from 0 to 3; Mm+ represents an organic cation with a valence of m; m is an integer of 1 or more]; [In the formula, Rp01 and Rp02 are each independently a hydrogen atom or an alkyl group; Rp03 is a hydrocarbon group, and Rp03 can also bond with either Rp01 or Rp02 to form a ring; Rp04 and Rp05 are each independently a hydrogen atom or an alkyl group; Rp06 is a hydrocarbon group, and Rp06 can also bond with either Rp04 or Rp05 to form a ring; Rp07 to Rp09 are each independently a hydrocarbon group, and Rp08 and Rp09 can also bond with each other to form a ring; Rp10 is a hydrocarbon group; Rp11a and Rp11b are each independently a hydrogen atom, a halogen atom, or an alkyl group; Rp12 is a hydrogen atom or a hydrocarbon group; Rp10 can also bond with Rp11a or Rp11b to form a ring; Rp11a or Rp11b can also bond with Rp12 to form a ring; * indicates the bonding site].

2. The inhibitor composition as claimed in claim 1, wherein the aforementioned Rpg is an acid-degrading group represented by the aforementioned general formula (r-pg-3).

3. The inhibitor composition of claim 1 or 2, wherein the aforementioned R10 is an aromatic hydrocarbon group that may have substituents, or a polycyclic alicyclic hydrocarbon group that may have substituents.

4. The inhibitor composition of claim 1 or 2, wherein the content of the aforementioned acid generating agent component (B) is 15 to 40 parts by mass relative to 100 parts by mass of the aforementioned base material component (A).

5. A method for forming a resist pattern, comprising the steps of forming a resist film on a support using a resist composition as claimed in claim 1 or 2, exposing the aforementioned resist film, and developing the exposed resist film to form the aforementioned resist pattern.

6. The resist pattern forming method of claim 5, wherein in the aforementioned step of exposing the resist film, the resist film is exposed to EUV (extreme ultraviolet light) or EB (electron beam).

7. A compound represented by the following general formula (b0); [In the formula, Rpg is an acid-decomposing group represented by any of the following general formulas (r-pg-1) to (r-pg-4); Rl0 is a cyclic organic group that may have substituents; L02 is a divalent linkage group; L01 is a divalent linkage group or a single bond; Rm1 is a substituent other than an iodine atom; Vb0 is a single bond, an alkyl group or a fluorinated alkyl group; R0 is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom; nb1 is an integer from 1 to 4, nb2 is an integer from 1 to 4, and nb3 is an integer from 0 to 3;] Mm+ represents an organic cation with a valence of m; m is an integer greater than or equal to 1; [wherein, Rp01 and Rp02 are each independently hydrogen atoms or alkyl groups; Rp03 is a hydrocarbon group, and Rp03 can also bond with either Rp01 or Rp02 to form a ring; Rp04 and Rp05 are each independently hydrogen atoms or alkyl groups; Rp06 is a hydrocarbon group, and Rp06 can also bond with either Rp04 or Rp05 to form a ring; Rp07 to Rp09 are each independently hydrocarbon groups, and Rp08 and Rp09 can also bond with each other to form a ring;] Rp10 is a hydrocarbon group; Rp11a and Rp11b are independently hydrogen atoms, halogen atoms, or alkyl groups, respectively; Rp12 is a hydrogen atom or a hydrocarbon group; Rp10 and Rp11a or Rp11b can also bond to each other to form a ring; Rp11a or Rp11b and Rp12 can also bond to each other to form a ring; * indicates the bonding site).

8. An acid generating agent comprising the compound of claim 7.