Resist composition, method for forming a resist pattern

Abstract

To provide a resist composition capable of further enhancing etching resistance and achieving higher sensitivity.SOLUTION: The resist composition contains a resin component having a constituent unit derived from a compound represented by general formula (a0-1). In the formula (a0-1), W01 is a polymerizable group-containing group; RAr is an aromatic group; Ra0 is an acid-dissociable group represented by general formula (a0-r-1); Ra01 is an aliphatic hydrocarbon group; Ra02, Ra03 and Ra04 are each a hydrocarbon group or a hydrogen atom; and Ra05 is a chain or alicyclic hydrocarbon group or a hydrogen atom.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a resist composition, a method for forming a resist pattern, a novel compound, and a polymer compound.

Background Art

[0002] In recent years, in the production of semiconductor devices and liquid crystal display devices, pattern miniaturization has been rapidly progressing due to the advancement of lithography technology. As a miniaturization technique, generally, the wavelength of the exposure light source is shortened (the energy is increased).

[0003] Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist composition containing a base material component whose solubility in a developer changes by the action of an acid and an acid generator component that generates an acid upon exposure has been conventionally used.

[0004] In a chemically amplified resist composition, generally, a resin having a plurality of structural units is used to improve lithography characteristics and the like. For example, Patent Document 1 proposes a resist composition containing a resin having two repeating units with a specific structure and having increased solubility in an alkaline developer by the action of an acid.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] As lithography technology continues to advance and resist patterns become increasingly miniaturized, for example, EUV and EB lithography aim to form patterns as small as tens of nanometers. As patterns become even smaller, the resist films become thinner, and there is an increasing need for improved etching resistance in resist materials when etching is performed using the resist pattern as a mask. In addition, as patterns become smaller, resist materials also require higher sensitivity to radiation. Conventional resist compositions need further performance improvements to meet these required characteristics.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a resist composition that can further improve etching resistance and sensitivity, a method for forming a resist pattern using the resist composition, a polymer compound useful for the resist composition, and a compound useful for producing the polymer compound. [Means for solving the problem]

[0008] To solve the above problems, the present invention employs the following configuration. In other words, a first aspect of the present invention is a resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition containing a resin component (A1) whose solubility in a developer changes due to the action of the acid, wherein the resin component (A1) has a constituent unit (a0) derived from a compound represented by the following general formula (a0-1).

[0009] [ka] [In formula (a0-1), W 01 R is a polymerizable group-containing group. Ar R is an aromatic group which may have substituents. a0 R is an acid-dissociable group represented by the general formula (a0-r-1) above. a01 R is an aliphatic hydrocarbon group. a02 , Ra03 and R a04 is, independently of each other, a hydrocarbon group which may have a substituent, or a hydrogen atom. R a01 and R a02 and may be bonded to each other to form an alicyclic structure. R a03 and R a04 and may be bonded to each other to form an aromatic ring structure or an alicyclic structure. Alternatively, R a01 and R a02 The alicyclic structure formed by their mutual bonding, and R a03 and R a04 The aromatic ring structure or alicyclic structure formed by their mutual bonding may be condensed. R a05 is a chain or alicyclic hydrocarbon group, or a hydrogen atom. * indicates that it is a bond to an oxy group (-O-) to which R a0 is bonded. ]

[0010] A second aspect of the present invention is a resist pattern forming method characterized by including a step of forming a resist film on a support using the resist composition according to the first aspect, a step of exposing the resist film, and a step of developing the resist film after the exposure to form a resist pattern.

[0011] A third aspect of the present invention is a compound characterized by being represented by the following general formula (a0-1).

[0012]

Chemical formula

[0013] A fourth aspect of the present invention is a polymer compound characterized by having a structural unit derived from a compound represented by the following general formula (a0-1).

[0014] [ka] [In formula (a0-1), W 01 R is a polymerizable group-containing group. Ar R is an aromatic group which may have substituents. a0 R is an acid-dissociable group represented by the general formula (a0-r-1) above. a01 R is an aliphatic hydrocarbon group. a02 , R a03 and R a04 Each of these is independently a hydrocarbon group which may have substituents, or a hydrogen atom. a01 and R a02 These may bond with each other to form an alicyclic structure. a03 and R a04 These may bond with each other to form an aromatic ring structure or an alicyclic structure. Alternatively, R a01 and R a02 A ring structure formed by the mutual bonding of R a03 and R a04 The aromatic ring structure or alicyclic structure formed by the mutual bonding of these elements may be condensed. a05 * is a chain-like or alicyclic hydrocarbon group, or a hydrogen atom.a0 This indicates that the bond is with the oxy group (-O-). [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a resist composition that can further enhance etching resistance and achieve high sensitivity, a method for forming a resist pattern using the resist composition, a polymer compound useful for the resist composition, and a compound useful for producing the polymer compound. [Modes for carrying out the invention]

[0016] In this specification and in the claims, "aliphatic" is defined as a concept relative to aromatic, meaning a group, compound, etc., that does not possess aromaticity. Unless otherwise specified, "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups within alkoxy groups. Unless otherwise specified, the term "alkylene group" includes linear, branched, and cyclic divalent saturated hydrocarbon groups. Examples of "halogen atoms" include fluorine, chlorine, bromine, and iodine atoms. "Constituent unit" refers to the monomer unit (monomer unit) that makes up a polymer compound (resin, polymer, copolymer). When it is stated that a group "may have substituents," this includes both cases where a hydrogen atom (-H) is substituted with a monovalent group and cases where a methylene group (-CH2-) is substituted with a divalent group. "Exposure" is a concept that includes all forms of radiation exposure.

[0017] A "base component" is an organic compound that has film-forming ability. Organic compounds used as base components are broadly classified into nonpolymers and polymers. Nonpolymers typically have a molecular weight of 500 or more and less than 4000. Hereinafter, "low molecular weight compound" refers to a nonpolymer with a molecular weight of 500 or more and less than 4000. Polymers typically have a molecular weight of 1000 or more. Hereinafter, "resin," "high molecular weight compound," or "polymer" refers to a polymer with a molecular weight of 1000 or more. The molecular weight of polymers shall be the weight-average molecular weight on a polystyrene basis calculated by GPC (gel permeation chromatography).

[0018] "Induced structural units" refer to structural units formed by the cleavage of multiple bonds between carbon atoms, such as ethylenic double bonds. "Acrylic acid ester" may have a substituent that replaces the hydrogen atom bonded to the α-carbon atom. αx ) is an atom or group other than a hydrogen atom. Also, substituents (R αx Itaconic acid diesters in which ) are substituted with substituents containing an ester bond, or substituents (R αx This also includes α-hydroxyacrylic esters in which the α group is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group thereof. Unless otherwise specified, the α-carbon atom of the acrylic acid ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereafter, acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom is replaced by a substituent are sometimes called α-substituted acrylic acid esters.

[0019] The term "derivative" refers to a compound in which the α-position hydrogen atom of the target compound is substituted with another substituent such as an alkyl group or alkyl halide, as well as derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound (which may have the α-position hydrogen atom substituted with a substituent) is substituted with an organic group; and those in which a substituent other than a hydroxyl group is bonded to the target compound (which may have the α-position hydrogen atom substituted with a substituent). Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. As substituents that substitute the hydrogen atom at the α-position of hydroxystyrene, R αx Similar examples include the above.

[0020] In this specification and in the claims, depending on the structure represented by the chemical formula, an asymmetric carbon may be present, and enantioisomers or diastereomers may exist. In such cases, a single chemical formula will represent all of these isomers. These isomers may be used individually or as a mixture.

[0021] (Resist composition) The resist composition according to the first aspect of the present invention generates acid upon exposure, and its solubility in a developer changes due to the action of the acid. The resist composition of this embodiment contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in the developer solution changes due to the action of an acid.

[0022] When a resist film is formed using the resist composition of this embodiment and selective exposure is performed on the resist film, acid is generated in the exposed areas of the resist film, and the solubility of component (A) in the developer changes due to the action of the acid, while the solubility of component (A) in the developer does not change in the unexposed areas of the resist film. As a result, a difference in solubility in the developer occurs between the exposed and unexposed areas of the resist film. The resist composition of this embodiment may be a positive-type resist composition or a negative-type resist composition. Furthermore, the resist composition of this embodiment may be for an alkaline development process that uses an alkaline developer for the development process during resist pattern formation, or it may be for a solvent development process that uses an organic developer for the development process. In other words, the resist composition of this embodiment is a "positive-type resist composition for alkaline development processes" that forms a positive-type resist pattern in an alkaline development process, and a "negative-type resist composition for solvent development processes" that forms a negative-type resist pattern in a solvent development process.

[0023] <(A) component> In the resist composition of this embodiment, component (A) 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, and component (A1) has a constituent unit (a0) derived from a compound represented by the general formula (a0-1). (A) The component used is at least component (A1), and at least one of other high-molecular-weight compounds and low-molecular-weight compounds may be used in combination with component (A1). In the resist composition of this embodiment, component (A) may be used alone or in combination of two or more types.

[0024] (A1) About the ingredients Component (A1) has a constituent unit (a0) derived from a compound represented by the general formula (a0-1) described below. Component (A1) may have constituent units other than constituent unit (a0) in addition to constituent unit (a0).

[0025] ≪Constituent Unit (a0)≫ The constituent unit (a0) is a constituent unit derived from the compound represented by the following general formula (a0-1). In such a constituent unit (a0), R in equation (a0-1) a0 This is an acid-dissociable group, and this acid-dissociable group protects the oxy group (-O-) of the carbonyloxy group [-C(=O)-O-] in formula (a0-1). Here, "acid-dissociable group" refers to a group that has the property of being able to break the bond between the acid-dissociable group and an adjacent oxygen atom (oxy group (-O-)) upon the action of an acid. When the acid-dissociable group dissociates due to the action of an acid, a polar group (carboxyl group) with higher polarity than the acid-dissociable group is generated, increasing the polarity. As a result, the overall polarity of component (A1) increases. Due to the increased polarity, the solubility of component (A1) in the developer changes relatively; solubility increases when the developer is an alkaline developer, and decreases when the developer is an organic developer.

[0026] [ka] [In formula (a0-1), W 01 R is a polymerizable group-containing group. Ar R is an aromatic group which may have substituents. a0 R is an acid-dissociable group represented by the general formula (a0-r-1) above. a01 R is an aliphatic hydrocarbon group. a02 , R a03 and R a04 Each of these is independently a hydrocarbon group which may have substituents, or a hydrogen atom. a01 and R a02 These may bond with each other to form an alicyclic structure. a03 and R a04 These may bond with each other to form an aromatic ring structure or an alicyclic structure. Alternatively, R a01 and R a02 A ring structure formed by the mutual bonding of R a03 and R a04 The aromatic ring structure or alicyclic structure formed by the mutual bonding of these elements may be condensed. a05 * is a chain-like or alicyclic hydrocarbon group, or a hydrogen atom. a0 This indicates that the bond is with the oxy group (-O-).

[0027] In the above formula (a0-1), W 01 This is a polymerizable group-containing group. W 01In this context, a "polymerizable group" refers to a group that enables a compound having a polymerizable group to be polymerized by radical polymerization or the like, and includes, for example, a group containing multiple bonds between carbon atoms, such as an ethylenic double bond. In the constituent unit (a0), the multiple bond in the polymerizable group is cleaved to form the main chain.

[0028] W 01 Examples of polymerizable groups in this material include vinyl group, allyl group, acryloyl group, methacryloyl group, fluorovinyl group, difluorovinyl group, trifluorovinyl group, difluorotrifluoromethylvinyl group, trifluoroallyl group, perfluoroallyl group, trifluoromethylacryloyl group, nonylfluorobutylacryloyl group, vinyl ether group, fluorinated vinyl ether group, allyl ether group, fluorinated allyl ether group, styryl group, vinylnaphthyl group, fluorinated styryl group, fluorinated vinylnaphthyl group, norbornyl group, fluorinated norbornyl group, and silyl group.

[0029] W 01 The "polymerizable group-containing group" in this context may be a group composed solely of polymerizable groups, or a group composed of a polymerizable group and other groups other than the polymerizable group. Examples of other groups other than the polymerizable group include divalent hydrocarbon groups which may have substituents, and divalent linking groups containing heteroatoms.

[0030] • Divalent hydrocarbon groups which may have substituents: If any group other than the polymerizable group is a divalent hydrocarbon group which may have substituents, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0031] Aliphatic hydrocarbon groups in groups other than the polymerizable group The aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0032] ...linear or branched aliphatic hydrocarbon groups The linear aliphatic 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 most preferably 1 to 3 carbon atoms. As for the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, specifically the methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0033] The linear or branched aliphatic hydrocarbon group described above may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0034] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in the structure include cyclic aliphatic hydrocarbon groups that may contain substituents containing heteroatoms in the ring structure (groups from which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0035] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. As the alkoxy group used as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are most preferred. Examples of halogen atoms used as substituents include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like, with fluorine atoms being preferred. Examples of halogenated alkyl groups as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. A cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure replaced by substituents containing heteroatoms. Preferred substituents containing heteroatoms are -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0036] Aromatic hydrocarbon groups in groups other than the polymerizable 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 having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of aromatic hydrocarbon groups include groups obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); groups obtained by removing two hydrogen atoms from aromatic compounds containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of an aryl group or heteroaryl group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) is substituted with an alkylene group (e.g., groups obtained by removing one more hydrogen atom from an aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0037] The aromatic hydrocarbon group may have its hydrogen atoms substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, and hydroxyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Examples of the substituents include alkoxy groups, halogen atoms, and alkyl halogens that substitute for hydrogen atoms on the cyclic aliphatic hydrocarbon group.

[0038] • Divalent linking groups containing heteroatoms: If the group other than the polymerizable group is a divalent linking group containing a heteroatom, preferred linking groups include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with substituents such as alkyl groups or acyl groups), -S-, -S(=O)2-, -S(=O)2-O-, and the general formula -Y21 -O-Y 22 -,-Y 21 -O-,-Y 21 -C(=O)-O-,-C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-Y 21 -O-C(=O)-Y 22 -or -Y 21 -S(=O)2-O-Y 22 -represented group [wherein, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m" is an integer of 0 to 3.] etc. are exemplified. When the divalent linking group containing the heteroatom is -C(=O)-NH-,-C(=O)-NH-C(=O)-,-NH-,-NH-C(=NH)-, the H thereof may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms. General formula -Y 21 -O-Y 22 -,-Y 21 -O-,-Y 21 -C(=O)-O-,-C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -,-Y 21 -O-C(=O)-Y 22 -or -Y 21 -S(=O)2-O-Y 22 -Among them, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same ones as those exemplified in the description of the divalent linking group (divalent hydrocarbon group which may have a substituent). Y 21Preferably, the group is a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, even more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. Y 22 The group is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group, or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula - [Y 21 -C(=O)-O] m” -Y 22 In the base represented by -, m'' is an integer between 0 and 3, preferably between 0 and 2, more preferably 0 or 1, and particularly preferably 1. That is, in the formula -[Y 21 -C(=O)-O] m” -Y 22 As a base represented by -, formula -Y 21 -C(=O)-OY 22 Groups represented by - are particularly preferred. Among them, the group represented by formula -(CH2) a’ -C(=O)-O-(CH2) b’ A base represented by - is preferred. In the formula, a' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1. b' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, even more preferably 1 or 2, and most preferably 1.

[0039] W 01 For example, the chemical formula is C(R X11 )(R X12 )=C(R X13 )-Ya x0 The group represented by - is preferably mentioned. In this chemical formula, R X11 , R X12 and R X13 These are, respectively, 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 x0It is a single bond or a divalent linking group.

[0040] R X11 , R X12 and R X13 The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. The halogenated alkyl group having 1 to 5 carbon atoms is 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. Fluorine atoms are particularly preferred as the halogen atoms. Among these, R X11 and R X12 Preferably, these are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, respectively. From the standpoint of industrial availability, a hydrogen atom and a methyl group are more preferred, and a hydrogen atom is particularly preferred. Also, R X13 Preferably, the group is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. Due to their industrial availability, a hydrogen atom or a methyl group is more preferable, and a hydrogen atom is particularly preferable.

[0041] Ya x0 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have substituents, a divalent linking group which contains a heteroatom, and so on, respectively. 01 This is similar to the divalent hydrocarbon groups that may have substituents and the divalent linking groups containing heteroatoms, which were exemplified as other groups besides polymerizable groups in the above.

[0042] Among the above, Ya x0 Preferably, the group consists of an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof, or a single bond. Among these, Yax0 As for the bond, an ester bond [-C(=O)-O-, -OC(=O)-] is more preferable, and a single bond is even more preferable.

[0043] In the above formula (a0-1), R Ar This is an aromatic group that may have substituents. R Ar Examples of aromatic groups in this context include groups obtained by removing two hydrogen atoms from an aromatic ring, which may have substituents. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Also, R Ar Examples of aromatic groups in this context include groups obtained by removing two hydrogen atoms from aromatic compounds containing two or more aromatic rings that may have substituents (e.g., biphenyl, fluorene, etc.).

[0044] R Ar The aromatic group in may or may not have substituents. Examples of substituents include alkyl groups, halogen atoms, alkyl halides, alkoxy groups, and hydroxyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Examples of halogen atoms used as substituents include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like, with fluorine atoms being preferred. Examples of halogenated alkyl groups as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. As the alkoxy group used as the substituent, an alkoxy group having 1 to 6 carbon atoms is preferred. The alkoxy group is preferably linear or branched. Specifically, examples include a group in which an alkyl group having 1 to 6 carbon atoms is linked to an oxygen atom (-O-), with methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, and tert-butoxy groups being preferred, methoxy and ethoxy groups being more preferred, and methoxy groups being even more preferred. From the viewpoint of increasing sensitivity, the substituent is preferably an alkoxy group or a hydroxyl group, and a hydroxyl group is particularly preferred. R Ar The number of substituents on the aromatic group in is determined according to the structure of the aromatic group, and is, for example, an integer from 0 to 3, preferably 0, 1, or 2, and more preferably 0 or 1.

[0045] Among the above, R Ar Preferably, the groups are those obtained by removing two hydrogen atoms from benzene, naphthalene, anthracene, or biphenyl, each of which may have substituents; more preferably, a group obtained by removing two hydrogen atoms from benzene, which may have substituents, or a group obtained by removing two hydrogen atoms from naphthalene, which may have substituents; and even more preferably, a group obtained by removing two hydrogen atoms from benzene, which may have substituents. Alternatively, from the standpoint of increasing sensitivity, R ArPreferably, the substituent is an aromatic group having a substituent selected from the group consisting of hydroxyl groups and alkoxy groups, and more preferably an aromatic group having a hydroxyl group as a substituent. Among these, a group obtained by removing two hydrogen atoms from benzene, naphthalene, anthracene, or biphenyl having a substituent selected from the group consisting of hydroxyl groups and alkoxy groups is more preferred, a group obtained by removing two hydrogen atoms from benzene having a substituent selected from the group consisting of hydroxyl groups and alkoxy groups is even more preferred, a group obtained by removing two hydrogen atoms from naphthalene having a substituent selected from the group consisting of hydroxyl groups and alkoxy groups is particularly preferred, and a group obtained by removing two hydrogen atoms from benzene having a hydroxyl group as a substituent is most preferred.

[0046] In the above formula (a0-1), R a0 is an acid-dissociable group represented by the general formula (a0-r-1) above. In formula (a0-r-1), * is R a0 This indicates that it is bonded to an oxy group (-O-). R a0 From the viewpoint of achieving high sensitivity, it is preferable that the group be in the form of a chain. R a0 From the viewpoint of etching resistance, it is preferable that the group be cyclic.

[0047] In the above formula (a0-r-1), R a01 It is an aliphatic hydrocarbon group. R a01 Examples of aliphatic hydrocarbon groups in this context include linear or branched hydrocarbon groups, with linear hydrocarbon groups being preferred. The number of carbon atoms in the linear or branched hydrocarbon group is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 4. R a01Specific examples of linear or branched alkyl groups in this compound include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups, with methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, and tert-butyl groups being preferred, methyl and ethyl groups being more preferred, and methyl groups being even more preferred.

[0048] In the above formula (a0-r-1), R a02 , R a03 and R a04 Each of these is independently a hydrocarbon group which may have substituents, or a hydrogen atom. R a02 , R a03 and R a04 The hydrocarbon group in is preferably an aliphatic hydrocarbon group, which may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group, but a saturated aliphatic hydrocarbon group is more preferable. R a02 , R a03 and R a04 Examples of saturated aliphatic hydrocarbon groups in this context include linear, branched, or cyclic alkyl groups.

[0049] R a02 , R a03 and R a04 Examples of linear or branched alkyl groups in this compound include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups, with methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, and tert-butyl groups being preferred, methyl and ethyl groups being more preferred, and methyl groups being even more preferred. R a02 , R a03 and R a04 Examples of cyclic alkyl groups in this context include alicyclic groups having 3 to 20 carbon atoms. These alicyclic groups may be monocyclic or polycyclic. Examples of monocyclic alicyclic groups include groups obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 10 carbon atoms, more preferably 4 to 8 carbon atoms, and even more preferably 5 to 6 carbon atoms. Specific examples of monocycloalkanes include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane. Among these, cyclopentane or cyclohexane are preferred. Examples of polycyclic alicyclic groups include groups obtained by removing one hydrogen atom from a polycycloalkane. The polycycloalkane preferably has 7 to 15 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 7 to 10 carbon atoms. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0050] R a02 , R a03 and R a04 Examples of substituents that the hydrocarbon group in the compound may have include alkyl groups, halogen atoms, and alkyl halogenated groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Examples of halogen atoms used as substituents include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like. Examples of halogenated alkyl groups as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms.

[0051] Among the above, R a02 , R a03 and R a04 Preferably, each of these is a linear or branched alkyl group or a hydrogen atom, with linear alkyl groups and hydrogen atoms being more preferred.

[0052] In the above formula (a0-r-1), R a01 and R a02These may bond with each other to form an alicyclic structure. a01 and R a02 Examples of the alicyclic structure formed by these are alicyclic groups having 3 to 20 carbon atoms. Here, the alicyclic group may be a monocyclic group or a polycyclic group, and a alicyclic group having 5 to 15 carbon atoms is preferred, for example, a cyclopentenyl group or a cyclohexenyl group is preferred, and a cyclopentenyl group is more preferred. Some of the carbon atoms constituting the alicyclic structure may be substituted with heteroatoms. Examples of heteroatoms here include oxygen atoms, sulfur atoms, nitrogen atoms, etc. However, from the viewpoint of acid dissociation, Ra 01 In this case, a carbon atom is bonded to the tertiary carbon atom that is bonded to the oxy group (-O-).

[0053] In the above formula (a0-r-1), R a03 and R a04 These elements may bond with each other to form an aromatic ring structure or an alicyclic structure. R a03 and R a04 The aromatic ring structure formed by these two components 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 this aromatic ring structure include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. R a03 and R a04 The alicyclic structure formed by the above R a01 and R a02 Examples include structures similar to the alicyclic structures formed by [the two components].

[0054] Alternatively, R a01 and R a02 A ring structure formed by the mutual bonding of R a03 and R a04 The aromatic ring structure or alicyclic structure formed by the bonding of these elements may be condensed.

[0055] In the above formula (a0-r-1), R a01 , and also, R a02 , R a03 and R a04 For example, R a01 R is a linear hydrocarbon group, a02 , R a03 and R a04 If all of them are hydrogen atoms; R a03 and R a04 When they are bonded to each other to form an aromatic ring structure; R a01 and R a02 A preferred example is when the two elements bond to each other to form an alicyclic structure. R a01 and R a02 In the case where these elements bond to each other to form an alicyclic structure, for example, R a01 and R a02 and are bonded to each other to form an alicyclic structure, R a03 and R a04 When each is a linear or branched alkyl group or hydrogen atom; R a01 and R a02 A ring structure formed by the mutual bonding of R a03 and R a04 Preferred cases include an aromatic ring structure formed by the bonding of these elements with each other, and a condensed ring structure formed by their condensation.

[0056] R a01 , and also, R a02 , R a03 and R a04 In particular, from the viewpoint of increasing sensitivity, it is preferable that the group be in the form of a chain, R a01 R is a linear hydrocarbon group, a02 , R a03 and R a04 A preferred case is when all of them are hydrogen atoms. R a01 , and also, R a02 , R a03 and R a04 In particular, from the viewpoint of etching resistance, it is preferable that it be a cyclic group, R a03 and Ra04 When they are bonded to each other to form an aromatic ring structure; R a01 and R a02 A preferred example is when the two elements bond to each other to form an alicyclic structure.

[0057] In the above formula (a0-r-1), R a05 These are chain-like or alicyclic hydrocarbon groups, or hydrogen atoms. R a05 The chain-like hydrocarbon groups in this context include linear or branched saturated hydrocarbon groups (alkyl groups), or linear or branched unsaturated hydrocarbon groups.

[0058] Specific examples of the linear or branched alkyl group include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, and the like.

[0059] More specifically, the unsaturated hydrocarbon groups in the linear or branched unsaturated hydrocarbon groups include unsaturated hydrocarbon groups having double bonds, such as alkenyl groups, alkadienyl groups, and alkatrineyl groups; and unsaturated hydrocarbon groups having triple bonds, such as alkynyl groups, groups obtained by removing one hydrogen atom from dialkynes, and groups obtained by removing one hydrogen atom from trialkynes.

[0060] Specific examples of the linear or branched alkenyl group include linear alkenyl groups such as vinyl group, propenyl group (allyl group), and 2-butenyl group; and branched alkenyl groups such as 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, and 2-methylpropenyl group.

[0061] Specific examples of the alkadienyl group include the propadienyl group and the butadienyl group. Specific examples of the alkatrineyl group include the butatrineyl group.

[0062] Specific examples of linear or branched alkynyl groups include linear alkynyl groups such as ethynyl group, propargyl group, and 3-pentynyl group; and branched alkynyl groups such as 1-methylpropargyl group.

[0063] A specific example of a group obtained by removing one hydrogen atom from a dialkyne is a group obtained by removing one hydrogen atom from diacetylene. A specific example of a group obtained by removing one hydrogen atom from the trialkine is a group obtained by removing one hydrogen atom from hexa-1,3,5-triyne.

[0064] R a05 In this context, specific examples of alicyclic hydrocarbon groups include monocyclic alicyclic groups and polycyclic alicyclic groups. As the monocyclic alicyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane or monocycloalkene is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane and cyclohexane. The monocycloalkene is preferably one having 3 to 6 carbon atoms, specifically cyclopentene and cyclohexene. The polycyclic alicyclic group is preferably a polycycloalkane or polycycloalkene from which one hydrogen atom has been removed. The polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. The polycycloalkene is preferably one having 7 to 12 carbon atoms, specifically adamantene, norbornene, isobornene, tricyclodecene, tetracyclododecene, etc.

[0065] In the above formula (a0-r-1), R a05 Among the above, linear or branched saturated hydrocarbon groups (alkyl groups) or hydrogen atoms are preferred. From the standpoint of etching resistance, R a05 It is preferable that it be a hydrogen atom. From the standpoint of sensitivity, R a05It is preferable that the hydrocarbon group is a chain-like or alicyclic hydrocarbon group.

[0066] The constituent unit (a0) is preferably the constituent unit represented by the following general formula (a0-1-u0) among the above.

[0067] [ka] [In the formula, R m L is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. 1 R is a divalent linking group or a single bond. a06 m is a hydrogen atom or an alkyl group. m is an integer between 0 and 3. n is a non-negative integer, where n ≤ 4 + 2m. a0 R is an acid-dissociable group represented by the following general formula (a0-r-1). a01 R is an aliphatic hydrocarbon group. a02 , R a03 and R a04 Each of these is independently a hydrocarbon group which may have substituents, or a hydrogen atom. a01 and R a02 These may bond with each other to form an alicyclic structure. a03 and R a04 These may bond with each other to form an aromatic ring structure or an alicyclic structure. Alternatively, R a01 and R a02 A ring structure formed by the mutual bonding of R a03 and R a04 The aromatic ring structure or alicyclic structure formed by the mutual bonding of these elements may be condensed. a05 * is a chain-like or alicyclic hydrocarbon group, or a hydrogen atom. a0 This indicates that the bond is with the oxy group (-O-).

[0068] In the above equation (a0-1-u0), R m This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. R mThe C1-C5 alkyl group is preferably a linear or branched alkyl group having C1-C5, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. A C1-C5 halogenated alkyl group is a group in which some or all of the hydrogen atoms of the C1-C5 alkyl group are substituted with halogen atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. Fluorine is particularly preferred as the halogen atom in alkyl halides. R m Preferably, the elements are hydrogen atoms, C1-C5 alkyl groups, or C1-C5 fluorinated alkyl groups, with hydrogen atoms or methyl groups being the most preferred due to their industrial availability.

[0069] In the above equation (a0-1-u0), L 1 This is a divalent linking group or a single bond. L 1 The divalent linking group in is not particularly limited, but preferred examples include a divalent hydrocarbon group which may have substituents, and a divalent linking group which contains a heteroatom, respectively. 01 This is similar to the divalent hydrocarbon groups that may have substituents and the divalent linking groups containing heteroatoms, which were exemplified as other groups besides polymerizable groups in the above. Among the above, L 1 Preferably, the bonds are ester bonds [-C(=O)-O-, -OC(=O)-], ether bonds (-O-), linear or branched alkylene groups, aromatic hydrocarbon groups or combinations thereof, or single bonds. Among these, L 1 As for the bond, an ester bond [-C(=O)-O-, -OC(=O)-] is more preferable, and a single bond is even more preferable.

[0070] In the above equation (a0-1-u0), R a06 This is a hydrogen atom or an alkyl group. R a06The alkyl group in is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group, and even more preferably a methyl group or ethyl group.

[0071] In the above formula (a0-1-u0), m is an integer between 0 and 3. When m is 0, it is a benzene structure; when m is 1, it is a naphthalene structure; when m is 2, it is an anthracene structure; and when m is 3, it is a tetracene structure. In the above formula (a0-1-u0), n is an integer greater than or equal to 0, preferably an integer between 1 and 5, more preferably an integer between 1 and 3, and even more preferably 1 or 2. However, n ≤ 4 + 2m.

[0072] In the above equation (a0-1-u0), R a0 is an acid-dissociable group represented by the general formula (a0-r-1). * is R a0 This indicates that it is bonded to an oxy group (-O-). In the above equation (a0-r-1), R a01 , R a02 , R a03 , R a04 and R a05 The same applies as above. In the above formula (a0-r-1), R a01 , and also, R a02 , R a03 and R a04 For example, R a01 R is a linear hydrocarbon group, a02 , R a03 and R a04 If all of them are hydrogen atoms; R a03 and R a04 When they are bonded to each other to form an aromatic ring structure; R a01 and R a02 A preferred example is when the two elements bond to each other to form an alicyclic structure. R a01 and R a02 In the case where these elements bond to each other to form an alicyclic structure, for example, R a01 and R a02and are bonded to each other to form an alicyclic structure, R a03 and R a04 When each is a linear or branched alkyl group or hydrogen atom; R a01 and R a02 A ring structure formed by the mutual bonding of R a03 and R a04 Preferred cases include an aromatic ring structure formed by the bonding of these elements with each other, and a condensed ring structure formed by their condensation.

[0073] The following are specific examples of constituent units (a0). In the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] [ka]

[0080] In the resist composition of this embodiment, the constituent unit (a0) is the constituent unit represented by the above chemical formulas (a0-1-u1) to (a0-1-u9), the constituent unit represented by the chemical formulas (a0-1-u10) to (a0-1-u18), the constituent unit represented by the chemical formulas (a0-1-u19) to (a0-1-u24), the constituent unit represented by the chemical formulas (a0-1-u25) to (a0-1-u28), the constituent unit represented by the chemical formulas (a0-1-u29) to (a0-1-u32), the constituent unit represented by the chemical formulas (a0-1-u33) to (a0-1-u38), and It is preferable that it be at least one selected from the group consisting of constituent units represented by the chemical formulas (a0-1-u39) to (a0-1-u44), and more preferably that it be at least one selected from the group consisting of constituent units represented by the chemical formulas (a0-1-u1) to (a0-1-u9), the constituent units represented by the chemical formulas (a0-1-u10) to (a0-1-u18), the constituent units represented by the chemical formulas (a0-1-u19) to (a0-1-u24), and the constituent units represented by the chemical formulas (a0-1-u39) to (a0-1-u44).

[0081] Alternatively, from the viewpoint of increasing sensitivity, the constituent unit (a0) is preferably at least one selected from the group consisting of constituent units represented by the chemical formulas (a0-1-u1), (a0-1-u10), (a0-1-u19), (a0-1-u25), (a0-1-u29), (a0-1-u33), and (a0-1-u39), more preferably at least one selected from the group consisting of constituent units represented by the chemical formulas (a0-1-u1), (a0-1-u10), and (a0-1-u19), and even more preferably at least one selected from the group consisting of constituent units represented by the chemical formulas (a0-1-u1) and (a0-1-u10). From the standpoint of etching resistance, the constituent unit (a0) is preferably at least one selected from the group consisting of constituent units represented by chemical formulas (a0-1-u2) to (a0-1-u9), constituent units represented by chemical formulas (a0-1-u11) to (a0-1-u18), constituent units represented by chemical formulas (a0-1-u20) to (a0-1-u24), constituent units represented by chemical formulas (a0-1-u26) to (a0-1-u28), constituent units represented by chemical formulas (a0-1-u30) to (a0-1-u32), constituent units represented by chemical formulas (a0-1-u34) to (a0-1-u38), and constituent units represented by chemical formulas (a0-1-u40) to (a0-1-u44), and the chemical formula ( It is more preferable that it be at least one selected from the group consisting of constituent units represented by chemical formulas (a0-1-u2) to (a0-1-u9), constituent units represented by chemical formulas (a0-1-u11) to (a0-1-u18), constituent units represented by chemical formulas (a0-1-u20) to (a0-1-u24), and constituent units represented by chemical formulas (a0-1-u40) to (a0-1-u44), and it is even more preferable that it be at least one selected from the group consisting of constituent units represented by chemical formulas (a0-1-u2) to (a0-1-u9), constituent units represented by chemical formulas (a0-1-u11) to (a0-1-u18), and constituent units represented by chemical formulas (a0-1-u40) to (a0-1-u44).

[0082] The constituent units (a0) of component (A1) may be one type or two or more types. The proportion of constituent units (a0) in component (A1) is preferably 20 mol% to 80 mol%, more preferably 30 mol% to 70 mol%, and even more preferably 40 mol% to 65 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). If the proportion of constituent unit (a0) is above the lower limit of the preferred range mentioned above, both sensitivity and etching resistance tend to be improved. On the other hand, if it is below the upper limit of the preferred range mentioned above, it becomes easier to balance it with other constituent units.

[0083] <<Other constituent units besides constituent unit (a0)>> Component (A1) may have other constituent units in addition to the constituent unit (a0) described above, as needed. Other constituent units include, for example, a constituent unit containing an acid-degradable group whose polarity increases with the action of an acid (a1); a constituent unit represented by the general formula (a10-1) described later (a10); a constituent unit that generates acid upon exposure (a5); a constituent unit containing a lactone-containing cyclic group (a2); and a constituent unit derived from a compound represented by the general formula (a8-1) described later (a8). Note that among the other constituent units, those corresponding to the constituent unit (a0) mentioned above are excluded.

[0084] Regarding the constituent unit (a1): Constituent unit (a1) is a constituent unit that contains an acid-degradable group whose polarity increases upon the action of an acid. However, those corresponding to constituent unit (a0) described above are excluded. An "acid-degradable group" is a group that has acid-degradability, meaning that at least some of the bonds in its structure can be cleaved by the action of an acid. Examples of acid-degradable groups whose polarity increases upon the action of an acid include groups that decompose upon the action of an acid to produce polar groups. Examples of these polar groups include carboxyl groups, hydroxyl groups, amino groups, and sulfo groups (-SO3H). More specifically, examples of acid-degradable groups include groups in which the aforementioned polar group is protected by an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

[0085] Examples of acid-dissociable groups include those previously proposed as acid-dissociable groups for base resins used in chemically amplified resist compositions. Specifically, the following types of acid-dissociable groups have been proposed for base resins used in chemically amplified resist compositions: "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," "tertiary alkyloxycarbonyl acid-dissociable groups," and "secondary alkyl ester-type acid-dissociable groups."

[0086] Acetal type acid dissociable group: Among the aforementioned polar groups, an example of an acid-dissociating group that protects a carboxyl group or a hydroxyl group is an acid-dissociating group represented by the following general formula (a1-r-1) (acetal-type acid-dissociating group).

[0087] [ka] [In the formula, Ra' 1 and Ra' 2 Each of these is either a hydrogen atom or an alkyl group. 3 Ra' is a hydrocarbon group. 3 Ra' 1 , Ra' 2 It may combine with any of the following to form a ring.

[0088] In formula (a1-r-1), Ra' 1 and Ra' 2 Preferably, at least one of them is a hydrogen atom, and more preferably, both are hydrogen atoms. Ra' 1 Or Ra' 2 If the alkyl group is an alkyl group, then an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, linear or branched alkyl groups are preferred. More specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc., with methyl group or ethyl group being more preferred, and methyl group being particularly preferred.

[0089] In formula (a1-r-1), Ra' 3 Examples of hydrocarbon groups include linear or branched alkyl groups, or cyclic hydrocarbon groups. 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. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. Among these, methyl group, ethyl group, or n-butyl group is preferred, and methyl group or ethyl group is more preferred.

[0090] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0091] Ra' 3 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a polycycloalkane from which one hydrogen atom has been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0092] Ra' 3 When the cyclic hydrocarbon group becomes 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 having 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, even more preferably 6 to 15, and particularly preferably 6 to 12. Examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of aromatic heterocycles include pyridine rings and thiophene rings. Ra' 3 Specific examples of aromatic hydrocarbon groups in this context include: a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0093] Ra' 3 The cyclic hydrocarbon group in may have substituents. Examples of such substituents include -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (These substituents are collectively referred to as "Ra") x5 It is also called "[...]." Examples include [...]. Here, R P1This is a monovalent linear 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. Also, R P2 These are single bonds, divalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms, divalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, or divalent aromatic hydrocarbon groups having 6 to 30 carbon atoms. However, R P1 and R P2 Some or all of the hydrogen atoms in the chain-like saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the substituents individually, or it may have one or more of each of the substituents. Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl, tricyclo[5.2.1.02,6]decanyl, tricyclo[3.3.1.13,7]decanyl, tetracyclo[6.2.1.13,6.02,7]dodecanyl, and adamantyl groups. Examples of monovalent aromatic hydrocarbon groups with 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.

[0094] Ra' 3 However, Ra' 1 , Ra' 2 When the cyclic group is bonded to any of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0095] Tertiary alkyl ester type acid-dissociating group: Among the polar groups mentioned above, an example of an acid-dissociating group that protects a carboxyl group is the acid-dissociating group represented by the following general formula (a1-r-2).

[0096] [ka] [In the formula, Ra' 4 ~Ra' 6 Each of these is a hydrocarbon group, Ra' 5 , Ra' 6 They may be joined to each other to form a ring.

[0097] Ra' 4 Examples of hydrocarbon groups include linear or branched alkyl groups, linear or cyclic alkenyl groups, or cyclic hydrocarbon groups. Ra' 4 In the above, linear or branched alkyl groups, cyclic hydrocarbon groups (monocyclic aliphatic hydrocarbon groups, polycyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups) are defined as Ra' 3 Similar examples include the above. Ra' 4 The linear or cyclic alkenyl group in this is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 The hydrocarbon group is the aforementioned Ra' 3 Similar examples include the above.

[0098] Ra' 5 and Ra' 6 When these groups bond to each other to form a ring, the following groups are preferred: the group represented by the general formula (a1-r2-1), the group represented by the general formula (a1-r2-2), and the group represented by the general formula (a1-r2-3). Meanwhile, Ra' 4 ~Ra' 6When these are independent hydrocarbon groups that are not bonded to each other, the groups represented by the following general formula (a1-r2-4) are preferred.

[0099] [ka] [In formula (a1-r2-1), Ra' 10 This represents a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups. 11 Ra' 10 This indicates a group that forms an aliphatic cyclic group with a bonded carbon atom. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. 101 ~Ra 103 Each of these is independently a hydrogen atom, a monovalent linear 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 these linear saturated hydrocarbon groups and aliphatic cyclic saturated hydrocarbon groups may be substituted. 101 ~Ra 103 Two or more of these may be bonded to each other 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 which may have substituents. In formula (a1-r2-4), Ra' 12 and Ra' 13 Each of these is independently a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group that may have substituents. * indicates a bond (the same applies hereafter).

[0100] In the above equation (a1-r2-1), Ra' 10This is a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups.

[0101] Ra' 10 In this context, the linear alkyl group has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra' 10 In this, the branched alkyl group is the Ra' 3 Similar examples include the above.

[0102] Ra' 10 In this case, the alkyl group may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Also, some of the carbon atoms constituting the alkyl group (such as a methylene group) may be substituted with a heteroatom-containing group. Examples of heteroatoms used here include oxygen atoms, sulfur atoms, 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-, -S(=O)2-O-, etc.

[0103] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed with the bonded carbon atom is Ra' in formula (a1-r-1). 3 The aliphatic hydrocarbon groups (alicyclic hydrocarbon groups) listed above, which are monocyclic or polycyclic groups, are preferred. Among these, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl groups and cyclohexyl groups are more preferred.

[0104] In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya is Ra' in formula (a1-r-1). 3Examples include groups obtained by further removing one or more hydrogen atoms from a cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group). The cyclic hydrocarbon group formed by Xa and Ya may have substituents. Examples of such substituents include the above-mentioned Ra' 3 Examples include substituents similar to those that may be present on the cyclic hydrocarbon group in the above. In formula (a1-r2-2), Ra 101 ~Ra 103 Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Ra 101 ~Ra 103 Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl, tricyclo[5.2.1.02,6]decanyl, tricyclo[3.3.1.13,7]decanyl, tetracyclo[6.2.1.13,6.02,7]dodecanyl, and adamantyl groups. Ra 101 ~Ra 103 Of these, from the viewpoint of ease of synthesis, hydrogen atoms and monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms are preferred, and among these, hydrogen atoms, methyl groups, and ethyl groups are more preferred, with hydrogen atoms being particularly preferred.

[0105] The above Ra 101 ~Ra 103 Examples of substituents on a chain-like saturated hydrocarbon group or an aliphatic cyclic saturated hydrocarbon group represented by the above-mentioned Ra x5 Similar bases can be cited.

[0106] Ra 101 ~Ra 103Groups containing a carbon-carbon double bond formed by two or more of these groups bonding to each other to form a cyclic structure include, for example, cyclopentenyl group, cyclohexenyl group, methylcyclopentenyl group, methylcyclohexenyl group, cyclopentylideneethenyl group, and cyclohexyllideneethenyl group. Among these, cyclopentenyl group, cyclohexenyl group, and cyclopentylideneethenyl group are preferred from the viewpoint of ease of synthesis.

[0107] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Ra' in formula (a1-r-1). 3 The aliphatic hydrocarbon groups listed above, which are monocyclic or polycyclic groups, are preferred. In formula (a1-r2-3), Ra 104 Aromatic hydrocarbon groups in this context include groups obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring with 5 to 30 carbon atoms. Among them, Ra 104 The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms with one or more hydrogen atoms removed; more preferably a group from benzene, naphthalene, anthracene, or phenanthrene with one or more hydrogen atoms removed; even more preferably a group from benzene, naphthalene, or anthracene with one or more hydrogen atoms removed; particularly preferably a group from benzene or naphthalene with one or more hydrogen atoms removed; and most preferably a group from benzene with one or more hydrogen atoms removed.

[0108] Ra in equation (a1-r2-3) 104 Examples of substituents that may be present include methyl groups, ethyl groups, propyl groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups (such as methoxy groups, ethoxy groups, propoxy groups, butoxy groups, etc.), and alkyloxycarbonyl groups.

[0109] In formula (a1-r2-4), Ra' 12 and Ra' 13 Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, or a hydrogen atom. 12 and Ra' 13In this context, the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms is the above-mentioned Ra 101 ~Ra 103 Examples include monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, hydrogen atoms and alkyl groups having 1 to 5 carbon atoms are preferred, alkyl groups having 1 to 5 carbon atoms are more preferred, methyl groups and ethyl groups are even more preferred, and methyl groups are particularly preferred. The above Ra' 12 and Ra' 13 When a chain-like saturated hydrocarbon group represented by is substituted, the substituent may be, for example, the above-mentioned Ra x5 Similar bases can be cited.

[0110] In formula (a1-r2-4), Ra' 14 Ra' is a hydrocarbon group that may have substituents. 14 Examples of hydrocarbon groups in this context include linear or branched alkyl groups, or cyclic hydrocarbon groups.

[0111] Ra' 14 The linear alkyl group in this compound preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. Among these, methyl group, ethyl group, or n-butyl group is preferred, and methyl group or ethyl group is more preferred.

[0112] Ra' 14 The branched alkyl group in this compound preferably has 3 to 10 carbon atoms, and more preferably 3 to 5. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0113] Ra'14 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a polycycloalkane from which one hydrogen atom has been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0114] Ra' 14 As for aromatic hydrocarbon groups in this context, Ra 104 Examples include those similar to aromatic hydrocarbon groups in [the text]. Among them, Ra' 14 The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms with one or more hydrogen atoms removed; more preferably a group from benzene, naphthalene, anthracene, or phenanthrene with one or more hydrogen atoms removed; even more preferably a group from benzene, naphthalene, or anthracene with one or more hydrogen atoms removed; particularly preferably a group from naphthalene or anthracene with one or more hydrogen atoms removed; and most preferably a group from naphthalene with one or more hydrogen atoms removed. Ra' 14 The substituents that may be present are Ra 104 Examples of substituents that may be present include those similar to those that may be present.

[0115] Ra' in equation (a1-r2-4) 14 If is a naphthyl group, the position where it bonds with the tertiary carbon atom in formula (a1-r2-4) may be either position 1 or position 2 of the naphthyl group. Ra' in equation (a1-r2-4) 14If is an anthyl group, the position where it bonds with the tertiary carbon atom in formula (a1-r2-4) may be position 1, 2, or 9 of the anthyl group.

[0116] Specific examples of the group represented by the above formula (a1-r2-1) are given below.

[0117] [ka]

[0118] [ka]

[0119] [ka]

[0120] Specific examples of the group represented by the above formula (a1-r2-2) are given below.

[0121] [ka]

[0122] [ka]

[0123] [ka]

[0124] Specific examples of the group represented by the above formula (a1-r2-3) are given below.

[0125] [ka]

[0126] Specific examples of the group represented by the above formula (a1-r2-4) are given below.

[0127] [ka]

[0128] Tertiary alkyloxycarbonyl acid dissociable group: Among the aforementioned polar groups, an example of an acid-dissociating group that protects a hydroxyl group is the acid-dissociating group represented by the following general formula (a1-r-3) (hereinafter sometimes referred to as a "tertiary alkyloxycarbonyl acid dissociating group" for convenience).

[0129] [ka] [In the formula, Ra' 7 ~Ra' 9 These are each alkyl groups.

[0130] In formula (a1-r-3), Ra' 7 ~Ra' 9 Each of these is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Furthermore, the total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0131] Secondary alkyl ester type acid-dissociating group: Among the polar groups mentioned above, an example of an acid-dissociating group that protects a carboxyl group is the acid-dissociating group represented by the following general formula (a1-r-4).

[0132] [ka] [In the formula, Ra' 10Ra' is a hydrocarbon group. 11a and Ra' 11b Each of these is independently a hydrogen atom, a halogen atom, or an alkyl group. 12 is a hydrogen atom or a hydrocarbon group. 10 And, Ra' 11a Or Ra' 11b These may be joined together to form a ring. 11a Or Ra' 11b And, Ra' 12 These may be joined together to form a ring. * indicates a bonding hand.

[0133] In the above formula (a1-r-4), Ra' 10 and Ra' 12 The hydrocarbon group in this is the Ra' 3 Similar examples include the above. In the above formula (a1-r-4), Ra' 11a and Ra' 11b The alkyl group in is the Ra' 1 Examples include alkyl groups similar to those in the above. In the above formula (a1-r-4), Ra' 10 and Ra' 12 The hydrocarbon group in, and Ra' 11a and Ra' 11b The alkyl group in may have substituents. For example, the above-mentioned Ra is an example of such substituent. x5 These are some examples.

[0134] Ra' 10 And, Ra' 11a Or Ra' 11b These elements may be joined together to form a ring. Ra' 11a Or Ra' 11b And, Ra' 12 These elements may be joined together to form a ring. The rings that may be formed by the bonding of these elements together may each be polycyclic or monocyclic, and may be alicyclic or aromatic rings. The alicyclic and aromatic rings may contain heteroatoms.

[0135] Ra' 10 And, Ra' 11a Or Ra' 11b The ring (ring(x)) formed by the bonding of these elements is preferably a monocycloalkene, a ring in which some of the carbon atoms of a monocycloalkene are substituted with heteroatoms (oxygen atoms, sulfur atoms, etc.), or a monocycloalkadiene, preferably a cycloalkene having 3 to 6 carbon atoms, and preferably cyclopentene or cyclohexene.

[0136] Ra' 11a Or Ra' 11b And, Ra' 12 Among the above, an aromatic ring is preferred as the ring (ring(y)) formed by the bonding of these elements, and benzene is particularly preferred. The aromatic ring may contain a heteroatom, for example, a thiophene ring.

[0137] Alternatively, the ring (x) and the ring (y) may be bonded to each other to form a fused ring. Specific examples of such fused rings include indane.

[0138] The aforementioned ring (x), ring (y), and the fused ring formed by the bonding of these two rings may each have substituents. For example, the above-mentioned Ra x5 These are some examples.

[0139] Specific examples of the group represented by the formula (a1-r-4) are given below.

[0140] [ka]

[0141] Examples of constituent units (a1) include constituent units derived from acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent, constituent units derived from acrylamide, constituent units derived from hydroxystyrene or hydroxystyrene derivatives in which at least a portion of the hydrogen atoms in the hydroxyl group of a constituent unit is protected by a substituent containing the acid-degradable group, and constituent units derived from vinyl benzoic acid or vinyl benzoic acid derivatives in which at least a portion of the hydrogen atoms in the -C(=O)-OH group is protected by a substituent containing the acid-degradable group.

[0142] The following are specific examples of constituent units (a1). In the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] [ka]

[0147] [ka]

[0148] [ka]

[0149] [ka]

[0150] [ka]

[0151] The constituent units (a1) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a1), the proportion of constituent units (a1) in component (A1) is preferably 20 mol% or less, and more preferably greater than 0 mol% and less than 20 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1).

[0152] Regarding the constituent unit (a10): The constituent unit (a10) is a constituent unit represented by the following general formula (a10-1).

[0153] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. x1 Wa is a single bond or a divalent linking group. x1 n is an aromatic hydrocarbon group which may have substituents. ax1 [ is an integer greater than or equal to 1.]

[0154] In the above formula (a10-1), 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, and more preferably a hydrogen atom, a methyl group, or a trifluoromethyl group due to their industrial availability, even more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

[0155] In the above formula (a10-1), Ya x1 It is a single bond or a divalent linking group. In the above chemical formula, Ya x1The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have substituents, a divalent linking group which contains a heteroatom, and so on, respectively, as described above in W 01 This is similar to the divalent hydrocarbon groups that may have substituents and the divalent linking groups containing heteroatoms, which were exemplified as other groups besides polymerizable groups in the above.

[0156] Ya x1 Preferably, the group is 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, with single bonds and ester bonds [-C(=O)-O-, -OC(=O)-] being more preferred.

[0157] In the above formula (a10-1), Wa x1 This is an aromatic hydrocarbon group which may have substituents. Wa x1 The aromatic hydrocarbon group in this context may be an aromatic ring that may have substituents (n ax1 A possible example is a group with (+1) hydrogen atoms removed. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Also, Wa x1 The aromatic hydrocarbon group in this context is an aromatic compound containing an aromatic ring which may have two or more substituents (e.g., biphenyl, fluorene, etc.) (n ax1 Another example is a group with (+1) hydrogen atoms removed. Among the above, Wa x1Examples include benzene, naphthalene, anthracene, or biphenyl (n ax1 A group with (+1) hydrogen atoms removed is preferred, and (n ax1 A group with (+1) hydrogen atoms removed is more preferable, and from benzene (n ax1 A group with (+1) hydrogen atoms removed is even more preferable.

[0158] Wa x1 The aromatic hydrocarbon group in this compound may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, and the like. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent are the above W 01 Examples of substituents for cyclic aliphatic hydrocarbon groups are similar to those listed above. The substituents are preferably linear or branched alkyl groups having 1 to 5 carbon atoms, more preferably linear or branched alkyl groups having 1 to 3 carbon atoms, even more preferably ethyl or methyl groups, and particularly preferably methyl groups. Wa x1 In this context, it is preferable that the aromatic hydrocarbon group does not have substituents.

[0159] In the above formula (a10-1), n ax1 is an integer greater than or equal to 1, preferably an integer between 1 and 10, more preferably an integer between 1 and 5, even more preferably 1, 2, or 3, and particularly preferably 1 or 2.

[0160] The following are specific examples of the constituent unit (a10) represented by the above formula (a10-1). In the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0161] [ka]

[0162] [ka]

[0163] [ka]

[0164] The constituent units (a10) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a10), the proportion of constituent units (a10) in component (A1) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 35 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). When the proportion of constituent unit (a10) is above the lower limit of the preferred range mentioned above, sensitivity can be more easily increased. On the other hand, when it is below the upper limit of the preferred range mentioned above, it becomes easier to balance it with other constituent units.

[0165] Regarding the constituent unit (a5) that generates acid upon exposure: In this embodiment, the constituent unit (a5) is a constituent unit that generates acid upon exposure, and known units can be used. Suitable constituent units (a5) include, for example, the constituent unit represented by the following general formula (a5-1).

[0166] [ka] [In the formula, R m This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. 1 This is a divalent linking group or a single bond. 050 This is a divalent hydrocarbon group which may have substituents. 0 It is a divalent linking group. 0 This is a divalent linking group that may have a heteroatom, or a single bond. 051 and Ra 052Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. n0 is an integer from 1 to 4. m is an integer of 1 or more, and M' m+ This is an onium cation with a valence of m.

[0167] {Anion Division} In the above formula (a5-1), R m This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. R m The C1-C5 alkyl group is preferably a linear or branched alkyl group having C1-C5, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. A C1-C5 halogenated alkyl group is a group in which some or all of the hydrogen atoms of the C1-C5 alkyl group are substituted with halogen atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. Fluorine is particularly preferred as the halogen atom in alkyl halides. R m Preferably, the elements are hydrogen atoms, C1-C5 alkyl groups, or C1-C5 fluorinated alkyl groups, with hydrogen atoms or methyl groups being the most preferred due to their industrial availability.

[0168] In the above formula (a5-1), La 1 This is a divalent linking group or a single bond. La 1 The divalent linking group in is not particularly limited, but preferred examples include a divalent hydrocarbon group which may have substituents, and a divalent linking group which contains a heteroatom, respectively. 01 This is similar to the divalent hydrocarbon groups that may have substituents and the divalent linking groups containing heteroatoms, which were exemplified as other groups besides polymerizable groups in the above. Among the above, La 1Preferably, the bonds are ester bonds [-C(=O)-O-, -OC(=O)-], ether bonds (-O-), linear or branched alkylene groups, aromatic hydrocarbon groups or combinations thereof, or single bonds. Among these, La 1 As such, ester bonds [-C(=O)-O-, -OC(=O)-] and single bonds are more preferable, and ester bonds [-C(=O)-O-, -OC(=O)-] are even more preferable.

[0169] In the above formula (a5-1), Ra 050 This is a divalent hydrocarbon group which may have substituents. Ra 050 The divalent hydrocarbon group in this expression may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0170] ··Ra 050 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0171] ...linear or branched aliphatic hydrocarbon groups The linear aliphatic 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 most preferably 1 to 3 carbon atoms. As for the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, specifically the methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0172] The linear or branched aliphatic hydrocarbon group described above may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0173] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in the structure include cyclic aliphatic hydrocarbon groups that may contain substituents containing heteroatoms in the ring structure (groups from which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0174] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. As the alkoxy group used as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are most preferred. Examples of halogen atoms used as substituents include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like, with fluorine atoms being preferred. Examples of halogenated alkyl groups as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. A cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure replaced by substituents containing heteroatoms. Preferred substituents containing heteroatoms are -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0175] ··Ra 050 Aromatic hydrocarbon groups in 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 having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of aromatic hydrocarbon groups include groups obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); groups obtained by removing two hydrogen atoms from aromatic compounds containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of an aryl group or heteroaryl group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) is substituted with an alkylene group (e.g., groups obtained by removing one more hydrogen atom from an aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0176] The aromatic hydrocarbon group may have its hydrogen atoms substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, and hydroxyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Examples of the substituents include alkoxy groups, halogen atoms, and alkyl halogens that substitute for hydrogen atoms on the cyclic aliphatic hydrocarbon group.

[0177] Among the above, 050 The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group containing a ring in its structure, more preferably a cyclic aliphatic hydrocarbon group which may contain substituents containing heteroatoms in its ring structure, and even more preferably an alicyclic hydrocarbon group which may have substituents and is a polycyclic or monocyclic group.

[0178] In the above formula (a5-1), La 0 It is a divalent linking group. La 0 Examples of divalent linking groups in this context include non-hydrocarbon oxygen atom-containing linking groups such as oxygen atoms (ether bond: -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 atom-containing linking groups with alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of such divalent linking groups include the linking groups represented by the following general formulas (L-al-1) to (L-al-8). Note that in the following general formulas (L-al-1) to (L-al-8), Ra in formula (a5-1) above 050 The combination with this is V' in the following general formulas (L-al-1)~(L-al-8). 101 That is the case.

[0179] [ka] [In the formula, V' 101V' is a single bond or an alkylene group with 1 to 5 carbon atoms. 102 It is a divalent saturated hydrocarbon group with 1 to 30 carbon atoms.

[0180] V' 102 The divalent saturated hydrocarbon group in 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.

[0181] V' 101 and V' 102 The alkylene group in this product may be a linear alkylene group or a branched alkylene group, but a linear alkylene group is preferred. V' 101 and V' 102 Specifically, the alkylene groups in these include: methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2 Examples include alkylethylene groups such as -CH2CH2CH2-; trimethylene groups (n-propylene groups) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; tetramethylene groups [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and pentamethylene groups [-CH2CH2CH2CH2CH2-]. Also, oshiV' 101 or V' 102 Some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is Ra' in formula (a1-r-1). 3A divalent group is preferred, which is obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group), and a cyclohexylene group, a 1,5-adamantilene group, or a 2,6-adamantilene group is more preferred.

[0182] La 0 Preferably, the linking group is a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, more preferably the linking groups represented by the above formulas (L-al-1) to (L-al-5) and (L-al-8), and even more preferably the linking group represented by (L-al-3) or (L-al-8).

[0183] In the above formula (a5-1), Ya 0 This is a divalent linking group that may have a heteroatom, or a single bond. Ya 0 The divalent linking group in this is not particularly limited, but preferred examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. Ya 0 In the above W, the divalent hydrocarbon group which may have substituents, and the divalent linking group which contains a heteroatom, are as follows: 01 This is similar to the divalent hydrocarbon groups that may have substituents and the divalent linking groups containing heteroatoms, which were exemplified as other groups besides polymerizable groups in the above. Among the above, Ya 0 The alkylene group is preferably a linear or branched alkylene group, or a single bond, with a single bond being more preferable.

[0184] In the above formula (a5-1), Ra 051 and Ra 052 Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. Ra 051 and Ra 052 The fluorinated alkyl groups in this compound are preferably linear or branched fluorinated alkyl groups having 1 to 5 carbon atoms, with a trifluoromethyl group being more preferred. In the above formula (a5-1), SO3 -Ra bonds to the adjacent carbon atom. 051 and Ra 052 From the viewpoint of acid strength, it is preferable that at least one of these atoms is a fluorine atom.

[0185] In the above formula (a5-1), n0 is an integer from 1 to 4, and is preferably 1, 2, or 3.

[0186] {cation part} In the above formula (a5-1), M' m+ This represents an m-valent onium cation. Among these, M' m+ The sulfonium cation and iodonium cation are preferred. m is an integer of 1 or more.

[0187] Preferred cation portion ((M' m+ ) 1 / m Examples of these include organic cations represented by the following general formulas (ca-1) to (ca-3).

[0188] [ka] [In the formula, R 201 ~R 207 Each of these independently represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group. 201 ~R 203 , R 206 ~R 207 These atoms may bond to each other to form a ring with the sulfur atom in the formula. 208 ~R 209 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 210 This is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. 201 This represents -C(=O)- or -C(=O)-O-.

[0189] In the above general formulas (ca-1) to (ca-3), R 201~R 207 Examples of aryl groups in this context include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. R 201 ~R 207 The alkyl group in this is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 Examples of substituents that may be present include alkyl groups, halogen atoms, alkyl halides, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by the following general formulas (ca-r-1) to (ca-r-8). Among these, halogen atoms and alkyl halides are preferred from the viewpoint of increasing sensitivity, and fluorine atoms and alkyl fluorides are more preferred.

[0190] [ka] [In the formula, R' 201 Each of these is independently a hydrogen atom, an optionally substituted cyclic group, an optionally substituted linear alkyl group, or an optionally substituted linear alkenyl group.

[0191] Cyclic groups that may have substituents: The cyclic group is preferably a cyclic hydrocarbon group, which may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not possess aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated.

[0192] R' 201The aromatic hydrocarbon group in this context is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this number of carbon atoms does not include the number of carbon atoms in substituents. R' 201 Specific examples of aromatic rings in aromatic hydrocarbon groups include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, nitrogen atoms, etc. R' 201 Specific examples of aromatic hydrocarbon groups in this context include groups obtained by removing one hydrogen atom from the aromatic ring (aryl groups: e.g., phenyl group, naphthyl group, etc.), and groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0193] R' 201 In this context, cyclic aliphatic hydrocarbon groups include aliphatic hydrocarbon groups that contain a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in this structure include alicyclic hydrocarbon groups (groups from which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among these, polycycloalkanes having a bridging ring polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; and polycycloalkanes having a fused ring polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferred.

[0194] Among them, R' 201 The cyclic aliphatic hydrocarbon group in is preferably a monocycloalkane or polycycloalkane from which one or more hydrogen atoms have been removed, more preferably a polycycloalkane from which one hydrogen atom has been removed, with adamantyl and norbornyl groups being particularly preferred, and the adamantyl group being the most preferred.

[0195] 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. As for the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, specifically the methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], pentamethylene group [-(CH2)5-], etc. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0196] Also, R' 201 The cyclic hydrocarbon groups in these compounds may contain heteroatoms, such as heterocycles. Specifically, these include lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7) described below, -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4) described below, and other heterocyclic groups represented by the chemical formulas (r-hr-1) to (r-hr-16) described below.

[0197] [ka]

[0198] R' 201 Examples of substituents on the cyclic group include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, and nitro groups. As alkyl groups used as substituents, alkyl groups having 1 to 5 carbon atoms are preferred, with methyl, ethyl, propyl, n-butyl, and tert-butyl groups being the most preferred. As the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are most preferred. As the halogen atom used as a substituent, a fluorine atom is preferred. Examples of alkyl halides used as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms are substituted with the halogen atoms. A carbonyl group as a substituent is a group that substitutes for a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0199] Chain-like alkyl groups that may have substituents: R' 201 The chain-like alkyl group may be either linear or branched. 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. Specifically, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0200] A chain-like alkenyl group which may have substituents: R' 201The linear alkenyl group 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 groups, propenyl groups (allyl groups), and butynyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups. Among the above, linear alkenyl groups are preferred as chain-like alkenyl groups, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0201] R' 201 Substituents in the chain-like alkyl or alkenyl group include, for example, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the above R' 201 Examples include cyclic groups in this context.

[0202] R' 201 In addition to those mentioned above, the optionally substituted cyclic groups, optionally substituted linear alkyl groups, or optionally substituted linear alkenyl groups may also include those similar to the acid-dissociable group represented by formula (a1-r-2) above, as optionally substituted cyclic groups or optionally substituted linear alkyl groups.

[0203] Among them, R' 201 The group is preferably a cyclic group which may have substituents, and more preferably a cyclic hydrocarbon group which may have substituents. More specifically, preferred groups include, for example, a phenyl group, a naphthyl group, a polycycloalkane from which one or more hydrogen atoms have been removed; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7) described below; and -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4) described below.

[0204] In the above general formulas (ca-1) to (ca-3), R 201 ~R203 , R 206 ~R 207 When these atoms bond to each other and form a ring with the sulfur atom in the formula, they may be heteroatoms such as sulfur, oxygen, or nitrogen atoms, or carbonyl groups, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R N is an alkyl group having 1 to 5 carbon atoms. ) may be bonded via functional groups such as ). The formed ring preferably has 3 to 10 members, and particularly preferably 5 to 7 members, including the sulfur atom in its ring skeleton. Specific examples of the formed ring include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthlene ring, a phenoxatiyne ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0205] R 208 ~R 209 Each of these independently represents 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. If an alkyl group is formed, it may bond with other elements to form a ring.

[0206] R 210 This is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 Examples of aryl groups in this context include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. R 210 The alkyl group in this is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 210In this context, the -SO2-containing cyclic group which may have substituents is preferably a "-SO2-containing polycyclic group," and more preferably a group represented by the general formula (b5-r-1) described later.

[0207] Specific examples of suitable cations represented by the above formula (ca-1) include the cations represented by the following chemical formulas (ca-1-1) to (ca-1-76). From the viewpoint of increasing sensitivity, a suitable cation represented by the formula (ca-1) is one having a fluorine atom or a fluorinated alkyl group as a substituent, and a cation selected from the group consisting of the cations represented by the following chemical formulas (ca-1-69) to (ca-1-75) is particularly preferred.

[0208] [ka]

[0209] [ka]

[0210] [ka] [In the formula, g1, g2, and g3 represent the number of repetitions, where 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.]

[0211] [ka]

[0212] [ka]

[0213] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the aforementioned R 201 ~R 207 , and R 210 ~R 212 These are the same as those listed as substituents that may be present.

[0214] [ka]

[0215] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0216] Specific examples of suitable cations represented by the above formula (ca-3) include the cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0217] [ka]

[0218] Among the above, the cation part ((M' m+ ) 1 / m As such, the organic cation represented by the general formula (ca-1) above is more preferred.

[0219] The following are some preferred examples of the constituent unit (a5). In the following equation, R α m and M' represent a hydrogen atom, a methyl group, or a trifluoromethyl group. m+ These are m and M' in the general formula (a5-1) above. m+ It is similar to that.

[0220] [ka]

[0221] [ka]

[0222] (A1) The constituent units (a5) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a5), the proportion of constituent units (a5) in component (A1) is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and even more preferably 5 to 15 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). When the proportion of constituent unit (a5) is above the lower limit of the preferred range mentioned above, sensitivity can be more easily increased. On the other hand, when it is below the upper limit of the preferred range mentioned above, it becomes easier to balance it with other constituent units.

[0223] Regarding the constituent unit (a2): Component (A1) may also have a constituent unit (a2) containing a lactone-containing cyclic group in addition to the constituent unit (a0) (excluding those corresponding to constituent units (a0) and (a1)). The lactone-containing cyclic group of component (a2) is effective in improving the adhesion of the resist film to the substrate when component (A1) is used to form a resist film. Furthermore, the presence of component (a2) improves lithography characteristics, for example, by appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0224] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -OC(=O)- within its cyclic skeleton. The lactone ring is counted as the first ring. If it consists only of a lactone ring, it is called a monocyclic group. If it also has other ring structures, it is called a polycyclic group regardless of those structures. A lactone-containing cyclic group may be a monocyclic group or a polycyclic group. Any lactone-containing cyclic group can be used in the constituent unit (a2) without any particular limitations. Specifically, examples include the groups represented by the following general formulas (a2-r-1) to (a2-r-7).

[0225] [ka] [In the formula, multiple Ra' 21 Each of these is 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, which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom, where n' is an integer from 0 to 2 and m' is 0 or 1. * indicates a bond.

[0226] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, etc. Among these, the methyl group or ethyl group is preferred, and the methyl group is particularly preferred. Ra' 21 The alkoxy group in is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the Ra' 21Examples of alkyl groups in this context include groups formed by linking an alkyl group with an oxygen atom (-O-). Ra' 21 In this mixture, a fluorine atom is preferred as the halogen atom. Ra' 21 The halogenated alkyl group in is the Ra' 21 Examples include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. Fluorinated alkyl groups are preferred as the halogenated alkyl group, and perfluoroalkyl groups are particularly preferred.

[0227] Ra' 21 In -COOR'' and -OC(=O)R'', R'' is either a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R'' can be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R'' is a linear or branched alkyl group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. When R'' is a cyclic alkyl group, it is preferably 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 monocycloalkanes which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, examples include groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane; and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Examples of lactone-containing cyclic groups in R'' include those similar to those represented by the general formulas (a2-r-1) to (a2-r-7) mentioned above. Ra'21 The hydroxyalkyl group in is preferably one having 1 to 6 carbon atoms, specifically the Ra' 21 Examples include groups in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0228] Ra' 21 Among the above, it is preferable that each is independently a hydrogen atom or a cyano group.

[0229] In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5) above, the alkylene group having 1 to 5 carbon atoms in A'' is preferably a linear or branched alkylene group, such as a methylene group, ethylene group, n-propylene group, isopropylene group, etc. If the alkylene group contains an oxygen atom or a sulfur atom, specific examples include a group in which -O- or -S- is interposed at the end or between carbon atoms of the alkylene group, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, -CH2-S-CH2-, etc. As A'', an alkylene group having 1 to 5 carbon atoms or -O- is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is most preferred.

[0230] Below are specific examples of groups represented by the general formulas (a²-r-1) to (a²-r-7).

[0231] [ka]

[0232] [ka]

[0233] Among the constituent units (a2), those derived from acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent are preferred. The constituent unit (a2) is preferably a constituent unit represented by the following general formula (a2-1).

[0234] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. 21 It is a single bond or a divalent linking group. 21 The group is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. However, La 21 If -O-, Ya 21 It does not become -CO-. 21 It is a lactone-containing cyclic group.

[0235] In formula (a2-1) above, R is the same as 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, and a hydrogen atom or a methyl group is particularly preferred due to their industrial availability.

[0236] In the above formula (a2-1), Ya 21 The divalent linking group in is not particularly limited, but preferably includes a divalent hydrocarbon group which may have substituents, a divalent linking group which contains a heteroatom, and so on, respectively, as described above in W 01 This is similar to the divalent hydrocarbon groups that may have substituents and the divalent linking groups containing heteroatoms, which were exemplified as other groups besides polymerizable groups in the above. Ya 21 The preferred elements are single bonds, ester bonds [-C(=O)-O-], ether bonds (-O-), linear or branched alkylene groups, or combinations thereof, with single bonds being particularly preferred.

[0237] In the above formula (a2-1), Ya 21 It is a single bond, La 21 It is preferable that it be -COO- or -OCO-.

[0238] In the above formula (a2-1), Ra 21 It is a lactone-containing cyclic group. Ra 21 Suitable lactone-containing cyclic groups in this compound include the groups represented by the general formulas (a2-r-1) to (a2-r-7) mentioned above. Among these, the groups represented by the general formulas (a2-r-1) or (a2-r-2) are preferred. Specifically, the groups represented by the chemical formulas (r-lc-1-1) to (r-lc-1-7) and (r-lc-2-1) to (r-lc-2-18) are preferred, and the groups represented by the chemical formulas (r-lc-1-1), (r-lc-2-1), or (r-lc-2-7) are even more preferred.

[0239] The constituent units (a2) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a2), the proportion of constituent units (a2) is preferably more than 0 mol% and 20 mol% or less, relative to the total amount (100 mol%) of all constituent units that make up component (A1). When the proportion of constituent unit (a2) is above the lower limit of the preferred range mentioned above, the effects of including constituent unit (a2) are fully obtained. On the other hand, when it is below the upper limit of the preferred range mentioned above, a balance can be achieved with other constituent units, resulting in good lithography characteristics.

[0240] Regarding the constituent unit (a8): The constituent unit (a8) is a constituent unit derived from the compound represented by the following general formula (a8-1).

[0241] [ka] [In the formula, W 2 This is a polymerizable group-containing group. x2 is a single bond or (n ax2 It is a linking group with a +1 valence. x2 and W 2 It may form a fused ring with R. 1R is a fluorinated alkyl group having 1 to 12 carbon atoms. 2 R is an organic group having 1 to 12 carbon atoms, which may contain a fluorine atom, or a hydrogen atom. 2 and Ya x2 These may be bonded to each other to form a ring structure. ax2 [This is an integer between 1 and 3.]

[0242] In the above formula (a8-1), W 2 The explanation of the polymerizable group-containing group in the above-mentioned general formula (a0-1) is W 01 This is similar to the explanation regarding polymerizable group-containing groups in [the relevant section]. W 2 Examples of polymerizable groups include those with the chemical formula: C(R X11 )(R X12 )=C(R X13 )-Ya x0 The group represented by - is preferably mentioned. In this chemical formula, R X11 , R X12 and R X13 These are, respectively, 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, and is W in the general formula (a0-1) described above. 01 The example given in the explanation of the chemical formula: C(R X11 )(R X12 )=C(R X13 )-Ya x0 This is similar to the base represented by -.

[0243] The following are specific examples of constituent units (a8). In the following formula, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0244] [ka]

[0245] The constituent units (a8) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a8), the proportion of constituent units (a8) is preferably more than 0 mol% and 20 mol% or less, relative to the total amount (100 mol%) of all constituent units that make up component (A1).

[0246] The (A1) component contained in the resist composition may be used alone or in combination of two or more types. In the resist composition of this embodiment, component (A1) includes a polymer compound having a repeating structure of the constituent unit (a0). (A1) Among the above, components containing polymer compounds having a repeating structure of constituent unit (a0) and constituent unit (a10) are preferred.

[0247] More specifically, suitable polymer compounds for component (A1) include polymer compounds consisting of a repeating structure of constituent unit (a0) and constituent unit (a10); polymer compounds consisting of a repeating structure of constituent unit (a0) and constituent unit (a10) and constituent unit (a5); and polymer compounds consisting of a repeating structure of constituent unit (a0) and constituent unit (a10) and constituent unit (a2).

[0248] In a polymer compound consisting of a repeating structure of constituent units (a0) and constituent units (a10), the proportion of constituent units (a0) is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 65 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. Furthermore, the proportion of constituent units (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 35 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound.

[0249] In a polymer compound consisting of a repeating structure of constituent units (a0), (a10), and (a5), the proportion of constituent unit (a0) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. Furthermore, the proportion of constituent units (a10) in the polymer compound is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, and even more preferably 20 to 40 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. Furthermore, the proportion of constituent units (a5) in the polymer compound is preferably greater than 0 mol% and 20 mol% or less, more preferably 5 to 20 mol%, and even more preferably 5 to 15 mol%, relative to the total amount of all constituent units (100 mol%) of the polymer compound.

[0250] In a polymer compound consisting of a repeating structure of constituent units (a0), (a10), and (a2), the proportion of constituent unit (a0) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. Furthermore, the proportion of constituent units (a10) in the polymer compound is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, and even more preferably 20 to 40 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. Furthermore, the proportion of constituent units (a2) in the polymer compound is preferably greater than 0 mol% and 20 mol% or less, more preferably 5 to 20 mol%, and even more preferably 5 to 15 mol%, relative to the total amount of all constituent units (100 mol%) of the polymer compound.

[0251] Such component (A1) can be produced by dissolving monomers that induce each constituent unit in a polymerization solvent and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the mixture and polymerizing it. Alternatively, such component (A1) can be produced by dissolving a monomer that induces the constituent unit (a0) and, if necessary, a monomer that induces a constituent unit other than the constituent unit (a0) (for example, the constituent unit (a10), etc.) in a polymerization solvent, adding the above-mentioned radical polymerization initiator to this solution and polymerizing it, and then carrying out a deprotection reaction. Furthermore, during polymerization, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH may be used in combination to introduce a -C(CF3)2-OH group at the terminal. Copolymers in which a hydroxyalkyl group, in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms, are introduced are effective in reducing development defects and LER (line edge roughness: uneven unevenness of the line sidewall).

[0252] The weight-average molecular weight (Mw) of component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) 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 25,000. If the Mw of component (A1) is below the preferred upper limit of this range, it has sufficient solubility in the resist solvent for use as a resist, and if it is above the preferred lower limit of this range, it has good dry etching resistance and a good cross-sectional shape of the resist pattern. (A1) The degree of dispersion of component (Mw / Mn) is not particularly limited, but is preferably 1.0 to 3.0, more preferably 1.0 to 2.5, and particularly preferably 1.0 to 2.0. Mn represents the number-average molecular weight.

[0253] (A2) About the ingredients The resist composition of this embodiment may also include, as component (A), a base component (hereinafter referred to as "component (A2)") that does not correspond to component (A1) and whose solubility in the developer solution changes due to the action of an acid. (A2) The component is not particularly limited and can be arbitrarily selected from a large number of components that have been conventionally known as base components for chemically amplified resist compositions. (A2) Component may be a single high-molecular-weight compound or a low-molecular-weight compound, or two or more may be used in combination.

[0254] The proportion of component (A1) in component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and may also be 100% by mass, based on the total mass of component (A). When the proportion is 25% by mass or more, it becomes easier to form a resist pattern that is excellent in various lithography characteristics such as high sensitivity, high resolution, film thinning suppression, and roughness improvement.

[0255] In the resist composition of this embodiment, the content of component (A) may be adjusted according to the resist film thickness to be formed.

[0256] <Other ingredients> The resist composition of this embodiment may further contain other components in addition to component (A) described above. Examples of other components include components (B), (D), (E), (F), and (S) shown below.

[0257] ≪Acid Generating Agent Component (B)≫ The resist composition of this embodiment preferably further contains an acid-generating component (B) that generates acid upon exposure. (B) The component is not particularly limited, and any acid generators previously proposed for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts; oximesulfonate-based acid generators; diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators, among many others.

[0258] Examples of onium salt-based acid generators include the compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), the compound represented by the general formula (b-2) (hereinafter also referred to as "component (b-2)"), or the compound represented by the general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0259] [ka] [In the formula, R 101 and R 104 ~R 108 Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 104 and R 105 These may be bonded to each other to form a ring structure. 102 This is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. 101 This is a divalent linking group or single bond containing an oxygen atom. 101 ~V 103 These are, independently, a single bond, an alkylene group, or a fluorinated alkylene group. 101 ~L 102 Each of these is independently either a single bond or an oxygen atom. 103 ~L 105 These are, independently, single bonds, -CO-, or -SO2-. m is an integer greater than or equal to 1, and M' m+ This is an onium cation with a valence of m.

[0260] {Anion Division} • Anion in component (b-1) In formula (b-1), R 101 This is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents.

[0261] Cyclic groups that may have substituents: The cyclic group is preferably a cyclic hydrocarbon group, which may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not possess aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated.

[0262] R 101 The aromatic hydrocarbon group in this formula is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this number of carbon atoms does not include the number of carbon atoms in substituents. R 101 Specific examples of aromatic rings in aromatic hydrocarbon groups include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, nitrogen atoms, etc. R 101 Specific examples of aromatic hydrocarbon groups in this context include groups obtained by removing one hydrogen atom from the aromatic ring (aryl groups: for example, phenyl groups, naphthyl groups, etc.), and groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (for example, arylalkyl groups such as benzyl groups, phenethyl groups, 1-naphthylmethyl groups, 2-naphthylmethyl groups, 1-naphthylethyl groups, and 2-naphthylethyl groups). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0263] R 101 In this context, cyclic aliphatic hydrocarbon groups include aliphatic hydrocarbon groups that contain a ring in their structure. Examples of aliphatic hydrocarbon groups containing a ring in this structure include alicyclic hydrocarbon groups (groups from which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 30 carbon atoms. Among these, polycycloalkanes having a bridging ring polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; and polycycloalkanes having a fused ring polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferred.

[0264] Among them, R 101 The cyclic aliphatic hydrocarbon group in is preferably a monocycloalkane or polycycloalkane from which one or more hydrogen atoms have been removed, more preferably a polycycloalkane from which one hydrogen atom has been removed, even more preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0265] The linear aliphatic hydrocarbon group, which 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. Examples of linear aliphatic hydrocarbon groups include linear alkylene groups, specifically methylene groups [-CH2-], ethylene groups [-(CH2)2-], trimethylene groups [-(CH2)3-], tetramethylene groups [-(CH2)4-], pentamethylene groups [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group, which 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. Preferred branched aliphatic hydrocarbon groups include branched alkylene groups, specifically alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0266] Also, R 101 The cyclic hydrocarbon group in this formula may contain heteroatoms, such as heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), heterocyclic groups represented by the chemical formulas (r-hr-1) to (r-hr-16), and -SO2-containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4). * in the formula represents Y in formula (b-1). 101 This represents a coupling that connects to something.

[0267] [ka] [In the formula, Rb' 51 Each of the following is 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, which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, and n' is an integer from 0 to 2. * indicates a bond.

[0268] In the above 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, or an oxygen atom or a sulfur atom. For B'', an alkylene group or -O- having 1 to 5 carbon atoms is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is even more preferred.

[0269] In the above general formulas (b5-r-1) to (b5-r-4), Rb' 51 Each of these is 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, and among these, each is preferably independently a hydrogen atom or a cyano group.

[0270] Below are specific examples of the groups represented by the general formulas (b5-r-1) to (b5-r-4). In the formulas, "Ac" indicates an acetyl group.

[0271] [ka]

[0272] [ka]

[0273] [ka]

[0274] R 101 Examples of substituents on the cyclic group include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, and nitro groups. As alkyl groups used as substituents, alkyl groups having 1 to 5 carbon atoms are preferred, with methyl, ethyl, propyl, n-butyl, and tert-butyl groups being the most preferred. As the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are most preferred. Examples of halogen atoms used as substituents include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with bromine atoms and iodine atoms being preferred, and iodine atoms being more preferred. Examples of alkyl halides used as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms are substituted with the halogen atoms. A carbonyl group as a substituent is a group that substitutes for a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0275] R 101The cyclic hydrocarbon group in may be a fused ring group containing a fused ring formed by the fusion of an aliphatic hydrocarbon ring and an aromatic ring. Examples of the fused ring include a polycycloalkane having a bridging ring system with one or more aromatic rings fused to it. Specific examples of the bridging ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring formed by the fusion of two or three aromatic rings to a bicycloalkane, and more preferably a group containing a fused ring formed by the fusion of two or three aromatic rings to bicyclo[2.2.2]octane. 101 Specific examples of fused ring groups in this context include the groups represented by the following formulas (r-br-1) to (r-br-2). * in the formula represents Y in formula (b-1). 101 This represents a coupling that connects to something.

[0276] [ka]

[0277] R 101 Examples of substituents that the fused ring group in the compound may have include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, aromatic hydrocarbon groups, and alicyclic hydrocarbon groups. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as substituents of the fused cyclic group are as described above in R 101 Examples of substituents on cyclic groups in the above are similar to those listed. Examples of aromatic hydrocarbon groups as substituents on the fused ring group include groups obtained by removing one hydrogen atom from an aromatic ring (aryl groups: for example, phenyl groups, naphthyl groups, etc.), groups in which one hydrogen atom of the aromatic ring is replaced by an alkylene group (for example, arylalkyl groups such as benzyl groups, phenethyl groups, 1-naphthylmethyl groups, 2-naphthylmethyl groups, 1-naphthylethyl groups, 2-naphthylethyl groups, etc.), and heterocyclic groups represented by the chemical formulas (r-hr-1) to (r-hr-6), respectively. Examples of alicyclic hydrocarbon groups as substituents on the fused cyclic group include: groups obtained by removing one hydrogen atom from monocycloalkanes such as cyclopentane and cyclohexane; groups obtained by removing one hydrogen atom from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7); -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4); and heterocyclic groups represented by the chemical formulas (r-hr-7) to (r-hr-16).

[0278] Chain-like alkyl groups that may have substituents: R 101 The chain-like alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15, and most preferably 1 to 10. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15, and most preferably 3 to 10. Specifically, examples include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

[0279] A chain-like alkenyl group which may have substituents: R 101 The linear alkenyl group may be linear or branched, and preferably has 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 groups, propenyl groups (allyl groups), and butynyl groups. Examples of branched alkenyl groups include 1-methylvinyl groups, 2-methylvinyl groups, 1-methylpropenyl groups, and 2-methylpropenyl groups. Among the above, linear alkenyl groups are preferred as chain-like alkenyl groups, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0280] R 101 Examples of substituents in the chain-like alkyl or alkenyl group include alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, amino groups, and the above R 101 Examples include cyclic groups in this context.

[0281] Among the above, R 101 The group is preferably a cyclic group which may have substituents, and more preferably a cyclic hydrocarbon group which may have substituents. More specifically, preferred cyclic hydrocarbon groups include aromatic hydrocarbon groups, groups obtained by removing one or more hydrogen atoms from polycycloalkanes, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), -SO2-containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4), and fused cyclic groups including fused rings formed by the fusion of an aliphatic hydrocarbon ring and an aromatic ring. More preferably, aromatic hydrocarbon groups and fused cyclic groups including fused rings formed by the fusion of an aliphatic hydrocarbon ring and an aromatic ring are preferred. Among them, R 101 More preferably, the group is an aryl group having a substituent selected from the group consisting of an alkyl group having 1 to 5 carbon atoms, a bromine atom, and an iodine atom, or a group represented by the above formulas (r-br-1) to (r-br-2).

[0282] In formula (b-1), Y 101 This is a divalent linking group or single bond containing an oxygen atom. Y 101 If Y is a divalent linking group containing an oxygen atom, 101 It may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms, etc. Examples of divalent linking groups containing an oxygen atom include non-hydrocarbon oxygen-containing linking groups such as oxygen atoms (ether bond: -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 such non-hydrocarbon oxygen-containing linking groups with alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of such divalent linking groups containing an oxygen atom include the linking groups represented by the following general formulas (y-al-1) to (y-al-7). Furthermore, in the following general formulas (y-al-1) to (y-al-7), R in formula (b-1) 101 The V' in the following general formulas (y-al-1)~(y-al-7) is what combines with it. 101 That is the case.

[0283] [ka] [In the formula, V' 101 V' is an alkylene group or single bond with 1 to 5 carbon atoms. 102 This is a divalent saturated hydrocarbon group or single bond having 1 to 30 carbon atoms.

[0284] V' 102 The divalent saturated hydrocarbon group in 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.

[0285] V' 101 and V' 102 The alkylene group in this product may be a linear alkylene group or a branched alkylene group, but a linear alkylene group is preferred. V' 101 and V' 102Specifically, the alkylene groups in these include: methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2 Examples include alkylethylene groups such as -CH2CH2CH2-; trimethylene groups (n-propylene groups) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; tetramethylene groups [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and pentamethylene groups [-CH2CH2CH2CH2CH2-]. Also, oshiV' 101 or V' 102 Some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is Ra' in formula (a1-r-1). 3 A divalent group is preferred, which is obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group), and a cyclohexylene group, a 1,5-adamantilene group, or a 2,6-adamantilene group is more preferred.

[0286] Y 101 Preferably, the linking group is a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and more preferably, an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), and the linking groups represented by the above formulas (y-al-1) to (y-al-5).

[0287] In formula (b-1), V 101 This is a single bond, an alkylene group, or a fluorinated alkylene group. 101 The alkylene group and fluorinated alkylene group in this product preferably have 1 to 4 carbon atoms. 101As for the fluorinated alkylene group in V 101 Examples include groups in which some or all of the hydrogen atoms of the alkylene group are replaced with fluorine atoms. Among these, V 101 It is preferable that it is a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0288] In formula (b-1), R 102 R is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 It is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0289] A specific example of the anion part represented by the above formula (b-1) is, for example, Y 101 When it is a single bond, examples include fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anions and perfluorobutanesulfonate anions; Y 101 When is a divalent linking group containing an oxygen atom, the anions can be represented by any of the following formulas (an-1) to (an-3).

[0290] [ka] [In the formula, R” 101 R” is an optionally substituted aliphatic cyclic group, an -SO2-containing cyclic group represented by the above general formulas (b5-r-1) to (b5-r-4), a monovalent heterocyclic group represented by the above chemical formulas (r-hr-1) to (r-hr-6), an optionally substituted aryl group, a fused cyclic group represented by the above chemical formula (r-br-1) or (r-br-2), or an optionally substituted linear alkyl group. 102 R” is an aliphatic cyclic group which may have substituents, a fused cyclic group represented by formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by the general formulas (a2-r-1), (a2-r-3) to (a2-r-7), respectively, or a -SO2-containing cyclic group represented by the general formulas (b5-r-1) to (b5-r-4), respectively. 103V” is an optionally substituted aromatic cyclic group, an optionally substituted aliphatic cyclic group, or an optionally substituted linear alkenyl group. 101 This is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102 [wherein 'v' is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; where 'v' is an independent integer from 0 to 3, where 'q' is an independent integer from 0 to 20, and where 'n' is 0 or 1.]

[0291] R" 101 , R” 102 and R” 103 The aliphatic cyclic group which may have substituents is R in formula (b-1) above. 101 It is preferable that the substituent is the group exemplified as a cyclic aliphatic hydrocarbon group in formula (b-1). 101 Examples include substituents similar to those that may be substituted for the cyclic aliphatic hydrocarbon group in the above.

[0292] R" 101 The aryl group which may have substituents is preferably an aryl group having substituents selected from the group consisting of alkyl groups having 1 to 5 carbon atoms, bromine atoms, and iodine atoms. From the viewpoint of increasing sensitivity, it is more preferably an aryl group having substituents selected from the group consisting of bromine atoms and iodine atoms, and even more preferably an aryl group having an iodine atom as a substituent.

[0293] R" 103 The aromatic cyclic group which may have substituents in formula (b-1) is R 101 It is preferable that the substituent is the aromatic hydrocarbon group exemplified in the cyclic hydrocarbon group in formula (b-1). 101 Examples include substituents similar to those that may be substituted for the aromatic hydrocarbon group in the above.

[0294] R" 101 The chain-like alkyl group which may have substituents in formula (b-1) is R 101It is preferable that the group is one of the examples given as a chain-like alkyl group in the compound. R" 103 The chain-like alkenyl group which may have substituents in formula (b-1) is R 101 It is preferable that the group is one of the examples given as a chain-like alkenyl group in the formula.

[0295] • Anion in component (b-2) In formula (b-2), R 104 and R 105 Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of them is R in formula (b-1). 101 Similar examples can be given. However, R 104 and R 105 These elements may be interconnected to form a ring. R 104 , R 105 The alkyl group is preferably a linear alkyl group which may have substituents, and more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The number of carbon atoms in the chain-like alkyl group is preferably 1 to 10, more preferably 1 to 7, and even more preferably 1 to 3. 104 , R 105 The number of carbon atoms in the chain-like alkyl group is preferably small within the above range of carbon atoms, for reasons such as good solubility in the resist solvent. R 104 , R 105 In the chain-like alkyl group, a larger number of hydrogen atoms substituted with fluorine atoms is preferable because it increases the acid strength and improves transparency to high-energy light and electron beams below 250 nm. The proportion of fluorine atoms in the chain-like alkyl group, i.e., 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 , V 103These are, independently, a single bond, an alkylene group, or a fluorinated alkylene group, and each is V in formula (b-1). 101 Similar examples include the above. In formula (b-2), L 101 , L 102 Each of these is independently either a single bond or an oxygen atom.

[0296] • Anion in component (b-3) In formula (b-3), R 106 ~R 108 Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of them is R in formula (b-1). 101 Similar examples include the above. In formula (b-3), L 103 ~L 105 These are, independently, single bonds, -CO-, or -SO2-.

[0297] Among the above, the anion in component (b-1) is preferred as the anion portion of component (B).

[0298] {cation part} In the above equations (b-1), (b-2), and (b-3), M' m+ This represents an m-valent onium cation. Among these, M' m+ The sulfonium cation and iodonium cation are preferred. m is an integer of 1 or more.

[0299] Preferred cation portion ((M' m+ ) 1 / m Examples of these include the organic cations represented by the general formulas (ca-1) to (ca-3) mentioned above.

[0300] Suitable cations represented by the above formula (ca-1) include, specifically, the cations represented by the above chemical formulas (ca-1-1) to (ca-1-76). From the viewpoint of increasing sensitivity, a suitable cation represented by the above formula (ca-1) is one having a fluorine atom or a fluorinated alkyl group as a substituent, and a cation selected from the group consisting of the cations represented by the above chemical formulas (ca-1-69) to (ca-1-75) is particularly preferred.

[0301] Specific examples of suitable cations represented by the above formula (ca-2) include diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation. Specific examples of suitable cations represented by the above formula (ca-3) include the cations represented by the above formulas (ca-3-1) to (ca-3-6), respectively.

[0302] Among the above, the cation part ((M' m+ ) 1 / m As such, the organic cation represented by the general formula (ca-1) above is more preferred.

[0303] The following are specific examples of suitable (B) components in the resist composition of this embodiment.

[0304] [ka]

[0305] [ka]

[0306] [ka]

[0307] In the resist composition of this embodiment, it is preferable to use at least one compound selected from the group consisting of compounds represented by the above chemical formulas (B-1) to (B-11) as component (B), and among these, it is more preferable to use at least one compound selected from the group consisting of compounds represented by the above chemical formulas (B-1) to (B-3) from the viewpoint of high sensitivity and high resolution.

[0308] In the resist composition of this embodiment, component (B) may be used alone or in combination of two or more types. If the resist composition contains component (B), the content of component (B) in the resist composition is preferably less than 60 parts by mass, more preferably 8 to 50 parts by mass, and even more preferably 20 to 50 parts by mass, per 100 parts by mass of component (A1). (B) By setting the content of component (B) within the preferred range described above, pattern formation is sufficiently achieved. Furthermore, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, which is preferable because it results in good storage stability for the resist composition.

[0309] ≪Basic component (D)≫ The resist composition of this embodiment preferably contains, in addition to component (A1), or in addition to components (A1) and (B), a base component (hereinafter also referred to as "component (D)") that traps the acid generated by exposure (i.e., controls the diffusion of the acid). Such component (D) acts as a quencher (acid diffusion control agent) that traps the acid generated by exposure in the resist composition. Examples of component (D) include a photo-disintegrating 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 fall under component (D1). Among these, a photo-disintegrating base (component (D1)) is preferred because it is easier to improve roughness reduction. Furthermore, including component (D1) makes it easier to improve both sensitivity and the suppression of coating defects.

[0310] • About the (D1) component By using a resist composition containing component (D1), the contrast between the exposed and unexposed areas 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 upon exposure and loses its acid diffusion controllability, and is preferably one or more compounds selected from the group consisting of the compound represented by the following general formula (d1-1) (hereinafter referred to as "(d1-1) component"), the compound represented by the following general formula (d1-2) (hereinafter referred to as "(d1-2) component"), and the compound represented by the following general formula (d1-3) (hereinafter referred to as "(d1-3) component"). Components (d1-1) to (d1-3) decompose in the exposed areas of the resist film and lose their acid diffusion control properties (basicity), so they do not act as quenchers, but they act as quenchers in the unexposed areas of the resist film.

[0311] [ka] [In the formula, Rd 1 ~Rd 4 Rd in formula (d1-2) is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 2 In this example, assume that no fluorine atoms are bonded to the carbon atoms adjacent to the sulfur atoms. 1 is a divalent linking group or a single bond. m is an integer greater than or equal to M m+ These are, independently, m-valent organic cations.

[0312] {(d1-1) component} ··Anion Club In formula (d1-1), Rd 1 R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of the above R' is... 201 Similar examples include the above. Among these, Rd 1The preferred elements are optionally substituted aromatic hydrocarbon groups, optionally substituted aliphatic cyclic groups, or optionally substituted linear alkyl groups, with optionally substituted aromatic hydrocarbon groups being more preferred. Substituents that these groups may have include hydroxyl groups, oxo groups, alkyl groups, aryl groups, fluorine atoms, bromine atoms, iodine atoms, fluorinated alkyl groups, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), ether bonds, ester bonds, or combinations thereof. When ether bonds or ester bonds are included as substituents, they may be mediated by alkylene groups, and in this case, the substituents are preferably the linking groups represented by the above formulas (y-al-1) to (y-al-5). 1 If the aromatic hydrocarbon group, aliphatic cyclic group, or linear alkyl group in has a linking group represented by the general formulas (y-al-1) to (y-al-7) as a substituent, then in the general formulas (y-al-1) to (y-al-7), Rd in formula (d1-1) 1 The carbon atom constituting the aromatic hydrocarbon group, aliphatic cyclic group, or linear alkyl group in the above general formula (y-al-1) to (y-al-7) is V'. 101 That is the case. Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and other ring structures). The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The linear alkyl group is preferably one with 1 to 10 carbon atoms, and specifically includes linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; and branched 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 groups.

[0313] When the chain-like alkyl group is a fluorinated alkyl group having 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 contain atoms other than fluorine. Examples of atoms other than fluorine include oxygen atoms, sulfur atoms, nitrogen atoms, and the like.

[0314] The following are some preferred specific examples of the anionic portion of component (d1-1).

[0315] [ka]

[0316] ··Cation section In formula (d1-1), M m+ This is an m-valent organic cation. M m+Suitable organic cations include those similar to those represented by the general formulas (Ca-1) to (Ca-3), with the cation represented by the general formula (Ca-1) being more preferred, and the cations represented by the chemical formulas (Ca-1-1) to (Ca-1-76) being even more preferred. From the viewpoint of increasing sensitivity, those having a fluorine atom or a fluorinated alkyl group as a substituent are preferred, and for example, cations selected from the group consisting of the cations represented by the chemical formulas (Ca-1-69) to (Ca-1-75) are particularly preferred. (d1-1) Component may be used alone or in combination of two or more types.

[0317] {(d1-2) component} ··Anion Club In formula (d1-2), Rd 2 R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 201 Similar examples include the above. However, Rd 2 In this mixture, we assume that the carbon atom adjacent to the S atom is not bonded to a fluorine atom (i.e., not fluorine-substituted). This results in the anions of components (d1-2) becoming appropriately weak acid anions, improving the quenching ability of component (D). Rd 2 Preferably, the group is a chain-like alkyl group which may have substituents, or an aliphatic cyclic group which may have substituents, and more preferably an aliphatic cyclic group which may have substituents.

[0318] The chain-like alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. The aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (it may have substituents); more preferably a group obtained by removing one or more hydrogen atoms from camphor.

[0319] Rd2 The hydrocarbon group may have substituents, and such substituents may be Rd of formula (d1-1). 1 Examples of substituents that may be present on hydrocarbon groups (aromatic hydrocarbon groups, aliphatic cyclic groups, and linear alkyl groups) in the above are similar to those mentioned above.

[0320] The following are preferred specific examples of the anionic portion of component (d1-2).

[0321] [ka]

[0322] ··Cation section In formula (d1-2), M m+ is an m-valent organic cation, and M in formula (d1-1) above. m+ It is similar to that. (d1-2) Components may be used individually or in combination of two or more.

[0323] {(d1-3) components} ··Anion Club In formula (d1-3), Rd 3 R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and the R' 201 Similar to the above, it is preferable that the group is a cyclic group containing a fluorine atom, a linear alkyl group, or a linear alkenyl group. Among these, a fluorinated alkyl group is preferred, and the above Rd 1 A fluorinated alkyl group similar to the one shown is more preferable.

[0324] In formula (d1-3), Rd 4 R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 201 Similar examples include the above. In particular, alkyl groups, alkoxy groups, alkenyl groups, and cyclic groups, which may have substituents, are preferred. Rd4 The alkyl group in is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. 4 Some of the hydrogen atoms in the alkyl group may be substituted with hydroxyl groups, cyano groups, etc. Rd 4 The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms. Specifically, examples of alkoxy groups having 1 to 5 carbon atoms include the methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, and tert-butoxy group. Among these, the methoxy group and ethoxy group are preferred.

[0325] Rd 4 The alkenyl group in R' 201 Examples of alkenyl groups similar to those in the above include vinyl groups, propenyl groups (allyl groups), 1-methylpropenyl groups, and 2-methylpropenyl groups, which are preferred. These groups may further have substituents of an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

[0326] Rd 4 The cyclic group in is R' 201 Examples of cyclic groups similar to those in the above include alicyclic groups obtained by removing one or more hydrogen atoms from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane, or aromatic groups such as phenyl groups and naphthyl groups. 4 When Rd is an alicyclic group, the resist composition dissolves well in organic solvents, resulting in good lithography properties. 4 When the group is an aromatic group, the resist composition exhibits excellent light absorption efficiency and good sensitivity and lithographic characteristics in lithography using EUV or the like as the exposure light source.

[0327] In formula (d1-3), Yd 1It is a single bond or a divalent linking group. Yd 1 The divalent linking group in is not particularly limited, but examples include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) which may have substituents, and divalent linking groups containing heteroatoms. These are respectively the same as above W 01 Other groups besides polymerizable groups include divalent hydrocarbon groups which may have substituents, and divalent linking groups containing heteroatoms, as exemplified above. Yd 1 The preferred members are carbonyl groups, ester bonds, amide bonds, alkylene groups, or combinations thereof. The alkylene group is more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

[0328] The following are preferred specific examples of the anionic parts of components (d1-3).

[0329] [ka]

[0330] [ka]

[0331] ··Cation section In formula (d1-3), M m+ is an m-valent organic cation, and M in formula (d1-1) above. m+ It is similar to that. (d1-3) Components may be used individually or in combination of two or more.

[0332] Component (D1) may consist of only one of the above components (d1-1) to (d1-3), or it may consist of a combination of two or more components. If the resist composition contains component (D1), the content of component (D1) in the resist composition is preferably 0.5 to 25 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 3 to 15 parts by mass, per 100 parts by mass of component (A1). When the content of component (D1) is above the lower limit of the preferred range described above, particularly good lithography characteristics and resist pattern shape are easily obtained. On the other hand, when it is below the upper limit of the preferred range described above, good sensitivity can be maintained and throughput is also excellent.

[0333] In the resist composition of this embodiment, component (D1) preferably includes the above-mentioned component (d1-1). In the resist composition of this embodiment, the content of component (d1-1) in the total (D) component is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. Component (D) may consist solely of compound (d1-1) component (100% by mass).

[0334] (D1) Method for producing component: The methods for producing the aforementioned components (d1-1) and (d1-2) are not particularly limited and can be produced by known methods. Furthermore, the method for producing components (d1-3) is not particularly limited and may be, for example, similar to the method described in US2012-0149916.

[0335] • About the (D2) component Component (D) may include nitrogen-containing organic compounds that do not fall under component (D1) above (hereinafter referred to as "component (D2)"). Component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and does not fall under component (D1), and any known component may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are more preferred. An aliphatic amine is an amine having one or more aliphatic groups, and it is preferable that the aliphatic groups have 1 to 12 carbon atoms. Examples of aliphatic amines include amines (alkylamines or alkyl alcoholamines) or cyclic amines in which at least one hydrogen atom of ammonia (NH3) is substituted with an alkyl group or hydroxyalkyl group having 12 or fewer carbon atoms. Specific examples of alkylamines and alkyl alcoholamines 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 alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 5 to 10 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine are particularly preferred.

[0336] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. These heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Examples of aliphatic monocyclic amines include piperidine and piperazine. As aliphatic polycyclic amines, those having 6 to 10 carbon atoms are preferred, and specifically, examples 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.

[0337] 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, triethanolamine triacetate, etc., with triethanolamine triacetate being preferred.

[0338] Furthermore, an aromatic amine may be used as component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, 2,6-di-tert-butylpyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, trimenzylamine, 2,6-diisopropylaniline, and N-tert-butoxycarbonylpyrrolidine.

[0339] Among the above, component (D2) is preferably an alkylamine, and more preferably a trialkylamine having 5 to 10 carbon atoms.

[0340] (D2) Component may be used alone or in combination of two or more types. If 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, per 100 parts by mass of component (A1). When the content of component (D2) is above the lower limit of the preferred range described above, particularly good lithography characteristics and resist pattern shape are easily obtained. On the other hand, when it is below the upper limit of the preferred range described above, good sensitivity can be maintained and throughput is also excellent.

[0341] <<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 and phosphorus oxoacids and their derivatives (hereinafter referred to as "component (E)"). Examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, among which salicylic acid is preferred. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred among these.

[0342] In the resist composition of this embodiment, component (E) may be used alone or in combination of two or more types. If the resist composition contains component (E), the content of component (E) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass, per 100 parts by mass of component (A1). By setting the content within the above range, the lithography characteristics are further improved.

[0343] ≪Fluorine additive component (F)≫ The resist composition of this embodiment may 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 and, when used as a separate resin from component (A), improves lithography properties. As component (F), for example, fluorine-containing polymer compounds described in Japanese Patent Publication No. 2010-002870, Japanese Patent Publication No. 2010-032994, Japanese Patent Publication No. 2010-277043, Japanese Patent Publication No. 2011-13569, and Japanese Patent Publication No. 2011-128226 can be used. More specifically, component (F) includes polymers having a constituent unit (f1) represented by the following general formula (f1-1). This polymer is preferably a polymer (homopolymer) consisting only of the constituent unit (f1) represented by the following formula (f1-1); a copolymer of the constituent unit (f1) and the constituent unit (a1); and more preferably a copolymer of the constituent unit (f1) and a constituent unit derived from acrylic acid or methacrylic acid and the constituent unit (a1). Here, the constituent unit (a1) copolymerized with the constituent unit (f1) is preferably a constituent unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, and more preferably a constituent unit derived from 1-methyl-1-adamantyl (meth)acrylate.

[0344] [ka] [In the formula, R is the same as above, and Rf 102 and Rf 103 Each of these independently represents 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 Rf 102 and Rf 103 They may be the same or different. 1 Rf is an integer between 0 and 5. 101 It is an organic group containing a fluorine atom.

[0345] In formula (f1-1), R bonded to the α-carbon atom is the same as described above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), Rf 102 and Rf 103 A fluorine atom is preferred as the halogen atom. Rf 102 and Rf 103 Examples of alkyl groups having 1 to 5 carbon atoms in R include those similar to the alkyl groups having 1 to 5 carbon atoms in R above, with methyl or ethyl groups being preferred. 102 and Rf103 Specifically, examples of halogenated alkyl groups having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Fluorine atoms are preferred as the halogen atoms, particularly Rf. 102 and Rf 103 Preferably, the element is 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), nf 1 is an integer between 0 and 5, preferably between 0 and 3, and more preferably 1 or 2.

[0346] In formula (f1-1), Rf 101 This is an organic group containing a fluorine atom, and preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing fluorine atoms may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and even more preferably 1 to 10 carbon atoms. Furthermore, in hydrocarbon groups containing fluorine atoms, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and particularly preferable that 60% or more are fluorinated, as this increases the hydrophobicity of the resist film during immersion exposure. Among them, Rf 101 More preferably, fluorinated hydrocarbon groups having 1 to 6 carbon atoms are used, with trifluoromethyl groups, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, and -CH2-CH2-CF2-CF2-CF2-CF3 being particularly preferred.

[0347] The weight-average molecular weight (Mw) of component (F) (based on polystyrene conversion by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. If it is below the upper limit of this range, it has sufficient solubility in resist solvents for use as a resist, and if it is above the lower limit of this range, the water repellency of the resist film is good. The degree of dispersion of component (F) (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0348] In the resist composition of this embodiment, component (F) may be used alone or in combination of two or more types. If the resist composition contains component (F), the content of component (F) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of component (A1).

[0349] ≪Organic solvent component (S)≫ The resist composition of this embodiment can be manufactured by dissolving the resist material in an organic solvent component (hereinafter referred to as "component (S)"). The (S) component can be any solvent that can dissolve each component used to form a homogeneous solution, and any solvent that is conventionally known as a solvent for chemically amplified resist compositions can be appropriately selected and used. (S) components include, for example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having ester bonds such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or monophenyl ether of the aforementioned polyhydric alcohols or compounds having ester bonds; etc. Examples include derivatives of polyhydric alcohols [of which propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and 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, phenethole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). In the resist composition of this embodiment, component (S) may be used alone or as a mixture of two or more solvents. Among these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0350] Furthermore, a mixed solvent obtained by mixing PGMEA and a polar solvent is also preferred as component (S). The mixing ratio (mass ratio) can be appropriately determined considering the compatibility of PGMEA and the polar solvent, but it is preferably in the range of 1:9 to 9:1, and more preferably in the range of 2:8 to 8:2. More specifically, when EL or cyclohexanone is used as the polar solvent, the mass ratio of PGMEA to EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. When PGME is used as the polar solvent, the mass ratio of PGMEA to 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, as the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferred. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5. The amount of component (S) used is not particularly limited and is set appropriately according to the coating thickness, at a concentration that can be applied to a substrate or the like. Generally, component (S) is used so that the solid content concentration of the resist composition is in the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0351] The resist composition of this embodiment may be subjected to removal of impurities after dissolving the resist material in component (S), using a polyimide porous membrane, a polyamide-imide porous membrane, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous membrane, a filter made of a polyamide-imide porous membrane, or a filter made 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 Publication No. 2016-155121.

[0352] As described above, the resist composition of this embodiment contains a resin component (A1) having a constituent unit (a0) derived from a compound represented by the general formula (a0-1). The aforementioned structural unit (a0) has an aromatic group (R) in its side chain. Ar ) and a specific acid-dissociating group (R a0 ) has a specific acid-dissociating group (R a0Because it has multiple carbon-carbon multiple bonds, including a triple bond, the resin component (A1) exhibits a resonance effect during the acid dissociation reaction, thereby enhancing its acid dissociability. In addition, the constituent unit (a0) is an aromatic group (R Ar ) and, because it has multiple carbon-carbon multiple bonds, the carbon ratio is increased in the resin component (A1) (the number of CH bonds is kept low). For these reasons, the resist composition of this embodiment containing the resin component (A1) having the aforementioned structural unit (a0) can achieve higher etching resistance and higher sensitivity.

[0353] (Method for forming resist patterns) A resist pattern formation method according to a second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition according to the first aspect of the present invention described above, exposing the resist film, and developing the exposed resist film to form a resist pattern. One embodiment of such a resist pattern formation method is, for example, a resist pattern formation method carried out as follows.

[0354] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and a bake (post-application bake (PAB)) treatment is performed for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of, for example, 80 to 150°C, to form a resist film. Next, the resist film is subjected to selective exposure using an exposure apparatus such as an electron beam lithography apparatus or an ArF exposure apparatus, either by exposure through a mask (mask pattern) on which a predetermined pattern has been formed, or by drawing by direct irradiation with an electron beam without going through a mask pattern. After this, a bake (post-exposure bake (PEB)) treatment is performed for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of, for example, 80 to 150°C. Next, the resist film is subjected to a developing process. In the case of an alkaline developing process, an alkaline developer is used, and in the case of a solvent developing process, a developer containing an organic solvent (organic developer) is used.

[0355] After the developing process, a rinsing process is preferably performed. In the case of an alkaline developing process, a water rinse using pure water is preferred, and in the case of a solvent developing process, a rinsing solution containing an organic solvent is preferred. In the case of a solvent-based development process, after the development or rinsing process, a process may be performed to remove the developer or rinse solution adhering to the pattern using a supercritical fluid. After development or rinsing, the film is dried. In some cases, a bake (post-bake) process may be performed after the development process. In this way, a resist pattern can be formed.

[0356] The support material is not particularly limited and can be any conventionally known material, such as a substrate for electronic components or a substrate on which a predetermined wiring pattern has been formed. More specifically, examples include silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and glass substrates. As for the wiring pattern material, for example, copper, aluminum, nickel, and gold can be used.

[0357] The wavelength used for exposure is not particularly limited, and can be used with 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 of the above-described embodiment is highly useful for KrF excimer lasers, ArF excimer lasers, EB, or EUV, more so for ArF excimer lasers, EB, or EUV, and particularly useful for EB or EUV. In other words, the resist pattern formation method of this embodiment is particularly useful when the step of exposing the resist film includes an operation of exposing the resist film with EUV (extreme ultraviolet) or EB (electron beam).

[0358] The method for exposing the resist film may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or it may be liquid immersion lithography. Immersion lithography is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is first filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. As the immersion medium, a solvent having a refractive index greater than that of air and less than that of the resist film being exposed is preferred. Examples include water, fluorinated inert liquids, silicon-based solvents, and hydrocarbon-based solvents. Water is preferably used as the immersion medium.

[0359] Examples of alkaline developers used in the alkaline development process include 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH) aqueous solution. In the solvent-based developing process, the content of organic solvent in the organic developer solution used for developing is usually 90% by mass or more, may be 95% by mass or more, may be 98% by mass or more, may be 100% by mass, and preferably 100% by mass, based on the total amount of the organic developer solution. The organic solvent contained in such an organic developer can be any solvent capable of dissolving 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.

[0360] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl 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-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0361] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0362] Organic developers may contain known additives as needed. Examples of such additives include surfactants. While not particularly limited, surfactants such as ionic or nonionic fluorine-based and / or silicone-based surfactants can be used. Nonionic surfactants are preferred, with nonionic fluorine-based surfactants or nonionic silicone-based surfactants being more preferred. When a surfactant is added, the amount added is usually 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.

[0363] The development process can be carried out by known development methods, such as immersing the support in a developer solution for a certain period of time (dip method), piling the developer solution onto the surface of the support using surface tension and leaving it still for a certain period of time (paddle method), spraying the developer solution onto the surface of the support (spray method), or continuously dispensing the developer solution onto a support rotating at a constant speed while scanning the developer dispensing nozzle at a constant speed (dynamic dispensing method).

[0364] As for the organic solvent contained in the rinsing solution used for rinsing after development in the solvent development process, for example, organic solvents that are less likely to dissolve the resist pattern can be appropriately selected and used from among the organic solvents listed as organic solvents used in the organic developer solution. 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-based solvent used in the rinsing solution is preferably a monohydric alcohol having 6 to 8 carbon atoms, and this 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, 3-octanol, 4-octanol, and benzyl alcohol. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred. These organic solvents may be used individually or in combination of two or more. They may also be mixed with other organic solvents or water. However, considering the developing 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 volume of the rinse solution. The rinse solution may contain known additives as needed. Examples of such additives include surfactants. Examples of surfactants are the same as those described above, with nonionic surfactants being preferred, and nonionic fluorine-based surfactants or nonionic silicone-based surfactants being more preferred. When a surfactant is added, the amount added is usually 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 volume of the rinse solution.

[0365] Rinsing (cleaning) using a rinsing solution can be carried out by known rinsing methods. Examples of such rinsing methods include continuously applying the rinsing solution onto a support rotating at a constant speed (rotary coating method), immersing the support in the rinsing solution for a certain period of time (dip method), and spraying the rinsing solution onto the surface of the support (spray method).

[0366] As described above, the resist pattern formation method of this embodiment uses the above-mentioned resist composition, which allows for increased sensitivity and easy formation of a resist pattern with enhanced etching resistance.

[0367] It is preferable that the resist composition of the above-described embodiment and the various materials used in the pattern formation method of the above-described embodiment (for example, resist solvent, developer, rinse solution, anti-reflective film forming composition, top coat forming composition, etc.) do not contain impurities such as metals, metal salts containing halogens, acids, alkalis, sulfur atoms, or phosphorus atoms. Examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The amount of impurities contained 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 absent (below the detection limit of the measuring device).

[0368] (Compounds represented by the general formula (a0-1)) The compound according to the third aspect of the present invention is represented by the following general formula (a0-1).

[0369] [ka] [In formula (a0-1), W 01 R is a polymerizable group-containing group. Ar R is an aromatic group which may have substituents. a0 R is an acid-dissociable group represented by the general formula (a0-r-1) above. a01 R is an aliphatic hydrocarbon group. a02 , R a03 and R a04 Each of these is independently a hydrocarbon group which may have substituents, or a hydrogen atom. a01 and R a02 These may bond with each other to form an alicyclic structure. a03 and R a04 These may bond with each other to form an aromatic ring structure or an alicyclic structure. Alternatively, R a01 and R a02 A ring structure formed by the mutual bonding of R a03 and R a04 The aromatic ring structure or alicyclic structure formed by the mutual bonding of these elements may be condensed. a05 * is a chain-like or alicyclic hydrocarbon group, or a hydrogen atom. a0 This indicates that the bond is with the oxy group (-O-).

[0370] The compound represented by general formula (a0-1) is the same as the compound represented by general formula (a0-1) in the resist composition of the embodiment described above.

[0371] In the above formula (a0-1), W 01 For example, the chemical formula is C(R X11 )(R X12 )=C(R X13 )-Ya x0 A group represented by - is preferably mentioned. In this chemical formula, R X11 , R X12 and R X13 These are, respectively, 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 x0R is a single bond or a divalent linking group. X11 and R X12 Preferably, these are a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and due to their ease of industrial availability, a hydrogen atom and a methyl group are more preferred, and a hydrogen atom is particularly preferred. Also, R X13 Preferably, the group is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. Due to their industrial availability, a hydrogen atom or a methyl group is more preferable, and a hydrogen atom is particularly preferred. x0 As for the bond, an ester bond [-C(=O)-O-, -OC(=O)-] is more preferable, and a single bond is even more preferable.

[0372] In the above formula (a0-1), R Ar Preferably, the groups are those obtained by removing two hydrogen atoms from benzene, naphthalene, anthracene, or biphenyl, each of which may have substituents; more preferably, a group obtained by removing two hydrogen atoms from benzene, which may have substituents, or a group obtained by removing two hydrogen atoms from naphthalene, which may have substituents; and even more preferably, a group obtained by removing two hydrogen atoms from benzene, which may have substituents. Alternatively, from the standpoint of increasing sensitivity, R ArPreferably, the substituent is an aromatic group having a substituent selected from the group consisting of hydroxyl groups and alkoxy groups, and more preferably an aromatic group having a hydroxyl group as a substituent. Among these, a group obtained by removing two hydrogen atoms from benzene, naphthalene, anthracene, or biphenyl having a substituent selected from the group consisting of hydroxyl groups and alkoxy groups is more preferred, a group obtained by removing two hydrogen atoms from benzene having a substituent selected from the group consisting of hydroxyl groups and alkoxy groups is even more preferred, a group obtained by removing two hydrogen atoms from naphthalene having a substituent selected from the group consisting of hydroxyl groups and alkoxy groups is particularly preferred, and a group obtained by removing two hydrogen atoms from benzene having a hydroxyl group as a substituent is most preferred.

[0373] In the above formula (a0-r-1), R a01 , and also, R a02 , R a03 and R a04 For example, R a01 R is a linear hydrocarbon group, a02 , R a03 and R a04 If all of them are hydrogen atoms; R a03 and R a04 When they are bonded to each other to form an aromatic ring structure; R a01 and R a02 A preferred example is when the two elements bond to each other to form an alicyclic structure. R a01 and R a02 In the case where these elements bond to each other to form an alicyclic structure, for example, R a01 and R a02 and are bonded to each other to form an alicyclic structure, R a03 and R a04 When each is a linear or branched alkyl group or hydrogen atom; R a01 and R a02 A ring structure formed by the mutual bonding of R a03 and R a04Preferred cases include an aromatic ring structure formed by the bonding of these elements with each other, and a condensed ring structure formed by their condensation.

[0374] In the above formula (a0-r-1), R a05 Among the above, linear or branched saturated hydrocarbon groups (alkyl groups) or hydrogen atoms are preferred.

[0375] The compound of this embodiment is preferably a compound represented by the following general formula (a0-1-m0).

[0376] [ka] [In the formula, R m L is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. 1 R is a divalent linking group or a single bond. a06 m is a hydrogen atom or an alkyl group. m is an integer between 0 and 3. n is a non-negative integer, where n ≤ 4 + 2m. a0 R is an acid-dissociable group represented by the following general formula (a0-r-1). a01 R is an aliphatic hydrocarbon group. a02 , R a03 and R a04 Each of these is independently a hydrocarbon group which may have substituents, or a hydrogen atom. a01 and R a02 These may bond with each other to form an alicyclic structure. a03 and R a04 These may bond with each other to form an aromatic ring structure or an alicyclic structure. Alternatively, R a01 and R a02 A ring structure formed by the mutual bonding of R a03 and R a04 The aromatic ring structure or alicyclic structure formed by the mutual bonding of these elements may be condensed. a05 * is a chain-like or alicyclic hydrocarbon group, or a hydrogen atom. a0 This indicates that the bond is with the oxy group (-O-).

[0377] In the above formula (a0-1-m0), R m The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. The halogenated alkyl group having 1 to 5 carbon atoms is 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. Fluorine atoms are particularly preferred as the halogen atoms. R m Preferably, the elements are hydrogen atoms, alkyl groups having 1 to 5 carbon atoms, or fluorinated alkyl groups having 1 to 5 carbon atoms, with hydrogen atoms or methyl groups being the most preferred due to their industrial availability.

[0378] In the above formula (a0-1-m0), L 1 , R a06 , m, n, R a0 , R a01 , R a02 , R a03 and R a04 This is L in the general formula (a0-1-u0) mentioned above. 1 , R a06 , m, n, R a0 , R a01 , R a02 , R a03 and R a04 These are identical to each other.

[0379] Preferred specific examples of the compounds of this embodiment are shown below. In the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0380] [ka]

[0381] [ka]

[0382] [ka]

[0383] [ka]

[0384] [ka]

[0385] [ka]

[0386] [Method for producing compound (a0-1)] The compound of this embodiment can be produced, for example, by a manufacturing method (P) that includes a step of reacting (esterifying) a compound represented by the following formula (C0-1) with a compound represented by the following formula (Alc-1) to obtain compound (a0-1).

[0387] [ka] [In formula (a0-1), W 01 R is a polymerizable group-containing group. Ar R is an aromatic group which may have substituents. a01 R is an aliphatic hydrocarbon group. a02 , R a03 and R a04 Each of these is independently a hydrocarbon group which may have substituents, or a hydrogen atom. a01 and R a02 These may bond with each other to form an alicyclic structure. a03 and R a04They may be bonded to each other to form an aromatic ring structure or an alicyclic ring structure. Alternatively, R a01 and R a02 The alicyclic ring structure formed by their bonding to each other and the aromatic ring structure or alicyclic ring structure formed by the bonding of R a03 and R a04 to each other may be condensed. R a05 is a chain or alicyclic hydrocarbon group or a hydrogen atom. R a0 is an acid dissociable group represented by the above general formula (a0-r-1). * indicates that it is a bond with an oxy group (-O-) to which R a0 is bonded. ]

[0388] W 01 , R Ar , R a0 , R a01 , R a02 , R a03 , R a04 and R a05 are the same as the above description.

[0389] Step (P): The reaction temperature condition of step (P) is not particularly limited and is, for example, about 0 to 120°C. The reaction time of step (P) is not particularly limited and is, for example, about 1 to 72 hours.

[0390] Examples of the reaction solvent used in step (P) include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide, dimethyl sulfoxide, and the like.

[0391] Also, in the reaction of step (P), a condensing agent and a basic catalyst may be used. Specific examples of the condensing agent include N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, carbonyldiimidazole (CDI), and the like. As the basic catalyst, specifically, tertiary amines such as trimethylamine, triethylamine, tributylamine; aromatic amines such as pyridine, dimethylaminopyridine, pyrrolidinopyridine; diazabicyclononene (DBN), diazabicycloundecene (DBU), etc. can be mentioned.

[0392] In the method for producing the above-mentioned compound (a0-1), after each reaction is completed, the compound in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be appropriately combined and used. The structure of the compound obtained as described above is 1 1H-nuclear magnetic resonance (NMR) spectroscopy, 13 13C-NMR spectroscopy, 19 19F-NMR spectroscopy, infrared absorption (IR) spectroscopy, mass spectrometry (MS), elemental analysis, X-ray crystallography, and other general organic analytical methods can be used for identification. The raw materials used in each step may be commercially available ones or synthesized ones.

[0393] The compound of the present embodiment described above is a monomer useful for producing a polymer compound according to the fourth aspect described later.

[0394] (Polymer compound) The polymer compound according to the fourth aspect of the present invention has a structural unit derived from a compound represented by the following general formula (a0-1).

[0395] [Chemical formula] [In formula (a0-1), W 01 is a polymerizable group-containing group. R Ar is an aromatic group which may have a substituent. R a0 is an acid dissociable group represented by the above general formula (a0-r-1). R a01 is an aliphatic hydrocarbon group. R a02 , R a03and R a04 Each of these is independently a hydrocarbon group which may have substituents, or a hydrogen atom. a01 and R a02 These may bond with each other to form an alicyclic structure. a03 and R a04 These may bond with each other to form an aromatic ring structure or an alicyclic structure. Alternatively, R a01 and R a02 A ring structure formed by the mutual bonding of R a03 and R a04 The aromatic ring structure or alicyclic structure formed by the mutual bonding of these elements may be condensed. a05 * is a chain-like or alicyclic hydrocarbon group, or a hydrogen atom. a0 This indicates that the bond is with the oxy group (-O-).

[0396] In the above equation (a0-1) W 01 , R Ar , R a0 , R a01 , R a02 , R a03 , R a04 and R a05 This is the same as the explanation above.

[0397] A polymer compound according to the fourth aspect of the present invention is preferably a polymer compound having a repeating structure of the above-described structural unit (a0) and structural unit (a10). Such polymer compounds are useful as base components for resist compositions. [Examples]

[0398] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0399] <Examples of compound synthesis> Compounds (a0-1-1) to (a0-1-8) were prepared using the synthesis methods described below.

[0400] [Synthesis of compound (a0-1-1)] 10.0 g of 4-vinylbenzoic acid was dissolved in 40 g of tetrahydrofuran, and this solution was added dropwise to a mixed solution of 12.8 g of diazabicycloundecene (DBU), 8.4 g of ethinylmethylvinylcarbinol, 15.3 g of carbonyldiimidazole (CDI), and 40 g of tetrahydrofuran under ice cooling. Subsequently, the mixture was stirred at 60°C for 4 hours, the solvent was removed by distillation, and 80 g of heptane was added to the residue. Impurities were removed by filtration. Compound (a0-1-1) was then obtained by purification by column chromatography.

[0401] [ka]

[0402] The obtained compound (a0-1-1) was subjected to NMR measurement, and its structure was identified based on the following data. 1 H-NMR (DMSO-d6, 400MHz): δ(ppm)=7.90(d, -Ar-, 2H), 7.60(d, -Ar-, 2H), 6.78-6.84(m, -CH=, 1H), 5.95(d, =CH2, 1H), 5.89(t, -CH=, 1H), 5.41(d, =CH2, 1H),5.25-5.30(m, =CH2, 2H), 3.61(s, ≡CH, 1H), 1.64(s, -CH3, 3H)

[0403] [Synthesis of compounds (a0-1-2) to (a0-1-8)] Compounds (a0-1-2) to (a0-1-8) were obtained using the corresponding starting alcohols and the same synthesis method as described in [Synthesis of Compound (a0-1-1)] above. The structures of the obtained compounds (a0-1-2) to (a0-1-8) and their NMR measurement data are shown below.

[0404] [ka]

[0405] The obtained compound (a0-1-2) was subjected to NMR measurement, and its structure was identified based on the following data. 1 H-NMR (DMSO-d6, 400MHz): δ(ppm)=7.88(d, -Ar-, 2H), 7.59(d, -Ar-, 2H), 7.28-7.33(m, -Ar, 5H), 6.77-6.84(m, -CH=, 1H), 5.94(d, =CH2, 1H), 5.42(d, =CH2, 1H), 3.59(s, ≡CH, 1H), 2.00(s, -CH3, 3H)

[0406] The obtained compound (a0-1-3) was subjected to NMR measurement, and its structure was identified based on the following data. 1 H-NMR (DMSO-d6, 400MHz): δ(ppm)=7.92(d, -Ar-, 2H), 7.60(d, -Ar-, 2H), 6.79-6.86(m, -CH=, 1H), 6.21(d, -CH=CH-, 1H), 5.96(d, =CH2, 1H), 5.81(d, -CH=CH-, 1H), 5.40(d, =CH2, 1H),3.62(s, ≡CH, 1H), 2.23-2.58(m, -CH2-CH2-, 4H)

[0407] The obtained compound (a0-1-4) was subjected to NMR measurement, and its structure was identified based on the following data. 1 H-NMR (DMSO-d6, 400MHz): δ(ppm)=7.90(d, -Ar-, 2H), 7.58(d, -Ar-, 2H), 6.77-6.84(m, -CH=, 1H), 5.96(d, =CH2, 1H), 5.67-5.80(m, -CH=CH-, 2H), 5.40(d, =CH2, 1H),3.58(s, ≡CH, 1H), 1.60-2.33(m, -(CH2)3-, 6H)

[0408] [ka]

[0409] The obtained compound (a0-1-5) was subjected to NMR measurement, and its structure was identified based on the following data. 1 H-NMR (DMSO-d6, 400MHz): δ(ppm)=10.75(s, -OH, 1H), 6.95-7.75(m, -Ar-, 3H), 6.65-6.74(m, -CH=, 1H), 5.89(t, -CH=, 1H), 5.72(d, =CH2, 1H), 5.17(d, =CH2, 1H),5.27-5.31(m, =CH2, 2H), 3.60(s, ≡CH, 1H), 1.62(s, -CH3, 3H)

[0410] The obtained compound (a0-1-6) was subjected to NMR measurement, and its structure was identified based on the following data. 1 H-NMR (DMSO-d6, 400MHz): δ(ppm)=10.71(s, -OH, 1H), 6.92-7.74(m, -Ar-, 3H), 6.62-6.70(m, -CH=, 1H), 5.68-5.79(m, -CH=CH-, =CH2, 3H), 5.18(d, =CH2, 1H),3.58(s, ≡CH, 1H), 1.62-2.35(m, -(CH2)3-, 6H)

[0411] The obtained compound (a0-1-7) was subjected to NMR measurement, and its structure was identified based on the following data. 1 H-NMR (DMSO-d6, 400MHz): δ(ppm)=10.72(s, -OH, 1H), 6.87-7.66(m, -Ar-, 3H), 6.60-6.75(m, -CH=, 1H), 5.59-5.76(m, -CH=CH-, =CH2, 3H), 5.25(d, =CH2, 1H), 1.62-2.35(m, -(CH2)3-, -CH3, 9H)

[0412] The obtained compound (a0-1-8) was subjected to NMR measurement, and its structure was identified based on the following data. 1 H-NMR (DMSO-d6, 400MHz): δ(ppm)=6.90-7.74(m, -Ar-, 3H), 6.66-6.72(m, -CH=, 1H), 5.90(t, -CH=, 1H), 5.73(d, =CH2, 1H), 5.19(d, =CH2, 1H),5.27-5.33(m, =CH2, 2H), 3.80(s,-OCH3,3H),3.61(s, ≡CH, 1H), 1.62(s, -CH3, 3H)

[0413] <Examples of polymer compound synthesis> Using the above compounds (a0-1-1) to (a0-1-8), and the following compounds (a10-1pre), (a10-2pre), (a10-3pre), (a5-1), (a1-1), (a1-2), (a6-1), and (a6-2), polymer compounds (A1-1) to (A1-11) and polymer compounds (A2-1) to (A2-4) were produced, respectively, by the synthesis method shown below.

[0414] [ka]

[0415] [ka]

[0416] [Synthesis of polymer compounds (A1-1)] 10.0 g of compound (a10-1pre), 15.0 g of compound (a0-1-1), and 7.5 g of azobis(isobutyrate)dimethyl (V-601) as a polymerization initiator were dissolved in 50 g of methyl ethyl ketone (MEK), and the mixture was stirred at 70°C for 5 hours under a nitrogen atmosphere. The reaction mixture was then cooled to room temperature to obtain a polymerization solution containing the polymer compound (A1-1pre). Next, 3.0 g of acetic acid and 60 g of methanol were added to the obtained polymerization solution, and a deprotection reaction was carried out at 30°C for 8 hours. After the reaction was complete, the obtained reaction solution was precipitated in 1200 g of a mixed solvent of methanol and water and washed. The resulting white solid was filtered and dried under reduced pressure overnight to obtain the target polymer compound (A1-1).

[0417] [ka]

[0418] For the obtained polymer compound (A1-1), the weight-average molecular weight (Mw) on a standard polystyrene basis, determined by GPC measurement, was 6100, and the molecular weight dispersion (Mw / Mn) was 1.56. Also, carbon-13 nuclear magnetic resonance spectrum ( 13 The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR was l / m = 40 / 60.

[0419] [Synthesis of polymer compound (A1-2) ~ polymer compound (A1-11), polymer compound (A2-1) ~ polymer compound (A2-4)] Polymer compounds (A1-2) to (A1-11) and polymer compounds (A2-1) to (A2-4) were obtained using the corresponding starting monomers and the same synthesis method (radical polymerization, deprotection reaction) as described in [Synthesis of Polymer Compound (A1-1)] above. The structures of each obtained polymer compound are shown below.

[0420] [ka]

[0421] [ka]

[0422] [ka]

[0423] [ka]

[0424] For each polymer compound obtained, 13 Table 1 shows the copolymerization composition ratio of the polymer compound (the proportion (molar ratio) of constituent units derived from each monomer compound) determined by 13C-NMR, as well as the weight-average molecular weight (Mw) and molecular weight dispersion (Mw / Mn) in terms of standard polystyrene, determined by GPC measurement.

[0425] [Table 1]

[0426] <Preparation of the resist composition> (Examples 1-11, Comparative Examples 1-4) Each of the components shown in Tables 2-3 was mixed and dissolved to prepare the resist compositions for each example.

[0427] [Table 2]

[0428] [Table 3]

[0429] In Tables 2 and 3, each abbreviation has the following meaning. The numbers in brackets [ ] represent the amount (parts by mass) of the ingredients. (A)-1 to (A)-11: The above polymer compounds (A1-1) to (A1-11). (A)-12~(A)-15: The above polymer compounds (A2-1)~(A2-4).

[0430] (B)-1: An acid generator consisting of a compound represented by the following chemical formula (B-1). (B)-2: An acid generator consisting of a compound represented by the following chemical formula (B-2). (B)-3: An acid generator consisting of a compound represented by the following chemical formula (B-3).

[0431] [ka]

[0432] (D)-1: An acid diffusion control agent comprising a compound represented by the following chemical formula (D1-1). (D)-2: An acid diffusion control agent comprising a compound represented by the following chemical formula (D1-2). (D)-3: An acid diffusion control agent consisting of compounds represented by the following chemical formulas (D1-3). (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60 / 40 (mass ratio).

[0433] [ka]

[0434] <Rating> Line-and-space patterns (hereinafter referred to as "LS patterns") were formed using the resist pattern formation method described below, and their sensitivity and etching resistance were evaluated.

[0435] Formation of a resist pattern Each example of the resist composition was applied to an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS) using a spinner, and a 50 nm thick resist film was formed by pre-baking (PAB) on a hot plate at 110°C for 60 seconds and drying. Next, the resist film was subjected to lithography (exposure) using an electron beam lithography system JEOL JBX-9300FS (manufactured by JEOL Ltd.) at an acceleration voltage of 100kV, creating an LS pattern with a target size of 50nm line width and 100nm pitch width. Subsequently, post-exposure heating (PEB) treatment was performed at 100°C for 60 seconds. Next, alkaline development was performed at 23°C for 60 seconds using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Afterward, a 15-second rinse was performed using pure water. As a result, in all examples, a 1:1 LS pattern with a line width of 50 nm and a space width of 50 nm was formed.

[0436] [Sensitivity evaluation] The optimal exposure amount Eop(μC / cm²) for forming a target-sized LS pattern through the above-described "resist pattern formation" is used. 2 We calculated this as "Eop(μC / cm²)". 2 )" is shown in Table 4.

[0437] [Evaluation of etching resistance] In the above-described "Formation of Resist Patterns," each 50 nm thick resist film obtained by PAB treatment and drying was subjected to a dry etching process using CF4 gas for 60 seconds with a dry etching apparatus TCA-3822 (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). The amount of residual film was determined from the thickness of the resist film before and after this dry etching process. The amount of residual resist film formed using each example's resist composition was expressed as a relative value with the amount of residual resist film formed using Comparative Example 1's resist composition set to 1.00, and this is shown in Table 4 as "etching resistance". A larger relative value indicates a relatively larger amount of residual film, resulting in reduced film loss and higher etching resistance.

[0438] [Table 4]

[0439] The results shown in Table 4 confirm that the resist compositions of Examples 1 to 11 to which the present invention was applied showed improved etching resistance and higher sensitivity compared to the resist compositions of Comparative Examples 1 to 2. The resist compositions of Comparative Examples 3 and 4 failed to resolve even after drawing (exposure), post-exposure heating (PEB) treatment, and alkaline development, and were unable to form the predetermined LS pattern (poor resolution).

Claims

1. A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, It contains a resin component (A1) whose solubility in the developer changes due to the action of acid, The resin component (A1) is a resist composition having a constituent unit (a0) derived from a compound represented by the following general formula (a0-1). 【Chemistry 1】 [In formula (a0-1), W ａ０５ , ａ０ , ａ０３ , ａ０４ , ａ０１ , ａ０２ is a group represented by the chemical formula: C(RX11)(RX12)=C(RX13)-Yax0-. In the said chemical formula, RX11, RX12 and RX13 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 Yax0 is an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group or a combination thereof, or a single bond. R Ａｒ is an aromatic group which may have a substituent. R ａ０ is an acid dissociable group represented by the above general formula (a0-r-1). R ａ０１ is an aliphatic hydrocarbon group. R ａ０２ , R ａ０３ and R ａ０４ are each independently a hydrocarbon group which may have a substituent, or a hydrogen atom. R ａ０１ and R ａ０２ may be bonded to each other to form an alicyclic structure. R ａ０３ and R ａ０４ may be bonded to each other to form an aromatic ring structure or an alicyclic structure. Alternatively, the alicyclic structure formed by the bonding of R ａ０１ and R ａ０２ and the aromatic ring structure or alicyclic structure formed by the bonding of R ａ０３ and R ａ０４ may be condensed. R ａ０５ is a chain or alicyclic hydrocarbon group, or a hydrogen atom. * indicates a bond with an oxy group (-O-) to which R ａ０ is bonded.]

2. In the above general formula (a0-1), R Ａｒ The resist composition according to claim 1, wherein the aromatic group is having a substituent selected from the group consisting of hydroxyl groups and alkoxy groups.

3. In the above general formula (a0-r-1), R ａ０１ and R ａ０２ The resist composition according to claim 1 or 2, wherein the two elements bond to each other to form an alicyclic structure.

4. In the above general formula (a0-r-1), R ａ０５ The resist composition according to any one of claims 1 to 3, wherein the group is a chain-like or alicyclic hydrocarbon group.

5. A method for forming a resist pattern, comprising the steps of: forming a resist film on a support using a resist composition according to any one of claims 1 to 4; exposing the resist film; and developing the exposed resist film to form a resist pattern.

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