Resist composition and method for forming a resist pattern

Abstract

To provide a resist composition which achieves high sensitivity, and enables formation of a resist pattern having good resolution and reduction in roughness.SOLUTION: A resist composition contains a resin component (A1) including a structural unit (a01) derived from a compound represented by general formula (a0-1), and a fluorine resin component (F1) having a structural unit represented by general formula (f1). In the formulae, W01 is a polymerizable group-containing group. Ya01 is a single bond or a divalent connection group. Ra01 is an acid-dissociable group. q is an integer of 0 to 3. n is an integer of 1 or more; with the proviso that n≤q×2+4. R is a hydrogen atom, a C1-C5 alkyl group or a C1-C5 halogenated alkyl group. X0 is a divalent connection group having no acid-dissociable part. Rf0 is an organic group having a fluorine atom.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resist composition and a resist pattern forming method. [Background technology]

[0002] In recent years, advances in lithography technology have led to rapid miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display elements. Generally, miniaturization is achieved by shortening the wavelength (increasing the energy) of the exposure light source.

[0003] Resist materials are required to possess lithography characteristics such as sensitivity to these exposure light sources and resolution that can reproduce patterns of fine dimensions. Conventionally, chemically amplified resist compositions have been used as resist materials that satisfy these requirements. These compositions contain a base component whose solubility in a developer changes due to the action of an acid, and an acid generator component that generates acid upon exposure.

[0004] In chemically amplified resist compositions, resins having specific structural units are generally used to improve lithography properties and other characteristics. For example, Patent Document 1 discloses a resist composition containing a resin component (A1) that includes a specific structural unit (a0) having both an acid-dissociable group and a phenolic hydroxyl group. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-067056 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] As lithography technology continues to advance and resist patterns become increasingly miniaturized, for example, EUV and EB lithography aim to form fine patterns of tens of nanometers. As resist pattern dimensions become smaller, it becomes necessary to improve lithographic characteristics such as sensitivity, resolution, and in-plane uniformity of pattern dimensions (CDU) without any trade-offs. However, with the conventional resist compositions described above, attempts to increase sensitivity tend to result in a degradation of resolution and CDU, making it difficult to satisfy both of these characteristics.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a resist composition that can be made highly sensitive and has good resolution and CDU, and a method for forming a resist pattern using the resist composition. [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, comprising a resin component (A1) whose solubility in a developer changes due to the action of the acid and a fluorine additive component (F) that exhibits decomposition in an alkaline developer, wherein the resin component (A1) has a constituent unit (a01) derived from a compound represented by the following general formula (a0-1), and the fluorine additive component (F) comprises a fluororesin component (F1) having a constituent unit represented by the following general formula (f1).

[0009] [ka] [In the formula, W 01 This is a polymerizable group-containing group. 01 Ra is a single bond or a divalent linking group. 01is an acid-dissociating group. q is an integer between 0 and 3. n is an integer greater than or equal to 1, where n ≤ q × 2 + 4.

[0010] [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. X 0 Rf is a divalent linking group that does not have an acid-dissociable site. 0 It is an organic group containing a fluorine atom.

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

[0012] According to the present invention, it is possible to provide a resist composition that can be made highly sensitive and has good resolution and CDU, as well as a method for forming a resist pattern using the resist composition. [Modes for carrying out the invention]

[0013] 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.

[0014] 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 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).

[0015] The term "acid-dissociable group" refers to both (i) a group that has acid-dissociability, in which the bond between the acid-dissociable group and an adjacent atom can be cleaved by the action of an acid, and (ii) a group in which, after some of the bonds are cleaved by the action of an acid, a decarboxylation reaction occurs, further causing the bond between the acid-dissociable group and an adjacent atom to be cleaved. The acid-dissociable group constituting the acid-degradable group must be less polar than the polar group generated by its dissociation. This means that when the acid-dissociable group dissociates due to the action of acid, a polar group with higher polarity is generated, increasing the polarity. As a result, the overall polarity of component (A1) increases. This increase in polarity relatively changes the solubility in the developer; solubility increases when the developer is an alkaline developer, and decreases when the developer is an organic developer.

[0016] 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).

[0017] "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.

[0018] The term "derivative" refers to a concept that includes those in which the hydrogen atom at the α-position of the target compound is substituted with another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound, in which the hydrogen atom at the α-position may be substituted with a substituent, is substituted with an organic group; those in which a substituent other than a hydroxyl group is bonded to the target compound, in which the hydrogen atom at the α-position may be substituted with a substituent, and the like. Herein, the α-position refers to the first carbon atom adjacent to the functional group, unless otherwise specified. Examples of the substituent that substitutes the hydrogen atom at the α-position of hydroxystyrene include R αx the same as those described above.

[0019] In this specification and the claims of this patent, depending on the structure represented by a chemical formula, there may be asymmetric carbons, and enantiomers or diastereomers may exist. In that case, those isomers are represented by one chemical formula. Those isomers may be used alone or as a mixture.

[0020] (Resist composition) The resist composition of this embodiment generates an acid upon exposure, and the solubility in a developer changes due to the action of the acid. Such a resist composition contains a base material component (A) (hereinafter also referred to as the "(A) component") whose solubility in a developer changes due to the action of an acid, and a fluorine additive component (F) (hereinafter also referred to as the "(F) component") that exhibits decomposability with respect to an alkaline developer.

[0021] In the resist composition of this embodiment, the (A) component may generate an acid upon exposure, or an additive component blended separately from the (A) component may generate an acid upon exposure. The resist composition of this embodiment may specifically (1) further contain an acid generating agent component (B) (hereinafter referred to as "component (B)") that generates acid upon exposure; (2) component (A) may be a component that generates acid upon exposure; or (3) component (A) may be a component that generates acid upon exposure and also contains component (B). In other words, in the cases of (2) and (3) above, component (A) is a "base component that generates acid upon exposure and whose solubility in the developer changes due to the action of the acid." When component (A) is a base component that generates acid upon exposure and whose solubility in the developer changes due to the action of the acid, it is preferable that component (A1), described later, is a resin that generates acid upon exposure and whose solubility in the developer changes due to the action of the acid. As such a resin, a polymer compound having a constituent unit that generates acid upon exposure can be used. Known constituent units that generate acid upon exposure can be used.

[0022] In this embodiment, the resist composition is preferably the one described in (1) above. That is, the resist composition of this embodiment preferably contains component (A) and component (B).

[0023] When a resist film is formed using the resist composition of this embodiment and selective exposure is performed on the resist film, for example, acid is generated from component (B) in the exposed areas of the resist film, and the solubility of component (A) in the developer changes due to the action of this 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. Therefore, when the resist film is developed, if the resist composition is positive type, the exposed areas of the resist film are dissolved and removed to form a positive type resist pattern, and if the resist composition is negative type, the unexposed areas of the resist film are dissolved and removed to form a negative type resist pattern.

[0024] 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 for a solvent development process that uses a developer containing an organic solvent (organic developer) for the development process.

[0025] <(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 the developer solution changes due to the action of an acid. By using component (A1), the polarity of the substrate component changes before and after exposure, so good development contrast can be obtained not only in the alkaline development process but also in the solvent development process. (A) Component (A1) may be used in combination with other high-molecular-weight compounds and / or low-molecular-weight compounds.

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

[0027] (A1) About the ingredients Component (A1) is a resin component whose solubility in the developer changes due to the action of acid.

[0028] ≪Component Unit (a01)≫ Component (A1) has a constituent unit (a01) derived from a compound represented by the following general formula (a0-1).

[0029] [ka] [In the formula, W 01 This is a polymerizable group-containing group. 01 Ra is a single bond or a divalent linking group. 01 is an acid-dissociating group. q is an integer between 0 and 3. n is an integer greater than or equal to 1, where n ≤ q × 2 + 4.

[0030] In formula (a0-1), W 01 This is a polymerizable group-containing group. W 01 In 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 (a01), the multiple bond in the polymerizable group is cleaved to form the main chain.

[0031] 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.

[0032] 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.

[0033] • 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.

[0034] 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.

[0035] ...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.

[0036] 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.

[0037] ...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.

[0038] 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-.

[0039] 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.

[0040] 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.

[0041] • 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 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 - is represented by the base [wherein Y 21 and Y 22 Each of these is a divalent hydrocarbon group which may have substituents independently, O is an oxygen atom, and m'' is an integer from 0 to 3. When the aforementioned divalent linking group containing a heteroatom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with substituents such as alkyl groups or acyl groups. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5. General formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -,-[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 - or -Y 21 -S(=O)2-OY 22 - Middle, Y 21 and Y 22 These are, independently, divalent hydrocarbon groups which may have substituents. Examples of such divalent hydrocarbon groups are the same as those listed in the description of divalent linking groups (divalent hydrocarbon groups which may have substituents). 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.

[0042] 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.

[0043] 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.

[0044] 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, etc., and the same applies to each of these as described above.

[0045] Among the above, Ya x0 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, Ya x0The combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group is more preferable, and a single bond is even more preferable.

[0046] In equation (a0-1), Ya 01 It is a single bond or a divalent linking group. 01 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, etc., and the same applies to each of these as described above.

[0047] In equation (a0-1), Ya 01 Among the above, it is preferable that the ester bond [-C(=O)-O-, -OC(=O)-], ether bond (-O-), linear or branched alkylene group, aromatic hydrocarbon group or a combination thereof, or single bond. Among these, Ya 01 The combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group is more preferable, and a single bond is even more preferable.

[0048] In formula (a0-1), Ra 01 It is an acid-dissociable group. Examples of acid-dissociable groups include the "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "secondary alkyl ester-type acid-dissociable groups," which are described below.

[0049] Acetal type acid dissociable group: Ra 01 Examples of acid-dissociating groups in this context include the acid-dissociating group represented by the following general formula (a0-r-1) (hereinafter sometimes referred to as the "acetal-type acid-dissociating group").

[0050] [ka] [In formula (a0-r-1), Ra 01 and Ra 02is, independently of each other, a hydrogen atom or an alkyl group. Ra 03 is a hydrocarbon group, and Ra 01 or Ra 02 may combine with any one of them to form a ring. * indicates a bond.]

[0051] In formula (a0-r-1), Ra 01 and Ra 02 are, independently of each other, a hydrogen atom or an alkyl group. In formula (a0-r-1), Ra 01 and Ra 02 Preferably, at least one of them is a hydrogen atom, and more preferably both are hydrogen atoms. Ra 01 or Ra 02 When it is an alkyl group, the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms. Specifically, a linear or branched alkyl group is preferably mentioned. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. are mentioned, a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable. In formula (a0-r-1), Ra 01 and Ra 02 Among the above, preferably, they are, independently of each other, a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom or a methyl group.

[0052] In formula (a0-r-1), Ra 03 As the hydrocarbon group, a linear or branched alkyl group, or a cyclic hydrocarbon group is mentioned. 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, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. are mentioned. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

[0053] The branched-chain alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, etc., and an isopropyl group is preferable.

[0054] Ra 03 When Ra 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 the aliphatic hydrocarbon group that is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, examples thereof include cyclopentane, cyclohexane, etc. As the aliphatic hydrocarbon group that is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferable. The polycycloalkane preferably has 7 to 12 carbon atoms, and specifically, examples thereof include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0055] Ra 03 When the cyclic hydrocarbon group of Ra is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This 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 of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still 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, phenanthrene; aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom, etc. Specific examples of the aromatic heterocycle include a pyridine ring, a thiophene ring, etc. Ra 03Specific 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.

[0056] Ra 03 The cyclic hydrocarbon group in may have substituents. Examples of substituents include the aforementioned Ra x5 Similar bases can be cited.

[0057] Ra 03 However, Ra 01 Ra 02 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.

[0058] Specific examples of acetal-type acid-dissociating groups are shown below. * indicates a bond.

[0059] [ka]

[0060] Tertiary alkyl ester type acid-dissociating group: Ra 01 Examples of acid-dissociable groups in this context include the acid-dissociable group represented by the following general formula (a0-r-2). Furthermore, among the acid-dissociable groups represented by the following formula (a0-r-2), those composed of alkyl groups may, for convenience, be referred to below as "tertiary alkyl ester type acid-dissociable groups."

[0061] [ka] [In formula (a0-r-2), Ra 04 ~Ra 06 Each of these is independently a hydrocarbon group, and Ra 05 and Ra 06 These elements may join with each other to form a ring. * indicates a bonding hand.

[0062] Ra 04 Examples of hydrocarbon groups include linear or branched alkyl groups, linear or cyclic alkenyl groups, or cyclic hydrocarbon groups. Ra 04 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 03 Similar examples include the above. Ra 04 The linear or cyclic alkenyl group in this is preferably an alkenyl group having 2 to 10 carbon atoms. Ra 05 Ra 06 As for the hydrocarbon group, the Ra 03 Similar examples include the above.

[0063] Ra 05 and Ra 06 When these groups bond to each other to form a ring, the following groups are preferred: the group represented by the general formula (a0-r2-01), the group represented by the general formula (a0-r2-02), and the group represented by the general formula (a0-r2-03). Meanwhile, Ra 04 ~Ra 06 When these are independent hydrocarbon groups that are not bonded to each other, the group represented by the following general formula (a0-r2-04) is preferred.

[0064] [ka] [In formula (a0-r2-01), Ra 001 This is a linear or branched alkyl group which may have substitutions. 0 Xaa is a carbon atom. 0 Yaa 0 It is a group that forms a cyclic hydrocarbon group together with other groups. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted, and some of the carbon atoms constituting the ring may be substituted with heteroatoms. * indicates a bond. In formula (a0-r2-02), Yab 0 Xab is a carbon atom. 0 Yab 0 It is a group that forms a cyclic hydrocarbon group together with [another group]. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted, and some of the carbon atoms constituting the ring may be substituted with heteroatoms. 002 ~Ra 004 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. 002 ~Ra 004 Two or more of these may be joined together to form a ring structure. * indicates a bonding hand. In formula (a0-r2-03), Yac 0 Xac is a carbon atom. 0 Yac 0 It is a group that forms a cyclic hydrocarbon group together with [another group]. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted, and some of the carbon atoms constituting the ring may be substituted with heteroatoms. 005 is an aromatic hydrocarbon group. Some or all of the hydrogen atoms in this aromatic hydrocarbon group may be substituted, and some of the carbon atoms constituting the ring may be substituted with heteroatoms. * indicates a bond. In formula (a0-r2-04), Ra 006 and Ra 007is, independently of each other, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms of this linear saturated hydrocarbon group may be substituted. Ra 008 is a hydrocarbon group which may have a substituent. * represents a bond.]

[0065] In formula (a0-r2-01), Ra 001 is a linear or branched alkyl group which may have a substitution. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group and the like can be mentioned. Among these, methyl group, ethyl group or n-butyl group is preferable, and methyl group or ethyl group is more preferable.

[0066] The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group and the like can be mentioned. [[ID=**16]]

[0067] Ra 001 Examples of the substituent which the linear or branched alkyl group in Ra may have include, for example, Ra described above x5 as mentioned above.

[0068] In formula (a0-r2-01), Ra 001 Among the above, it is preferably a linear alkyl group having 1 to 5 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms, more preferably a linear alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 to 5 carbon atoms, and still more preferably a linear alkyl group having 1 to 3 carbon atoms.

[0069] In formula (a0-r2-01), Yaa 0 is a carbon atom, and Xaa 0 is Yaa0 It is a group that forms a cyclic hydrocarbon group together with other groups. The cyclic hydrocarbon group may be an aliphatic hydrocarbon group, a fused cyclic hydrocarbon group formed by an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and may be a polycyclic or monocyclic group.

[0070] As a monocyclic aliphatic hydrocarbon group, a group obtained by removing two or more hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and preferably one having 5 or 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a polycycloalkane from which two or more hydrogen atoms have been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0071] In a fused cyclic hydrocarbon group formed by an aliphatic hydrocarbon group and an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This 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.

[0072] The following are specific examples of fused cyclic hydrocarbon groups formed by the combination of an aliphatic hydrocarbon group and an aromatic hydrocarbon group.

[0073] [ka]

[0074] Some or all of the hydrogen atoms in the above-mentioned cyclic hydrocarbon group may be substituted, and some of the carbon atoms constituting the ring may be substituted with heteroatoms. Specifically, as substituents that replace some or all of the hydrogen atoms of the above-mentioned cyclic hydrocarbon group, the above-mentioned Ra x5 Examples include oxygen atoms, sulfur atoms, and nitrogen atoms, when some of the carbon atoms constituting the ring are substituted with heteroatoms.

[0075] In formula (a0-r2-01), Xaa 0 And, Yaa 0 Among the above, the cyclic hydrocarbon group formed by the two is preferably a monocyclic or polycyclic aliphatic hydrocarbon group, more preferably a monocyclic aliphatic hydrocarbon group, and even more preferably a monocyclic aliphatic hydrocarbon group having 5 or 6 carbon atoms.

[0076] In formula (a0-r2-02), Yab 0 Xab is a carbon atom, 0 Yab 0 It is a group that forms a cyclic hydrocarbon group together with the above. This cyclic hydrocarbon group is Xaa 0 And, Yaa 0 Examples include cyclic hydrocarbon groups similar to those formed by [the compound].

[0077] In formula (a0-r2-02), Ra 002 ~Ra 004 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.

[0078] Ra 002 ~Ra 004Examples 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 002 ~Ra 004 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.

[0079] Ra 002 ~Ra 004 In the above, some or all of the hydrogen atoms of the chain-like saturated hydrocarbon group and the aliphatic cyclic saturated hydrocarbon group may be substituted. Specifically, as substituents that substitute some or all of the hydrogen atoms of the chain-like saturated hydrocarbon group and the aliphatic cyclic saturated hydrocarbon group, the above-mentioned Ra x5 Examples include oxygen atoms, sulfur atoms, and nitrogen atoms, when some of the carbon atoms constituting the ring are substituted with heteroatoms.

[0080] Ra 002 ~Ra 004 Groups 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.

[0081] In formula (a0-r2-02), Ra 002 ~Ra 004Among the above, hydrogen atoms and monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms are preferred, hydrogen atoms, methyl groups, and ethyl groups are more preferred, and hydrogen atoms are even more preferred.

[0082] In formula (a0-r2-03), Yac 0 Xac is a carbon atom, 0 Yac 0 It is a group that forms a cyclic hydrocarbon group together with the above. This cyclic hydrocarbon group is Xaa 0 And, Yaa 0 Examples include cyclic hydrocarbon groups similar to those formed by [the compound].

[0083] In formula (a0-r2-03), Ra 005 The aromatic hydrocarbon group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms from which one or more hydrogen atoms have been removed, more preferably a group from which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, even more preferably a group from which one or more hydrogen atoms have been removed from benzene or naphthalene, and particularly preferably a group from which one or more hydrogen atoms have been removed from benzene.

[0084] Some or all of the hydrogen atoms in the above aromatic hydrocarbon group may be substituted, and some of the carbon atoms constituting the ring may be substituted with heteroatoms. Specifically, as substituents that replace some or all of the hydrogen atoms of the above aromatic hydrocarbon group, the above-mentioned Ra x5 Examples include oxygen atoms, sulfur atoms, and nitrogen atoms, when some of the carbon atoms constituting the ring are substituted with heteroatoms.

[0085] In formula (a0-r2-04), Ra 006 and Ra 007 These are, independently, monovalent, chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms. Ra 006 and Ra 007 In this context, the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms is the aforementioned Ra 002 ~Ra004 Examples thereof include those similar to monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms.

[0086] In formula (a0-r2-04), Ra 006 and Ra 007 Among them, an alkyl group having 1 to 5 carbon atoms is preferable, a methyl group or an ethyl group is more preferable, and a methyl group is even more preferable. Ra 006 and Ra 007 When the chain saturated hydrocarbon group represented by is substituted, examples of the substituent include, for example, the same groups as Ra x5 described above.

[0087] In formula (a0-r2-04), Ra 008 is a hydrocarbon group which may have a substituent. The hydrocarbon group in Ra 008 includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0088] Ra 008 The linear alkyl group in 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 a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

[0089] Ra 008 The branched alkyl group in preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, etc., and an isopropyl group is preferable.

[0090] Ra 008 When Ra is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may also 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.

[0091] Ra 008 As for aromatic hydrocarbon groups in this context, Ra 005 Examples include those similar to aromatic hydrocarbon groups in [the text]. Among them, Ra 008 The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms from which one or more hydrogen atoms have been removed; more preferably a group from which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene; even more preferably a group from which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene; particularly preferably a group from which one or more hydrogen atoms have been removed from naphthalene or anthracene; and most preferably a group from which one or more hydrogen atoms have been removed from naphthalene. Ra 008 A substituent that may be present is Ra 005 Examples of substituents that may be present include those similar to those that the molecule may have.

[0092] Ra in equation (a0-r2-04) 008 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 (a0-r2-04) 008 If is an anthyl group, the position where it bonds with the tertiary carbon atom in formula (a0-r2-04) may be position 1, 2, or 9 of the anthyl group.

[0093] In formula (a0-r2-04), Ra 008Among the above, alkyl groups having 1 to 5 carbon atoms are preferred, methyl groups and ethyl groups are more preferred, and methyl groups are even more preferred.

[0094] Specific examples of the group represented by the above formula (a0-r2-01) are given below.

[0095] [ka]

[0096] [ka]

[0097] [ka]

[0098] Specific examples of the group represented by the formula (a0-r2-02) are given below.

[0099] [ka]

[0100] [ka]

[0101] [ka]

[0102] Specific examples of the group represented by the above formula (a0-r2-03) are given below.

[0103] [ka]

[0104] Specific examples of the group represented by the above formula (a0-r2-04) are given below.

[0105] [ka]

[0106] Secondary alkyl ester type acid-dissociating group: Ra 01 Examples of acid-dissociable groups in this context include the acid-dissociable group represented by the following general formula (a0-r-3).

[0107] [ka] [In formula (a0-r-3), Ra 07 Ra is a hydrocarbon group. 08a and Ra 08b Each of these is independently a hydrogen atom, a halogen atom, or an alkyl group. 09 is a hydrogen atom or a hydrocarbon group. 07 and Ra 08a Or Ra 08b These may be joined together to form a ring. 08a Or Ra 08b And, Ra 09 These elements may bond to each other to form a ring. * indicates a bond with the oxygen atom (-O-) in the general formula (a0-1).

[0108] In the formula, Ra 07 and Ra 09 The hydrocarbon group in this is the Ra 01 Similar examples include the above. In the formula, Ra 08a and Ra 08b The alkyl group in is the Ra 01 Examples include alkyl groups similar to those in the above. In the formula, Ra 07 and Ra 09 The hydrocarbon group in, and Ra 08a and Ra 08b The alkyl group in may have substituents. For example, the above-mentioned Ra is an example of such substituent. x5 These are some examples.

[0109] Ra 07 and Ra 08a Or Ra 08b These elements may be bonded to each other to form a ring. This ring may be polycyclic or monocyclic, and may be an alicyclic or aromatic ring. The alicyclic and aromatic rings may also contain heteroatoms.

[0110] Ra 07 and Ra 08a Or Ra 08b The rings formed by the bonding of these elements are preferably monocycloalkenes, rings in which some of the carbon atoms of a monocycloalkene are substituted with heteroatoms (oxygen atoms, sulfur atoms, etc.), monocycloalkadienes, cycloalkenes having 3 to 6 carbon atoms, and cyclopentene or cyclohexene.

[0111] Ra 07 and Ra 08a Or Ra 08b The ring formed by the bonding of these elements may be a fused ring. Specific examples of such fused rings include indane.

[0112] Ra 07 and Ra 08a Or Ra 08b The ring formed by the bonding of these elements may have substituents. For example, the above-mentioned Ra x5 These are some examples.

[0113] Ra 08a Or Ra 08b And, Ra 09 These may be bonded together to form a ring, and the ring may be Ra 07 and Ra 08a Or Ra 08b Examples include rings formed by the bonding of these elements together.

[0114] In the above formula (a0-r-3), Ra 07 and Ra 08a Or Ra 08bIn this case, among the above, it is preferable that they bond to each other to form a ring, more preferably that they bond to each other to form a monoring, and even more preferably that they bond to each other to form a monoring alicyclic ring. 09 It is preferable that it be a hydrogen atom. Also, Ra 07 and Ra 08a Or Ra 08b The ring formed by the bonding of these elements may have substituents, preferably alkyl groups having 1 to 5 carbon atoms, more preferably alkyl groups having 1 to 3 carbon atoms, and even more preferably methyl or ethyl groups.

[0115] Specific examples of the group represented by the formula (a0-r-3) are given below.

[0116] [ka]

[0117] In the above formula (a0-1), Ra 01 The acid-dissociable group in is preferably a tertiary alkyl ester type acid-dissociable group, more preferably an acid-dissociable group represented by either formula (a0-r2-01) or (a0-r2-04), and even more preferably an acid-dissociable group represented by formula (a0-r2-01).

[0118] In the above formula (a0-1), q is an integer between 0 and 3. When q is 0, it is a benzene structure; when q is 1, it is a naphthalene structure; when q is 2, it is an anthracene structure; and when q is 3, it is a tetracene structure.

[0119] In the above formula (a0-1), n ​​is an integer of 1 or more, preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2.

[0120] In the above equation (a0-1), n ​​≤ q × 2 + 4. For example, if q is 1 and the structure is naphthalene, then the naphthalene is a polymerizable group containing (W 01) and -Ya 01 -(C=O)-O-Ra 01 All hydrogen atoms other than those substituted with a hydroxyl group may be substituted with a hydroxyl group. In addition, in the naphthalene, polymerizable group-containing group (W 01 ), -Ya 01 -(C=O)-O-Ra 01 The substitution positions of the group and the hydroxyl group are not particularly limited.

[0121] The constituent unit (a01) is preferably a constituent unit represented by the following general formula (a0-1-1) among the above.

[0122] [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. 001 It is a single bond or a divalent linking group. 01 It is a single bond or a divalent linking group. Rax 01 is an acid-dissociable group represented by the general formula (a0-r-1), (a0-r-2), or (a0-r-3) described above. q is an integer between 0 and 3. n is an integer greater than or equal to 1, where n ≤ q × 2 + 4.

[0123] In formula (a0-1-1), the C1-C5 alkyl group of R 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 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. Fluorine atoms are particularly preferred as the halogen atoms. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, with a hydrogen atom or a methyl group being the most preferred due to their industrial availability.

[0124] In equation (a0-1-1), Ya 001 It is a single bond or a divalent linking group. Ya 001 The divalent linking group in is not particularly limited, but suitable 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 group and the divalent linking group containing a heteroatom in [the given material].

[0125] Among the above, Ya 001 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, Ya 001 The combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group is more preferable, and a single bond is even more preferable.

[0126] In equation (a0-1-1), Ya 01 This is Ya in the above equation (a0-1) 01 It is identical to [the other one].

[0127] In formula (a0-1-1), Rax 01 This is an acid-dissociable group represented by the general formulas (a0-r-1), (a0-r-2), or (a0-r-3) mentioned above. In formula (a0-1-1), Rax 01 Among the above, it is preferable that the acid-dissociable group is represented by either formula (a0-r2-01) or (a0-r2-04), and more preferably that it is represented by formula (a0-r2-01).

[0128] In equation (a0-1-1), q and n are the same as q and n in equation (a0-1) above.

[0129] The following are specific examples of the constituent unit (a01). In each of the following formulas, Rα represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0130] [ka]

[0131] [ka]

[0132] [ka]

[0133] [ka]

[0134] In the resist composition of this embodiment, the constituent unit (a01) is preferably a constituent unit represented by any of the above formulas (a01-1a-2), (a01-1a-8), (a01-1a-28), (a01-1a-31), (a01-1a-34), or (a01-1a-37), and more preferably a constituent unit represented by any of the above formulas (a01-1a-2), (a01-1a-31), (a01-1a-34), or (a01-1a-37).

[0135] The constituent units (a01) of component (A1) may be one type or two or more types. The proportion of constituent units (a01) in component (A1) is preferably 10 mol% or more, more preferably 20 mol% or more, even more preferably 30 mol% or more, and may be 100 mol%, based on the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of the constituent unit (a01) above the aforementioned preferred lower limit, sensitivity can be further improved without reducing resolution. Furthermore, since appropriate solubility in the developer can be ensured, fine resolution can be further improved. For example, the proportion of constituent unit (a01) in component (A1) is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, and even more preferably 30 to 70 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1).

[0136] <<Other constituent units>> Component (A1) may have other constituent units in addition to the constituent unit (a01) as needed. Other constituent units include, for example, constituent units (a1) containing acid-degradable groups whose polarity increases with the action of an acid (excluding those corresponding to the aforementioned constituent unit (a01)); constituent units (a10) represented by the general formula (a10-1) described later; constituent units (a2) containing lactone-containing cyclic groups; and constituent units (a8) derived from compounds represented by the general formula (a8-1) described later.

[0137] Regarding the constituent unit (a1): Component (A1) may have, in addition to the aforementioned constituent unit (a01), further constituent unit (a1). The constituent unit (a1) is a constituent unit that contains an acid-degradable group whose polarity increases due to the action of an acid (excluding those corresponding to the aforementioned constituent unit (a01)).

[0138] Examples of acid-dissociable groups include those previously proposed as acid-dissociable groups for base resins used in chemically amplified resist compositions. Specifically, examples of acid-dissociable groups proposed for base resins used in chemically amplified resist compositions include the aforementioned "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "secondary alkyl ester-type acid-dissociable groups," as well as the "tertiary alkyloxycarbonyl acid-dissociable groups" described below.

[0139] Tertiary alkyloxycarbonyl acid dissociable group: Examples of acid-dissociating groups that protect hydroxyl groups include the acid-dissociating group represented by the following general formula (a1-r-3) (hereinafter sometimes referred to as the "tertiary alkyloxycarbonyl acid dissociating group" for convenience).

[0140] [ka] [In the formula, Ra' 7 ~Ra' 9 These are each alkyl groups.

[0141] 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.

[0142] 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.

[0143] As for the constituent unit (a1), among the above, a constituent unit derived from an acrylic acid ester in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent is preferred. A preferred specific example of such a constituent unit (a1) is a constituent unit represented by the following general formula (a1-1) or (a1-2).

[0144] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 1 n is a divalent hydrocarbon group which may have an ether bond. a1 is an integer between 0 and 2. 1 This is an acid-dissociable group represented by the general formula (a0-r-1), (a0-r-2), or (a0-r-3) described above. 1 is n a2 It is a +1 valent hydrocarbon group, n a2 is an integer between 1 and 3, and Ra 2 This is an acid-dissociable group represented by the general formula (a0-r-1) or (a1-r-3) mentioned above.

[0145] In formula (a1-1), the C1-C5 alkyl group of R 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. The 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. Fluorine atoms are particularly preferred as the halogen atoms. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, with a hydrogen atom or a methyl group being the most preferred due to their industrial availability.

[0146] In the above formula (a1-1), Va 1 The divalent hydrocarbon group in this expression may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0147] Va 1 The aliphatic hydrocarbon group as a divalent hydrocarbon group in this compound may be saturated or unsaturated, but is usually preferred to be saturated. More specifically, examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0148] 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.

[0149] Examples of aliphatic hydrocarbon groups containing a ring in the aforementioned structure include alicyclic hydrocarbon groups (groups obtained by removing two hydrogen atoms 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. Examples of the linear or branched aliphatic hydrocarbon group include those similar to the linear or branched aliphatic hydrocarbon group described above. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. A preferred monocyclic alicyclic hydrocarbon group is a monocycloalkane from which two hydrogen atoms have been removed. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a polycycloalkane from which two hydrogen atoms have been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0150] Va 1 In this context, an aromatic hydrocarbon group as a divalent hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this carbon number does not include the carbon atoms in substituents. Specific examples of aromatic rings in aromatic hydrocarbon groups include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, 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. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); and a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) in which one hydrogen atom is replaced by an alkylene group (for example, a group obtained by removing one more hydrogen atom from the aryl group in an arylalkyl group such as a 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.

[0151] In the above formula (a1-1), Ra 1 This is an acid-dissociable group represented by the above formula (a0-r-1), (a0-r-2), or (a0-r-3), among which it is preferably an acid-dissociable group represented by the above formula (a0-r-2), more preferably an acid-dissociable group represented by either the above formula (a0-r2-01) or (a0-r2-04), and even more preferably an acid-dissociable group represented by the above formula (a0-r2-01).

[0152] In the above formula (a1-2), Wa 1 n in a2 The +1 valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group that is a combination of a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in its structure. The aforementioned n a2 The +1 valent is preferably 2 to 4 valent, and more preferably 2 or 3 valent.

[0153] In the above formula (a1-2), Ra 2 This is an acid-dissociable group represented by the general formula (a0-r-1) or (a1-r-3) above.

[0154] The following are specific examples of the constituent units represented by the above formula (a1-1). In each of the following formulas, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0155] [ka]

[0156] [ka]

[0157] [ka]

[0158] [ka]

[0159] [ka]

[0160] [ka]

[0161] [ka]

[0162] [ka]

[0163] The constituent units (a1) of component (A1) may be one type or two or more types. As for the constituent unit (a1), the constituent unit represented by formula (a1-1) is more preferable because it is easier to improve the characteristics (sensitivity, shape, etc.) in electron beam or EUV lithography.

[0164] The proportion of constituent units (a1) in component (A1) is preferably 1 to 80 mol%, more preferably 5 to 70 mol%, and even more preferably 10 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of the constituent unit (a1) to be above the lower limit of the preferred range mentioned above, the resolution is further improved. On the other hand, if it is below the upper limit of the preferred range mentioned above, a balance can be achieved with the other constituent units, resulting in good lithography characteristics in various aspects.

[0165] Regarding the constituent unit (a10): Component (A1) may also have a constituent unit (a10) represented by the following general formula (a10-1) (excluding those corresponding to constituent unit (a01) or constituent unit (a1)).

[0166] [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.]

[0167] In the above formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. For R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, and due to their industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is more preferred, a hydrogen atom or a methyl group is even more preferred, and a hydrogen atom is particularly preferred.

[0168] In the above formula (a10-1), Ya x1 It is a single bond or a divalent linking group. In the above chemical formula, Ya x1 The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms.

[0169] 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, and single bonds being even more preferred.

[0170] 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 group with 1+1 hydrogen atoms removed is an example. 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 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.

[0171] Wa x1 The aromatic hydrocarbon group in may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, and alkyl halides. Examples of alkyl groups, alkoxy groups, halogen atoms, and alkyl halides as substituents include Ya x1 Examples of substituents include those similar to those listed for the cyclic alicyclic hydrocarbon group in [the relevant section]. The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, even more preferably an ethyl group or a methyl group, and particularly preferably a methyl group. x1 In this context, it is preferable that the aromatic hydrocarbon group does not have substituents.

[0172] 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.

[0173] The following are specific examples of the constituent unit (a10) represented by the above formula (a10-1). In each of the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0174] [ka]

[0175] [ka]

[0176] [ka]

[0177] Among the above, the constituent unit (a10) is preferably the constituent unit represented by the above formula (a10-1-1).

[0178] 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 20 to 70 mol%, and even more preferably 30 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of constituent unit (a10) above the lower limit, sensitivity and CDU can be more easily increased. On the other hand, by setting it below the upper limit, it becomes easier to balance it with other constituent units.

[0179] Regarding the constituent unit (a2): Component (A1) may further have a constituent unit (a2) containing a lactone-containing cyclic group (excluding those corresponding to constituent unit (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.

[0180] 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).

[0181] [ka] [In the formula, 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 (the same applies below).

[0182] 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.

[0183] 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.

[0184] Ra' 21 Among the above, it is preferable that each is independently a hydrogen atom or a cyano group.

[0185] 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, or isopropylene group. When 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-, or -CH2-S-CH2-. A'' is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0186] The following are specific examples of the groups represented by the general formulas (a²-r-1) to (a²-r-7).

[0187] [ka]

[0188] [ka]

[0189] 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).

[0190] [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 R' 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.

[0191] 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.

[0192] In the above formula (a2-1), Ya 21 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.

[0193] Ya 21 Preferably, the group is a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0194] In the above formula (a2-1), Ya 21 It is a single bond, La 21 It is preferable that it be -COO- or -OCO-.

[0195] 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 those represented by the general formulas (a2-r-1) to (a2-r-7) mentioned above.

[0196] 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 1 to 20 mol%, more preferably 1 to 15 mol%, and even more preferably 1 to 10 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). If the proportion of constituent unit (a2) is set above a preferred lower limit, the effects of including constituent unit (a2) are fully obtained due to the effects described above, and if it is below the upper limit, a balance can be achieved with other constituent units, resulting in good lithography characteristics.

[0197] 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). However, this excludes components (a01) or components (a1).

[0198] [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. 1 R 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.]

[0199] W 2 In the context of polymerizable group-containing groups, "polymerizable group" refers to a group that enables a compound containing a polymerizable group to polymerize by radical polymerization or the like, and includes, for example, a group containing multiple bonds between carbon atoms, such as an ethylenic double bond.

[0200] The polymerizable group-containing group may be a group composed solely of a polymerizable group, 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 which contain heteroatoms. 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 It is a single bond or a divalent linking group.

[0201] Ya x2 and W 2 The condensed ring formed by these is W 2 Polymerizable groups of the site and Ya x2 The condensed ring formed by and W 2 Other groups besides the polymerizable group of the site and Ya x2 A condensed ring formed by these is one example. Ya x2 and W 2 The fused ring formed by these two components may have substituents.

[0202] 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.

[0203] [ka]

[0204] Among the examples above, the constituent unit (a8) is preferably at least one selected from the group consisting of constituent units represented by the chemical formulas (a8-1-01) to (a8-1-04), (a8-1-06), (a8-1-08), (a8-1-09), and (a8-1-10), and more preferably at least one selected from the group consisting of constituent units represented by the chemical formulas (a8-1-01) to (a8-1-04) and (a8-1-09).

[0205] The constituent units (a8) of component (A1) may be one type or two or more types. The proportion of constituent unit (a8) in component (A1) is preferably 50 mol% or less, and more preferably 0 to 30 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1).

[0206] The (A1) component contained in the resist composition may be used alone or in combination of two or more types.

[0207] The (A1) component is preferably a polymer compound having a repeating structure of a constituent unit (a01), more preferably a polymer compound having a repeating structure of a constituent unit (a01) and a repeating structure of a constituent unit (a10); more preferably a polymer compound having a repeating structure of a constituent unit (a01) and a repeating structure of a constituent unit (a1). More specifically, the (A1) component is preferably a polymer compound consisting of a repeating structure of the constituent unit (a01); a polymer compound consisting of a repeating structure of the constituent unit (a01) and a repeating structure of the constituent unit (a1); a polymer compound consisting of a repeating structure of the constituent unit (a01) and a repeating structure of the constituent unit (a10); or a polymer compound consisting of a repeating structure of the constituent unit (a01), a repeating structure of the constituent unit (a1), and a repeating structure of the constituent unit (a10).

[0208] In a polymer compound consisting of a repeating structure of constituent unit (a01) and a repeating structure of constituent unit (a1), the proportion of constituent unit (a01) is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. Furthermore, the proportion of constituent units (a1) in the polymer compound is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound.

[0209] In a polymer compound consisting of a repeating structure of constituent unit (a01) and a repeating structure of constituent unit (a10), the proportion of constituent unit (a01) is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total 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 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound.

[0210] In a polymer compound consisting of a repeating structure of constituent unit (a01), a repeating structure of constituent unit (a1), and a repeating structure of constituent unit (a10), the proportion of constituent unit (a01) is preferably 10 to 90 mol%, more preferably 5 to 60 mol%, even more preferably 10 to 50 mol%, and particularly 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 (a1) in the polymer compound is preferably 5 to 70 mol%, more preferably 10 to 60 mol%, even more preferably 30 to 50 mol%, and particularly 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 (a10) in the polymer compound is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound.

[0211] 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 a constituent unit (a01) and, if necessary, a monomer that induces other constituent units (for example, a compound in which the hydroxyl group of the monomer that induces a constituent unit (a10) is protected) in a polymerization solvent, adding a radical polymerization initiator as described above, polymerizing the mixture, and then, if necessary, 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).

[0212] 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 20,000. 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 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Mn represents the number-average molecular weight.

[0213] (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 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.

[0214] 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, CDU, resolution, and roughness improvement.

[0215] In the resist composition of this embodiment, the content of component (A) may be adjusted according to the resist film thickness to be formed.

[0216] <(F) component> In the resist composition of this embodiment, component (F) includes a fluororesin component (F1) (hereinafter also referred to as "component (F1)") having a constituent unit represented by the following general formula (f1).

[0217] [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. X 0 Rf is a divalent linking group that does not have an acid-dissociable site.0 It is an organic group containing a fluorine atom.

[0218] In the above general formula (f1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. The C1-C5 alkyl group in R 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. The C1-C5 alkyl halide in R 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, with fluorine atoms being particularly preferred. For R, a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 fluorinated alkyl group is preferred, and for ease of industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is more preferred, a hydrogen atom or a methyl group is even more preferred, and a methyl group is particularly preferred.

[0219] In the above general formula (f1), X 0 It is a divalent linking group that does not have an acid-dissociable site. An "acid-dissociable site" refers to a site within an organic group that dissociates when exposed to acid, as described above in the "acid-dissociable group." Specifically, it refers to the oxygen atom of the (-C(=O)-O-) bonded to the main chain and Rf 0 However, they do not dissociate due to the action of acid.

[0220] X 0 Examples of divalent linking groups that do not have an acid-dissociable site include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms.

[0221] • Hydrocarbon groups which may have substituents In groups other than polymerizable groups, a hydrocarbon group being "substituted" means that some or all of the hydrogen atoms in the hydrocarbon group are substituted with a group or atom other than a hydrogen atom. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromaticity. Such aliphatic hydrocarbon groups may be saturated or unsaturated, but are usually preferably saturated.

[0222] More specifically, examples of aliphatic hydrocarbon groups include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in their structure.

[0223] The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, even more preferably 1 to 5, particularly preferably 1 to 3, and most preferably 2. As for the linear aliphatic hydrocarbon group, linear alkylene groups are preferred, specifically, methylene groups, ethylene groups [-(CH2)2-], trimethylene groups [-(CH2)3-], tetramethylene groups [-(CH2)4-], pentamethylene groups [-(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 -CH(CH2CH3)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. The linear (linear or branched) aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated lower alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and oxygen atoms (=O).

[0224] Examples of aliphatic hydrocarbon groups containing a ring include cyclic aliphatic hydrocarbon groups (groups obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and groups in which the cyclic aliphatic hydrocarbon group is bonded to the ends of the aforementioned chain-like aliphatic hydrocarbon group or interposed in the middle of the chain-like aliphatic hydrocarbon group. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic group is a monocycloalkane with 3 to 6 carbon atoms from which two hydrogen atoms have been removed. Examples of such monocycloalkanes include cyclopentane and cyclohexane. The polycyclic group is preferably a polycycloalkane having 7 to 12 carbon atoms with two hydrogen atoms removed. Specific examples of such polycycloalkanes include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include lower alkyl groups having 1 to 5 carbon atoms, fluorine atoms, fluorinated lower alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and oxygen atoms (=O).

[0225] Examples of aromatic hydrocarbon groups include phenyl, biphenyl, fluorenyl, naphthyl, anthryl, and phenanthryl groups, which are divalent aromatic hydrocarbon groups obtained by removing one more hydrogen atom from the nucleus of a monovalent aromatic hydrocarbon group; An aromatic hydrocarbon group in which some of the carbon atoms constituting the ring of the divalent aromatic hydrocarbon group are replaced by heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms; Examples include arylalkyl groups such as benzyl groups, phenethyl groups, 1-naphthylmethyl groups, 2-naphthylmethyl groups, 1-naphthylethyl groups, and 2-naphthylethyl groups, and aromatic hydrocarbon groups from which one hydrogen atom has been further removed from the nucleus of the aromatic hydrocarbon. Among these, the divalent aromatic hydrocarbon group is preferred, and an aromatic hydrocarbon group obtained by removing one more hydrogen atom from a phenyl group, and an aromatic hydrocarbon group obtained by removing one more hydrogen atom from a naphthyl group are particularly preferred. The number of carbon atoms in the alkyl chain of the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1. The aromatic hydrocarbon group may or may not have substituents. Examples of substituents include lower alkyl groups having 1 to 5 carbon atoms, fluorine atoms, fluorinated lower alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and oxygen atoms (=O).

[0226] Among the above, linear, branched, or cyclic aliphatic hydrocarbon groups and divalent aromatic hydrocarbon groups are more preferred as hydrocarbon groups that may have substituents, and methylene groups, ethylene groups, -CH(CH3)-, groups obtained by removing one more hydrogen atom from a tetracyclododecanyl group, and aromatic hydrocarbon groups obtained by removing one more hydrogen atom from a phenyl group are particularly preferred.

[0227] • Divalent linking group containing a heteroatom Heteroatoms are atoms other than carbon atoms and hydrogen atoms, such as oxygen atoms, nitrogen atoms, sulfur atoms, and halogen atoms. Examples of divalent linking groups containing heteroatoms include -O-, -C(=O)-, -C(=O)-O-, carbonate bond (-OC(=O)-O-), -NH-, and -NR 04 (R 04 Examples include alkyl groups, -NH-C(=O)-, =N-, or combinations of "these groups" with divalent hydrocarbon groups. Examples of divalent hydrocarbon groups include those similar to the hydrocarbon groups that may have substituents as described above, and linear or branched aliphatic hydrocarbon groups are preferred. In particular, as a divalent linking group containing a heteroatom, a combination of "these groups" and a divalent hydrocarbon group is more preferred, and specifically, a combination of "these groups" and the above aliphatic hydrocarbon group, and a combination of the above aliphatic hydrocarbon group, "these groups," and the above aliphatic hydrocarbon group are particularly preferred.

[0228] In the above general formula (f1), Rf 0 This is an organic group having 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, even more preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Furthermore, the number of fluorine atoms in the hydrocarbon group containing fluorine atoms is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 3. Furthermore, in hydrocarbon groups containing fluorine atoms, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, and more preferably that 40% or more are fluorinated. Among them, Rf 0 More preferably, the group is a fluorinated hydrocarbon group having 1 to 6 carbon atoms, with trifluoromethyl, -CH2-CF3, -CH2-CH2-CF3, -CH2-CF2-CF3, and -CH(CF3)2 being preferred.

[0229] The (F1) component preferably has a constituent unit represented by the following general formula (f1-1) or a constituent unit represented by the following general formula (f1-2).

[0230] ≪Constituent units represented by general formula (f1-1)≫

[0231] [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. X 01 Rf is a divalent linking group that does not have an acid-dissociable site. 01 It is an organic group containing a fluorine atom.

[0232] The R in the above general formula (f1-1) is the same as the R in the above formula (f1).

[0233] X in the above general formula (f1-1) 01 As a divalent linking group in which there is no acid-dissociable site, the X in formula (f1) described above is 0 Similar examples include the above.

[0234] X in the above general formula (f1-1) 01 Specifically, the divalent linking group in which there is no acid-dissociable site is preferably a linear or branched aliphatic hydrocarbon group which may have substituents, or an aromatic hydrocarbon group which may have substituents, more preferably a linear or branched aliphatic hydrocarbon group which may have a fluorine atom, or an aromatic hydrocarbon group which may have substituents, and even more preferably a linear aliphatic hydrocarbon group, a branched aliphatic hydrocarbon group which has a fluorine atom, or an aromatic hydrocarbon group which may have substituents. The aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 5 carbon atoms. The aromatic hydrocarbon group which may have the substituent is preferably a group represented by **-(ArX)-O-RZ-*. In the formula, ArX is a divalent aromatic hydrocarbon group, RZ is a divalent linear or branched aliphatic hydrocarbon group, ** indicates a bond with (-O-) in formula (f1-1), and * indicates a bond with the carbon atom of -(C=O)-O- in formula (f1-1). A phenylene group is preferred as the ArX group. RZ is preferably a divalent linear aliphatic hydrocarbon group having 1 to 5 carbon atoms, and more preferably a divalent linear aliphatic hydrocarbon group having 1 to 3 carbon atoms.

[0235] Rf in the above general formula (f1-1) 01 As for Rf in equation (f1) above 0 Similar examples include fluorinated hydrocarbon groups having 1 to 6 carbon atoms, with trifluoromethyl groups, -CH2-CF3, -CH2-CH2-CF3, -CH2-CF2-CF3, and -CH(CF3)2 being more preferred, and -CH2-CF3, -CH2-CH2-CF3, and -CH(CF3)2 being even more preferred.

[0236] A preferred example of a constituent unit represented by the general formula (f1-1) is shown below. In each of the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0237] [ka]

[0238] Among the constituent units represented by the general formula (f1-1), the constituent unit represented by the formula (f1-1-2) is preferred.

[0239] ≪Constituent units represented by general formula (f1-2)≫

[0240] [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. X 021 is a cyclic group. Some or all of the hydrogen atoms of the cyclic group may be substituted with substituents. 022 Rf is a divalent linking group that does not have a single bond or an acid-dissociable site. 02 It is an organic group containing a fluorine atom.

[0241] The R in the above general formula (f1-2) is the same as the R in formula (f1) described above.

[0242] X in the above general formula (f1-2) 021 The group is a cyclic group, and some or all of the hydrogen atoms of the cyclic group may be substituted with substituents. Examples of substituents include lower alkyl groups having 1 to 5 carbon atoms, fluorine atoms, fluorinated lower alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, oxygen atoms (=O), and the like. Examples of such cyclic groups include aliphatic cyclic groups, arylene groups, and heteroarylene groups.

[0243] The aliphatic cyclic group may be a polycyclic group or a monocyclic group. A preferred monocyclic group is a monocycloalkane having 3 to 6 carbon atoms with two hydrogen atoms removed. Examples of such monocycloalkanes include cyclopentane and cyclohexane. The polycyclic group is preferably a polycycloalkane having 7 to 12 carbon atoms with two hydrogen atoms removed. Specific examples of such polycycloalkanes include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0244] A phenylene group is preferred as the arylene group. Examples of heteroarylene groups include thienylene groups and isoxazolene groups.

[0245] X in the above general formula (f1-2) 021 Among the above, an arylene group is preferred, and a phenylene group is more preferred.

[0246] X in the above general formula (f1-2) 022 As a divalent linking group in which there is no acid-dissociable site, the X in formula (f1) described above is 0 Similar examples include the above.

[0247] X in the above general formula (f1-1) 022Specifically, as the divalent linking group in which there is no acid-dissociable site, a linear or branched aliphatic hydrocarbon group which may have substituents is preferred, and a linear aliphatic hydrocarbon group which may have substituents is more preferred. The aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 5 carbon atoms. The linear aliphatic hydrocarbon group which may have substituents is preferably a group represented by **-O-RY-*. In the formula, RY is a divalent linear or branched aliphatic hydrocarbon group, ** indicates a bond with (-O-) in formula (f1-1), and * indicates a bond with the carbon atom of -(C=O)-O- in formula (f1-1). RY is preferably a divalent linear aliphatic hydrocarbon group having 1 to 5 carbon atoms, and more preferably a divalent linear aliphatic hydrocarbon group having 1 to 3 carbon atoms.

[0248] Rf in the above general formula (f1-2) 01 As for Rf in equation (f1) above 0 Similar examples include fluorinated hydrocarbon groups having 1 to 6 carbon atoms, with trifluoromethyl groups, -CH2-CF3, -CH2-CH2-CF3, -CH2-CF2-CF3, and -CH(CF3)2 being more preferred, and -CH2-CF2-CF3 being even more preferred.

[0249] The following are preferred examples of the constituent units represented by the general formula (f1-2). In each of the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0250] [ka]

[0251] <<Other constituent units>> The (F1) component may have, as necessary, other constituent units in addition to the constituent units represented by the general formula (f1-1) or the general formula (f1-2) described above. Other constituent units here include, for example, the above constituent unit (a1), the above constituent unit (a2), a constituent unit derived from acrylic acid, and a constituent unit derived from methacrylic acid.

[0252] Specifically, the (F1) component is preferably a polymer compound having a repeating structure of constituent unit (f1), more preferably a polymer compound having a repeating structure of constituent unit (f1) and a repeating structure of constituent unit (a1) or (a2), and even more preferably a polymer compound having a repeating structure of constituent unit (f1), a repeating structure of constituent unit (a1) or (a2) and a constituent unit derived from acrylic acid or methacrylic acid. More specifically, the (F1) component is preferably a polymer compound consisting of a repeating structure of constituent unit (f1); a polymer compound consisting of a repeating structure of constituent unit (f1) and a repeating structure of constituent unit (a1); a polymer compound consisting of a repeating structure of constituent unit (f1) and a repeating structure of constituent unit (a2); a polymer compound consisting of a repeating structure of constituent unit (f1), a repeating structure of constituent unit (a1), and a repeating structure of constituent unit derived from acrylic acid or methacrylic acid; more preferably a polymer compound consisting of a repeating structure of constituent unit (f1) and a repeating structure of constituent unit (a1); more preferably a polymer compound consisting of a repeating structure of constituent unit (f1), a repeating structure of constituent unit (a1), and a repeating structure of constituent unit derived from acrylic acid or methacrylic acid; and even more preferably a polymer compound consisting of a repeating structure of constituent unit (f1), a repeating structure of constituent unit (a1), and a repeating structure of constituent unit derived from acrylic acid or methacrylic acid. Here, the constituent unit (a1) copolymerized with the constituent unit (f1) is a constituent unit represented by the above general formula (a1-1), and Ra in the formula 1 However, a constituent unit that is an acid-dissociable group represented by the general formula (a0-r-1) described above is preferred. Furthermore, it is preferable that the constituent unit (f1) is a constituent unit represented by the general formula (f1-1) or (f1-2) described above.

[0253] In a polymer compound consisting of a repeating structure of constituent unit (f1) and a repeating structure of constituent unit (a1), the proportion of constituent unit (f1) is preferably 40 to 95 mol%, more preferably 50 to 90 mol%, and even more preferably 60 to 80 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. Furthermore, the proportion of constituent units (a1) 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.

[0254] In a polymer compound consisting of a repeating structure of constituent unit (f1) and a repeating structure of constituent unit (a2), the proportion of constituent unit (f1) is preferably 40 to 95 mol%, more preferably 50 to 90 mol%, and even more preferably 60 to 80 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 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.

[0255] In a polymer compound comprising a repeating structure of constituent unit (f1), a repeating structure of constituent unit (a1), and a repeating structure of constituent unit derived from acrylic acid or methacrylic acid, the proportion of constituent unit (f1) is preferably 40 to 95 mol%, more preferably 50 to 90 mol%, and even more preferably 60 to 80 mol%, relative to the total amount (100 mol%) of all constituent units constituting the polymer compound. Furthermore, the proportion of constituent units (a1) in the polymer compound is preferably 1 to 50 mol%, more preferably 5 to 40 mol%, and even more preferably 10 to 30 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. Furthermore, the proportion of constituent units derived from acrylic acid or methacrylic acid in the polymer compound is preferably 1 to 40 mol%, more preferably 1 to 30 mol%, and even more preferably 5 to 20 mol%, relative to the total amount (100 mol%) of all constituent units constituting the polymer compound.

[0256] The weight-average molecular weight (Mw) of component (F1) (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 (Mw / Mn) of component (F1) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0257] In the resist composition of this embodiment, component (F1) may be used alone or in combination of two or more types. In the resist composition of this embodiment, the content of component (F1) is preferably 0.5 to 15 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 3 to 7 parts by mass, per 100 parts by mass of component (A1). If the content of component (F1) is above the preferred lower limit mentioned above, resolution and CDU will be further improved. Furthermore, if the content of component (F1) is below the preferred upper limit mentioned above, the sensitivity will be further improved.

[0258] The resist composition of this embodiment may also include a fluororesin component (F2) that does not correspond to the above-mentioned (F1) component (hereinafter referred to as "(F2) component") as component (F), but it is preferable that the fluororesin component consists only of component (F1). One embodiment of the resist composition excludes resist compositions containing component (F2).

[0259] The proportion of component (F1) in component (F) 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, relative to the total mass of component (F). 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, resolution, and roughness improvement.

[0260] <Other ingredients> The resist composition of this embodiment may further contain other components in addition to the above-described components (A) and (F). Examples of other components include components (B), (D), (E), and (S) shown below.

[0261] ≪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.

[0262] 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)").

[0263] [ka] [In the formula, R 101 and R 104 ~R108 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.

[0264] {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.

[0265] 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 have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated.

[0266] R 101The 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.

[0267] 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.

[0268] 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.

[0269] 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.

[0270] Also, R 101 The cyclic hydrocarbon group in the 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), the -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by the chemical formulas (r-hr-1) to (r-hr-16). In the formulas, * represents Y in formula (b-1). 101 This represents a coupling that connects to something.

[0271] [ka] [In the formula, Rb' 51Each 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.

[0272] 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.

[0273] 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.

[0274] Specific examples of the groups represented by the general formulas (b5-r-1) to (b5-r-4) are given below. In the formulas, "Ac" indicates an acetyl group.

[0275] [ka]

[0276] [ka]

[0277] [ka]

[0278] [ka]

[0279] 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, chlorine, bromine, and iodine atoms, with fluorine being 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.

[0280] 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 those represented by the following formulas (r-br-1) to (r-br-2). In the formulas, * represents Y in formula (b-1). 101 This represents a coupling that connects to something.

[0281] [ka]

[0282] 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 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, 2-naphthylethyl groups, etc.), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of alicyclic hydrocarbon groups as substituents on the aforementioned 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 formulas (r-hr-7) to (r-hr-16).

[0283] 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.

[0284] 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, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0285] 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.

[0286] Among the above, R 101 The cyclic group is preferably a cyclic group which may have substituents, and more preferably a cyclic hydrocarbon group which may have substituents. Furthermore, if the cyclic group or cyclic hydrocarbon group has substituents, iodine atoms are preferred as substituents. More specifically, preferred cyclic hydrocarbon groups are phenyl groups, naphthyl groups, and 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); and -SO2-containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4). More preferably, phenyl groups and groups obtained by removing one or more hydrogen atoms from polycycloalkanes are preferred, and phenyl groups and adamantyl groups are even more preferred.

[0287] In formula (b-1), Y 101 It is a single bond or a divalent linking group 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). Note that in the following general formulas (y-al-1) to (y-al-7), R in formula (b-1) above 101 The V' in the following general formulas (y-al-1)~(y-al-7) is what combines with it. 101 That is the case.

[0288] [ka] [In the formula, V' 101 V' 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.

[0289] 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.

[0290] 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.

[0291] Y 101 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 formulas (y-al-1) to (y-al-5), and even more preferably the linking group represented by formula (y-al-1).

[0292] 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. 101 As for the fluorinated alkylene group in V101 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 the fluorinated alkylene group is a single bond or a linear chain having 1 to 4 carbon atoms.

[0293] 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.

[0294] 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).

[0295] [ka] [In the formula, R” 101 R” is an optionally substituted aliphatic cyclic group, a monovalent heterocyclic group represented by the above chemical formulas (r-hr-1) to (r-hr-6), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), an optionally substituted linear alkyl group, or an optionally substituted aromatic cyclic 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. 103 V” 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.]

[0296] 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.

[0297] R" 101 and 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.

[0298] R" 101 The chain-like alkyl 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 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.

[0299] • Anion in component (b-2) In formula (b-2), R 104 , R 105Each 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 , R 105 These may be bonded to each other 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. 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 103 These 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 either a single bond or an oxygen atom, independently of the others.

[0300] • Anion in component (b-3) In formula (b-3), R 106 ~R 108Each 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-.

[0301] Among the above, the anion in component (b-1) is preferred as the anion portion of component (B).

[0302] {cation part} In the above equations (b-1), (b-2), and (b-3), M' m+ This represents an onium cation with an m-valence. Among these, sulfonium cations and iodonium cations are preferred. m is an integer greater than or equal to 1.

[0303] Preferred cation portion ((M' m+ ) 1 / m Examples of these include organic cations represented by the following general formulas (ca-1) to (ca-3).

[0304] [ka] [In the formula, R 201 ~R 207 Each of these independently represents an aryl group, alkyl group, or alkenyl group, which may have substituents. 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. 201This represents -C(=O)- or -C(=O)-O-.

[0305] 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-7).

[0306] [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.

[0307] 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 have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated.

[0308] 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.

[0309] 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.

[0310] 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.

[0311] 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.

[0312] Also, R' 201 The cyclic hydrocarbon group in the above 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), -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by the above chemical formulas (r-hr-1) to (r-hr-16).

[0313] 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.

[0314] 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.

[0315] A chain-like alkenyl group which may have substituents: R' 201 The 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, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0316] 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.

[0317] 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.

[0318] Among them, R' 201 The cyclic 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); and -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4).

[0319] In the above general formulas (ca-1) to (ca-3), R 201 ~R 203 , 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 )-(the R Nis an alkyl group having 1 to 5 carbon atoms. ) may be bonded via functional groups such as ). The formed ring is preferably a 3 to 10-membered ring, and particularly preferably a 5 to 7-membered ring, 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, a tetrahydrothiopyranium ring, and the like.

[0320] 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 to each other to form a ring.

[0321] 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 210 In 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 above.

[0322] Specific examples of the cation represented by the above formula (ca-1) are shown below.

[0323] 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-1-70).

[0324] [ka]

[0325] [ka]

[0326] [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.]

[0327] [ka]

[0328] [ka]

[0329] [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.

[0330] Suitable cations represented by the formula (ca-2) include, specifically, diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0331] 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).

[0332] [ka]

[0333] 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 5 to 40 parts by mass, more preferably 10 to 40 parts by mass, and even more preferably 10 to 30 parts by mass, per 100 parts by mass of component (A1). (B) If the content of component (B) is above the lower limit of the preferred range described above, lithography characteristics such as sensitivity, CDU, resolution performance, and LWR (linewise roughness) reduction are further improved in resist pattern formation. On the other hand, if it is below the upper limit of the preferred range, a uniform solution is more easily obtained when each component of the resist composition is dissolved in an organic solvent, and the storage stability of the resist composition is further improved.

[0334] ≪Basic component (D)≫ The resist composition of this embodiment preferably further contains a basic component (hereinafter also referred to as "component (D)") that traps (i.e., controls the diffusion of) the acid generated by exposure. Component (D) acts as a quencher (acid diffusion 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.

[0335] • 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.

[0336] [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 single bond or a divalent linking group. m is an integer greater than or equal to M m+ These are each independently m-valent organic cations.

[0337] {(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 1Preferred substituents are optionally substituted aromatic hydrocarbon groups, optionally substituted aliphatic cyclic groups, or optionally substituted linear alkyl groups. Examples of substituents these groups may have include hydroxyl groups, oxo groups, alkyl groups, aryl groups, fluorine 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 via alkylene groups, and in this case, preferred substituents are the linking groups represented by the general formulas (y-al-1) to (y-al-5). Note that Rd 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 (d3-1) 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.

[0338] 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.

[0339] The following are some preferred specific examples of the anionic portion of component (d1-1).

[0340] [ka]

[0341] ··Cation section In formula (d1-1), M m+ This is an m-valent organic cation. M m+ Suitable organic cations include those similar to the cations represented by the general formulas (ca-1) to (ca-3), respectively, with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the general formulas (ca-1-1) to (ca-1-70) being even more preferred.

[0342] (d1-1) Component may be used alone or in combination of two or more types.

[0343] {(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 2In 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.

[0344] 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.

[0345] Rd 2 The hydrocarbon group may have substituents, and such substituents may be Rd of formula (d1-1). 1 Examples include substituents similar to those that may be present on hydrocarbon groups (aromatic hydrocarbon groups, aliphatic cyclic groups, and linear alkyl groups) in the above.

[0346] The following are preferred specific examples of the anionic portion of component (d1-2).

[0347] [ka]

[0348] ··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.

[0349] {(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.

[0350] 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. Rd 4 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.

[0351] Rd 4 The alkenyl group in R' 201Examples 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.

[0352] 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.

[0353] In formula (d1-3), Yd 1 It is a single bond or a divalent linking group. Yd 1 The divalent linking group in formula (a2-1) is not particularly limited, but may include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) which may have substituents, and divalent linking groups containing heteroatoms. 21 Examples include divalent hydrocarbon groups that may have substituents, and divalent linking groups containing heteroatoms, as mentioned in the explanation of divalent linking groups in [reference]. 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.

[0354] The following are preferred specific examples of the anionic parts of components (d1-3).

[0355] [ka]

[0356] [ka]

[0357] ··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.

[0358] 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 15 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 8 parts by mass, per 100 parts by mass of component (A1). When the content of component (D1) is above the preferred lower limit, particularly good lithography characteristics and resist pattern shape are easily obtained. On the other hand, when it is below the upper limit, good sensitivity can be maintained and throughput is also excellent.

[0359] 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, preferably 70% by mass or more, and more preferably 90% by mass or more, and component (D) may consist only of compound (d1-1).

[0360] (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.

[0361] • 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 group has 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.

[0362] 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.

[0363] 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.

[0364] Furthermore, an aromatic amine may be used as component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or their derivatives, trimenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, and 2,6-di-tert-butylpyridine.

[0365] Among the above, component (D2) is preferably an alkylamine, and more preferably a trialkylamine having 5 to 10 carbon atoms.

[0366] (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 preferred lower limit, particularly good lithography characteristics and resist pattern shape are easily obtained. On the other hand, when it is below the upper limit, good sensitivity can be maintained and throughput is also excellent.

[0367] <<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.

[0368] 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.

[0369] ≪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)"). In the resist composition of this embodiment, component (S) may be used alone or as a mixture of two or more solvents. Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether, γ-butyrolactone, diacetone alcohol, ethyl lactate (EL), and cyclohexanone are preferred.

[0370] 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 between PGMEA and the polar solvent. 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.

[0371] 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.

[0372] The resist composition of this embodiment described above contains a resin component (A1) having the above-mentioned structural unit (a01) and a fluororesin component (F1) having a structural unit represented by the general formula (f1). Since the constituent unit (a01) has both an acid-dissociable group and a phenolic hydroxyl group, the content of phenolic hydroxyl groups can be increased without reducing the content of acid-dissociable groups in the resin component (A1). Therefore, sensitivity can be improved without reducing resolution. On the other hand, since the constituent unit (a01) has a relatively hydrophobic structure, its affinity for developer and hydrophilicity are relatively low. Therefore, by combining it with a fluororesin component (F1) that has a specific constituent unit that exhibits decomposition in alkaline developers, the affinity for developer and hydrophilicity are improved, allowing the resist film to be uniformly dissolved in the alkaline development process and the water rinsing process, thereby improving CDU and further enhancing resolution. Therefore, according to the resist composition of this embodiment, it is possible to form a resist pattern that is highly sensitive and has good resolution and roughness reduction.

[0373] (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.

[0374] 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 through exposure via a mask (mask pattern) on which a predetermined pattern has been formed, or 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.

[0375] 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 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.

[0376] 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.

[0377] 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.

[0378] 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.

[0379] Examples of alkaline developers used in the alkaline development process include 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH) aqueous solution. The organic solvent contained in the organic developer solution used in the solvent development process 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.

[0380] 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.

[0381] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0382] 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.

[0383] 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).

[0384] In the solvent-based development process, the rinsing solution used for rinsing after development can contain an organic solvent that is less likely to dissolve the resist pattern, selected from among the organic solvents listed above for use in the organic developer. Typically, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. These organic solvents may be used individually or in combination of two or more. They may also be used in mixtures with other organic solvents or water.

[0385] 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).

[0386] As described above, the resist pattern formation method of this embodiment uses the above-mentioned resist composition, making it possible to form a resist pattern that is highly sensitive and has good resolution and CDU.

[0387] The resist compositions of the embodiments described above, and the various materials used in the pattern forming methods of the embodiments described above (for example, resist solvents, developers, rinse solutions, anti-reflective film forming compositions, topcoat forming compositions, etc.) are preferably free from impurities such as metals, metal salts containing halogens, acids, alkalis, sulfur atoms, or phosphorus atoms. Examples of metal atom-containing impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The impurity content in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device). [Examples]

[0388] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0389] <Preparation of the resist composition> (Examples 1-18, Comparative Examples 1-4) Each of the components shown in Tables 1-3 was mixed and dissolved to prepare the resist compositions for each example.

[0390] [Table 1]

[0391] [Table 2]

[0392] [Table 3]

[0393] In Tables 1-3, each abbreviation has the following meaning. The numbers in brackets [ ] represent the amount (parts by mass) of the ingredients.

[0394] (A) component (A) Meaning of the component abbreviations, weight-average molecular weight (Mw) and molecular weight dispersion (Mw / Mn) in standard polystyrene equivalent determined by GPC measurement, and 13 The copolymerization composition ratio (the proportion (molar ratio) of each constituent unit in the structural formula) determined by 13C-NMR is shown below.

[0395] (A1)-1: A polymer compound represented by the following chemical formula (A1-1). The weight-average molecular weight (Mw) of polymer compound (A1-1) is 6600, and the molecular weight dispersion (Mw / Mn) is 1.56. (A1)-2: A polymer compound represented by the following chemical formula (A1-2). The weight-average molecular weight (Mw) of polymer compound (A1-2) is 6400, and the molecular weight dispersion (Mw / Mn) is 1.57. (A1)-3: A polymer compound represented by the following chemical formula (A1-3). The weight-average molecular weight (Mw) of polymer compound (A1-3) is 6500, the molecular weight dispersion (Mw / Mn) is 1.63, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 50 / 50. (A1)-4: A polymer compound represented by the following chemical formula (A1-4). The weight-average molecular weight (Mw) of polymer compound (A1-4) is 6800, the molecular weight dispersion (Mw / Mn) is 1.67, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 50 / 50. (A1)-5: A polymer compound represented by the following chemical formula (A1-5). The weight-average molecular weight (Mw) of polymer compound (A1-5) is 6900, the molecular weight dispersion (Mw / Mn) is 1.60, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 50 / 50. (A1)-6: A polymer compound represented by the following chemical formula (A1-6). The weight-average molecular weight (Mw) of polymer compound (A1-6) is 6800, the molecular weight dispersion (Mw / Mn) is 1.62, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 50 / 50. (A1)-7: A polymer compound represented by the following chemical formula (A1-7). The weight-average molecular weight (Mw) of polymer compound (A1-7) is 7200, the molecular weight dispersion (Mw / Mn) is 1.68, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 50 / 50.

[0396] [ka]

[0397] (A1)-8: A polymer compound represented by the following chemical formula (A1-8). The weight-average molecular weight (Mw) of polymer compound (A1-8) is 6800, and the molecular weight dispersion (Mw / Mn) is 1.58. The copolymerization ratio (the proportion (molar ratio) of each constituent unit in the structural formula) is l / m = 50 / 50. (A1)-9: A polymer compound represented by the following chemical formula (A1-9). The weight-average molecular weight (Mw) of polymer compound (A1-9) is 6800, the molecular weight dispersion (Mw / Mn) is 1.71, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m / n = 50 / 30 / 20. (A2)-1: A polymer compound represented by the chemical formula (A2-1) shown below. The weight-average molecular weight (Mw) of polymer compound (A2-1) is 6600, the molecular weight dispersion (Mw / Mn) is 1.66, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 50 / 50.

[0398] [ka]

[0399] (B)-1: An acid generator consisting of a compound represented by the following chemical formula (B-1). (D)-1: An acid diffusion control agent consisting of a compound represented by the following chemical formula (D-1).

[0400] [ka]

[0401] (F1)-1: A polymer compound represented by the chemical formula (F1-1) shown below. The weight-average molecular weight (Mw) of polymer compound (F1-1) is 15000, the molecular weight dispersion (Mw / Mn) is 1.70, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 70 / 30. (F1)-2: A polymer compound represented by the following chemical formula (F1-2). The weight-average molecular weight (Mw) of polymer compound (F1-2) is 15000, the molecular weight dispersion (Mw / Mn) is 1.70, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 70 / 30. (F1)-3: A polymer compound represented by the following chemical formula (F1-3). The weight-average molecular weight (Mw) of polymer compound (F1-3) is 15000, the molecular weight dispersion (Mw / Mn) is 1.70, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 70 / 30. (F1)-4: A polymer compound represented by the following chemical formula (F1-4). The weight-average molecular weight (Mw) of polymer compound (F1-4) is 15000, the molecular weight dispersion (Mw / Mn) is 1.70, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 70 / 30.

[0402] [ka]

[0403] (F1)-5: A polymer compound represented by the following chemical formula (F1-5). The weight-average molecular weight (Mw) of polymer compound (F1-5) is 15000, the molecular weight dispersion (Mw / Mn) is 1.70, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m / n = 70 / 20 / 10. (F1)-6: A polymer compound represented by the following chemical formula (F1-6). The weight-average molecular weight (Mw) of polymer compound (F1-6) is 15000, the molecular weight dispersion (Mw / Mn) is 1.70, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 70 / 30. (F1)-7: A polymer compound represented by the following chemical formula (F1-7). The weight-average molecular weight (Mw) of polymer compound (F1-7) is 15000, the molecular weight dispersion (Mw / Mn) is 1.70, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 70 / 30. (F1)-8: A polymer compound represented by the following chemical formula (F1-8). The weight-average molecular weight (Mw) of polymer compound (F1-8) is 15000, the molecular weight dispersion (Mw / Mn) is 1.70, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 70 / 30.

[0404] [ka]

[0405] (F1)-9: A polymer compound represented by the following chemical formula (F1-9). The weight-average molecular weight (Mw) of polymer compound (F1-9) is 15000, the molecular weight dispersion (Mw / Mn) is 1.70, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 70 / 30. (F1)-10: A polymer compound represented by the following chemical formula (F1-10). The weight-average molecular weight (Mw) of polymer compound (F1-10) is 15000, the molecular weight dispersion (Mw / Mn) is 1.70, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m / n = 70 / 20 / 10. (F2)-1: A polymer compound represented by the chemical formula (F2-1) shown below. The weight-average molecular weight (Mw) of polymer compound (F2-1) is 15000, the molecular weight dispersion (Mw / Mn) is 1.70, and the copolymerization composition ratio (proportion of each constituent unit in the structural formula (molar ratio)) is l / m = 70 / 30.

[0406] [ka]

[0407] (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / ethyl lactate / diacetone alcohol = 45 / 25 / 15 / 15 (mass ratio).

[0408] <Resist pattern formation> 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 a JEOL-JBX-9300FS electron beam lithography system (manufactured by JEOL Ltd.) at an acceleration voltage of 100kV to create a contact hole pattern (hereinafter referred to as the "CH pattern") in which holes with a diameter of 32nm were arranged at equal intervals (pitch of 64nm). Subsequently, a 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.). After that, a water rinse was performed with pure water for 15 seconds. As a result, a CH pattern was formed in which holes with a diameter of 32 nm were arranged at equal intervals (pitch of 64 nm).

[0409] [Evaluation of optimal exposure (Eop)] The optimal exposure amount Eop(μC / cm²) for forming a CH pattern of the target size by the resist pattern formation method described above is 2 The results were calculated. The results are shown in Tables 4 and 5.

[0410] [Evaluation of in-plane uniformity (CDU) of pattern dimensions] The CH pattern formed by the above <resist pattern formation> was observed from above using a measuring SEM (scanning electron microscope, acceleration voltage 800V, product name: S-9380, Hitachi High-Tech Corporation), and the hole diameter (nm) of each hole was measured. Then, the value of three times the standard deviation (σ) calculated from the measurement results (3σ) was determined. The results are shown in Tables 4 and 5 as "CDU (nm)". The smaller the 3σ value obtained in this way, the higher the uniformity of the dimensions (CD) of the multiple holes formed in the resist film.

[0411] [Evaluation of limiting resolution] The critical resolution at the optimal exposure dose (Eop) for forming the CH pattern described above, specifically the hole diameter (nm) of the pattern that is resolved when gradually decreasing the exposure dose from the optimal exposure dose (Eop) to form the CH pattern, was determined using a scanning electron microscope S-9380 (Hitachi High-Tech Corporation). The results are shown in Tables 4 and 5.

[0412] [Table 4]

[0413] [Table 5]

[0414] As shown in Tables 4 and 5, the resist compositions of the examples were found to have improved sensitivity while also exhibiting good resolution and CDU compared to the resist compositions of the comparative examples.

Claims

1. A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, A resin component (A1) whose solubility in the developer changes due to the action of acid, It contains a fluorine additive component (F) that exhibits decomposition in an aqueous solution of tetramethylammonium hydroxide at a concentration of 0.1% by mass or more, The resin component (A1) has a constituent unit (a01) derived from a compound represented by the following general formula (a0-1), The fluorine additive component (F) is a resist composition comprising a fluororesin component (F1) having a constituent unit represented by the following general formula (f1). 【Chemistry 1】 [In the formula, W ０１ This is a polymerizable group-containing group. ０１ It is a single bond or a divalent linking group. Ra ０１ [where n is an acid-dissociating group; q is an integer between 0 and 3; n is an integer greater than or equal to 1, where n ≤ q × 2 + 4] 【Chemistry 2】 [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. X ０ Rf is a divalent linking group that does not have an acid-dissociable site. ０ It is an organic group containing a fluorine atom.

2. The resist composition according to claim 1, wherein the fluororesin component (F1) has a constituent unit represented by the following general formula (f1-1). 【Transformation 3】 [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. X ０１ Rf is a divalent linking group that does not have an acid-dissociable site. ０１ It is an organic group containing a fluorine atom.

3. The resist composition according to claim 1, wherein the fluororesin component (F1) has a constituent unit represented by the following general formula (f1-2). 【Chemistry 4】 [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X ０２１ is a cyclic group. Some or all of the hydrogen atoms of the cyclic group may be substituted with substituents. X ０２２ is a divalent linking group having no single bond or acid dissociable site. Rf ０２ is an organic group having a fluorine atom. ]

4. The resist composition according to claim 1, wherein the fluororesin component (F1) further comprises a constituent unit (a1) that includes an acid-degradable group whose polarity increases upon the action of an acid.

5. The resist composition according to claim 1, wherein the constituent unit (a01) is a constituent unit represented by the following general formula (a0-1-1). 【Transformation 5】 [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. Ya ００１ It is a single bond or a divalent linking group. ０１ It is a single bond or a divalent linking group. Rax ０１ is an acid-dissociable group represented by the following general formulas: (a0-r-1), (a0-r-2), or (a0-r-3). q is an integer between 0 and 3. n is an integer greater than or equal to 1, where n ≤ q × 2 + 4. 【Transformation 6】 [In formula (a0-r-1), Ra ０１ and Ra ０２ Each of these is independently a hydrogen atom or an alkyl group. Ra ０３ It is a hydrocarbon group, Ra ０１ or Ra ０２ It may combine with any of the following to form a ring. * indicates a bonding hand. In formula (a0-r-2), Ra ０４ ~Ra ０６ Each of these is independently a hydrocarbon group, and Ra ０５ and Ra ０６ These elements may join together to form a ring. * indicates a bonding hand. In formula (a0-r-3), Ra ０７ It is a hydrocarbon group. Ra ０８ａ and Ra ０８ｂ Each of these is independently a hydrogen atom, a halogen atom, or an alkyl group. Ra ０９ is a hydrogen atom or a hydrocarbon group. Ra ０７ and Ra ０８ａ or Ra ０８ｂ These may be joined together to form a ring. ０８ａ or Ra ０８ｂ And, Ra ０９ These may be joined together to form a ring. * indicates a bonding hand.

6. A method for forming a resist pattern, comprising the steps of: forming a resist film on a support using the resist composition described in claim 1; exposing the resist film; and developing the exposed resist film to form a resist pattern.

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

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