Resist composition and method for forming a resist pattern

Abstract

To provide a resist composition which achieves higher sensitivity, suppresses film thickness loss, and is excellent in roughness reduction, and a resist pattern forming method using the resist composition.SOLUTION: The resist composition contains: a resin component which has a constituent unit (a01) having a polycyclic lactone-containing cyclic group and a constituent unit (a02) represented by general formula (a0-2); and a compound (B0) represented by general formula (b0). In the formulae, Ra05-Ra08 each independently represent a hydrogen atom or the like; X0 represents a bromine atom or an iodine atom; Rm represents a hydroxy group or the like; 1≤nb1+nb2≤5; Yb0 represents a divalent linking group or a single bond; Vb0 represents a single bond or the like; R0 represents a hydrogen atom or the like; Mm+ represents an m-valent organic cation; and m represents an integer of 1 or more.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 using shorter wavelengths (higher energy) exposure light sources.

[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 multiple constituent units are generally used to improve lithography properties and other characteristics. Furthermore, in the formation of resist patterns, the behavior of acids generated from acid-generating agent components upon exposure is also considered a significant factor influencing lithography characteristics. A wide variety of acid generators have been proposed for use in chemically amplified resist compositions. For example, onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators are known.

[0005] For example, Patent Document 1 discloses a resist composition containing a resin comprising a structural unit having a hydroxystyrene skeleton, a structural unit having a non-crosslinked lactone, and a structural unit having a specific acid-dissociable group, and an onium salt-based acid generator. This resist composition is disclosed to improve affinity to the developer, thereby improving sensitivity, roughness reduction, and resolution. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-085916 [Overview of the project] [Problems that the invention aims to solve]

[0007] 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 the dimensions of the resist patterns become smaller, a reduction in roughness and high sensitivity to the exposure light source are required. Therefore, conventionally, resins containing structural units derived from parahydroxystyrene, which can improve acid generation efficiency as a proton source, as described in Patent Document 1, have been used. On the other hand, resins containing these structural units have high solubility in developing solutions, which leads to the problem of thin film thickness in the unexposed areas after development. Since the film thickness in the unexposed areas after development affects etching resistance, maintaining the film thickness in the unexposed areas is a challenge.

[0008] 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, has reduced film loss and good roughness reduction, and a resist pattern formation method using the resist composition. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention adopts the following configuration. That is, a first aspect of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, containing a resin component (A1) whose solubility in a developer changes due to the action of the acid, and an acid generator component (B) that generates an acid upon exposure, wherein the resin component (A1) has a structural unit (a01) represented by the following general formula (a0-1) and a structural unit (a02) represented by the following general formula (a0-2), and the acid generator component (B) contains a compound (B0) represented by the following general formula (b0).

[0010] [Chemical formula] [In the formula, R 01 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya 01 is a single bond or a divalent linking group. La 01 is -O-, -COO-, -CON(R’)-, -OCO-, -CONHCO-, or -CONHCS-, and R’ represents a hydrogen atom or a methyl group. However, when La 01 is -O-, Ya 01 is not -CO-. Ra 01 is a polycyclic lactone-containing cyclic group.]

[0011] [Chemical formula] [In formula (a0-2), R 02 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ra 05 to Ra 08 are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Ra 05 to Ra 08 may be bonded to each other to form an aliphatic cyclic structure.]

[0012] [Chemical formula] [where, X 0 R is a bromine atom or an iodine atom. m nb1 is an integer between 1 and 5, nb2 is an integer between 0 and 4, and 1 ≤ nb1 + nb2 ≤ 5. 0 This is a divalent linking group or a single bond. Vb 0 R is a single bond, an alkylene group, or a fluorinated alkylene group. 0 This is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. m+ This represents an m-valent organic cation, where m is an integer greater than or equal to 1.

[0013] 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]

[0014] According to the present invention, it is possible to provide a resist composition that achieves high sensitivity, suppresses film loss, and has good roughness reduction properties, as well as a resist pattern formation method using the resist composition. [Modes for carrying out the invention]

[0015] 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.

[0016] 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).

[0017] 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.

[0018] 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).

[0019] "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.

[0020] The term "derivative" refers to a compound in which the α-position hydrogen atom of the target compound is substituted with another substituent such as an alkyl group or alkyl halide, as well as derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound (which may have the α-position hydrogen atom substituted with a substituent) is substituted with an organic group; and those in which a substituent other than a hydroxyl group is bonded to the target compound (which may have the α-position hydrogen atom substituted with a substituent). Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. As substituents that substitute the hydrogen atom at the α-position of hydroxystyrene, R αx Similar examples include the above.

[0021] In this specification and in the claims, depending on the structure represented by the chemical formula, an asymmetric carbon may be present, and enantioisomers or diastereomers may exist. In such cases, a single chemical formula will represent all of these isomers. These isomers may be used individually or as a mixture.

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

[0023] When a resist film is formed using the resist composition of this embodiment and selective exposure is performed on the resist film, acid is generated from component (B) in the exposed areas of the resist film. 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] In this specification, a resist composition in which the exposed portion of the resist film is dissolved and removed to form a positive-type resist pattern is referred to as a positive-type resist composition, and a resist composition in which the unexposed portion of the resist film is dissolved and removed to form a negative-type resist pattern is referred to as a negative-type resist composition. 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 using an alkaline developer in the development process during resist pattern formation, or for a solvent development process using a developer containing an organic solvent (organic developer) in 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 that 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] When an alkaline development process is applied, the substrate component containing component (A1) is poorly soluble in the alkaline developer before exposure. For example, when acid is generated from component (B) upon exposure, the polarity increases due to the action of the acid, and the solubility in the alkaline developer increases. Therefore, when a resist film obtained by coating the resist composition onto a support is selectively exposed during the formation of a resist pattern, the exposed parts of the resist film change from poorly soluble to soluble in the alkaline developer, while the unexposed parts of the resist film remain poorly soluble in the alkali. Thus, a positive-type resist pattern is formed by alkaline development.

[0027] On the other hand, when a solvent development process is applied, the substrate component containing component (A1) is highly soluble in organic developer before exposure. When acid is generated from component (B) upon exposure, the polarity increases due to the action of the acid, and the solubility in organic developer decreases. Therefore, when selectively exposing the resist film obtained by coating the resist composition onto a support during the formation of a resist pattern, the exposed parts of the resist film change from soluble to poorly soluble in organic developer, while the unexposed parts of the resist film remain soluble. Thus, by developing with an organic developer, a contrast can be created between the exposed and unexposed parts, and a negative-type resist pattern is formed.

[0028] In the resist composition of this embodiment, component (A) may be used alone or in combination of two or more types.

[0029] (A1) About the ingredients Component (A1) is a resin component whose solubility in the developer changes due to the action of acid. Component (A1) comprises a constituent unit (a01) represented by the above general formula (a0-1) and a constituent unit (a02) represented by the above general formula (a0-2).

[0030] <Component Unit (a01)> The constituent unit (a01) is a constituent unit represented by the following general formula (a0-1).

[0031] [ka] [In the formula, R 01 This is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. 01 It is a single bond or a divalent linking group. 01 The group is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. However, La 01 If -O-, Ya 01 It does not become -CO-. 01 It is a polycyclic lactone-containing cyclic group.

[0032] In the above general formula (a0-1), R 01 This is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. R 01 The alkyl group having 1 to 5 carbon atoms 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. R 01 The C1-C5 alkyl halide in this context 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 01 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. More preferably, due to their industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is preferred, a hydrogen atom or a methyl group is even more preferred, and a methyl group is particularly preferred.

[0033] In the above general formula (a0-1), Ya 01The 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.

[0034] • Divalent hydrocarbon groups which may have substituents: Ya 01 If is a divalent hydrocarbon group which may have substituents, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0035] ··Ya 01 Aliphatic hydrocarbon groups in An 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 preferable 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.

[0036] ...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.

[0037] The linear or branched aliphatic hydrocarbon group 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.

[0038] ...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 obtained by removing two hydrogen atoms 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.

[0039] 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 more 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 even more preferred. A fluorine atom is preferred as the halogen atom used as the substituent. 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-.

[0040] ··Ya 01 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. 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. 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.

[0041] 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, hydroxyl groups, and the like. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more 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 halides that substitute for hydrogen atoms on the cyclic aliphatic hydrocarbon group.

[0042] • Divalent linking groups containing heteroatoms: Ya 01 When is a divalent linking group containing a heteroatom, preferred linking groups include -O-, -C(=O)-O-, -OC(=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 -Y 021 -OY 022 -, -Y 021 -O-, -Y 021 -C(=O)-O-, -C(=O)-OY 021 -,-[Y 021 -C(=O)-O] m” -Y 022 -, -Y 021 -OC(=O)-Y 022 - or -Y 021 -S(=O)2-OY 022 - is represented by the base [wherein Y 021 and Y 022 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 divalent linking group containing the 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 021 -OY022 -, -Y 021 -O-, -Y 021 -C(=O)-O-, -C(=O)-OY 021 -,-[Y 021 -C(=O)-O] m” -Y 022 -, -Y 021 -OC(=O)-Y 022 - or -Y 021 -S(=O)2-OY 022 - Middle, Y 021 and Y 022 Each of these is independently a divalent hydrocarbon group which may have substituents. The divalent hydrocarbon group is the aforementioned Ya 01 Examples include those similar to the divalent linking groups (divalent hydrocarbon groups that may have substituents) mentioned in the description of divalent linking groups in [the relevant section]. Y 021 Preferably, 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 022 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 021 -C(=O)-O] m” -Y 022 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 021 -C(=O)-O] m” -Y 022 As a base represented by -, formula -Y 021 -C(=O)-OY 022 Groups represented by - are particularly preferred. Among them, the group represented by formula -(CH2) a’ -C(=O)-O-(CH2) b’The group represented by - is preferred. In this formula, a' is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, still 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, still more preferably 1 or 2, and most preferably 1.

[0043] Among the above, Ya 01 is preferably a single bond, -COO-, -OCO-, -O-, a linear or branched alkylene group, or a combination thereof, and more preferably a single bond, -COO-, or a combination of -COO- and a linear or branched alkylene group.

[0044] In the general formula (a0-1) above, La 01 is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO- or -CONHCS-, and R' represents a hydrogen atom or a methyl group. However, when La 01 is -O-, Ya 01 will not be -CO-. In the general formula (a0-1) above, La 01 is preferably -COO- or -OCO- among the above, and more preferably -COO-.

[0045] In the general formula (a0-1) above, Ra 01 is a polycyclic lactone-containing cyclic group. The "polycyclic lactone-containing cyclic group" is a polycyclic cyclic group containing a ring (lactone ring) containing -O-C(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and it further has other ring structures. In the general formula (a0-1) above, Ra 01 The polycyclic lactone-containing cyclic group in is preferably a polycyclic lactone-containing cyclic group represented by any of the following general formulas (a01-r-1) to (a01-r-6).

[0046]

Chemical formula

[0047] In the general formulas (a01-r-1) to (a01-r-6), Ra’ 21 As the alkyl group in, an alkyl group having 1 to 6 carbon atoms is preferable. The alkyl group is preferably linear or branched. 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, a hexyl group and the like can be mentioned. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable. Ra’ 21 As the alkoxy group in, an alkoxy group having 1 to 6 carbon atoms is preferable. The alkoxy group is preferably linear or branched. Specifically, a group in which the alkyl group mentioned as the alkyl group in the above Ra’ 21 is linked to an oxygen atom (-O-) can be mentioned. Ra’ 21 As the halogen atom in, a fluorine atom is preferable. Ra’ 21 As the halogenated alkyl group in, a group in which part or all of the hydrogen atoms of the alkyl group in the above Ra’ 21 is substituted with the halogen atom can be mentioned. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

[0048] Ra’ 21In -COOR'' and -OC(=O)R'', R'' is either a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2--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.

[0049] 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.

[0050] Examples of lactone-containing cyclic groups in R'' include groups similar to those represented by any of the general formulas (a01-r-1) to (a01-r-6) above, as well as monocyclic lactone-containing cyclic groups (for example, groups with a γ-butyrolactone structure).

[0051] In R'', a carbonate-containing cyclic group refers to a cyclic group that contains a ring (carbonate ring) containing -OC(=O)-O- within its cyclic framework. The carbonate ring is counted as the first ring. If it consists only of a carbonate 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 carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. Specifically, carbonate ring-containing cyclic groups include those represented by the general formulas (ax3-r-1) to (ax3-r-3), which will be described later. In R'', a -SO2-containing cyclic group refers to a cyclic group that contains a ring with -SO2- in its cyclic skeleton. Specifically, it is a cyclic group in which the sulfur atom (S) in -SO2- forms part of the cyclic skeleton. The ring containing -SO2- in its cyclic skeleton is counted as the first ring. If it consists only of this ring, it is called a monocyclic group; if it has other ring structures, it is called a polycyclic group regardless of its structure. A -SO2-containing cyclic group may be a monocyclic group or a polycyclic group.

[0052] The -SO2--containing cyclic group is preferably a cyclic group that contains -O-SO2- in its cyclic skeleton, that is, a cyclic group that contains a sultone ring in which the -OS- in -O-SO2- forms part of the cyclic skeleton. Specifically, examples of -SO2- containing cyclic groups include the groups represented by the general formulas (a5-r-1) to (a5-r-4), which will be described later.

[0053] 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.

[0054] In the above general formulas (a01-r-1) to (a01-r-6), Ra' 21 Among the above, it is preferable that each is independently a hydrogen atom or a cyano group.

[0055] In the above general formulas (a01-r-1) to (a01-r-6), n01 is an integer between 0 and 3, and is preferably 0 or 1.

[0056] In the general formulas (a01-r-1), (a01-r-2), and (a01-r-4), as the alkylene group having 1 to 5 carbon atoms in A”, a linear or branched alkylene group is preferable, and examples thereof include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, and the like. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is interposed at the terminal or between carbon atoms of the alkylene group, and examples thereof include -O-CH2-, -CH2-O-CH2-, -S-CH2-, -CH2-S-CH2-, and the like. Among the above, as A”, an alkylene group having 1 to 5 carbon atoms or -O- is preferable, and a methylene group or -O- is more preferable.

[0057] Specific examples of the groups represented by the general formulas (a01-r-1) to (a01-r-6) are given below.

[0058] [Chemical formula]

[0059] [Chemical formula]

[0060] Among the above, the constitutional unit (a01) is preferably a constitutional unit represented by the following general formula (a0-1-1).

[0061] [Chemical formula] [In the formula, R 01 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 01 is a divalent linking group. n a01 is an integer of 0 to 2. Ra’ 21is an alkyl group, alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, -COOR'', -OC(=O)R'', hydroxyalkyl group, or cyano group; R'' is a hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or -SO2--containing cyclic group. n01 is an integer from 0 to 3. 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.

[0062] In the above general formula (a0-1-1), R 01 , Ra' 21 n01 and A'' are R in the general formula (a0-1) described above. 01 , Ra' 21 These are identical to n01 and A'', respectively.

[0063] In the above general formula (a0-1-1), Va 01 This is a divalent linking group, and Ya in the general formula (a0-1) described above 01 Similar examples include the above. Va 01 Among these, it is preferably a linear or branched alkylene group having 1 to 5 carbon atoms, more preferably a linear alkylene group having 1 to 3 carbon atoms, and even more preferably a methylene group.

[0064] In the above general formula (a0-1-1), n a01 This is an integer between 0 and 2, preferably 0 or 1.

[0065] The following are suitable examples of constituent units (a01). In each of the following formulas, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0066] [ka]

[0067] 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 1 to 70 mol%, more preferably 1 to 60 mol%, even more preferably 5 to 50 mol%, and particularly preferably 10 to 40 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 (a01) to above the lower limit of the preferred range described above, the reduction of roughness is further improved. On the other hand, if it is below the upper limit of the preferred range described above, a balance can be achieved with the other constituent units, resulting in better various lithography characteristics.

[0068] <Component unit (a02)> The constituent unit (a02) is a constituent unit represented by the following general formula (a0-2).

[0069] [ka] [In formula (a0-2), R 02 Ra is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. 05 ~Ra 08 Each of these is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. 05 ~Ra 08 Two or more of these may be bonded to each other to form an aliphatic cyclic structure.

[0070] In the above general formula (a0-2), R 02 This is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. R 02 The alkyl group having 1 to 5 carbon atoms 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. R 02The C1-C5 alkyl halide in this context 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 02 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. More preferably, due to their industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is preferred, a hydrogen atom or a methyl group is even more preferred, and a methyl group is particularly preferred.

[0071] In the above general formula (a0-2), Ra 05 ~Ra 08 Each of these is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. 05 ~Ra 08 The alkyl group in is the above R 02 Examples include alkyl groups similar to those exemplified above.

[0072] In the above general formula (a0-2), Ra 05 ~Ra 08 Two or more of these may be bonded to each other to form an aliphatic cyclic structure. That is, Ra 05 ~Ra 08 Two or more of these may bond with each other to form a fused ring with the benzene ring in the general formula (a0-2) above. However, it is preferable that no cross-linking structure is formed. For example, Ra 05 And, Ra 06 and are combined with each other, or Ra 06 And, Ra 07 These may be bonded to each other to form a monocyclic aliphatic cyclic structure. Specifically, Ra 05 And, Ra 06 and are combined with each other, or Ra 06 And, Ra 07 These may bond with each other to form a tetraline structure together with the benzene ring in formula (a0-2).

[0073] In the above general formula (a0-2), Ra 05 ~Ra 08Among the above, each is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably both are hydrogen atoms.

[0074] The proportion of constituent units (a02) in component (A1) is preferably 1 to 70 mol%, more preferably 1 to 60 mol%, even more preferably 5 to 50 mol%, and particularly preferably 10 to 40 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 (a02) to above the lower limit of the preferred range described above, the reduction in film loss is further improved. On the other hand, if it is below the upper limit of the preferred range described above, a balance can be achieved with the other constituent units, resulting in better various lithography characteristics.

[0075] <<Other constituent units>> Component (A1) may have other constituent units in addition to the constituent units (a01) and (a02) described above, as needed. Other constituent units include, for example, a constituent unit containing an acid-degradable group whose polarity increases with the action of an acid (a1); a constituent unit containing a monocyclic lactone-containing cyclic group, a -SO2--containing cyclic group, or a carbonate-containing cyclic group (a2); a constituent unit containing a polar group-containing aliphatic hydrocarbon group (a3); a constituent unit containing an acid-nondissociable aliphatic cyclic group (a4); a constituent unit represented by the following general formula (a10-1) (a10); and a constituent unit derived from styrene or a styrene derivative (st).

[0076] <Constituent unit (a1)> The constituent unit (a1) is a constituent unit that contains an acid-degradable group whose polarity increases upon the action of an acid.

[0077] Examples of acid-dissociable groups include those previously proposed as acid-dissociable groups for base resins used in chemically amplified resist compositions. Specifically, proposed acid-dissociable groups for base resins used in chemically amplified resist compositions include the following: "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," and "tertiary alkyloxycarbonyl acid-dissociable groups."

[0078] Acetal type acid dissociable group: Examples of acid-dissociable groups that protect a carboxyl group or a hydroxyl group among the aforementioned polar groups include the acid-dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid-dissociable group").

[0079] [ka] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. 3 Ra' is a hydrocarbon group. 3 Ra' 1 , Ra' 2 It may combine with any of the following to form a ring.

[0080] In formula (a1-r-1), Ra' 1 and Ra' 2 Preferably, at least one of them is a hydrogen atom, and more preferably, both are hydrogen atoms. Ra' 1 Or Ra' 2 If the alkyl group is an alkyl group, the alkyl group can be the same as those listed in the description of the α-substituted acrylic acid ester above as substituents that may be bonded to the carbon atom at the α position, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, linear or branched alkyl groups are preferred. More specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc., with methyl group or ethyl group being more preferred, and methyl group being particularly preferred.

[0081] In formula (a1-r-1), Ra' 3 Examples of hydrocarbon groups include linear or branched alkyl groups, or cyclic hydrocarbon groups. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. Among these, methyl group, ethyl group, or n-butyl group is preferred, and methyl group or ethyl group is more preferred.

[0082] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0083] Ra' 3 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a polycycloalkane from which one hydrogen atom has been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0084] Ra' 3 When the cyclic hydrocarbon group becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced by heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of aromatic heterocycles include pyridine rings and thiophene rings. Ra' 3 Specific examples of aromatic hydrocarbon groups in this context include: a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0085] Ra' 3 The cyclic hydrocarbon group in may have substituents. Examples of substituents include -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (These substituents are collectively referred to as "Ra")x5 It is also called "[...]." Examples include [...]. Here, R P1 This is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Also, R P2 This refers to a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, R P1 and R P2 Some or all of the hydrogen atoms in the chain-like saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of the substituents individually, or it may have one or more of each of the substituents. Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl, tricyclo[5.2.1.02,6]decanyl, tricyclo[3.3.1.13,7]decanyl, tetracyclo[6.2.1.13,6.02,7]dodecanyl, and adamantyl groups. Examples of monovalent aromatic hydrocarbon groups with 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring, such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0086] Ra' 3 However, Ra' 1 , Ra' 2When 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.

[0087] Tertiary alkyl ester type acid-dissociating group: Among the polar groups mentioned above, an example of an acid-dissociating group that protects a carboxyl group is the acid-dissociating group represented by the following general formula (a1-r-2). Furthermore, among the acid-dissociable groups represented by the following formula (a1-r-2), those composed of alkyl groups may, for convenience, be referred to below as "tertiary alkyl ester type acid-dissociable groups."

[0088] [ka] [In the formula, Ra' 4 ~Ra' 6 Each of these is a hydrocarbon group, Ra' 5 , Ra' 6 They may be joined to each other to form a ring.

[0089] Ra' 4 Examples of hydrocarbon groups include linear or branched alkyl groups, linear or cyclic alkenyl groups, or cyclic hydrocarbon groups. Ra' 4 In the above, linear or branched alkyl groups, cyclic hydrocarbon groups (monocyclic aliphatic hydrocarbon groups, polycyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups) are defined as Ra' 3 Similar examples include the above. Ra' 4 The linear or cyclic alkenyl group in this is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 The hydrocarbon group is the aforementioned Ra' 3 Similar examples include the above.

[0090] Ra' 5 and Ra'6 When these groups bond to each other to form a ring, the following groups are preferred: the group represented by the general formula (a1-r2-1), the group represented by the general formula (a1-r2-2), and the group represented by the general formula (a1-r2-3). Meanwhile, Ra' 4 ~Ra' 6 When these are independent hydrocarbon groups that are not bonded to each other, the groups represented by the following general formula (a1-r2-4) are preferred.

[0091] [ka] [In formula (a1-r2-1), Ra' 10 This represents a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups. 11 Ra' 10 This indicates a group that forms an aliphatic cyclic group with a bonded carbon atom. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. 101 ~Ra 103 Each of these is independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in these linear saturated hydrocarbon groups and aliphatic cyclic saturated hydrocarbon groups may be substituted. 101 ~Ra 103 Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra 104 is an aromatic hydrocarbon group which may have substituents. In formula (a1-r2-4), Ra' 12 and Ra' 13 Each of these is independently a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. 14This is a hydrocarbon group that may have substituents. * indicates a bond.

[0092] In the above equation (a1-r2-1), Ra' 10 This is a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with halogen atoms or heteroatom-containing groups.

[0093] Ra' 10 In this context, the linear alkyl group has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra' 10 In this, the branched alkyl group is the Ra' 3 Similar examples include the above.

[0094] Ra' 10 In this case, the alkyl group may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Also, some of the carbon atoms constituting the alkyl group (such as a methylene group) may be substituted with a heteroatom-containing group. Examples of heteroatoms used here include oxygen atoms, sulfur atoms, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, -S(=O)2-O-, etc.

[0095] Ra' 10 Among the above, linear or branched alkyl groups having 1 to 5 carbon atoms are preferred, and linear or branched alkyl groups having 1 to 3 carbon atoms are more preferred.

[0096] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed with the bonded carbon atom is Ra' in formula (a1-r-1). 3The aliphatic hydrocarbon groups (alicyclic hydrocarbon groups) listed above, which are monocyclic or polycyclic groups, are preferred, and among them, cyclopentyl, cyclohexyl, and adamantyl groups are more preferred, with cyclopentyl and adamantyl groups being even more preferred.

[0097] In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya is Ra' in formula (a1-r-1). 3 Examples include groups obtained by further removing one or more hydrogen atoms from a cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group). The cyclic hydrocarbon group formed by Xa and Ya may have substituents. Examples of such substituents include the above-mentioned Ra' 3 Examples include substituents similar to those that may be present on the cyclic hydrocarbon group in the above. In formula (a1-r2-2), Ra 101 ~Ra 103 Examples of monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, and decyl groups. Ra 101 ~Ra 103 Examples of monovalent aliphatic cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, and cyclododecyl groups; and polycyclic aliphatic saturated hydrocarbon groups such as bicyclo[2.2.2]octanyl, tricyclo[5.2.1.02,6]decanyl, tricyclo[3.3.1.13,7]decanyl, tetracyclo[6.2.1.13,6.02,7]dodecanyl, and adamantyl groups. Ra 101 ~Ra 103 Of these, from the viewpoint of ease of synthesis, hydrogen atoms and monovalent chain saturated hydrocarbon groups having 1 to 10 carbon atoms are preferred, and among these, hydrogen atoms, methyl groups, and ethyl groups are more preferred, with hydrogen atoms being particularly preferred.

[0098] The above Ra101 ~Ra 103 Examples of substituents on a chain-like saturated hydrocarbon group or an aliphatic cyclic saturated hydrocarbon group represented by the above-mentioned Ra x5 Similar bases can be cited.

[0099] Ra 101 ~Ra 103 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.

[0100] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Ra' in formula (a1-r-1). 3 The aliphatic hydrocarbon groups listed above, which are monocyclic or polycyclic groups, are preferred. In formula (a1-r2-3), Ra 104 Aromatic hydrocarbon groups in this context include groups obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring with 5 to 30 carbon atoms. Among them, Ra 104 The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms with one or more hydrogen atoms removed; more preferably a group from benzene, naphthalene, anthracene, or phenanthrene with one or more hydrogen atoms removed; even more preferably a group from benzene, naphthalene, or anthracene with one or more hydrogen atoms removed; particularly preferably a group from benzene or naphthalene with one or more hydrogen atoms removed; and most preferably a group from benzene with one or more hydrogen atoms removed.

[0101] Ra in equation (a1-r2-3) 104 Examples of substituents that may be present include methyl groups, ethyl groups, propyl groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups (such as methoxy groups, ethoxy groups, propoxy groups, butoxy groups, etc.), and alkyloxycarbonyl groups.

[0102] In formula (a1-r2-4), Ra' 12 and Ra' 13 Each of these is independently a monovalent, chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, or a hydrogen atom. 12 and Ra' 13 In this context, the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms is the above-mentioned Ra 101 ~Ra 103 Examples include monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, hydrogen atoms and alkyl groups having 1 to 5 carbon atoms are preferred, alkyl groups having 1 to 5 carbon atoms are more preferred, methyl groups and ethyl groups are even more preferred, and it is particularly preferred that all of them be methyl groups. The above Ra' 12 and Ra' 13 When a chain-like saturated hydrocarbon group represented by is substituted, the substituent may be, for example, the above-mentioned Ra x5 Similar bases can be cited.

[0103] In formula (a1-r2-4), Ra' 14 Ra' is a hydrocarbon group that may have substituents. 14 Examples of hydrocarbon groups in this context include linear or branched alkyl groups, or cyclic hydrocarbon groups.

[0104] Ra' 14 The linear alkyl group in this compound preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2. Specifically, examples include methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. Among these, methyl group, ethyl group, or n-butyl group is preferred, and methyl group or ethyl group is more preferred.

[0105] Ra' 14The branched alkyl group in this compound preferably has 3 to 10 carbon atoms, and more preferably 3 to 5. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0106] Ra' 14 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a polycycloalkane from which one hydrogen atom has been removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically including adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

[0107] Ra' 14 As for aromatic hydrocarbon groups in this context, Ra 104 Examples include those similar to aromatic hydrocarbon groups in [the text]. Among them, Ra' 14 The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms with one or more hydrogen atoms removed; more preferably a group from benzene, naphthalene, anthracene, or phenanthrene with one or more hydrogen atoms removed; even more preferably a group from benzene, naphthalene, or anthracene with one or more hydrogen atoms removed; particularly preferably a group from benzene or naphthalene with one or more hydrogen atoms removed; and most preferably a group from benzene with one or more hydrogen atoms removed. Ra' 14 A substituent that may be present is Ra 104 Examples of substituents that may be present include those similar to those that the molecule may have.

[0108] Ra' in equation (a1-r2-4)14 If is a naphthyl group, the position where it bonds with the tertiary carbon atom in formula (a1-r2-4) may be either position 1 or position 2 of the naphthyl group. Ra' in equation (a1-r2-4) 14 If is an anthyl group, the position where it bonds with the tertiary carbon atom in formula (a1-r2-4) may be position 1, 2, or 9 of the anthyl group.

[0109] Ra' in equation (a1-r2-4) 14 Among the above, it is preferable that the aromatic hydrocarbon group may have substituents. The aromatic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene, or phenanthrene, even more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from benzene or naphthalene, and most preferably a group obtained by removing one or more hydrogen atoms from benzene. Furthermore, among these, a phenyl group without substituents is preferred.

[0110] Specific examples of the group represented by the above formula (a1-r2-1) are given below.

[0111] [ka]

[0112] [ka]

[0113] [ka]

[0114] Specific examples of the group represented by the above formula (a1-r2-2) are given below.

[0115] [ka]

[0116] [ka]

[0117] [ka]

[0118] Specific examples of the group represented by the above formula (a1-r2-3) are given below.

[0119] [ka]

[0120] Specific examples of the group represented by the above formula (a1-r2-4) are given below.

[0121] [ka]

[0122] Tertiary alkyloxycarbonyl acid dissociable group: Among the aforementioned polar groups, an example of an acid-dissociating group that protects a hydroxyl group is the acid-dissociating group represented by the following general formula (a1-r-3) (hereinafter, for convenience, this may be referred to as a "tertiary alkyloxycarbonyl acid dissociating group").

[0123] [ka] [In the formula, Ra' 7 ~Ra' 9 These are each alkyl groups.

[0124] In formula (a1-r-3), Ra' 7 ~Ra' 9Each 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.

[0125] 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 are 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 are protected by a substituent containing the acid-degradable group.

[0126] 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).

[0127] [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 (a1-r-1) or (a1-r-2) above. 1 is n a2 It is a +1 valent hydrocarbon group, n a2 is an integer between 1 and 3, and Ra 2This is an acid-dissociable group represented by the general formula (a1-r-1) or (a1-r-3) above.

[0128] In formula (a1-1), 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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 with two hydrogen atoms 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 with two hydrogen atoms removed, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0133] 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 number of carbon atoms does not include the number of 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 an arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0134] In the above formula (a1-1), Ra 1 This is an acid-dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

[0135] 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.

[0136] In the above formula (a1-2), Ra 2 This is an acid-dissociable group represented by the general formula (a1-r-1) or (a1-r-3) above.

[0137] 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.

[0138] [ka]

[0139] [ka]

[0140] [ka]

[0141] [ka]

[0142] [ka]

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] 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. Among these, the constituent unit (a1) is particularly preferred if it includes a constituent unit represented by the following general formula (a1-1-1).

[0147] [ka] [In the formula, Ra 1 " is an acid-dissociable group represented by the general formula (a1-r2-1), (a1-r2-3), or (a1-r2-4).

[0148] In the above formula (a1-1-1), R, Va 1 and n a1 R, Va in the above formula (a1-1) 1 and n a1 It is similar to that. The explanation of the acid-dissociable groups represented by general formulas (a1-r2-1), (a1-r2-3), or (a1-r2-4) is as described above. In particular, it is preferable to select those in which the acid-dissociable group is a cyclic group, as this enhances reactivity for EB or EUV applications.

[0149] In the above formula (a1-1-1), Ra 1 " is preferably an acid-dissociable group represented by the general formula (a1-r2-1) or (a1-r2-4) among the above.

[0150] The proportion of constituent units (a1) in component (A1) 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 component (A1). By setting the proportion of the constituent unit (a1) to be above the lower limit of the preferred range described above, lithography characteristics such as sensitivity, resolution, and roughness improvement are enhanced. On the other hand, if it is below the upper limit of the preferred range described above, a balance can be achieved with other constituent units, resulting in good lithography characteristics in various aspects.

[0151] Regarding the constituent unit (a2): Component (A1) may further have a constituent unit (a2) containing a monocyclic lactone-containing cyclic group, an -SO2--containing cyclic group, or a carbonate-containing cyclic group (excluding those corresponding to constituent unit (a1) or constituent unit (a01)).

[0152] Specifically, examples of monocyclic lactone-containing cyclic groups include the group represented by the following general formula (a2-r-1).

[0153] [ka] [In the formula, Ra' 21n' is a hydrogen atom, alkyl group, alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, -COOR'', -OC(=O)R'', hydroxyalkyl group, or cyano group, where R'' is a hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or -SO2--containing cyclic group, and n' is an integer from 0 to 2.

[0154] Ra' in the above general formula (a²-r-1) 21 As for the above, Ra' in the general formula (a0-1) 21 Similar examples can be given. n' is an integer between 0 and 2, and is preferably 1.

[0155] A "-SO2-containing cyclic group" refers to a cyclic group that contains a ring with -SO2- in its cyclic skeleton. Specifically, it is a cyclic group in which the sulfur atom (S) in -SO2- forms part of the cyclic skeleton. The ring containing -SO2- in its cyclic skeleton is counted as the first ring. If it consists only of this ring, it is called a monocyclic group. If it has other ring structures, it is called a polycyclic group regardless of those structures. A -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2--containing cyclic group is preferably a cyclic group that contains -O-SO2- in its cyclic skeleton, that is, a cyclic group that contains a sultone ring in which the -OS- in -O-SO2- forms part of the cyclic skeleton. More specifically, examples of -SO2- containing cyclic groups include the groups represented by the following general formulas (a5-r-1) to (a5-r-4).

[0156] [ka] [In the formula, Ra' 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, a carbonate-containing cyclic group, or a -SO2--containing cyclic group; A'' 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.

[0157] In the general formulas (a5-r-1) to (a5-r-2) above, A'' is the same as A'' in the general formulas (a2-r-2), (a2-r-3), and (a2-r-5) above. Ra' 51 In this formula, the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'', and hydroxyalkyl group are, respectively, Ra' in the general formula (a2-r-1). 21 The same things mentioned in the explanation about this topic can be cited. Specific examples of the groups represented by the general formulas (a5-r-1) to (a5-r-4) are given below. In the formulas, "Ac" indicates an acetyl group.

[0158] [ka]

[0159] [ka]

[0160] [ka]

[0161] A "carbonate-containing cyclic group" refers to a cyclic group that contains a ring (carbonate ring) containing -OC(=O)-O- within its cyclic framework. The carbonate ring is counted as the first ring. If it consists only of a carbonate 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 carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. Any carbonate ring-containing cyclic group can be used without any particular limitations. Specifically, examples include the groups represented by the following general formulas (ax3-r-1) to (ax3-r-3).

[0162] [ka] [In the formula, Ra' x31 Each of the following is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group; R'' is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2--containing cyclic group; A'' 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, p' is an integer from 0 to 3, and q' is 0 or 1.

[0163] In the above general formulas (ax3-r-2) to (ax3-r-3), A'' is the same as A'' in the above general formulas (a2-r-2), (a2-r-3), and (a2-r-5). Ra' 31 In this formula, the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR'', -OC(=O)R'', and hydroxyalkyl group are, respectively, Ra' in the general formula (a2-r-1). 21 The same things mentioned in the explanation about this topic can be cited. The following are specific examples of groups represented by the general formulas (ax3-r-1) to (ax3-r-3).

[0164] [ka]

[0165] 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 40 mol%, more preferably 1 to 30 mol%, and even more preferably 1 to 20 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.

[0166] Regarding the constituent unit (a3): Component (A1) may also have a constituent unit (a3) ​​containing a polar group-containing aliphatic hydrocarbon group in addition to constituent unit (a1) (excluding those corresponding to constituent unit (a01), constituent unit (a1), or constituent unit (a2)). The presence of constituent unit (a3) ​​in component (A1) increases the hydrophilicity of component (A), contributing to improved resolution. Furthermore, the acid diffusion length can be appropriately adjusted.

[0167] Examples of polar groups include hydroxyl groups, cyano groups, carboxyl groups, and hydroxyalkyl groups in which some of the hydrogen atoms of an alkyl group are replaced with fluorine atoms, with hydroxyl groups being particularly preferred. Examples of aliphatic hydrocarbon groups include linear or branched hydrocarbon groups having 1 to 10 carbon atoms (preferably alkylene groups) and cyclic aliphatic hydrocarbon groups (cyclic groups). The cyclic group may be monocyclic or polycyclic, and can be appropriately selected from among the many proposed options for resins used in resist compositions for ArF excimer lasers.

[0168] When the cyclic group is a monocyclic group, it is more preferable that the number of carbon atoms be 3 to 10. Among these, structural units derived from acrylic acid esters containing an aliphatic monocyclic group containing a hydroxyl group, a cyano group, a carboxyl group, or a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms are more preferred. Examples of such monocyclic groups include groups obtained by removing two or more hydrogen atoms from a monocycloalkane. Specifically, these include groups obtained by removing two or more hydrogen atoms from monocycloalkanes such as cyclopentane, cyclohexane, and cyclooctane. Among these monocyclic groups, groups obtained by removing two or more hydrogen atoms from cyclopentane and groups obtained by removing two or more hydrogen atoms from cyclohexane are industrially preferred.

[0169] If the cyclic group is a polycyclic group, it is more preferable that the number of carbon atoms in the polycyclic group is 7 to 30. Among these, structural units derived from acrylic acid esters containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxyl group, or a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms are more preferred. Examples of such polycyclic groups include groups obtained by removing two or more hydrogen atoms from bicycloalkanes, tricycloalkanes, tetracycloalkanes, etc. Specifically, examples include groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, groups obtained by removing two or more hydrogen atoms from adamantane, norbornane, and tetracyclododecane are industrially preferred.

[0170] As for the constituent unit (a3), any unit containing a polar group-containing aliphatic hydrocarbon group can be used without any particular limitations. The constituent unit (a3) ​​is preferably 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, and which includes a polar group-containing aliphatic hydrocarbon group. As for the constituent unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, a constituent unit derived from hydroxyethyl ester of acrylic acid is preferred. Furthermore, as for the constituent unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, the constituent unit represented by formula (a3-1), formula (a3-2), and formula (a3-3) below are preferred; when it is a monocyclic group, the constituent unit represented by formula (a3-4) is preferred.

[0171] [ka] [In the formula, R is the same as above, j is an integer between 1 and 3, k is an integer between 1 and 3, t' is an integer between 1 and 3, l is an integer between 0 and 5, and s is an integer between 1 and 3.]

[0172] In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3rd position of the adamantyl group. It is preferable that j is 1, and it is particularly preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0173] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

[0174] In formula (a3-3), t' is preferably 1. l is preferably 1. s is preferably 1. These are preferably formed by a 2-norbornyl group or a 3-norbornyl group bonded to the terminal end of the carboxyl group of the acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

[0175] In formula (a3-4), t' is preferably 1 or 2. l is preferably 0 or 1. s is preferably 1. The fluorinated alkyl alcohol is preferably bonded to the 3 or 5 position of the cyclohexyl group.

[0176] (A1) The constituent units (a3) ​​of component (A1) may be one type or two or more types. If component (A1) has constituent units (a3), the proportion of constituent units (a3) ​​is preferably 1 to 30 mol%, more preferably 1 to 25 mol%, and even more preferably 1 to 20 mol%, relative to the total (100 mol%) of all constituent units that make up component (A1). By setting the proportion of constituent unit (a3) ​​above a preferred lower limit, the effects of including constituent unit (a3) ​​are fully obtained through the aforementioned effects. If it is below a preferred upper limit, a balance with other constituent units can be maintained, resulting in good lithography characteristics.

[0177] Regarding the constituent unit (a4): Component (A1) may further have a constituent unit (a4) containing an acid-nondissociable aliphatic cyclic group, in addition to the constituent unit (a1). The presence of component (A1) as a constituent unit (a4) improves the dry etching resistance of the formed resist pattern. Additionally, the hydrophobicity of component (A) increases. This improved hydrophobicity contributes to improvements in resolution, resist pattern shape, and other properties, particularly in solvent development processes. In the constituent unit (a4), the "acid-non-dissociating cyclic group" is a cyclic group that remains in the constituent unit without dissociating when acid is generated in the resist composition due to exposure (for example, when acid is generated from a constituent unit or component (B) that generates acid due to exposure).

[0178] As the constituent unit (a4), for example, a constituent unit derived from an acrylic acid ester containing an acid-nondissociable aliphatic cyclic group is preferred. Many of the cyclic groups that have been conventionally known to be used as resin components in resist compositions for ArF excimer lasers, KrF excimer lasers (preferably for ArF excimer lasers), etc., can be used. The cyclic group is preferably at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group, due to their industrial availability and other factors. These polycyclic groups may have linear or branched alkyl groups having 1 to 5 carbon atoms as substituents. Specifically, the constituent units (a4) can be exemplified by the constituent units represented by the following general formulas (a4-1) to (a4-7).

[0179] [ka] [In the formula, R α This is the same as above.

[0180] (A1) The constituent units (a4) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a4), the proportion of constituent units (a4) is preferably 1 to 40 mol%, and more preferably 1 to 20 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). By setting the proportion of constituent unit (a4) above a preferred lower limit, the effects of including constituent unit (a4) can be fully obtained. On the other hand, by setting it below a preferred upper limit, it becomes easier to balance it with other constituent units.

[0181] Regarding the constituent unit (a10): A constituent unit (a10) is a constituent unit represented by the following general formula (a10-1) (excluding those corresponding to constituent unit (a02)).

[0182] [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.]

[0183] 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. The alkyl group having 1 to 5 carbon atoms in R 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. 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. Fluorine atoms are particularly preferred as the halogen 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 methyl group is particularly preferred.

[0184] 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.

[0185] • Divalent hydrocarbon groups which may have substituents: Ya x1If is a divalent hydrocarbon group which may have substituents, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0186] ··Ya x1 Aliphatic hydrocarbon groups in An 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 preferable 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.

[0187] ...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.

[0188] The linear or branched aliphatic hydrocarbon group 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.

[0189] ...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 obtained by removing two hydrogen atoms 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.

[0190] 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 more 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 even more preferred. A fluorine atom is preferred as the halogen atom used as the substituent. 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-.

[0191] ··Ya x1 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. 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. 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.

[0192] 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, hydroxyl groups, and the like. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more 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 halides that substitute for hydrogen atoms on the cyclic aliphatic hydrocarbon group.

[0193] • Divalent linking groups containing heteroatoms: Ya x1 When is a divalent linking group containing a heteroatom, preferred linking groups include -O-, -C(=O)-O-, -OC(=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 -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 - 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 divalent linking group containing the 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 -OY22 -, -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 Each of these is independently a divalent hydrocarbon group which may have substituents. The divalent hydrocarbon group is the aforementioned Ya x1 Examples include those similar to the divalent linking groups (divalent hydrocarbon groups that may have substituents) mentioned in the description of divalent linking groups in [the relevant section]. Y 21 Preferably, 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.

[0194] Among the above, 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.

[0195] 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 Examples include groups with 1+1 hydrogen atoms removed. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system with 4n+2 π electrons, and may be monocyclic or polycyclic. The 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 replaced by 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.

[0196] 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 for cyclic aliphatic hydrocarbon groups in are similar to those listed above. The substituents are preferably linear or branched alkyl groups having 1 to 5 carbon atoms, more preferably linear or branched alkyl groups having 1 to 3 carbon atoms, even more preferably ethyl or methyl groups, and particularly preferably methyl groups. x1 In this context, it is preferable that the aromatic hydrocarbon group does not have substituents.

[0197] 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.

[0198] 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.

[0199] [ka]

[0200] [ka]

[0201] [ka]

[0202] 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 1 to 20 mol%, and more preferably 1 to 10 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 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.

[0203] Regarding the constituent unit (st): The constituent unit (st) is a constituent unit derived from styrene or a styrene derivative. "Constituent unit derived from styrene" means a constituent unit formed by the cleavage of the ethylenic double bond of styrene. "Constituent unit derived from a styrene derivative" means a constituent unit formed by the cleavage of the ethylenic double bond of a styrene derivative.

[0204] A "styrene derivative" refers to a compound in which at least some of the hydrogen atoms of styrene are substituted with substituents. Examples of styrene derivatives include those in which the hydrogen atom at the α-position of styrene is substituted with a substituent, those in which one or more hydrogen atoms of the benzene ring of styrene are substituted with substituents, and those in which the hydrogen atom at the α-position of styrene and one or more hydrogen atoms of the benzene ring are substituted with substituents.

[0205] Examples of substituents that substitute for the α-hydrogen atom of styrene include alkyl groups having 1 to 5 carbon atoms, or alkyl halogens having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms 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, and the like. The aforementioned C1-C5 alkyl halide 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. Preferably, the substituent that substitutes the α-hydrogen atom of styrene is an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms or a fluorinated alkyl group having 1 to 3 carbon atoms, and even more preferably a methyl group due to its industrial availability.

[0206] Examples of substituents that substitute for hydrogen atoms in the benzene ring of styrene include alkyl groups, alkoxy groups, halogen atoms, and alkyl halides. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more 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 even more preferred. A fluorine atom is preferred as the halogen atom used as the substituent. 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. Preferably, substituents that substitute a hydrogen atom in the benzene ring of styrene are alkyl groups having 1 to 5 carbon atoms, more preferably methyl or ethyl groups, and even more preferably methyl groups.

[0207] The constituent unit (st) is preferably a constituent unit derived from styrene, or a constituent unit derived from a styrene derivative in which the hydrogen atom at the α position of styrene is substituted with an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; more preferably a constituent unit derived from styrene, or a constituent unit derived from a styrene derivative in which the hydrogen atom at the α position of styrene is substituted with a methyl group; and even more preferably a constituent unit derived from styrene.

[0208] (A1) The constituent units (st) of the component may be one type or two or more types. (A1) If component (A1) has constituent units (st), the proportion of constituent units (st) is preferably 1 to 30 mol%, and more preferably 3 to 20 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1).

[0209] The (A1) component contained in the resist composition may be used alone or in combination of two or more types. In the resist composition of this embodiment, component (A1) is a polymer compound having a repeating structure of constituent units (a01) and constituent units (a02), and among these, it is preferable that it is a polymer compound (polymer) having a repeating structure of constituent units (a1), constituent units (a01), and constituent units (a02).

[0210] In a polymer compound having a repeating structure of constituent unit (a1), constituent unit (a01), and constituent unit (a02), the proportion of constituent unit (a1) 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 (a01) in the polymer compound is preferably 1 to 70 mol%, more preferably 1 to 60 mol%, even more preferably 5 to 50 mol%, and particularly preferably 10 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 (a02) in the polymer compound is preferably 1 to 70 mol%, more preferably 1 to 60 mol%, even more preferably 5 to 50 mol%, and particularly preferably 10 to 40 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound.

[0211] In a polymer compound having a repeating structure of constituent unit (a1), constituent unit (a01), and constituent unit (a02), the molar ratio of constituent unit (a01):constituent unit (a02) is preferably 10:90 to 45:55, more preferably 15:85 to 45:55, and even more preferably 15:85 to 30:70.

[0212] Component (A1) in the resist composition of this embodiment is a polymer compound having a repeating structure of constituent unit (a1), constituent unit (a01), and constituent unit (a02), The proportion of the constituent unit (a1) 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%, The proportion of the constituent unit (a01) is preferably 1 to 70 mol%, more preferably 1 to 60 mol%, even more preferably 5 to 50 mol%, and particularly preferably 10 to 40 mol%. The proportion of the constituent unit (a02) is preferably 1 to 70 mol%, more preferably 1 to 60 mol%, even more preferably 5 to 50 mol%, and particularly preferably 10 to 40 mol%, and It is preferable that the polymer compound has a molar ratio (a1:a2) of constituent unit (a01) to constituent unit (a02) that is preferably 10:90 to 45:55, more preferably 15:85 to 45:55, and even more preferably 15:85 to 30:70.

[0213] Such component (A1) can be produced by dissolving monomers that induce constituent unit (a1), monomers that induce constituent unit (a01), and monomers that induce constituent unit (a02) in a polymerization solvent, adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the mixture and polymerizing it, followed by 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).

[0214] 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.

[0215] (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.

[0216] 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, resolution, and roughness improvement.

[0217] In the resist composition of this embodiment, the content of component (A) may be adjusted according to the resist film thickness to be formed.

[0218] <Acid generating agent component (B)> In the resist composition of this embodiment, component (B) includes a compound (B0) represented by the following general formula (b0) (hereinafter also referred to as "component (B0)").

[0219] ≪Compound (B0)≫ Component (B0) is a compound represented by the following general formula (b0).

[0220] [ka] [where, X 0 R is a bromine atom or an iodine atom. m nb1 is an integer between 1 and 5, nb2 is an integer between 0 and 4, and 1 ≤ nb1 + nb2 ≤ 5. 0 This is a divalent linking group or a single bond. Vb 0 R is a single bond, an alkylene group, or a fluorinated alkylene group. 0 This is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. m+ This represents an m-valent organic cation, where m is an integer greater than or equal to 1.

[0221] {(B0) component anion part} In the above general formula (b0), X 0 This atom is either a bromine atom or an iodine atom, and is preferably an iodine atom.

[0222] In the above general formula (b0), R m R is a hydroxyl group, an alkyl group, a fluorine atom, or a chlorine atom. m The alkyl group in is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group or an ethyl group. In the above general formula (b0), R m Among the above, a hydroxyl group is preferred.

[0223] In the above general formula (b0), nb1 is an integer between 1 and 5, nb2 is an integer between 0 and 4, and 1 ≤ nb1 + nb2 ≤ 5. nb1 is preferably an integer between 1 and 3, more preferably 2 or 3, and even more preferably 3. nb2 is preferably an integer between 0 and 3, more preferably 0 or 1, and even more preferably 0.

[0224] In the above general formula (b0), Yb 0 Yb is a divalent linking group or a single bond. 0 In this context, a divalent linking group containing an oxygen atom is preferred. Yb 0 If Yb is a divalent linking group containing an oxygen atom, 0 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.

[0225] In the above general formula (b0), Vb 0 This represents an alkylene group, a fluorinated alkylene group, or a single bond. Vb 0 The alkylene group and fluorinated alkylene group in each are preferably having 1 to 4 carbon atoms, and more preferably having 1 to 3 carbon atoms. Vb 0 Examples of fluorinated alkylene groups include groups in which some or all of the hydrogen atoms of the alkylene group are replaced with fluorine atoms. Among these, Vb 0 It is preferably an alkylene group having 1 to 4 carbon atoms, a fluorinated alkylene group having 1 to 4 carbon atoms, or a single bond, and more preferably an alkylene group having 1 to 3 carbon atoms in which some of the hydrogen atoms are replaced by fluorine atoms, or a single bond.

[0226] In the above equation (b0), R 0 R is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. 0 It is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0227] In this embodiment, the anion portion of component (B0) is preferably an anion represented by the following general formula (b0-an0).

[0228] [ka] [where, X 0 R is a bromine atom or an iodine atom.m nb1 is a hydroxyl group, an alkyl group, a fluorine atom, or a chlorine atom. nb1 is an integer from 1 to 5, nb2 is an integer from 0 to 4, and 1 ≤ nb1 + nb2 ≤ 5. 01 and L 02 These are, independently, single bonds, alkylene groups, -O-, -CO-, -OCO-, -COO-, -SO2-, and -N(R) a )-C(=O)-,-N(R a )-,-C(R a )(R a )-N(R a )-,-C(R a )(N(R a )(R a ))-, or -C(=O)-N(R a )- is. R a Each of these is independently either a hydrogen atom or an alkyl group. z is an integer between 0 and 10. Vb 0 R is a single bond, an alkylene group, or a fluorinated alkylene group. 0 This is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom.

[0229] X in the above general formula (b0-an0) 0 , R m , nb1, nb2, Vb 0 , and R 0 These are the X in the general formula (b0) mentioned above. 0 , R m , nb1, nb2, Vb 0 , and R 0 These are identical to each other.

[0230] In the above general formula (b0-an0), L 01 and L 02 These are, independently, single bonds, alkylene groups, -O-, -CO-, -OCO-, -COO-, -SO2-, and -N(R) a )-C(=O)-,-N(R a )-,-C(R a )(R a )-N(R a )-,-C(R a )(N(R a )(Ra ))-, or -C(=O)-N(R a )- is. R a Each of these is independently either a hydrogen atom or an alkyl group. L 01 and L 02 The alkylene group in, and R a The alkyl groups in each are preferably having 1 to 4 carbon atoms, and more preferably having 1 to 3 carbon atoms.

[0231] In the above general formula (b0-an0), L 01 and L 02 Among the above, it is preferable that one of them is -OCO- or -COO-, L 01 However, it is -OCO- or -COO-, L 02 However, a single bond, -OCO-, or -COO- is more preferable.

[0232] More specifically, in the above general formula (b0-an0), -L 01 -(CH2)zL 02 -Vb 0 - is -COO-Vb 0 -, -OCO-Vb 0 -, or -COO-(CH2)z-COO-Vb 0 - is preferable.

[0233] In the above general formula (b0-an0), z is an integer between 0 and 10, preferably between 0 and 5, and more preferably between 0 and 3.

[0234] The following shows a specific example of the anion portion of component (B0).

[0235] [ka]

[0236] [ka]

[0237] {(B0) component cation} In the above general formula (b0), M m+ This represents an m-valent organic cation. Among these, sulfonium cations and iodonium cations are preferred. m is an integer greater than or equal to 1.

[0238] Preferred cation portion ((M m+ ) 1 / m Examples of these include organic cations represented by the following general formulas (ca-1) to (ca-5).

[0239] [ka] [In the formula, R 201 ~R 207 , and R 211 ~R 212 Each of these independently represents an aryl group, alkyl group, or alkenyl group, which may have substituents. 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 These atoms may bond to each other to form a ring with the sulfur atom in the formula. 208 ~R 209 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 210 This is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted SO2-containing cyclic group. 201 This represents -C(=O)- or -C(=O)-O-. 201 Each of these independently represents an arylene group, an alkylene group, or an alkenylene group. x is either 1 or 2. 201 This represents a (x+1) valence linking group.

[0240] In the above general formulas (ca-1) to (ca-5), R 201 ~R 207 , and R 211 ~R 212Examples 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 , and R 211 ~R 212 The alkyl group in this is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 , and R 211 ~R 212 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 ~R 212 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).

[0241] [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.

[0242] 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.

[0243] 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.

[0244] 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.

[0245] 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.

[0246] 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.

[0247] 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 (a01-r-1) to (a01-r-6) and (a2-r-1), respectively; -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively; and other heterocyclic groups represented by the above chemical formulas (r-hr-1) to (r-hr-16).

[0248] 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.

[0249] 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.

[0250] 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.

[0251] 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.

[0252] 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.

[0253] 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 (a01-r-1) to (a01-r-6) and (a2-r-1), respectively; and -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively.

[0254] In the above general formulas (ca-1) to (ca-5), R 201 ~R 203 , R 206 ~R 207 , R 211 ~R 212 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 preferably has 3 to 10 members, and particularly preferably 5 to 7 members, including the sulfur atom in its ring skeleton. Specific examples of the formed ring include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthlene ring, a phenoxatiyne ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0255] R 208 ~R 209 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. If an alkyl group is formed, it may bond with other elements to form a ring.

[0256] 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 (a5-r-1).

[0257] Y 201 Each of these independently represents an arylene group, an alkylene group, or an alkenylene group. Y 201 The arylene group in the above formula (b-1) is R101 An example of an aromatic hydrocarbon group in this context is the aryl group exemplified above, with one hydrogen atom removed. Y 201 The alkylene group and alkenylene group in the above formula (b-1) are R 101 Examples of the chain-like alkyl groups and chain-like alkenyl groups mentioned above include groups obtained by removing one hydrogen atom from the examples provided.

[0258] In the above equation (ca-4), x is either 1 or 2. W 201 This is a (x+1) valence, i.e., a divalent or trivalent linking group. W 201 In this, the divalent linking group is preferably a divalent hydrocarbon group which may have substituents, and Ya in the general formula (a2-1) described above. 21 Examples of divalent hydrocarbon groups that may have substituents, similar to the above, can be given. 201 The divalent linking group in this compound may be linear, branched, or cyclic, with cyclic being preferred. Among these, a group in which two carbonyl groups are combined at both ends of an arylene group is preferred. Examples of arylene groups include phenylene groups and naphthylene groups, with phenylene groups being particularly preferred. W 201 The trivalent linking group in is the aforementioned W 201 Examples include a group obtained by removing one hydrogen atom from a divalent linking group, and a group in which another divalent linking group is bonded to the aforementioned divalent linking group. 201 In this compound, a trivalent linking group is preferably a group in which two carbonyl groups are bonded to an arylene group.

[0259] 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).

[0260] [ka]

[0261] [ka]

[0262] [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.]

[0263] [ka]

[0264] [ka]

[0265] [ka]

[0266] [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.

[0267] Suitable cations represented by the formula (ca-2) include, specifically, diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0268] 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).

[0269] [ka]

[0270] Specific examples of suitable cations represented by the above formula (ca-4) include the cations represented by the following formulas (ca-4-1) to (ca-4-2).

[0271] [ka]

[0272] Specific examples of suitable cations represented by the above formula (ca-5) include the cations represented by the following general formulas (ca-5-1) to (ca-5-3).

[0273] [ka]

[0274] Among the above, the cation part ((M m+ ) 1 / m The cation represented by the general formula (ca-1) is preferred.

[0275] In the resist composition of this embodiment, component (B0) is preferably a compound represented by the following general formula (b0-1) among the above.

[0276] [ka] [where, X 0 R is a bromine atom or an iodine atom. m nb1 is a hydroxyl group, an alkyl group, a fluorine atom, or a chlorine atom. nb1 is an integer from 1 to 5, nb2 is an integer from 0 to 4, and 1 ≤ nb1 + nb2 ≤ 5. 01 and L 02 These are, independently, single bonds, alkylene groups, -O-, -CO-, -OCO-, -COO-, -SO2-, and -N(R) a )-C(=O)-,-N(R a )-,-C(Ra )(R a )-N(R a )-,-C(R a )(N(R a )(R a ))-, or -C(=O)-N(R a )- is. R a Each of these is independently either a hydrogen atom or an alkyl group. z is an integer between 0 and 10. Vb 0 R is a single bond, an alkylene group, or a fluorinated alkylene group. 0 This is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. m+ This represents an m-valent organic cation, where m is an integer greater than or equal to 1.

[0277] The anionic portion of the compound represented by the above general formula (b0-1) is identical to the anion represented by the above general formula (b0-an0). The cation portion of the compound represented by the above general formula (b0-1) is the same as the cation portion of the compound represented by the above general formula (b0).

[0278] Specific examples of component (B0) are listed below, but are not limited to these.

[0279] [ka]

[0280] [ka]

[0281] [ka]

[0282] In the resist composition of this embodiment, component (B0) may be used alone or in combination of two or more types. In the resist composition of this embodiment, the content of component (B0) is preferably 5 to 40 parts by mass, more preferably 10 to 40 parts by mass, and even more preferably 15 to 35 parts by mass, per 100 parts by mass of component (A). If the content of component (B0) is above the lower limit of the preferred range described above, lithography characteristics such as sensitivity, resolution, LWR (linewise roughness) reduction, film thinning reduction, and shape are further improved during 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.

[0283] In the resist composition of this embodiment, the proportion of component (B0) to the total amount of component (B) is, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 95% by mass or more. It may also be 100% by mass.

[0284] The resist composition of this embodiment may contain an acid generating agent component (B1) other than the above-described component (B0) (hereinafter also referred to as "component (B1)").

[0285] ≪(B1) Component≫ (B1) The components include a wide variety of substances such as onium salt-based acid generators like iodonium salts and sulfonium salts; oxime sulfonate-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.

[0286] 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)").

[0287] [ka] [In the formula, R 101 and R 104 ~R 108 Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 104 and R 105 These may be bonded to each other to form a ring structure. 102 This is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. 101 This is a divalent linking group or single bond containing an oxygen atom. 101 ~V 103 These are, independently, a single bond, an alkylene group, or a fluorinated alkylene group. 101 ~L 102 Each of these is independently either a single bond or an oxygen atom. 103 ~L 105 These are, independently, single bonds, -CO-, or -SO2-. m is an integer greater than or equal to 1, and M' m+ This is an onium cation with a valence of m.

[0288] {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.

[0289] 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.

[0290] 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.

[0291] 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.

[0292] 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.

[0293] 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.

[0294] 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 (a01-r-1) to (a01-r-6) and (a2-r-1), respectively, -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively, and heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16). In the formula, * represents Y in formula (b-1). 101 This represents a coupling that connects to something.

[0295] [ka]

[0296] 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.

[0297] R 101 The 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.

[0298] [ka]

[0299] 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 groups 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 (a01-r-1) to (a01-r-6) and (a2-r-1), respectively; -SO2-containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively; and heterocyclic groups represented by the formulas (r-hr-7) to (r-hr-16), respectively.

[0300] 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.

[0301] 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.

[0302] 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.

[0303] Among the above, R 101Preferably, the group is a cyclic group which may have substituents, and more preferably, a cyclic hydrocarbon group which may have substituents. More specifically, the cyclic hydrocarbon group is a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane; a lactone-containing cyclic group represented by the general formulas (a01-r-1) to (a01-r-6) and (a2-r-1), respectively; a -SO2-containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), respectively; more preferably, a group obtained by removing one or more hydrogen atoms from a polycycloalkane or a -SO2-containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), respectively; and even more preferably, an adamantyl group or a -SO2-containing cyclic group represented by the general formula (a5-r-1).

[0304] If the cyclic hydrocarbon group has substituents, the substituents are preferably hydroxyl groups.

[0305] 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 101The V' in the following general formulas (y-al-1)~(y-al-7) is what combines with it. 101 That is the case.

[0306] [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.

[0307] 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.

[0308] V' 101 and V' 102 The alkylene group in this product may be a linear alkylene group or a branched alkylene group, but a linear alkylene group is preferred. V' 101 and V' 102 Specifically, the alkylene groups in these include: methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2 Examples include alkylethylene groups such as -CH2CH2CH2-; trimethylene groups (n-propylene groups) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; tetramethylene groups [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and pentamethylene groups [-CH2CH2CH2CH2CH2-]. Also, oshiV' 101 or V'102 Some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is Ra' in formula (a1-r-1). 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.

[0309] Y 101 Preferably, the linking group is a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and more preferably the linking groups represented by the above formulas (y-al-1) to (y-al-5).

[0310] 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 V 101 Examples include groups in which some or all of the hydrogen atoms of the alkylene group are replaced with fluorine atoms. Among these, V 101 It is preferable that it is a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0311] 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.

[0312] 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 101When 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).

[0313] [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), or an optionally substituted linear alkyl group. 102 R” is an aliphatic cyclic group which may have substituents, a fused cyclic group represented by formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by the general formulas (a01-r-1) to (a01-r-6) and (a2-r-1), respectively, or a -SO2-containing cyclic group represented by the general formulas (a5-r-1) to (a5-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.]

[0314] 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.

[0315] R" 103The 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.

[0316] 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.

[0317] • Anion in component (b-2) In formula (b-2), R 104 , R 105 Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of them is R in formula (b-1). 101 Similar examples can be given. However, R 104 , 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 105In 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.

[0318] • Anion in component (b-3) In formula (b-3), R 106 ~R 108 Each of these is independently a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of them is R in formula (b-1). 101 Similar examples include the above. In formula (b-3), L 103 ~L 105 These are, independently, single bonds, -CO-, or -SO2-.

[0319] Among the above, the anion in component (b-1) is preferred as the anion portion of component (B). Among these, an anion represented by any of the above general formulas (an-1) to (an-3) is more preferred, an anion represented by either general formula (an-1) or (an-2) is even more preferred, and an anion represented by general formula (an-2) is particularly preferred.

[0320] {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.

[0321] Preferred cation portion ((M' m+ ) 1 / m Examples of these include the organic cations represented by the general formulas (ca-1) to (ca-5) mentioned above.

[0322] In the resist composition of this embodiment, component (B1) may be used alone or in combination of two or more types. If the resist composition contains component (B1), the content of component (B1) in the resist composition is preferably less than 40 parts by mass, more preferably 1 to 30 parts by mass, and even more preferably 1 to 20 parts by mass, per 100 parts by mass of component (A). (B1) By setting the content of component B1 within the preferred range described above, pattern formation is sufficiently achieved. Furthermore, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, which is preferable as it results in good storage stability for the resist composition.

[0323] <Other ingredients> The resist composition of this embodiment may further contain other components in addition to the above-described components (A) and (B). Examples of other components include components (D), (E), (F), and (S) shown below.

[0324] ≪Basic component (D)≫ The resist composition of this embodiment preferably further contains, in addition to components (A) and (B), a basic component (component (D)) that traps the acid generated by exposure (i.e., controls the diffusion of the acid). 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.

[0325] • 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.

[0326] [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.

[0327] {(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 1 Preferred 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 (a01-r-1) to (a01-r-6) and (a2-r-1), respectively, 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 above formulas (y-al-1) to (y-al-5), respectively. 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.

[0328] 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.

[0329] In formula (d1-1), Rd 1 Among the above, a chain-like alkyl group which may have substituents is preferred, a chain-like alkyl group having at least a fluorine atom as a substituent is more preferred, and a chain-like alkyl group having a fluorine atom and a hydroxyl group as substituents is even more preferred.

[0330] The following are some preferred specific examples of the anionic portion of component (d1-1).

[0331] [ka]

[0332] ··Cation section In formula (d1-1), M m+ This is an m-valent organic cation. M m+Suitable organic cations include those similar to those represented by the general formulas (ca-1) to (ca-5), with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the formulas (ca-1-1) to (ca-1-78) being even more preferred. (d1-1) Component may be used alone or in combination of two or more types.

[0333] {(d1-2) component} ··Anion Club In formula (d1-2), Rd 2 R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 201 Similar examples include the above. However, Rd 2 In this mixture, we assume that the carbon atom adjacent to the S atom is not bonded to a fluorine atom (i.e., not fluorine-substituted). This results in the anions of components (d1-2) becoming appropriately weak acid anions, improving the quenching ability of component (D). Rd 2 Preferably, the group is a chain-like alkyl group which may have substituents, or an aliphatic cyclic group which may have substituents, and more preferably an aliphatic cyclic group which may have substituents.

[0334] 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.

[0335] Rd 2 The hydrocarbon group may have substituents, and such substituents may be Rd of formula (d1-1). 1Examples 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.

[0336] (d1-2) Among the above, the camphor sulfonate anion is preferred as the anionic portion of component (d1-2).

[0337] The following are preferred specific examples of the anionic portion of component (d1-2).

[0338] [ka]

[0339] ··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.

[0340] {(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.

[0341] 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.

[0342] Rd 4 The alkenyl group in R' 201 Examples of alkenyl groups similar to those in the above include vinyl groups, propenyl groups (allyl groups), 1-methylpropenyl groups, and 2-methylpropenyl groups, which are preferred. These groups may further have substituents of an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

[0343] 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.

[0344] 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.

[0345] The following are preferred specific examples of the anionic parts of components (d1-3).

[0346] [ka]

[0347] [ka]

[0348] ··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.

[0349] 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 20 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 3 to 10 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.

[0350] 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).

[0351] (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.

[0352] • 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.

[0353] 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.

[0354] 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.

[0355] 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, and N-tert-butoxycarbonylpyrrolidine.

[0356] Among the above, component (D2) is preferably an alkylamine, and more preferably a trialkylamine having 5 to 10 carbon atoms.

[0357] (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.

[0358] <<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. Examples of derivatives of phosphorus oxoacids include esters obtained by substituting the hydrogen atoms of the above oxoacid with hydrocarbon groups, and examples of hydrocarbon groups include alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 15 carbon atoms. Examples of phosphoric acid derivatives include phosphate esters such as di-n-butyl phosphate and diphenyl phosphate. Examples of phosphonic acid derivatives include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate. Examples of phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid.

[0359] 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 (A). By setting the content within the above range, the lithography characteristics are further improved.

[0360] ≪Fluorine additive component (F)≫ The resist composition of this embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") in order to impart water repellency to the resist film or to improve lithography properties. As component (F), for example, fluorine-containing polymer compounds described in Japanese Patent Publication No. 2010-002870, Japanese Patent Publication No. 2010-032994, Japanese Patent Publication No. 2010-277043, Japanese Patent Publication No. 2011-13569, and Japanese Patent Publication No. 2011-128226 can be used. More specifically, component (F) includes polymers having a constituent unit (f1) represented by the following general formula (f1-1). This polymer is preferably a polymer (homopolymer) consisting only of the constituent unit (f1) represented by the following formula (f1-1); a copolymer of the constituent unit (f1) and the constituent unit (a1); and more preferably a copolymer of the constituent unit (f1) and a constituent unit derived from acrylic acid or methacrylic acid and the constituent unit (a1). Here, the constituent unit (a1) copolymerized with the constituent unit (f1) is preferably a constituent unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, and more preferably a constituent unit derived from 1-methyl-1-adamantyl (meth)acrylate.

[0361] [ka] [In the formula, R is the same as above, and Rf 102 and Rf 103 Each of these independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf 102 and Rf 103 They may be the same or different. 1 Rf is an integer between 0 and 5. 101 It is an organic group containing a fluorine atom.

[0362] In formula (f1-1), R bonded to the α-carbon atom is the same as described above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), Rf 102 and Rf 103 A fluorine atom is preferred as the halogen atom. Rf 102 and Rf 103 Examples of alkyl groups having 1 to 5 carbon atoms in R include those similar to the alkyl groups having 1 to 5 carbon atoms in R above, with methyl or ethyl groups being preferred. 102 and Rf 103 Specifically, examples of halogenated alkyl groups having 1 to 5 carbon atoms include groups in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Fluorine atoms are preferred as the halogen atoms, particularly Rf. 102 and Rf 103 Preferably, the element is a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms; more preferably, a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group; and even more preferably, a hydrogen atom. In formula (f1-1), nf 1 is an integer between 0 and 5, preferably between 0 and 3, and more preferably 1 or 2.

[0363] In formula (f1-1), Rf 101 This is an organic group containing a fluorine atom, and preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing fluorine atoms may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. Furthermore, in hydrocarbon groups containing fluorine atoms, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and particularly preferable that 60% or more are fluorinated, as this increases the hydrophobicity of the resist film during immersion exposure. Among them, Rf 101More preferably, fluorinated hydrocarbon groups having 1 to 6 carbon atoms are used, with trifluoromethyl groups, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, and -CH2-CH2-CF2-CF2-CF2-CF3 being particularly preferred.

[0364] The weight-average molecular weight (Mw) of component (F) (based on polystyrene conversion by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. If it is below the upper limit of this range, it has sufficient solubility in resist solvents for use as a resist, and if it is above the lower limit of this range, the water repellency of the resist film is good. The degree of dispersion of component (F) (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0365] In the resist composition of this embodiment, component (F) may be used alone or in combination of two or more types. If the resist composition contains component (F), the content of component (F) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of component (A).

[0366] ≪Organic solvent component (S)≫ The resist composition of this embodiment can be manufactured by dissolving the resist material in an organic solvent component (hereinafter referred to as "component (S)"). The (S) component can be any solvent that can dissolve each component used to form a homogeneous solution, and any solvent that is conventionally known as a solvent for chemically amplified resist compositions can be appropriately selected and used. (S) components include, for example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having ester bonds such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or monophenyl ether of the aforementioned polyhydric alcohols or compounds having ester bonds; etc. Examples include derivatives of polyhydric alcohols [of which propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenethole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). In the resist composition of this embodiment, component (S) may be used alone or as a mixture of two or more solvents. Among these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0367] Furthermore, a mixed solvent obtained by mixing PGMEA and a polar solvent is also preferred as component (S). The mixing ratio (mass ratio) can be appropriately determined considering the compatibility of PGMEA and the polar solvent, but it is preferably in the range of 1:9 to 9:1, and more preferably in the range of 2:8 to 8:2. More specifically, when EL or cyclohexanone is used as the polar solvent, the mass ratio of PGMEA to EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. When PGME is used as the polar solvent, the mass ratio of PGMEA to PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred. Furthermore, as the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferred. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5. The amount of component (S) used is not particularly limited and is set appropriately according to the coating thickness, at a concentration that can be applied to a substrate or the like. Generally, component (S) is used so that the solid content concentration of the resist composition is in the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0368] The resist composition of this embodiment may further contain, if desired, miscible additives such as additional resins to improve the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, etc.

[0369] 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.

[0370] The resist composition of this embodiment described above contains a resin component (A1) having constituent units (a01) and (a02), and a compound (B0) (component (B0)) represented by general formula (b0). The constituent unit (a02) has lower solubility in the developer than the constituent unit derived from p-hydroxystyrene, which is conventionally used as a proton source, thus allowing for better maintenance of the film thickness in the unexposed areas of the resist film after development. On the other hand, resins containing the constituent unit (a02) have a lower Tg than resins containing the constituent unit derived from p-hydroxystyrene, which is conventionally used as a proton source, so the acid diffusion length of the acid generated from component (B) increases, and the roughness tends to deteriorate. The constituent unit (a01) has a polycyclic lactone-containing cyclic group, which gives it a moderate affinity for the developer and allows for an increase in Tg. Therefore, by using both component units (a01) and (a02), it is possible to maintain the film thickness of the unexposed areas of the resist film after development while suppressing the deterioration of roughness. In addition, component (B0) has an iodine atom in its anion portion that has a high absorption cross-section for EUV and EB. Therefore, it can improve sensitivity to EUV and EB compared to conventional acid generators that do not contain an iodine atom. Furthermore, because component (B0) has an iodine atom in its anion portion, its solubility in the developer is also appropriately adjusted. Based on the above, the resist composition of this embodiment makes it possible to form a resist pattern that is highly sensitive, has reduced film loss, and exhibits good roughness reduction.

[0371] (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.

[0372] 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.

[0373] 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. In this way, a resist pattern can be formed.

[0374] 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. Furthermore, the support may be a substrate as described above on which an inorganic and / or organic film is provided. An example of an inorganic film is an inorganic anti-reflective film (inorganic BARC). An example of an organic film is an organic anti-reflective film (organic BARC) or an organic film such as the underlayer organic film in the multilayer resist method. Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are placed on a substrate, and the resist pattern formed on the upper resist film is used as a mask to pattern the lower organic film, and it is said that a high aspect ratio pattern can be formed. In other words, with the multilayer resist method, the required thickness can be secured by the lower organic film, so the resist film can be made thinner, and a fine pattern with a high aspect ratio can be formed. Multilayer resist methods can be broadly divided into two types: a two-layer resist method consisting of an upper resist film and a lower organic film, and a three-layer resist method consisting of three or more layers, with one or more intermediate layers (such as a thin metal film) placed between the upper resist film and the lower organic film.

[0375] The wavelength used for exposure is not particularly limited, and the process can be carried out using radiation such as ArF excimer lasers, KrF excimer lasers, F2 excimer lasers, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays. The resist composition is highly useful for KrF excimer lasers, ArF excimer lasers, EB, or EUV, even more useful for ArF excimer lasers, EB, or EUV, and particularly useful for EB or EUV. In other words, the resist pattern formation method of this embodiment is particularly useful when the step of exposing the resist film includes an operation of exposing the resist film with EUV (extreme ultraviolet) or EB (electron beam).

[0376] The method for exposing the resist film may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or liquid immersion lithography, but liquid immersion lithography is preferred. 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. The refractive index of such a solvent is not particularly limited as long as it is within the aforementioned range. Examples of solvents having a refractive index greater than that of air and less than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, and hydrocarbon-based solvents. Specific examples of fluorinated inert liquids include liquids mainly composed of fluorinated compounds such as C3HCl2F5, C4F9OCH3, C4F9OC2H5, and C5H3F7, with a boiling point of 70 to 180°C being preferred, and more preferably 80 to 160°C. Having a boiling point within the above range of the fluorinated inert liquid is preferable because it allows for the easy removal of the immersion medium after exposure. As fluorinated inert liquids, perfluoroalkyl compounds in which all hydrogen atoms of the alkyl group are replaced with fluorine atoms are particularly preferred. Specific examples of perfluoroalkyl compounds include perfluoroalkyl ether compounds and perfluoroalkylamine compounds. More specifically, perfluoro(2-butyl-tetrahydrofuran) (boiling point 102°C) can be cited as the perfluoroalkyl ether compound, and perfluorotributylamine (boiling point 174°C) can be cited as the perfluoroalkylamine compound. Water is preferred as the immersion medium from the viewpoints of cost, safety, environmental issues, and versatility.

[0377] 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. Ketone solvents are organic solvents that contain CC(=O)-C in their structure. Ester solvents are organic solvents that contain CC(=O)-OC in their structure. Alcohol solvents are organic solvents that contain an alcoholic hydroxyl group in their structure. An "alcoholic hydroxyl group" refers to a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Nitrile solvents are organic solvents that contain a nitrile group in their structure. Amide solvents are organic solvents that contain an amide group in their structure. Ether solvents are organic solvents that contain COC in their structure. Some organic solvents contain multiple functional groups in their structure that characterize each of the above-mentioned solvents. In such cases, the organic solvent shall be considered to belong to any of the solvent categories that contain the functional groups it possesses. For example, diethylene glycol monomethyl ether shall belong to either the alcohol-based solvent or the ether-based solvent category in the above classification. Hydrocarbon solvents consist of hydrocarbons that may be halogenated and do not have substituents other than halogen atoms. Fluorine atoms are preferred as the halogen atom. Among the above, polar solvents are preferred as organic solvents contained in organic developers, and ketone solvents, ester solvents, nitrile solvents, etc., are preferred.

[0378] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, and methyl amyl ketone (2-heptanone). Among these, methyl amyl ketone (2-heptanone) is preferred as the ketone solvent.

[0379] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyethyl acetate, ethyl ethoxyethyl acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl 4-Ethoxybutyl acetate, 4-Propoxybutyl acetate, 2-Methoxypentyl acetate, 3-Methoxypentyl acetate, 4-Methoxypentyl acetate, 2-Methyl-3-Methoxypentyl acetate, 3-Methyl-3-Methoxypentyl acetate, 3-Methyl-4-Methoxypentyl acetate, 4-Methyl-4-Methoxypentyl acetate, Propylene glycol diacetate, Methyl formate, Ethyl formate, Butyl formate, Propyl formate, Ethyl lactate, Butyl lactate, Propyl lactate Examples include butyl acetate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, etc. Among these, butyl acetate is preferred as the ester solvent.

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

[0381] Organic developers may contain known additives as needed. Examples of such additives include surfactants. While not particularly limited, surfactants such as ionic or nonionic fluorine-based and / or silicone-based surfactants can be used. Nonionic surfactants are preferred, with nonionic fluorine-based surfactants or nonionic silicone-based surfactants being more preferred. When a surfactant is added, the amount added is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and more preferably 0.01 to 0.5% by mass, relative to the total amount of the organic developer.

[0382] 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).

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

[0384] 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).

[0385] According to the resist pattern formation method of this embodiment described above, since the above-mentioned resist composition is used, it is possible to form a resist pattern that is highly sensitive, has reduced film loss, and exhibits good roughness reduction. [Examples]

[0386] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0387] <Manufacturing of polymer compounds> The polymer compounds (A1-1) to (A1-11) and (A2-1) to (A2-7) used in this example were obtained by radical polymerization using monomers that induce the constituent units of each polymer compound in a predetermined molar ratio, followed by a deprotection reaction. For each obtained polymer compound, the weight-average molecular weight (Mw) and molecular weight dispersion (Mw / Mn) were determined by GPC measurement (converted to standard polystyrene). Furthermore, for each obtained polymer compound, the copolymerization composition ratio (the proportion (molar ratio) of each constituent unit in the structural formula) was determined by the carbon-13 nuclear magnetic resonance spectrum (600 MHz_ 13 This was determined by 13C-NMR.

[0388] [ka]

[0389] Polymer compound (A1-1): Weight average molecular weight (Mw) 7100, molecular weight dispersity (Mw / Mn) 1.72, l / m / n=40 / 10 / 50. Polymer compound (A1-2): Weight average molecular weight (Mw) 7200, molecular weight dispersity (Mw / Mn) 1.74, l / m / n=30 / 20 / 50. Polymer compound (A1-3): Weight average molecular weight (Mw) 7100, molecular weight dispersity (Mw / Mn) 1.72, l / m / n=20 / 30 / 50. Polymer compound (A1-4): Weight average molecular weight (Mw) 6800, molecular weight dispersity (Mw / Mn) 1.73, l / m / n=30 / 20 / 50. Polymer compound (A1-5): Weight average molecular weight (Mw) 7300, molecular weight dispersity (Mw / Mn) 1.77, l / m / n=30 / 20 / 50. Polymer compound (A1-6): Weight average molecular weight (Mw) 7100, molecular weight dispersity (Mw / Mn) 1.69, l / m / n=30 / 20 / 50. Polymer compounds (A1-1) to (A1-3) are identical in their constituent units, but differ in the ratio of each constituent unit.

[0390] [ka]

[0391] Polymer compound (A1-7): Weight average molecular weight (Mw) 6900, molecular weight dispersity (Mw / Mn) 1.73, l / m / n=30 / 20 / 50. Polymer compound (A1-8): Weight average molecular weight (Mw) 7500, molecular weight dispersity (Mw / Mn) 1.77, l / m / n=30 / 20 / 50. Polymer compound (A1-9): Weight average molecular weight (Mw) 7200, molecular weight dispersity (Mw / Mn) 1.71, l / m / n=30 / 20 / 50. Polymer compound (A1-10): Weight average molecular weight (Mw) 7600, molecular weight dispersity (Mw / Mn) 1.78, l / m / n=30 / 20 / 50. Polymer compound (A1-11): Weight average molecular weight (Mw) 7100, molecular weight dispersity (Mw / Mn) 1.72, l / m / n=30 / 20 / 50.

[0392] [ka]

[0393] Polymer compound (A2-1): Weight average molecular weight (Mw) 6900, molecular weight dispersity (Mw / Mn) 1.73, l / m / n=30 / 20 / 50. Polymer compound (A2-2): Weight average molecular weight (Mw) 6100, molecular weight dispersity (Mw / Mn) 1.83, l / m / n=30 / 20 / 50. Polymer compound (A2-3): Weight average molecular weight (Mw) 6300, molecular weight dispersity (Mw / Mn) 1.55, l / m=50 / 50. Polymer compound (A2-4): Weight average molecular weight (Mw) 7400, molecular weight dispersity (Mw / Mn) 1.80, l / m / n=30 / 20 / 50.

[0394] [ka]

[0395] Polymer compound (A2-5): Weight average molecular weight (Mw) 7700, molecular weight dispersity (Mw / Mn) 1.81, l / m / n=30 / 20 / 50. Polymer compound (A2-6): Weight average molecular weight (Mw) 6500, molecular weight dispersity (Mw / Mn) 1.65, l / m / n=30 / 20 / 50. Polymer compound (A2-7): Weight average molecular weight (Mw) 7500, molecular weight dispersity (Mw / Mn) 1.76, l / m / n=30 / 20 / 50.

[0396] <Preparation of the resist composition> (Examples 1-28, Comparative Examples 1-8) Each of the components shown in Tables 1-3 was mixed and dissolved to prepare the resist compositions for each example.

[0397] [Table 1]

[0398] [Table 2]

[0399] [Table 3]

[0400] In Tables 1-3, each abbreviation has the following meaning. The numbers in brackets [ ] represent the amount (parts by mass) of the ingredients. (A1)-1 to (A1)-11: The above polymer compounds (A1-1) to (A1-11). (A2)-1~(A2)-7: The above polymer compounds (A2-1)~(A2-7). (B0)-1 to (B0)-10: Acid generators consisting of compounds represented by the following chemical formulas (B0-1) to (B0-10).

[0401] [ka]

[0402] [ka]

[0403] [ka]

[0404] (B1)-1: An acid generator consisting of a compound represented by the following chemical formula (B1-1). (D)-1: An acid diffusion control agent consisting of a compound represented by the following chemical formula (D-1). (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60 / 40 (mass ratio).

[0405] [ka]

[0406] <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 lithography (exposure) using an electron beam lithography system JEOL JBX-9300FS (manufactured by JEOL Ltd.) at an acceleration voltage of 100kV, with a target size of a 1:1 line-and-space pattern (hereinafter referred to as "LS pattern") with a line width of 50nm. 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.). Afterward, a 15-second rinse was performed using pure water. As a result, a 1:1 LS pattern with a line width of 50 nm was formed.

[0407] [Evaluation of optimal exposure (Eop)] The optimal exposure amount Eop(μC / cm²) for forming the target-sized LS pattern through the above <resist pattern formation> method is to form the resist pattern. 2 We calculated this as "Eop(μC / cm²)". 2 )" is shown in Tables 4-6.

[0408] [LWR (Line Wise Roughness) Evaluation] For the LS pattern formed in the above <Formation of Resist Pattern>, 3σ, a measure of LWR, was determined. This is shown as "LWR(nm)" in Tables 4-6. "3σ" represents three times the standard deviation (σ) (unit: nm) obtained from measurements of 400 line positions along the longitudinal direction of the line using a scanning electron microscope (acceleration voltage 800V, product name: S-9380, manufactured by Hitachi High-Tech Corporation). A smaller value of 3σ indicates less roughness on the line sidewalls, resulting in a more uniformly wide LS pattern.

[0409] [Resolution evaluation] The limiting resolution in the above Eop, specifically the minimum space width of the pattern that can be resolved when gradually decreasing the exposure from the optimal exposure Eop to form the LS pattern, was determined using a scanning electron microscope S-9380 (Hitachi High-Technologies Corporation). This is shown as "resolution (nm)" in Tables 4-6.

[0410] [Evaluation of residual film percentage] The residual film rate was determined by measuring the thickness of the resist film after PAB in the large unexposed area described above (<Formation of Resist Pattern>) and after rinsing, and calculating the residual film rate (%) from the decrease in thickness. This is shown as "Residual Film Rate (%)" in Tables 4-6.

[0411] [Table 4]

[0412] [Table 5]

[0413] [Table 6]

[0414] As shown in Tables 4-6, the resist compositions of Examples 1-28 were found to exhibit higher sensitivity in resist pattern formation, suppressed film loss, and superior roughness reduction compared to the resist compositions of Comparative Examples 1-8.

[0415] • Position of the hydroxyl group in polyhydroxystyrene From a comparison of the resist compositions of Example 2 and Comparative Examples 1 and 2, it was confirmed that the evaluation results differed significantly depending on the position of the hydroxyl group in polyhydroxystyrene. The resist composition of Example 2 contains a polymer compound (A1-2) which includes a structural unit having a hydroxyl group at the meta position. The resist composition of Comparative Example 1 contains a polymer compound (A2-1) that includes a structural unit having a hydroxyl group at the para position. The resist composition of Comparative Example 2 contains a polymer compound (A2-2) that includes a structural unit having a hydroxyl group in the ortho position. Although the resist composition of Comparative Example 1 had high sensitivity, the residual film rate was inferior to that of the resist composition of Example 2 because the polymer compound (A2-1) had higher solubility in the developer than the polymer compound (A1-2). Furthermore, the LWR was also inferior due to the lower residual film rate. The resist composition of Comparative Example 2 showed a significant decrease in acid generation efficiency, resulting in inferior Eop and resolution compared to the resist composition of Example 2.

[0416] • Structure of lactone-containing cyclic groups (monocyclic, polycyclic) A comparison of the resist compositions in Example 2 and Comparative Example 4 confirmed that the evaluation results differed significantly depending on the structure of the lactone-containing cyclic group. The resist composition of Example 2 contains polymer compounds (A1-2) that include structural units having polycyclic lactone-containing cyclic groups. The resist composition of Comparative Example 4 contains a polymer compound (A2-4) that includes a constituent unit having a monocyclic lactone-containing cyclic group. Because polymer compound (A2-4) has a lower Tg than polymer compound (A1-2), the acid diffusion length suppression effect was reduced in the resist composition of Comparative Example 4, resulting in inferior LWR and resolution compared to the resist composition of Example 2.

[0417] • Ratio of constituent unit (a01) to constituent unit (a02) A comparison of the resist compositions of Examples 1 to 3 revealed that the resist compositions of Examples 1 and 2, which had a higher proportion of constituent unit (a02) than constituent unit (a01), exhibited superior Eop, LWR, resolution, and residual film rate compared to the resist composition of Example 3.

[0418] • Number of iodine atoms in the anionic part of component (B0) A comparison of the resist compositions of Examples 4-12 revealed that the resist compositions of Examples 4, 5, and 9-12, which contain component (B0) with three iodine atoms in the anionic portion, exhibited superior Eop, LWR, resolution, and residual film ratio compared to the resist composition of Example 6, which contains component (B0) with one iodine atom in the anionic portion, and the resist compositions of Examples 4 and 5, which contain component (B0) with two iodine atoms in the anionic portion. This suggests that increasing the number of iodine atoms increased the electron beam absorption efficiency, improving Eop and resolution. Furthermore, it is presumed that increasing the number of iodine atoms decreased solubility in the developer, improving the residual film ratio, which in turn improved LWR. The importance of having iodine atoms in the anionic portion can be confirmed by comparing the resist compositions of Examples 2, 6, and 8, which differ only in the number of iodine atoms in the anionic portion of the acid generator.

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 an acid-generating agent component (B) that generates acid upon exposure, The resin component (A1) includes a polymer compound having a constituent unit (a1) represented by the following general formula (a1-1) or (a1-2), a constituent unit (a01) represented by the following general formula (a0-1), and a constituent unit (a02) represented by the following general formula (a0-2). The proportion of the aforementioned constituent unit (a1) is 10 to 90 mol% of the total amount of all constituent units (100 mol%) that make up the polymer compound. The proportion of the aforementioned constituent unit (a01) is 1 to 70 mol% of the total amount of all constituent units (100 mol%) that make up the polymer compound. The proportion of the aforementioned constituent unit (a02) is 1 to 70 mol% relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. The acid generator component (B) is a resist composition comprising a compound (B0) represented by the following general formula (b0). 【Chemistry 1】 [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. 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 following general formula (a1-r-1) or (a1-r-2). Wa １ han 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 following general formula (a1-r-1) or (a1-r-3). 【Chemistry 2】 [In the formula, Ra' １ , Ra' ２ is a hydrogen atom or an alkyl group. Ra' ３ is a hydrocarbon group, and Ra' ３ may combine with any one of Ra' １ , Ra' ２ to form a ring.] 【Transformation 3】 [In the formula, Ra' ４ ~Ra' ６ Each of these is a hydrocarbon group, Ra' ５ , Ra' ６ They may be joined to each other to form a ring. 【Chemistry 4】 [In the formula, Ra' ７ ~Ra' ９ These are each alkyl groups. 【Transformation 5】 [In the formula, R ０１ This is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. ０１ It is a single bond or a divalent linking group. La ０１ The group is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. However, La ０１ If -O-, Ya ０１ It does not become -CO-. Ra ０１ This is a polycyclic lactone-containing cyclic group represented by the following general formula (a01-r-1). 【Transformation 6】 [In the formula, Ra' ２１ Each of these is independently 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, a carbonate-containing cyclic group, or -SO ２ - It contains a cyclic group. n01 is an integer from 0 to 3. A'' is a methylene group or -O-. 【Transformation 7】 [In formula (a0-2), R ０２ Ra is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. ０５ ~Ra ０８ This is a hydrogen atom. 【Transformation 8】 [In the formula, X ０ R is a bromine atom or an iodine atom. ｍ This is a hydroxyl group, an alkyl group, a fluorine atom, or a chlorine atom. nb1 is an integer between 1 and 5, nb2 is an integer between 0 and 4, and 1 ≤ nb1 + nb2 ≤ 5. Yb ０ Vb is a divalent linking group or a single bond. ０ R is a single bond, an alkylene group, or a fluorinated alkylene group. ０ This is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. ｍ＋ This represents an m-valent organic cation, where m is an integer greater than or equal to 1.

2. The resist composition according to claim 1, wherein the compound (B0) comprises a compound (B01) represented by the following general formula (b0-1). 【Chemistry 9】 [In the formula, X ０ R is a bromine atom or an iodine atom. ｍ This is a hydroxyl group, an alkyl group, a fluorine atom, or a chlorine atom. nb1 is an integer between 1 and 5, nb2 is an integer between 0 and 4, and 1 ≤ nb1 + nb2 ≤ 5. ０１ and L ０２ These are, independently, a single bond, an alkylene group, -O-, -CO-, -OCO-, -COO-, and -SO-, respectively. ２ -, -N(R ａ )-C(=O)-,-N(R ａ )-,-C(R ａ ) (Caution ａ )-N(R ａ )-,-C(R ａ ) (N(R ａ ) (Caution ａ ))-, or -C(=O)-N(R ａ ) - is R ａ Each of these is independently either a hydrogen atom or an alkyl group. z is an integer between 0 and 10. Vb ０ R is a single bond, an alkylene group, or a fluorinated alkylene group. ０ This is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. ｍ＋ This represents an m-valent organic cation, where m is an integer greater than or equal to 1.

3. The resist composition according to claim 1 or 2, wherein the molar ratio (a01:a02) of the constituent unit (a01):a02 in the resin component (A1) is 10:90 to 45:

55.

4. The resist composition according to any one of claims 1 to 3, wherein the constituent unit (a01) is a constituent unit represented by the following general formula (a0-1-1). 【Chemistry 10】 [In the formula, R ０１ This is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. Va ０１ n is a divalent linking group. ａ０１ Ra' is an integer between 0 and 2. ２１ is an alkyl group, alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, -COOR'', -OC(=O)R'', hydroxyalkyl group or cyano group; R'' is a hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or -SO ２ - It contains a cyclic group. n01 is an integer from 0 to 3. A'' is a methylene group or -O-.

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

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