Resist composition, resist pattern formation method, and compound

Abstract

To provide a resist composition which achieves high sensitivity and improves resolution, when a resist pattern is formed, a resist pattern formation method using the resist composition, and a compound which is useful as a raw material of a base material component used in the resist composition.SOLUTION: A resist composition contains a resin component (A1) having a structural unit represented by general formula (a0-0). Ra01 is an acid dissociable group represented by formula (a0-ra). R02 and R03 form a chain hydrocarbon group or a cyclic group, and have a carbon-carbon unsaturated bond. A group which is selected from a hydroxy group, a carboxy group, a sulfo group, an amino group, a phosphate group, an amide group, an ether group, an imino group and a thioether group and has 10 or less carbon atoms is bonded to at least one of the carbon atoms constituting the carbon-carbon unsaturated bond.SELECTED DRAWING: None

Description

[Technical Field]

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

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

[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. In chemically amplified resist compositions, a resin having multiple structural units is generally used as the substrate component to improve lithography properties and other characteristics.

[0004] For example, Patent Document 1 discloses a resist composition containing a resin component having a structural unit to which an acid-dissociable group having an unsaturated bond is attached. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-085916 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Further advancements in lithography technology and the expansion of its application fields are leading to rapid miniaturization of patterns. Consequently, when manufacturing semiconductor devices and other components, there is a demand for technologies that can form fine patterns with good shape. For example, in EUV and EB lithography, the goal is to form fine patterns of several tens of nanometers. However, conventional resist compositions, such as those described in Patent Document 1, require further improvement in resolution.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a resist composition that can be made highly sensitive and has improved resolution when forming a resist pattern, a method for forming a resist pattern using the resist composition, and a compound useful as a raw material for a substrate component used in the resist composition. [Means for solving the problem]

[0008] To solve the above problems, the present invention employs the following configuration. In other words, a first aspect of the present invention is a resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition containing a resin component (A1) whose solubility in a developer changes due to the action of the acid, wherein the resin component (A1) has a constituent unit (a0) represented by the following general formula (a0-0).

[0009] [ka] [In the formula, R 01 This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, or a hydrogen atom. 01 This is a divalent linking group or a single bond. 01is an acid dissociable group represented by the formula (a0-ra). * in the formula (a0-ra) represents a bond with the oxygen atom (-O-) in the formula (a0-0). C 01 is a secondary carbon atom or a tertiary carbon atom. C 01 When C is a secondary carbon atom, R 02 and R 03 are each independently a chain hydrocarbon group which may have a substituent, or R<000000۸>and R<000000۹>are bonded to each other to form a cyclic group which may have a substituent together with C 01 , and R 04 is a hydrogen atom. R 02 and R 03 When R and R are chain hydrocarbon groups which may have a substituent, one or more of the chain hydrocarbon groups formed by R 02 and R 03 has a carbon-carbon unsaturated bond formed by the carbon atom at the α-position of C[[ID=۲۷]] 01 [[ID=۲۸]]and the carbon atom at the β-position of C[[ID=۲۹]] 01 [[ID=۳۰]]. R[[ID=۳۱]] 02 [[ID=۳۲]]and R[[ID=۳۳]] 03 [[ID=۳۴]]are bonded to each other to form a cyclic group which may have a substituent together with C[[ID=۳۵]] 01 [[ID=۳۶]], when R[[ID=۳۷]] 02 [[ID=۳۸]]and R[[ID=۳۹]] 03 [[ID=۴۰]]the cyclic group formed by has a carbon-carbon unsaturated bond formed by the carbon atom at the α-position of C[[ID=۴۱]] 01 [[ID=۴۲]]and the carbon atom at the β-position of C[[ID=۴۳]] 01 [[ID=۴۴]]. At least one of the carbon atoms constituting the carbon-carbon unsaturated bond in R[[ID=۴۵]] 02 [[ID=۴۶]]and R[[ID=۴۷]] 03 [[ID=۴۸]]is bonded to a group having 10 or less carbon atoms and selected from the group consisting of a hydroxy group, a carboxy group, a sulfo group, an amino group, a phosphoric acid group, an amide group, an ether group, an imino group and a thioether group. [[ID=۴۹]] [[ID=۵۰]]C[[ID=۵۱]] 01 [[ID=۵۲]]When C is a tertiary carbon atom, R[[ID=۵۳]] 02 [[ID=۵۴]]and R[[ID=۵۵]] 03 [[ID=۵۶]]are each independently a chain hydrocarbon group which may have a substituent, or R[[ID=۵۷]] 02 [[ID=۵۸]]and R[[ID=۵۹]] 03 [[ID=۶۰]]are bonded to each other to form C[[ID=۶۱]] 01Together, it forms a cyclic group which may have substituents, R 04 R is a chain-like hydrocarbon group which may have substituents. 02 and R 03 If R is a chain-like hydrocarbon group which may have substituents, 02 , R 03 and R 04 One or more of the chain-like hydrocarbon groups formed by have a carbon-carbon unsaturated bond. 02 and R 03 and are combined with each other, C 01 When forming a cyclic group which may have substituents, R 02 and R 03 The cyclic group formed by and R 04 One or more of the chain-like hydrocarbon groups formed by the group have a carbon-carbon unsaturated bond. 02 , R 03 and R 04 In the above, at least one of the carbon atoms constituting the carbon-carbon unsaturated bond is bonded to a group having 10 or fewer carbon atoms, which is selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfo group, an amino group, a phosphate group, an amide group, an ether group, an imino group, and a thioether group.

[0010] 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.

[0011] A third aspect of the present invention is a compound represented by the following general formula (a0-m0).

[0012] [ka] [In the formula, R 01 This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, or a hydrogen atom. 01 This is a divalent linking group or a single bond. 01This is an acid-dissociating group represented by formula (a0-ra). In formula (a0-ra), * represents a bond with the oxygen atom (-O-) in formula (a0-m0). C 01 These are secondary or tertiary carbon atoms. C 01 If R is a secondary carbon atom, 02 and R 03 Each of these is independently a chain hydrocarbon group which may have substituents, or R 02 and R 03 and are combined with each other, C 01 Together, it forms a cyclic group which may have substituents, R 04 R is a hydrogen atom. 02 and R 03 If R is a chain-like hydrocarbon group which may have substituents, 02 and R 03 One or more of the chain-like hydrocarbon groups formed by are C 01 The carbon atom at the α position and C 01 It has a carbon-carbon unsaturated bond formed by the carbon atom at the β position. 02 and R 03 and are combined with each other, C 01 When forming a cyclic group which may have substituents, R 02 and R 03 The cyclic group formed by is C 01 The carbon atom at the α position and C 01 It has a carbon-carbon unsaturated bond formed by the carbon atom at the β position. 02 and R 03 In the above, at least one of the carbon atoms constituting the carbon-carbon unsaturated bond is bonded to a group having 10 or fewer carbon atoms, which has one or more selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfo group, an amino group, a phosphate group, an amide group, an ether group, an imino group, and a thioether group. C 01 If R is a tertiary carbon atom, 02 and R 03 Each of these is independently a chain hydrocarbon group which may have substituents, or R 02 and R 03 and are combined with each other, C 01Together with, it forms a cyclic group which may have a substituent, R 04 is an optionally substituted chain hydrocarbon group. R 02 and R 03 is an optionally substituted chain hydrocarbon group, when R 02 、R 03 and R 04 one or more of the chain hydrocarbon groups formed by have a carbon-carbon unsaturated bond. R 02 and R 03 are bonded to each other to form, together with C 01 a cyclic group which may have a substituent, when R 02 and R 03 the cyclic group formed by and R 04 one or more selected from the group consisting of the chain hydrocarbon group formed by have a carbon-carbon unsaturated bond. R 02 、R 03 and R 04 At least one of the carbon atoms constituting the carbon-carbon unsaturated bond in is bonded to a group having 10 or less carbon atoms selected from the group consisting of a hydroxy group, a carboxy group, a sulfo group, an amino group, a phosphoric acid group, an amide group, an ether group, an imino group and a thioether group.]

Advantages of the Invention

[0013] According to the present invention, when forming a resist pattern, a resist composition capable of achieving high sensitivity and further improving resolution, a resist pattern forming method using the resist composition, and a compound useful as a raw material for a substrate component used in the resist composition can be provided.

Modes for Carrying Out the Invention

[0014] In this specification and the claims, "aliphatic" is a relative concept with respect to aromatic, and is defined to mean a group, compound, etc. having no aromaticity. "Alkyl group" includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in an alkoxy group. Unless otherwise specified, the "alkylene group" shall include linear, branched and cyclic divalent saturated hydrocarbon groups. Examples of the "halogen atom" include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. The "constitutional unit" means a monomer unit (monomeric unit) that constitutes a high molecular compound (resin, polymer, copolymer). When it is described that "it may have a substituent", it includes both the case where a hydrogen atom (-H) is substituted with a monovalent group and the case where a methylene group (-CH2-) is substituted with a divalent group. "Exposure" is a concept that includes the entire irradiation of radiation.

[0015] The "acid-decomposable group" is a group having acid-decomposability in which at least a part of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group. Examples of the polar group include a carboxy group, a hydroxy group, an amino group, a sulfo group (-SO3H), etc. More specifically, examples of the acid-decomposable group include a group in which the polar group is protected by an acid dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid dissociable group).

[0016] The "acid dissociable group" refers to both (i) a group having acid dissociability in which the bond between the acid dissociable group and the atom adjacent to the acid dissociable group can be cleaved by the action of an acid, or (ii) a group in which, after a part of the bonds are cleaved by the action of an acid, a decarboxylation reaction further occurs, whereby the bond between the acid dissociable group and the atom adjacent to the acid dissociable group can be cleaved. The acid dissociable group that constitutes the acid-decomposable group needs to be a group with lower polarity than the polar group generated by the dissociation of the acid dissociable group. Thus, when the acid dissociable group dissociates by the action of an acid, a polar group with higher polarity than the acid dissociable group is generated, increasing the polarity. As a result, the polarity of the entire (A1) component increases. By increasing the polarity, relatively, the solubility in the developer changes. When the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility decreases.

[0017] The "base material component" is an organic compound having film-forming ability. The organic compounds used as the base material component are roughly classified into non-polymers and polymers. As the non-polymer, usually, those with a molecular weight of 500 or more and less than 4000 are used (hereinafter referred to as "low molecular weight compounds"). Hereinafter, when referring to "resin", "high molecular weight compound" or "polymer", it indicates a polymer with a molecular weight of 1000 or more. The molecular weight of the polymer shall be the weight average molecular weight in terms of polystyrene by GPC (gel permeation chromatography).

[0018] The "derived structural unit" means a structural unit formed by the cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond. The "acrylic acid ester" may have a hydrogen atom bonded to the α-position carbon atom substituted by a substituent. The substituent (R αx ) is an atom or group other than a hydrogen atom. Also, it shall include itaconic acid diesters in which the substituent (R[[ID=1s]] αx ) is substituted by a substituent containing an ester bond, and α-hydroxyacrylic esters in which the substituent (R αx ) is substituted by a hydroxyalkyl group or a group obtained by modifying its hydroxyl group. The α-position carbon atom of the acrylic acid ester is, unless otherwise specified, the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, the acrylic acid ester in which the hydrogen atom bonded to the α-position carbon atom is substituted by a substituent may be referred to as an α-substituted acrylic acid ester.

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

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

[0021] (Resist composition) The resist composition 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. In the resist composition of this embodiment, component (A) includes a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer solution changes due to the action of an acid. Component (A1) has a constituent unit (a0) represented by the general formula (a0-0) described later. Furthermore, the resist composition of this embodiment may further contain other components in addition to component (A). Examples of other components include components (B), (D), (E), (F), and (S), which will be described later.

[0022] In the resist composition of this embodiment, component (A) may generate acid upon exposure, or an additive component formulated separately from component (A) may generate acid upon exposure. The resist composition of this embodiment may specifically (1) further contain an acid generating agent component (B) (hereinafter referred to as "component (B)") that generates acid upon exposure; (2) component (A) may be a component that generates acid upon exposure; or (3) component (A) may be a component that generates acid upon exposure and also contains component (B). In other words, in the cases of (2) and (3) above, component (A) is a "base component that generates acid upon exposure and whose solubility in the developer changes due to the action of the acid." When component (A) is a base component that generates acid upon exposure and whose solubility in the developer changes due to the action of the acid, it is preferable that component (A1), described later, is a resin that generates acid upon exposure and whose solubility in the developer changes due to the action of the acid. As such a resin, a polymer compound having a constituent unit that generates acid upon exposure can be used. As a constituent unit that generates acid upon exposure, the constituent unit (a5) described later can be used.

[0023] In this embodiment, the resist composition is preferably the one described in (1) above. That is, the resist composition of this embodiment preferably contains component (A) and component (B).

[0024] When a resist film is formed using the resist composition of this embodiment and selective exposure is performed on the resist film, for example, acid is generated from component (B) in the exposed areas of the resist film, and the solubility of component (A) in the developer changes due to the action of this acid, while the solubility of component (A) in the developer does not change in the unexposed areas of the resist film. As a result, a difference in solubility in the developer occurs between the exposed and unexposed areas. Therefore, when the resist film is developed, if the resist composition is positive type, the exposed areas of the resist film are dissolved and removed to form a positive type resist pattern, and if the resist composition is negative type, the unexposed areas of the resist film are dissolved and removed to form a negative type resist pattern.

[0025] The resist composition of this embodiment may be a positive-type resist composition or a negative-type resist composition. Furthermore, the resist composition of this embodiment may be for an alkaline development process that uses an alkaline developer for the development process during resist pattern formation, or for a solvent development process that uses a developer containing an organic solvent (organic developer) for the development process.

[0026] <(A) component> In the resist composition of this embodiment, 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.

[0027] In the resist composition of this embodiment, component (A) may be used alone or in combination of two or more types.

[0028] (A1) About the ingredients Component (A1) is a resin component whose solubility in the developer changes due to the action of acid. Component (A1) has a constituent unit (a0) represented by the general formula (a0-0) described below. (A1) component may have other structural units in addition to the structural unit (a0) if necessary.

[0029] ≪Structural unit (a0)≫ The structural unit (a0) is a structural unit represented by the following general formula (a0-0). In such a structural unit (a0), Ra in the formula (a0-0) 01 is an acid-dissociable group, and this acid-dissociable group protects the oxygen atom (-O-) side of the carbonyloxy group [-C(=O)-O-] in the formula (a0-0). Here, the "acid-dissociable group" has acid-dissociability such that the bond between the acid-dissociable group and the oxygen atom (oxy group (-O-)) adjacent to the acid-dissociable group can be cleaved by the action of an acid. When the acid-dissociable group dissociates due to the action of an acid, a polar group (carboxy group) having a higher polarity than the acid-dissociable group is generated, and the polarity increases. As a result, the polarity of the whole (A1) component increases. Due to the increase in polarity, the solubility of the (A1) component in the developer changes relatively. When the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility decreases.

[0030]

Chemical formula

[0031] In the above equation (a0-0), 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 hydrogen atom is particularly preferred.

[0032] In the above equation (a0-0), Ya 01 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.

[0033] Ya 01 Among the above, it is preferable that the group is an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group or a combination thereof, or a single bond.

[0034] Ya 01 In this product, the linear alkylene 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. Examples of linear alkylene groups include methylene group [-CH2-], ethylene group [-(CH2)2-], trimethylene group [-(CH2)3-], tetramethylene group [-(CH2)4-], and pentamethylene group [-(CH2)5-]. Ya 01 In this product, the branched alkylene 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. Examples of branched alkylene groups include 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 alkyltetramethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2CH2-. In the alkylalkylene group, linear alkyl groups having 1 to 5 carbon atoms are preferred.

[0035] The linear or branched alkylene group described above may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0036] Ya 01 In this context, an aromatic 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.

[0037] The aforementioned aromatic 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, with alkoxy groups and hydroxyl groups being preferred from the viewpoint of increasing sensitivity. 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, a methoxy group and an ethoxy group are even more preferred, and a methoxy group is particularly 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.

[0038] Ya 01 The combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group, a combination of an ester bond [-C(=O)-O-, -OC(=O)-] and an aromatic hydrocarbon group, or a single bond is more preferable, and a combination of an ester bond [-C(=O)-O-, -OC(=O)-] and an aromatic hydrocarbon group, or a single bond is even more preferable.

[0039] C 01 If R is a secondary carbon atom, 02 and R 03 Each of these may independently be a chain-like hydrocarbon group which may have substituents. The number of carbon atoms in the chain-like hydrocarbon group is preferably 1 to 20, more preferably 1 to 15, even more preferably 1 to 10, and particularly preferably 1 to 5. R 02 and R 03 If is a chain hydrocarbon group which may have substituents, then R which has a carbon-carbon unsaturated bond 02 or R 03 The number of carbon atoms is preferably 2 to 20, more preferably 2 to 15, even more preferably 2 to 10, and particularly preferably 2 to 5. R 02 and R 03 The chain-like hydrocarbon group in the above may be linear or branched.

[0040] The substituents that the chain hydrocarbon group may have are not particularly limited, for example, -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" below) 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.

[0041] Alternatively, C 01 If R is a secondary carbon atom, 02 and R 03 and are combined with each other, C 01Along with this, a cyclic group which may have substituents may be formed. The cyclic group is preferably an alicyclic hydrocarbon group. An alicyclic hydrocarbon group means a cyclic group which does not have aromaticity. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group, and a monocyclic group is preferred. When the cyclic group is an alicyclic hydrocarbon group, the alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12, and even more preferably 3 to 8 carbon atoms. The substituents that the cyclic group may have are not particularly limited and include the same substituents that the chain hydrocarbon group may have.

[0042] C 01 If C is a secondary carbon atom, 01 Preferably, the α-carbon atom of the atom is bonded to a group having 10 or fewer carbon atoms, which has one or more groups selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfo group, an amino group, a phosphate group, an amide group, an ether group, an imino group, and a thioether group.

[0043] C 01 If R is a secondary carbon atom, 02 and R 03 In this material, it is preferable that at least one of the carbon atoms constituting the carbon-carbon unsaturated bond has a group having 10 or fewer carbon atoms, which is selected from the group consisting of a hydroxyl group and an ether group, bonded to it, and more preferably a group having 10 or fewer carbon atoms and which has an ether group.

[0044] C 01 The following are specific examples of acid-dissociable groups when is a secondary carbon atom. In the following formulas, * represents the bond with the oxygen atom (-O-) in formula (a0-0).

[0045] [ka]

[0046] [ka]

[0047] [ka]

[0048] C 01 If R is a tertiary carbon atom, 02 and R 03 Each of these may independently be a chain-like hydrocarbon group which may have substituents. R 02 and R 03 If is a chain hydrocarbon group which may have substituents, the chain hydrocarbon group is C 01 When R is a secondary carbon atom, 02 and R 03 Examples of chain hydrocarbon groups that may have substituents are similar to those listed above. R 02 and R 03 If R is a chain-like hydrocarbon group which may have substituents, 02 , R 03 and R 04 One or more of the chain-like hydrocarbon groups formed by are C 01 The carbon atom at the α position and C 01 It is preferable that the atom has a carbon-carbon unsaturated bond formed with the carbon atom at the β position.

[0049] Alternatively, C 01 If R is a tertiary carbon atom, 02 and R 03 and are combined with each other, C 01 Along with this, a cyclic group which may have substituents may be formed. The aforementioned cyclic group is C 01 When R is a secondary carbon atom, 02 and R 03 and are combined with each other, C 01 In addition, the same types of cyclic groups that may have substituents as listed above can be cited. The aforementioned cyclic group is C 01 The carbon atom at the α position and C01 It is preferable that the atom has a carbon-carbon unsaturated bond formed with the carbon atom at the β position. C 01 The carbon atom at the α position and C 01 The carbon-carbon unsaturated bond that can be formed with the carbon atom at the β position preferably forms part of the ring structure of the cyclic group.

[0050] C 01 If C is a tertiary carbon atom, 01 Preferably, the α-carbon atom of the atom is bonded to a group having 10 or fewer carbon atoms, which has one or more groups selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfo group, an amino group, a phosphate group, an amide group, an ether group, an imino group, and a thioether group.

[0051] C 01 If R is a tertiary carbon atom, 02 , R 03 and R 04 In this material, it is preferable that at least one of the carbon atoms constituting the carbon-carbon unsaturated bond is bonded to a group having 10 or fewer carbon atoms, which has one or more selected from the group consisting of a hydroxyl group and an ether group, and it is more preferable that a group having 10 or fewer carbon atoms and an ether group is bonded to it.

[0052] C 01 The following are specific examples of acid-dissociable groups when is a tertiary carbon atom. In the following formulas, * represents the bond with the oxygen atom (-O-) in formula (a0-0).

[0053] [ka]

[0054] [ka]

[0055] The aforementioned structural unit (a0) is preferably a structural unit represented by the following general formula (a0-1) because it is easier to improve sensitivity and resolution.

[0056] [ka] [In the formula, Ya x1 Wa is a single bond or a divalent linking group. x1 R is an aromatic hydrocarbon group which may have substituents. 01 and Ra 01 These are, respectively, R in the above formula (a0-0). 01 and Ra 01 It is identical to [this].

[0057] 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. 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.

[0058] Wa x1 Examples of aromatic hydrocarbon groups include groups obtained by removing two hydrogen atoms from an aromatic ring, which may have substituents. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Also, Wa x1Examples of aromatic hydrocarbon groups in this context include groups obtained by removing two hydrogen atoms from aromatic compounds containing aromatic rings that may have substituents (e.g., biphenyl, fluorene, etc.). Among the above, Wa x1 Preferably, the group is one obtained by removing two hydrogen atoms from benzene, naphthalene, anthracene, or biphenyl; more preferably, one obtained by removing two hydrogen atoms from benzene or naphthalene; and even more preferably, one obtained by removing two hydrogen atoms from benzene.

[0059] Wa x1 The aromatic hydrocarbon group in this compound may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, and the like. The alkyl group 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, a methoxy group and an ethoxy group are even more preferred, and a methoxy group is particularly 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. Among the substituents mentioned above, alkoxy groups and hydroxyl groups having 1 to 5 carbon atoms are preferred from the viewpoint of increasing sensitivity, and methoxy groups and hydroxyl groups are more preferred.

[0060] The following are specific examples of constituent units (a0). In each of the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0061] [ka]

[0062] The constituent units (a0) of component (A1) may be one type or two or more types. The proportion of constituent units (a0) in component (A1) is preferably 40 to 80 mol%, more preferably 45 to 75 mol%, and even more preferably 45 to 70 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). When the content of constituent unit (a0) is above the lower limit of the preferred range described above, sensitivity and resolution tend to be improved. On the other hand, keeping it below the upper limit makes it easier to balance with other constituent units.

[0063] <<Other constituent units>> Component (A1) may have other constituent units in addition to the constituent unit (a0) described above, as needed. Other constituent units include, for example, constituent units (a1) containing acid-degradable groups whose polarity increases with the action of acid (excluding those corresponding to constituent unit (a0)); constituent units (a10) represented by the general formula (a10-1) described later; constituent units (a5) that generate acid upon exposure; constituent units (a2) containing lactone-containing cyclic groups; and constituent units (a8) derived from compounds represented by the general formula (a8-1) described later.

[0064] Regarding the constituent unit (a1): Constituent unit (a1) is a constituent unit that contains an acid-degradable group whose polarity increases upon the action of an acid. However, constituent units corresponding to constituent unit (a0) are excluded from constituent unit (a1).

[0065] 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."

[0066] 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").

[0067] [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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] Ra' 3 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic alicyclic 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. As a polycyclic group, a alicyclic hydrocarbon group is preferred, which is a group obtained by removing one hydrogen atom from a polycycloalkane, and as a polycycloalkane, those having 7 to 12 carbon atoms are preferred, and specific examples include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0072] 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.

[0073] 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" below) x5 It is also called "[...]." Examples include [...]. Here, R P1This is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Also, R P2 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.

[0074] Ra' 3 However, Ra' 1 , Ra' 2 When the cyclic group is bonded to any of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0075] 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."

[0076] [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.

[0077] Ra' 4 Examples of hydrocarbon groups include linear or branched alkyl groups, linear or cyclic alkenyl groups, linear alkynyl groups, or cyclic hydrocarbon groups. Ra' 4 In the above, linear or branched alkyl groups, cyclic hydrocarbon groups (monocyclic alicyclic hydrocarbon groups, polycyclic alicyclic hydrocarbon groups, aromatic hydrocarbon groups) are defined as the 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.

[0078] Ra' 5 and Ra' 6When 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.

[0079] [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. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group that may have substituents. * indicates a bond (the same applies hereafter).

[0080] 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.

[0081] 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.

[0082] 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.

[0083] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed with the bonded carbon atom is Ra' in formula (a1-r-1). 3 The groups listed as monocyclic or polycyclic alicyclic hydrocarbon groups are preferred. Among these, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl groups and cyclohexyl groups are more preferred.

[0084] 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 (alicyclic 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.

[0085] The above Ra 101 ~Ra 103 Examples of substituents on a chain-like saturated hydrocarbon group or an aliphatic cyclic saturated hydrocarbon group represented by the above-mentioned Ra x5 Similar bases can be cited.

[0086] 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.

[0087] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Ra' in formula (a1-r-1). 3 The groups listed as monocyclic or polycyclic alicyclic hydrocarbon 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.

[0088] 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.

[0089] 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. 12 and Ra' 13In this context, the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms is the above-mentioned Ra 101 ~Ra 103 Examples include monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, hydrogen atoms and alkyl groups having 1 to 5 carbon atoms are preferred, alkyl groups having 1 to 5 carbon atoms are more preferred, methyl groups and ethyl groups are even more preferred, and methyl groups are particularly preferred. The above Ra' 12 and Ra' 13 When a chain-like saturated hydrocarbon group represented by is substituted, the substituent may be, for example, the above-mentioned Ra x5 Similar bases can be cited.

[0090] 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.

[0091] 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.

[0092] Ra' 14 The branched alkyl group in this compound preferably has 3 to 10 carbon atoms, and more preferably 3 to 5. Specifically, examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., with isopropyl group being preferred.

[0093] Ra'14 When the hydrocarbon group is a cyclic hydrocarbon group, the hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As a monocyclic alicyclic 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. As a polycyclic group, a alicyclic hydrocarbon group is preferred, which is a group obtained by removing one hydrogen atom from a polycycloalkane, and as a polycycloalkane, those having 7 to 12 carbon atoms are preferred, and specific examples include adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0094] Ra' 14 As for aromatic hydrocarbon groups in this context, Ra 104 Examples include those similar to aromatic hydrocarbon groups in [the text]. Among them, Ra' 14 The group is preferably an aromatic hydrocarbon ring having 6 to 15 carbon atoms with one or more hydrogen atoms removed; more preferably a group from benzene, naphthalene, anthracene, or phenanthrene with one or more hydrogen atoms removed; even more preferably a group from benzene, naphthalene, or anthracene with one or more hydrogen atoms removed; particularly preferably a group from naphthalene or anthracene with one or more hydrogen atoms removed; and most preferably a group from naphthalene with one or more hydrogen atoms removed. Ra' 14 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.

[0095] Ra' in equation (a1-r2-4) 14 If is a naphthyl group, the position where it bonds with the tertiary carbon atom in formula (a1-r2-4) may be either position 1 or position 2 of the naphthyl group. Ra' in equation (a1-r2-4) 14If is an anthyl group, the position where it bonds with the tertiary carbon atom in formula (a1-r2-4) may be position 1, 2, or 9 of the anthyl group.

[0096] Specific examples of the group represented by the above formula (a1-r2-1) are given below.

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] Specific examples of the group represented by the above formula (a1-r2-2) are given below.

[0101] [ka]

[0102] [ka]

[0103] [ka]

[0104] Specific examples of the group represented by the above formula (a1-r2-3) are given below.

[0105] [ka]

[0106] Specific examples of the group represented by the above formula (a1-r2-4) are given below.

[0107] [ka]

[0108] 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").

[0109] [ka] [In the formula, Ra' 7 ~Ra' 9 These are each alkyl groups.

[0110] In formula (a1-r-3), Ra' 7 ~Ra' 9 Each of these is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Furthermore, the total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0111] Secondary alkyl ester type acid-dissociating group: Among the polar groups mentioned above, an example of an acid-dissociating group that protects a carboxyl group is the acid-dissociating group represented by the following general formula (a1-r-4).

[0112] [ka] [In the formula, Ra' 10 Ra' is a hydrocarbon group. 11a and Ra' 11b Each of these is independently a hydrogen atom, a halogen atom, or an alkyl group. 12is a hydrogen atom or a hydrocarbon group. 10 and Ra' 11a Or Ra' 11b These elements may be joined together to form a ring. 11a Or Ra' 11b And, Ra' 12 These elements may be joined together to form a ring.

[0113] In the formula, Ra' 10 and Ra' 12 The hydrocarbon group in this is the Ra' 3 Similar examples include the above. In the formula, Ra' 11a and Ra' 11b The alkyl group in is the aforementioned Ra' 1 Examples include alkyl groups similar to those in the above. In the formula, Ra' 10 and Ra' 12 The hydrocarbon group in, and Ra' 11a and Ra' 11b The alkyl group in may have substituents. For example, the above-mentioned Ra is an example of such substituent. x5 These are some examples.

[0114] Ra' 10 and Ra' 11a Or Ra' 11b These elements may be bonded to each other to form a ring. This ring may be polycyclic or monocyclic, and may be an alicyclic or aromatic ring. The alicyclic and aromatic rings may also contain heteroatoms.

[0115] Ra' 10 and Ra' 11a Or Ra' 11b The rings formed by the bonding of these elements are preferably monocycloalkenes, rings in which some of the carbon atoms of a monocycloalkene are substituted with heteroatoms (oxygen atoms, sulfur atoms, etc.), monocycloalkadienes, cycloalkenes having 3 to 6 carbon atoms, and cyclopentene or cyclohexene.

[0116] Ra' 10 and Ra' 11a Or Ra' 11b The ring formed by the bonding of these elements may be a fused ring. Specific examples of such fused rings include indane.

[0117] Ra' 10 and Ra' 11a Or Ra' 11b The ring formed by the bonding of these elements may have substituents. For example, the above-mentioned Ra x5 These are some examples.

[0118] Ra' 11a Or Ra' 11b And, Ra' 12 These elements may be bonded together to form a ring, and the ring may be Ra' 10 and Ra' 11a Or Ra' 11b Examples include rings formed by the bonding of these elements together.

[0119] Specific examples of the group represented by the above formula (a1-r-4) are given below.

[0120] [ka]

[0121] 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.

[0122] 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).

[0123] [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), (a1-r-2), or (a1-r-4) above. 1 is n a2 It is a +1 valent hydrocarbon group, n a2 is an integer between 1 and 3, and Ra 2 This is an acid-dissociable group represented by the general formula (a1-r-1) or (a1-r-3) above.

[0124] 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.

[0125] In the above formula (a1-1), Va 1The divalent hydrocarbon group in this expression may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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).

[0131] In the above formula (a1-2), Wa 1 n in a2The +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.

[0132] 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.

[0133] The following are specific examples of constituent units (a1). In each of the following equations, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0134] [ka]

[0135] [ka]

[0136] [ka]

[0137] [ka]

[0138] [ka]

[0139] [ka]

[0140] [ka]

[0141] [ka]

[0142] 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 properties (CDU, etc.) in lithography using electron beams or EUV.

[0143] [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). * indicates a bond.

[0144] 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.

[0145] If component (A1) contains constituent unit (a1), the proportion of constituent unit (a1) in component (A1) is preferably 1 to 30 mol%, more preferably 1 to 20 mol%, and even more preferably 1 to 10 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). 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, CDU, 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 across various fields.

[0146] 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 (a1)).

[0147] [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.]

[0148] In the above formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halide having 1 to 5 carbon atoms. For R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferred, and due to their industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is more preferred, a hydrogen atom or a methyl group is even more preferred, and a hydrogen atom is particularly preferred.

[0149] In the above formula (a10-1), Ya x1 It is a single bond or a divalent linking group. In the above chemical formula, Ya x1The divalent linking group in this is not particularly limited, but suitable examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms.

[0150] 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.

[0151] In the above formula (a10-1), Wa x1 This is an aromatic hydrocarbon group which may have substituents. Wa x1 The aromatic hydrocarbon group in this context may be an aromatic ring that may have substituents (n ax1 A group with 1+1 hydrogen atoms removed is an example. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system with 4n+2 π electrons. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are 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 x1 Examples include benzene, naphthalene, anthracene, or biphenyl (n ax1 A group with (+1) hydrogen atoms removed is preferred, and (n ax1A 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.

[0152] Wa x1 The aromatic hydrocarbon group in may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, and alkyl halides. Examples of alkyl groups, alkoxy groups, halogen atoms, and alkyl halides as substituents include Ya x1 Examples of substituents include those similar to those listed for the cyclic alicyclic hydrocarbon group in [the relevant section]. The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, even more preferably an ethyl group or a methyl group, and particularly preferably a methyl group. x1 In this context, it is preferable that the aromatic hydrocarbon group does not have substituents.

[0153] 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.

[0154] 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.

[0155] [ka]

[0156] [ka]

[0157] [ka]

[0158] The constituent units (a10) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a10), the proportion of constituent units (a10) in component (A1) is preferably 20 to 60 mol%, more preferably 25 to 55 mol%, and even more preferably 30 to 55 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.

[0159] Unit of composition (a5): In this embodiment, the constituent unit (a5) is a constituent unit that generates acid upon exposure, and known units can be used. The presence of the constituent unit (a5) makes it easier for the acid generated by exposure to be uniformly distributed within the resist film. Suitable constituent units (a5) include, for example, the constituent unit represented by the following general formula (a5-1).

[0160] [ka] [In the formula, R m This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. 1 This is a divalent linking group or a single bond. 050 n is a divalent hydrocarbon group which may have substituents. a5 It is an integer between 0 and 2 (inclusive). 0 It is a divalent linking group. 0 This is a divalent linking group that may have a heteroatom, or a single bond. 051 and Ra 052 Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. n0 is an integer from 1 to 4. m is an integer of 1 or more, and M' m+This is an onium cation with a valence of m.

[0161] {Anion Division} In the above formula (a5-1), R m This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. R m The C1-C5 alkyl group is preferably a linear or branched alkyl group having C1-C5, specifically including methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups. A C1-C5 halogenated alkyl group is a group in which some or all of the hydrogen atoms of the C1-C5 alkyl group are substituted with halogen atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. Fluorine is particularly preferred as the halogen atom in alkyl halides. R m Preferably, the elements are hydrogen atoms, C1-C5 alkyl groups, or C1-C5 fluorinated alkyl groups, with hydrogen atoms or methyl groups being the most preferred due to their industrial availability.

[0162] In the above formula (a5-1), La 1 This is a divalent linking group or a single bond. La 1 The divalent linking group in is not particularly limited, but preferred examples include a divalent hydrocarbon group which may have substituents, and a divalent linking group which contains a heteroatom, respectively. x1 This is similar to the divalent linking groups exemplified in the above, such as divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. Among the above, La 1 Preferably, the bonds are ester bonds [-C(=O)-O-, -OC(=O)-], ether bonds (-O-), linear or branched alkylene groups, aromatic hydrocarbon groups or combinations thereof, or single bonds. Among these, La 1As such, ester bonds [-C(=O)-O-, -OC(=O)-] and single bonds are more preferable, and ester bonds [-C(=O)-O-, -OC(=O)-] are even more preferable.

[0163] In the above formula (a5-1), Ra 050 This is a divalent hydrocarbon group which may have substituents. Ra 050 The divalent hydrocarbon group in this expression may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0164] ··Ra 050 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group refers to a hydrocarbon group that does not possess aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, but is usually preferred to be saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, or aliphatic hydrocarbon groups containing a ring in their structure.

[0165] ...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.

[0166] The linear or branched aliphatic hydrocarbon group described above may or may not have substituents. Examples of substituents include fluorine atoms, fluorinated alkyl groups having 1 to 5 carbon atoms substituted with fluorine atoms, and carbonyl groups.

[0167] ...Aliphatic hydrocarbon groups containing a ring in their structure Examples of aliphatic hydrocarbon groups containing a ring in the structure include cyclic aliphatic hydrocarbon groups that may contain substituents containing heteroatoms in the ring structure (groups from which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), groups in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. A preferred monocyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. A preferred polycyclic alicyclic hydrocarbon group is a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0168] The cyclic aliphatic hydrocarbon group may or may not have substituents. Examples of substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, and carbonyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. As the alkoxy group used as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferred, and a methoxy group and an ethoxy group are most preferred. Examples of halogen atoms used as substituents include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like, with fluorine atoms being preferred. Examples of halogenated alkyl groups as substituents include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. A cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting its ring structure replaced by substituents containing heteroatoms. Preferred substituents containing heteroatoms are -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0169] ··Ra 050 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in substituents. Specific examples of aromatic rings include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Specific examples of aromatic hydrocarbon groups include groups obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); groups obtained by removing two hydrogen atoms from aromatic compounds containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and groups in which one hydrogen atom of an aryl group or heteroaryl group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) is substituted with an alkylene group (e.g., groups obtained by removing one more hydrogen atom from an aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0170] The aromatic hydrocarbon group may have its hydrogen atoms substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of such substituents include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, and hydroxyl groups. The alkyl group used as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, ethyl group, propyl group, n-butyl group, or tert-butyl group. Examples of the substituents include alkoxy groups, halogen atoms, and alkyl halogens that substitute for hydrogen atoms on the cyclic aliphatic hydrocarbon group.

[0171] n a5 is an integer between 0 and 2 (inclusive). Among the above, 050 The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group containing a ring in its structure, more preferably a cyclic aliphatic hydrocarbon group which may contain substituents containing heteroatoms in its ring structure, and even more preferably an alicyclic hydrocarbon group which may have substituents and is a polycyclic or monocyclic group. Alternatively, among the above, Ra 050 Aromatic hydrocarbon groups are preferred.

[0172] n a5 If it is 2, then 2 Ra 050 These may all be alicyclic hydrocarbon groups which may have substituents, or they may all be aromatic hydrocarbon groups which may have substituents, or they may be a combination of alicyclic hydrocarbon groups which may have substituents and aromatic hydrocarbon groups which may have substituents.

[0173] In the above formula (a5-1), La 0 It is a divalent linking group. La 0 Examples of divalent linking groups in this context include non-hydrocarbon oxygen-containing linking groups such as oxygen atoms (ether bond: -O-), ester bonds (-C(=O)-O-), oxycarbonyl groups (-OC(=O)-), amide bonds (-C(=O)-NH-), carbonyl groups (-C(=O)-), and carbonate bonds (-OC(=O)-O-); and combinations of these non-hydrocarbon oxygen-containing linking groups with alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of such divalent linking groups include the linking groups represented by the following general formulas (L-al-1) to (L-al-8). Note that in the following general formulas (L-al-1) to (L-al-8), Ra in formula (a5-1) above 050 The combination with this is V' in the following general formulas (L-al-1)~(L-al-8). 101 That is the case.

[0174] [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.

[0175] 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.

[0176] V' 101 and V' 102 The alkylene group in this product may be a linear alkylene group or a branched alkylene group, but a linear alkylene group is preferred. V' 101 and V' 102Specifically, the alkylene groups in these include: methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2 Examples include alkylethylene groups such as -CH2CH2CH2-; trimethylene groups (n-propylene groups) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; tetramethylene groups [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and pentamethylene groups [-CH2CH2CH2CH2CH2-]. Also, oshiV' 101 or V' 102 Some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is Ra' in formula (a1-r-1). 3 A divalent group is preferred, which is obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group), and a cyclohexylene group, a 1,5-adamantilene group, or a 2,6-adamantilene group is more preferred.

[0177] La 0 Preferably, the linking group is a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, more preferably the linking groups represented by the above formulas (L-al-1) to (L-al-5) and (L-al-8), and even more preferably the linking group represented by (L-al-3) or (L-al-8).

[0178] In the above formula (a5-1), Ya 0 This is a divalent linking group that may have a heteroatom, or a single bond. Ya 0The divalent linking group in this is not particularly limited, but preferred examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. Ya 0 In the above, the divalent hydrocarbon group which may have substituents, and the divalent linking group which contains a heteroatom, are as follows: x1 This is similar to the divalent linking groups exemplified in the above, such as divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. Among the above, Ya 0 The alkylene group is preferably a linear or branched alkylene group, or a single bond, with a single bond being more preferable.

[0179] In the above formula (a5-1), Ra 051 and Ra 052 Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated alkyl group. Ra 051 and Ra 052 The fluorinated alkyl groups in this compound are preferably linear or branched fluorinated alkyl groups having 1 to 5 carbon atoms, with a trifluoromethyl group being more preferred. In the above formula (a5-1), SO3 - Ra bonds to the adjacent carbon atom. 051 and Ra 052 From the viewpoint of acid strength, it is preferable that at least one of them is a fluorine atom.

[0180] In the above formula (a5-1), n0 is an integer from 1 to 4, and is preferably 1, 2, or 3.

[0181] {cation part} In the above formula (a5-1), M' m+ This represents an m-valent onium cation. Among these, M' m+ The sulfonium cation and iodonium cation are preferred. m is an integer of 1 or more.

[0182] Preferred cation portion ((M' m+ ) 1 / mExamples of these include organic cations represented by the following general formulas (ca-1) to (ca-3).

[0183] [ka] [In the formula, R 201 ~R 207 Each of these independently represents an aryl group, alkyl group, or alkenyl group, which may have substituents. 201 ~R 203 , R 206 ~R 207 These atoms may bond to each other to form a ring with the sulfur atom in the formula. 208 ~R 209 Each of these independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 210 This is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. 201 This represents -C(=O)- or -C(=O)-O-.

[0184] In the above general formulas (ca-1) to (ca-3), R 201 ~R 207 Examples of aryl groups in this context include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. R 201 ~R 207 The alkyl group in this is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210 Examples of substituents that may be present include alkyl groups, halogen atoms, alkyl halides, carbonyl groups, cyano groups, amino groups, aryl groups, and groups represented by the following general formulas (ca-r-1) to (ca-r-7).

[0185] [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.

[0186] 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.

[0187] R' 201 The 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' 201Specific 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.

[0188] 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.

[0189] Among them, R' 201The 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.

[0190] 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.

[0191] Also, R' 201The cyclic hydrocarbon group in the above formula may contain heteroatoms, such as heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by the above chemical formulas (r-hr-1) to (r-hr-16).

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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.

[0197] Among them, R' 201 The cyclic group is preferably a cyclic group which may have substituents, and more preferably a cyclic hydrocarbon group which may have substituents. More specifically, preferred groups include, for example, a phenyl group, a naphthyl group, a polycycloalkane from which one or more hydrogen atoms have been removed; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7); and -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4).

[0198] In the above general formulas (ca-1) to (ca-3), R 201 ~R 203 , R 206 ~R 207 When these atoms bond to each other and form a ring with the sulfur atom in the formula, they may be heteroatoms such as sulfur, oxygen, or nitrogen atoms, or carbonyl groups, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(the R N is an alkyl group having 1 to 5 carbon atoms. ) may be bonded via functional groups such as ). The formed ring preferably has 3 to 10 members, and particularly preferably 5 to 7 members, including the sulfur atom in its ring skeleton. Specific examples of the formed ring include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthlene ring, a phenoxatiyne ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0199] 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.

[0200] R 210 This is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 Examples of aryl groups in this context include unsubstituted aryl groups having 6 to 20 carbon atoms, with phenyl and naphthyl groups being preferred. R 210 The alkyl group in this is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in this compound preferably has 2 to 10 carbon atoms. R 210 In this context, the -SO2-containing cyclic group which may have substituents is preferably a "-SO2-containing polycyclic group," and more preferably a group represented by the general formula (b5-r-1) described above.

[0201] Specific examples of the cation represented by the above formula (ca-1) are shown below.

[0202] Specific examples of suitable cations represented by the above formula (ca-1) include the cations represented by the following chemical formulas.

[0203] [ka]

[0204] [ka]

[0205] [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.]

[0206] [ka]

[0207] [ka]

[0208] [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.

[0209] [ka]

[0210] Suitable cations represented by the formula (ca-2) include, specifically, diphenyliodonium cation and bis(4-tert-butylphenyl)iodonium cation.

[0211] 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).

[0212] [ka]

[0213] The cation portion in the above formula (a5-1) ((M' m+ ) 1 / m As for the cation, a sulfonium cation is preferred, the cations represented by formulas (ca-1) to (ca-3) are more preferred, the cation represented by formula (ca-1) is even more preferred, and the cations represented by formulas (ca-1-1) to (ca-1-83) are particularly preferred.

[0214] The following are some preferred examples of the constituent unit (a5). In the following equation, R αm and M' represent a hydrogen atom, a methyl group, or a trifluoromethyl group. m+ These are m and M' in the general formula (a5-1) above. m+ It is similar to that.

[0215] [ka]

[0216] [ka]

[0217] [ka]

[0218] (A1) The constituent units (a5) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a5), the proportion of constituent units (a5) in component (A1) is preferably 5 to 25 mol%, more preferably 10 to 20 mol%, and even more preferably 15 to 20 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). If the proportion of the constituent unit (a5) is above the lower limit of the preferred range mentioned above, it becomes easier to achieve further increases in sensitivity and resolution. On the other hand, if it is below the upper limit of the preferred range mentioned above, it becomes easier to balance it with the other constituent units.

[0219] Regarding the constituent unit (a2): Component (A1) may further have a constituent unit (a2) containing a lactone-containing cyclic group (excluding those corresponding to constituent unit (a1)). The lactone-containing cyclic group of component (a2) is effective in improving the adhesion of the resist film to the substrate when component (A1) is used to form a resist film. Furthermore, the presence of component (a2) improves lithography characteristics, for example, by appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0220] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -OC(=O)- within its cyclic skeleton. The lactone ring is counted as the first ring. If it consists only of a lactone ring, it is called a monocyclic group. If it also has other ring structures, it is called a polycyclic group regardless of those structures. A lactone-containing cyclic group may be a monocyclic group or a polycyclic group. Any lactone-containing cyclic group can be used in the constituent unit (a2) without any particular limitations. Specifically, examples include the groups represented by the following general formulas (a2-r-1) to (a2-r-7).

[0221] [ka] [In the formula, Ra' 21 Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group; R'' is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group; A'' is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom, where n' is an integer from 0 to 2, and m' is 0 or 1. * indicates a bond (the same applies below).

[0222] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, examples include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, etc. Among these, the methyl group or ethyl group is preferred, and the methyl group is particularly preferred. Ra' 21 The alkoxy group in is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the Ra' 21 Examples of alkyl groups in this context include groups formed by linking an alkyl group with an oxygen atom (-O-). Ra' 21 In this mixture, a fluorine atom is preferred as the halogen atom. Ra' 21 The halogenated alkyl group in is the Ra' 21 Examples include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. Fluorinated alkyl groups are preferred as the halogenated alkyl group, and perfluoroalkyl groups are particularly preferred.

[0223] Ra' 21 In -COOR'' and -OC(=O)R'', R'' is either a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R'' can be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R'' is a linear or branched alkyl group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. When R'' is a cyclic alkyl group, it is preferably 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, examples include groups obtained by removing one or more hydrogen atoms from monocycloalkanes which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, examples include groups obtained by removing one or more hydrogen atoms from monocycloalkanes such as cyclopentane and cyclohexane; and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Examples of lactone-containing cyclic groups in R'' include those similar to those represented by the general formulas (a2-r-1) to (a2-r-7) mentioned above. Ra' 21 The hydroxyalkyl group in is preferably one having 1 to 6 carbon atoms, specifically the Ra' 21 Examples include groups in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0224] Ra' 21 Among the above, it is preferable that each is independently a hydrogen atom or a cyano group.

[0225] In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5) above, the alkylene group having 1 to 5 carbon atoms in A'' is preferably a linear or branched alkylene group, such as a methylene group, ethylene group, n-propylene group, isopropylene group, etc. If the alkylene group contains an oxygen atom or a sulfur atom, specific examples include a group in which -O- or -S- is interposed at the end or between carbon atoms of the alkylene group, such as -O-CH2-, -CH2-O-CH2-, -S-CH2-, -CH2-S-CH2-, etc. As A'', an alkylene group having 1 to 5 carbon atoms or -O- is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is most preferred.

[0226] The following are specific examples of groups represented by the general formulas (a²-r-1) to (a²-r-7).

[0227] [ka]

[0228] [ka]

[0229] Among the constituent units (a2), those derived from acrylic acid esters in which the hydrogen atom bonded to the α-carbon atom may be substituted with a substituent are preferred. The constituent unit (a2) is preferably a constituent unit represented by the following general formula (a2-1).

[0230] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkyl halogen having 1 to 5 carbon atoms. 21 It is a single bond or a divalent linking group. 21The R' is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. However, La 21 If -O-, Ya 21 It does not become -CO-. 21 It is a lactone-containing cyclic group.

[0231] In formula (a2-1) above, R is the same as above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or a methyl group is particularly preferred due to their industrial availability.

[0232] In the above formula (a2-1), Ya 21 The divalent linking group in this is not particularly limited, but preferred examples include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms.

[0233] Ya 21 Preferably, the group is a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0234] In the above formula (a2-1), Ya 21 It is a single bond, La 21 It is preferable that it be -COO- or -OCO-.

[0235] In the above formula (a2-1), Ra 21 It is a lactone-containing cyclic group. Ra 21 Suitable lactone-containing cyclic groups in this compound include those represented by the general formulas (a2-r-1) to (a2-r-7) mentioned above.

[0236] The constituent units (a2) of component (A1) may be one type or two or more types. If component (A1) has constituent units (a2), the proportion of constituent units (a2) is preferably 1 to 20 mol%, more preferably 1 to 15 mol%, and even more preferably 1 to 10 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). If the proportion of constituent unit (a2) is set above a preferred lower limit, the effects of including constituent unit (a2) are fully obtained due to the effects described above, and if it is below the upper limit, a balance can be achieved with other constituent units, resulting in good lithography characteristics.

[0237] Regarding the constituent unit (a8): The constituent unit (a8) is a constituent unit derived from the compound represented by the following general formula (a8-1). However, those corresponding to constituent unit (a0) are excluded.

[0238] [ka] [In the formula, W 2 This is a polymerizable group-containing group. x2 is a single bond or (n ax2 It is a linking group with a +1 valence. x2 and W 2 It may form a fused ring with R. 1 R is a fluorinated alkyl group having 1 to 12 carbon atoms. 2 R is an organic group having 1 to 12 carbon atoms, which may contain a fluorine atom, or a hydrogen atom. 2 and Ya x2 These may be bonded to each other to form a ring structure. ax2 [This is an integer between 1 and 3.]

[0239] W 2 In the context of polymerizable group-containing groups, "polymerizable group" refers to a group that enables a compound containing a polymerizable group to polymerize by radical polymerization or the like, and includes, for example, a group containing multiple bonds between carbon atoms, such as an ethylenic double bond.

[0240] The polymerizable group-containing group may be a group composed solely of a polymerizable group, or a group composed of a polymerizable group and other groups other than the polymerizable group. Examples of other groups other than the polymerizable group include divalent hydrocarbon groups which may have substituents, and divalent linking groups which contain heteroatoms. Examples of polymerizable groups include those with the chemical formula: C(R X11 )(R X12 )=C(R X13 )-Ya x0 The group represented by - is preferably mentioned. In this chemical formula, R X11 , R X12 and R X13 These are, respectively, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya x0 It is a single bond or a divalent linking group.

[0241] Ya x2 and W 2 The condensed ring formed by these is W 2 Polymerizable groups of the site and Ya x2 The condensed ring formed by and W 2 Other groups besides the polymerizable group of the site and Ya x2 A condensed ring formed by these is one example. Ya x2 and W 2 The fused ring formed by these two components may have substituents.

[0242] The following are specific examples of constituent units (a8). In the following formula, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0243] [ka]

[0244] Among the examples above, the constituent unit (a8) is preferably at least one selected from the group consisting of constituent units represented by the chemical formulas (a8-1-01) to (a8-1-04), (a8-1-06), (a8-1-08), (a8-1-09), and (a8-1-10), and more preferably at least one selected from the group consisting of constituent units represented by the chemical formulas (a8-1-01) to (a8-1-04) and (a8-1-09).

[0245] The constituent units (a8) of component (A1) may be one type or two or more types. The proportion of constituent unit (a8) in component (A1) is preferably 50 mol% or less, and more preferably 0 to 30 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1).

[0246] The (A1) component contained in the resist composition may be used alone or in combination of two or more types. The proportion of constituent units (a0) in component (A1) is preferably 40 to 80 mol%, more preferably 45 to 75 mol%, and even more preferably 45 to 70 mol%, relative to the total amount (100 mol%) of all constituent units that make up component (A1). When the content of constituent unit (a0) is above the lower limit of the preferred range described above, sensitivity and resolution tend to be higher. On the other hand, keeping it below the upper limit makes it easier to balance with other constituent units, resulting in better resolution.

[0247] (A1) Among the above, polymer compounds having a repeating structure of constituent unit (a0) and constituent unit (a10) are preferred as component (A1), and polymer compounds consisting only of a repeating structure of constituent unit (a0) and constituent unit (a10) are more preferred.

[0248] In a polymer compound having a repeating structure of constituent units (a0) and constituent units (a10), the proportion of constituent units (a0) is preferably 40 to 80 mol%, more preferably 45 to 75 mol%, and even more preferably 45 to 70 mol%, relative to the total amount (100 mol%) of all constituent units constituting the polymer compound. Furthermore, the proportion of constituent units (a10) in the polymer compound is preferably 20 to 60 mol%, more preferably 25 to 55 mol%, and even more preferably 30 to 55 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound.

[0249] Alternatively, as component (A1), among the above, a polymer compound containing a repeating structure of constituent unit (a0), constituent unit (a10), and constituent unit (a5) is preferred, and a polymer compound consisting only of a repeating structure of constituent unit (a0), constituent unit (a10), and constituent unit (a5) is more preferred.

[0250] In a polymer compound having a repeating structure of constituent units (a0), (a10), and (a5), the proportion of constituent unit (a0) is preferably 40 to 80 mol%, more preferably 45 to 70 mol%, and even more preferably 45 to 65 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. The proportion of constituent units (a10) in the polymer compound is preferably 15 to 55 mol%, more preferably 20 to 45 mol%, and even more preferably 20 to 40 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. The proportion of constituent units (a5) in the polymer compound is preferably 5 to 25 mol%, more preferably 10 to 20 mol%, and even more preferably 15 to 20 mol%, relative to the total amount (100 mol%) of all constituent units that make up the polymer compound. However, the sum of the proportions of constituent units (a0), (a10), and (a5) shall not exceed 100 mol%.

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

[0252] The weight-average molecular weight (Mw) of component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 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.

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

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

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

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

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

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

[0259] 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)").

[0260] [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 Each of these is independently a single bond, an alkylene group, or a fluorinated alkylene group. However, Y 101 and V 101 L cannot be a single bond at the same time. 101 ~L102 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.

[0261] {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.

[0262] 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 is preferably saturated.

[0263] R 101 The aromatic hydrocarbon group in this formula is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, this number of carbon atoms does not include the number of carbon atoms in substituents. R 101 Specific examples of aromatic rings in aromatic hydrocarbon groups include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, nitrogen atoms, etc. R 101Specific 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, benzyl groups, phenethyl groups, 1-naphthylmethyl groups, 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.

[0264] 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.

[0265] Among them, R 101The 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.

[0266] 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.

[0267] Also, R 101The cyclic hydrocarbon group in the formula may contain heteroatoms, such as heterocycles. Specifically, examples include lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), the -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by the chemical formulas (r-hr-1) to (r-hr-16). In the formulas, * represents Y in formula (b-1). 101 This represents a coupling that connects to something.

[0268] [ka] [In the formula, Rb' 51 Each of the following is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group; R'' is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or a -SO2--containing cyclic group; B'' is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, and n' is an integer from 0 to 2. * indicates a bond.

[0269] In the above general formulas (b5-r-1) to (b5-r-2), B'' is an alkylene group having 1 to 5 carbon atoms, which may contain an oxygen atom or a sulfur atom, or an oxygen atom or a sulfur atom. For B'', an alkylene group or -O- having 1 to 5 carbon atoms is preferred, an alkylene group having 1 to 5 carbon atoms is more preferred, and a methylene group is even more preferred.

[0270] In the above general formulas (b5-r-1) to (b5-r-4), Rb' 51 Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR'', -OC(=O)R'', a hydroxyalkyl group, or a cyano group, and among these, each is preferably independently a hydrogen atom or a cyano group.

[0271] Specific examples of the groups represented by the general formulas (b5-r-1) to (b5-r-4) are given below. In the formulas, "Ac" indicates an acetyl group.

[0272] [ka]

[0273] [ka]

[0274] [ka]

[0275] [ka]

[0276] 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 the alkyl group used as a substituent, an alkyl group having 1 to 5 carbon atoms is 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. Preferred halogen atoms as substituents are fluorine, bromine, and iodine atoms. 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.

[0277] 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.

[0278] [ka]

[0279] R 101 Examples of substituents that the fused ring group in the compound may have include alkyl groups, alkoxy groups, halogen atoms, alkyl halides, hydroxyl groups, carbonyl groups, nitro groups, aromatic hydrocarbon groups, and alicyclic hydrocarbon groups. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as substituents of the fused cyclic group are as described above in R 101 Examples of substituents on cyclic groups in the above are similar to those listed. Examples of aromatic hydrocarbon groups as substituents on the fused ring group include groups obtained by removing one hydrogen atom from an aromatic ring (aryl groups: for example, phenyl groups, naphthyl groups, etc.), groups in which one of the hydrogen atoms of the aromatic ring is replaced by an alkylene group (for example, arylalkyl groups such as benzyl groups, phenethyl groups, 1-naphthylmethyl groups, 2-naphthylmethyl groups, 1-naphthylethyl groups, 2-naphthylethyl groups, etc.), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of alicyclic hydrocarbon groups as substituents on the aforementioned fused cyclic group include: groups obtained by removing one hydrogen atom from monocycloalkanes such as cyclopentane and cyclohexane; groups obtained by removing one hydrogen atom from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7); -SO2--containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4); and heterocyclic groups represented by the formulas (r-hr-7) to (r-hr-16).

[0280] 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.

[0281] A chain-like alkenyl group which may have substituents: R 101The 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.

[0282] 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.

[0283] 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 the linking groups represented by the following general formulas (y-al-1) to (y-al-7). Note that in the following general formulas (y-al-1) to (y-al-7), R in formula (b-1) above 101 The V' in the following general formulas (y-al-1)~(y-al-7) is what combines with it. 101 That is the case.

[0284] [ka] [In the formula, V' 101 V' is a single bond or an alkylene group with 1 to 5 carbon atoms. 102It is a divalent saturated hydrocarbon group with 1 to 30 carbon atoms.

[0285] 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.

[0286] V' 101 and V' 102 The alkylene group in this product may be a linear alkylene group or a branched alkylene group, but a linear alkylene group is preferred. V' 101 and V' 102 Specifically, the alkylene groups in these include: methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2 Examples include alkylethylene groups such as -CH2CH2CH2-; trimethylene groups (n-propylene groups) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; tetramethylene groups [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and pentamethylene groups [-CH2CH2CH2CH2CH2-]. Also, oshiV' 101 or V' 102 Some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is Ra' in formula (a1-r-1). 3A divalent group is preferred, which is obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group), and a cyclohexylene group, a 1,5-adamantilene group, or a 2,6-adamantilene group is more preferred.

[0287] In formula (b-1), V 101 These are single bonds, alkylene groups, or fluorinated alkylene groups. Among them, V 101 It is preferable that the fluorinated alkylene group is a single bond or a linear chain having 1 to 4 carbon atoms.

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

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

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

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

[0292] R" 101 and R” 103 The aromatic cyclic group which may have substituents in formula (b-1) is R 101 It is preferable that the substituent is the aromatic hydrocarbon group exemplified in the cyclic hydrocarbon group in formula (b-1). 101 Examples include substituents similar to those that may be substituted for the aromatic hydrocarbon group in the above.

[0293] 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.

[0294] • 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 105 In the chain-like alkyl group, a larger number of hydrogen atoms substituted with fluorine atoms is preferable because it increases the acid strength and improves transparency to high-energy light and electron beams below 250 nm. The proportion of fluorine atoms in the chain-like alkyl group, i.e., the fluorination rate, is preferably 70-100%, more preferably 90-100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 , V 103 These are, independently, a single bond, an alkylene group, or a fluorinated alkylene group, and each is V in formula (b-1).101 Similar examples include the above. In formula (b-2), L 101 , L 102 Each of these is either a single bond or an oxygen atom, independently of the others.

[0295] • 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-.

[0296] Among the above, the anion portion of component (B) is preferably the anion in component (b-1), and more preferably the anion represented by the formula (an-1).

[0297] {cation part} In the above equations (b-1), (b-2), and (b-3), M' m+ This represents an m-valent onium cation. Among these, sulfonium cations and iodonium cations are preferred. m is an integer of 1 or greater. In the above equations (b-1), (b-2), and (b-3), M' m+ As for M' in the above formula (a5-1), m+ It is similar to that.

[0298] Among the above, sulfonium cations are preferred as the cation portion of component (B), cations represented by formulas (ca-1) to (ca-3) are more preferred, the cation represented by formula (ca-1) is even more preferred, and cations represented by formulas (ca-1-1) to (ca-1-83) are particularly preferred.

[0299] In the resist composition of this embodiment, component (B) may be used alone or in combination of two or more types. In the resist composition, the content of component (B) is preferably less than 50 parts by mass, and more preferably 10 to 40 parts by mass, per 100 parts by mass of component (A). (B) By setting the content of component (B) within the preferred range described above, pattern formation is sufficiently achieved. Furthermore, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, which is preferable because it results in good storage stability for the resist composition.

[0300] When component (A1) has a repeating structure of constituent unit (a5), the content of component (B) in the resist composition is preferably less than 50 parts by mass, more preferably 0 to 40 parts by mass, and even more preferably 0 to 30 parts by mass, per 100 parts by mass of component (A).

[0301] ≪Basic component (D)≫ The resist composition of this embodiment may further contain, in addition to component (A), a basic component (component (D)) that traps (i.e., controls the diffusion of) the acid generated by exposure. Component (D) acts as a quencher (acid diffusion control agent) that traps the acid generated by exposure in the resist composition. Examples of component (D) include a photo-disintegrating base (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure and loses its ability to control acid diffusion, 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 the characteristics of high sensitivity, roughness reduction, and suppression of coating defects.

[0302] • 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.

[0303] [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.

[0304] {(d1-1) component} ··Anion Club In formula (d1-1), Rd 1 R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents, and each of the above R' is... 201 Similar examples include the above. Among these, Rd 1Preferred substituents are optionally substituted aromatic hydrocarbon groups, optionally substituted aliphatic cyclic groups, or optionally substituted linear alkyl groups. Examples of substituents these groups may have include hydroxyl groups, oxo groups, alkyl groups, aryl groups, fluorine atoms, fluorinated alkyl groups, lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), ether bonds, ester bonds, or combinations thereof. When ether bonds or ester bonds are included as substituents, they may be mediated via alkylene groups, and in this case, preferred substituents are the linking groups represented by the general formulas (y-al-1) to (y-al-5). Note that Rd 1 If the aromatic hydrocarbon group, aliphatic cyclic group, or linear alkyl group in has a linking group represented by the general formulas (y-al-1) to (y-al-7) as a substituent, then in the general formulas (y-al-1) to (y-al-7), Rd in formula (d3-1) 1 The carbon atom constituting the aromatic hydrocarbon group, aliphatic cyclic group, or linear alkyl group in the above general formula (y-al-1) to (y-al-7) is V'. 101 That is the case. Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and other ring structures). The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The linear alkyl group is preferably one with 1 to 10 carbon atoms, and specifically includes linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups; and branched alkyl groups such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, and 4-methylpentyl groups.

[0305] 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.

[0306] The following are preferred specific examples of the anionic portion of component (d1-1).

[0307] [ka]

[0308] ··Cation section In formula (d1-1), M m+ This is an m-valent organic cation. M m+ Suitable organic cations include those similar to the cations represented by the general formulas (ca-1) to (ca-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-1-83) being even more preferred. (d1-1) Component may be used alone or in combination of two or more types.

[0309] {(d1-2) component} ··Anion Club In formula (d1-2), Rd 2 R' is a cyclic group which may have substituents, a linear alkyl group which may have substituents, or a linear alkenyl group which may have substituents. 201 Similar examples include the above. However, Rd 2In this mixture, we assume that the carbon atom adjacent to the S atom is not bonded to a fluorine atom (i.e., not fluorine-substituted). This results in the anions of components (d1-2) becoming appropriately weak acid anions, improving the quenching ability of component (D). Rd 2 Preferably, the group is a chain-like alkyl group which may have substituents, or an aliphatic cyclic group which may have substituents. The chain-like alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10. The aliphatic cyclic group preferably has one or more hydrogen atoms removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have substituents); more preferably has one or more hydrogen atoms removed from camphor, etc. Rd 2 The hydrocarbon group may have substituents, and such substituents may be Rd of formula (d1-1). 1 Examples include substituents similar to those that may be present on hydrocarbon groups (aromatic hydrocarbon groups, aliphatic cyclic groups, and linear alkyl groups) in the above.

[0310] The following are preferred specific examples of the anionic portion of component (d1-2).

[0311] [ka]

[0312] ··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.

[0313] {(d1-3) components} ··Anion Club In formula (d1-3), Rd 3R' 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 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.

[0314] 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.

[0315] 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.

[0316] Rd 4 The cyclic group in is the 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.

[0317] 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.

[0318] The following are preferred specific examples of the anionic parts of components (d1-3).

[0319] [ka]

[0320] [ka]

[0321] ··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.

[0322] 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 2 to 8 parts by mass, per 100 parts by mass of component (A1). When the content of component (D1) is above the preferred lower limit, particularly good lithography characteristics and resist pattern shape are easily obtained. On the other hand, when it is below the upper limit, good sensitivity can be maintained and throughput is also excellent.

[0323] (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.

[0324] • About the (D2) component Component (D) may include nitrogen-containing organic compounds that do not fall under component (D1) above (hereinafter referred to as "component (D2)"). Component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and does not fall under component (D1), and any known component may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are more preferred. An aliphatic amine is an amine having one or more aliphatic groups, and it is preferable that the aliphatic groups have 1 to 12 carbon atoms. Examples of aliphatic amines include amines (alkylamines or alkyl alcoholamines) or cyclic amines in which at least one hydrogen atom of ammonia (NH3) is substituted with an alkyl group or hydroxyalkyl group having 12 or fewer carbon atoms. Specific examples of alkylamines and alkyl alcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine are particularly preferred.

[0325] 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.

[0326] 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.

[0327] Furthermore, an aromatic amine may be used as component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or their derivatives, trimenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, and 2,6-di-tert-butylpyridine.

[0328] (D2) Component may be used alone or in combination of two or more types. When the resist composition contains component (D2), the content of component (D2) in the resist composition is usually in the range of 0.01 to 5 parts by mass per 100 parts by mass of component (A1). By using this range, the resist pattern shape, settling stability over time, etc., are improved.

[0329] <<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. 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, sensitivity and lithography characteristics are improved.

[0330] ≪Fluorine additive component (F)≫ The resist composition of this embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") as a hydrophobic resin. Component (F) is used to impart water repellency to the resist film and, when used as a resin separate from component (A), can 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.

[0331] [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.

[0332] 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.

[0333] 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.

[0334] 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.

[0335] 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).

[0336] ≪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. 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.

[0337] Furthermore, a mixed solvent obtained by mixing PGMEA and a polar solvent is also preferred as component (S). The mixing ratio (mass ratio) can be appropriately determined considering the compatibility between PGMEA and the polar solvent. Furthermore, as the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferred. In this case, the mass ratio of the former to the latter is preferably 70:30 to 95:5. The amount of component (S) used is not particularly limited and is set appropriately according to the coating thickness, at a concentration that can be applied to a substrate or the like. Generally, component (S) is used so that the solid content concentration of the resist composition is in the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0338] 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.

[0339] 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.

[0340] The resist composition of this embodiment described above includes a resin component (A1) having a constituent unit (a0) represented by the general formula (a0-0). The constituent unit (a0) is a group having 10 or fewer carbon atoms, having one or more selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfo group, an amino group, a phosphate group, an amide group, an ether group, an imino group, and a thioether group, as well as an acid-dissociable group (Ra) having an unsaturated bond.01 It contains ). Acid dissociable group (Ra 01 The carbocation generated when (a0) dissociates is more stable and has a lower activation energy for the acid dissociation reaction compared to the carbocation generated when an acid-dissociable group without an unsaturated bond dissociates, resulting in a faster deprotection rate. Therefore, the acid-dissociability of the constituent unit (a0) is improved, and the acid-dissociable group dissociates at a lower exposure level. As a result, the resist composition of this embodiment has increased sensitivity. Acid dissociable group (Ra 01 Because the group has 10 or fewer carbon atoms, it has high hydrophilicity, and therefore the deprotecting agent has high solubility in the developer. As a result, the resist composition of this embodiment has further improved sensitivity and resolution.

[0341] (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.

[0342] 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.

[0343] 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.

[0344] 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.

[0345] The wavelength used for exposure is not particularly limited, and can be used with radiation such as ArF excimer lasers, KrF excimer lasers, F2 excimer lasers, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays.

[0346] The method for exposing the resist film may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or it may be liquid immersion lithography. Immersion lithography is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is first filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. As the immersion medium, a solvent having a refractive index greater than that of air and less than that of the resist film being exposed is preferred. Examples include water, fluorinated inert liquids, silicon-based solvents, and hydrocarbon-based solvents. Water is preferably used as the immersion medium.

[0347] 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.

[0348] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0349] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0350] Organic developers may contain known additives as needed. Examples of such additives include surfactants.

[0351] 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).

[0352] In the solvent-based development process, the rinsing solution used for rinsing after development can contain an organic solvent that is less likely to dissolve the resist pattern, selected from among the organic solvents listed above for use in the organic developer. Typically, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. These organic solvents may be used individually or in combination of two or more. They may also be used in mixtures with other organic solvents or water.

[0353] 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).

[0354] It is preferable that the resist composition of the above-described embodiment and the various materials used in the resist pattern formation method of the above-described embodiment (for example, resist solvent, developer, rinse solution, anti-reflective film forming composition, top coat forming composition, etc.) do not contain impurities such as metals, metal salts containing halogens, acids, alkalis, sulfur atoms, or phosphorus atoms. Examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The amount of impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially absent (below the detection limit of the measuring device).

[0355] As described above, the resist pattern formation method of this embodiment uses the resist composition described above, making it possible to form a resist pattern with high sensitivity and good resolution.

[0356] (compound) The compound of this embodiment is represented by the following general formula (a0-m0) (hereinafter also referred to as "compound (a0)").

[0357] [ka] [In the formula, R 01 This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, or a hydrogen atom. 01 This is a divalent linking group or a single bond. 01 This is an acid-dissociating group represented by formula (a0-ra). In formula (a0-ra), * represents the bond with the oxygen atom (-O-) in formula (a0-m0). C 01 These are secondary or tertiary carbon atoms. C 01 If R is a secondary carbon atom, 02 and R 03 Each of these is independently a chain hydrocarbon group which may have substituents, or R 02 and R 03 and are combined with each other, C 01 Together, it forms a cyclic group which may have substituents, R 04 R is a hydrogen atom. 02 and R 03One or more selected from the group consisting of the chain-like hydrocarbon group and the cyclic group formed by C 01 The carbon atom at the α position and C 01 It has a carbon-carbon unsaturated bond formed with the carbon atom at the β position. 02 and R 03 In this compound, at least one of the carbon atoms constituting the carbon-carbon unsaturated bond is bonded to a group having 10 or fewer carbon atoms, which has one or more groups selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfo group, an amino group, a phosphate group, an amide group, an ether group, an imino group, and a thioether group. C 01 If R is a tertiary carbon atom, 02 and R 03 Each of these is independently a chain hydrocarbon group which may have substituents, or R 02 and R 03 and are combined with each other, C 01 Together, it forms a cyclic group which may have substituents, R 04 R is a chain-like hydrocarbon group which may have substituents. 02 , R 03 and R 04 One or more of the groups formed by the chain-like hydrocarbon group and the cyclic group have a carbon-carbon unsaturated bond. 02 , R 03 and R 04 In this compound, at least one of the carbon atoms constituting the carbon-carbon unsaturated bond is bonded to a group having 10 or fewer carbon atoms, which is selected from the group consisting of a hydroxyl group, carboxyl group, sulfo group, amino group, phosphate group, amide group, ether group, imino group, and thioether group.

[0358] In the above equation (a0-m0), R 01 Ya 01 Ra 01 , R 02 , R 03 and R 04 This is R in the general formula (a0-0) mentioned above. 01 Ya 01 Ra 01 , R 02 , R 03 and R04 These are the same as above.

[0359] Compound (a0) is preferably a compound represented by the following general formula (a0-m1).

[0360] [ka] [In the formula, Ya x1 Wa is a single bond or a divalent linking group. x1 R is an aromatic hydrocarbon group which may have substituents. 01 and Ra 01 These are R in the above formula (a0-m0) and the above formula (a0-ra), respectively. 01 and Ra 01 It is identical to [this].

[0361] In the above formula (a0-m1), R 01 Ya x1 Wa x1 and Ra 01 This is R in the general formula (a0-1) mentioned above. 01 , R 01 Ya x1 Wa x1 and Ra 01 These are the same as above.

[0362] The following are specific examples of compound (a0), but are not limited to these. In the following formula, R α This represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0363] [ka]

[0364] (Method of producing compounds) The method for producing the compound of this embodiment is not particularly limited and can be produced by appropriately combining known methods.

[0365] The compound of this embodiment is useful for producing the resin component (A1) in the first embodiment, which is the base resin of the resist composition.

[0366] <Polymer compounds> The polymer compound of this embodiment has a constituent unit (constituent unit (a0)) derived from the above compound (a0). That is, the polymer compound of this embodiment is the same as the resin component (A1) in the first embodiment and is useful as a base resin for a resist composition. [Examples]

[0367] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0368] <Examples of compound synthesis> Monomers (m01) to (m10) were produced using the synthesis methods described below.

[0369] [Synthesis Example 1: Synthesis of monomer (m01)] 40.0 g of (m01-pre1), 101.3 g of 37 wt% formaldehyde aqueous solution, 101 g of THF, and 50.8 g of N,N-dimethylaminopyridine were placed in a three-necked flask and stirred for 12 hours. 5 wt% hydrochloric acid was added to the resulting reaction solution to stop the reaction, and the organic layer was washed with 5 wt% sodium bicarbonate aqueous solution and deionized water. The organic layer was concentrated to obtain 43.0 g of (m01-pre2).

[0370] [ka]

[0371] Next, 40.0 g of (m01-pre2), 57.0 g of potassium carbonate, 54.0 g of iodomethane, and 200 g of DMF were placed in a three-necked flask and stirred for 3 hours. 200 g of dichloromethane and 200 g of deionized water were added to the resulting reaction mixture and extracted. The organic layer was washed with 5% sodium hydroxide aqueous solution and deionized water, and the organic layer was recovered. The organic layer was concentrated using a rotary evaporator to obtain 34.7 g of (m01-pre3).

[0372] [ka]

[0373] Next, 34.0 g of (m01-pre3), 110.5 g of cerium chloride heptahydrate, and 340 g of methanol were placed in a three-necked flask and stirred in an ice bath. 12.2 g of sodium borohydride was added to the resulting reaction solution, and after aging for 3 hours, 340 g of diethyl ether and 340 g of deionized water were added and extracted. The organic layer was washed with deionized water and recovered. The organic layer was concentrated using a rotary evaporator to obtain 27.3 g of (m01-pre4).

[0374] [ka]

[0375] 27.0 g of (m01-pre4), 28.8 g of triethylamine, 2.32 g of N,N-dimethylaminopyridine, and 189 g of dichloromethane were placed in a three-necked flask and stirred. 25.8 g of methacrylate chloride was added, and the mixture was stirred for 2 hours. Then, 200.0 g of water was added to terminate the reaction, and the organic layer was concentrated using a rotary evaporator to obtain 33.5 g of monomer (m01).

[0376] [ka]

[0377] The obtained monomer (m01) was subjected to NMR measurement, and its structure was identified based on the following data. 1H-NMR (DMSO-D6, 400MHz): δ(ppm)=1.65(2H,m),1.93(2H,m),2.01(3H,t),2.06(2 H,m),3.31(3H,s),4.04(2H,s),5.13(1H,t),5.48(1H,t),6.40(1H,m),6.48(1H,m)

[0378] [Synthesis Examples 2-5: Synthesis of Monomers (m02)-(m05)] Monomer (m02): Monomer (m02) was obtained in the same manner as in "Synthesis Example 1: Synthesis of Monomer (m01)" above, except that the raw material iodomethane was changed to iodoethane.

[0379] [ka]

[0380] The 1H-NMR measurement results for monomer (m02) are shown below. 1H-NMR (DMSO-D6, 400MHz): δ(ppm)=1.18(3H,t),1.65(2H,m),1.93(2H,m),2.01(3H,t),2 .06(2H,m),3.53(2H,q),4.04(2H,s),5.13(1H,t),5.48(1H,t),6.40(1H,m),6.48(1H,m)

[0381] Monomer (m03): Monomer (m03) was obtained in the same manner as in "Synthesis Example 1: Synthesis of Monomer (m01)" above, except that the raw material iodomethane was changed to 1-iodopropane.

[0382] [ka]

[0383] The 1H-NMR measurement results for monomer (m03) are shown below. 1H-NMR (DMSO-D6, 400MHz): δ(ppm)=0.99(3H,t),1.49(2H,m),1.65(2H,m),1.93(2H,m),2.01(3 H,t),2.06(2H,m),3.35(2H,q),4.04(2H,s),5.13(1H,t),5.48(1H,t),6.40(1H,m),6.48(1H,m)

[0384] Monomer (m04): Monomer (m04) was obtained in the same manner as in "Synthesis Example 1: Synthesis of Monomer (m01)" above, except that the raw material methacrylate chloride was changed to 4-vinylbenzoic acid chloride.

[0385] [ka]

[0386] The 1H-NMR measurement results for monomer (m04) are shown below. 1H-NMR (DMSO-D6, 400MHz): δ(ppm)=1.65(2H,m),2.07(4H,m),3.31(3H,s),4.04(2H,s),5 .13(1H,t),5.25(1H,m),5.48(1H,t),5.78(1H,m),6.72(1H,m),7.45(2H,m),7.57(2H,m)

[0387] Monomer (m05): Monomer (m05) was obtained in the same manner as in "Synthesis Example 1: Synthesis of Monomer (m01)" above, except that the raw material methacrylate chloride was changed to 3-vinylbenzoic acid chloride.

[0388] [ka]

[0389] The 1H-NMR measurement results for monomer (m05) are shown below. 1H-NMR (DMSO-D6, 400MHz): δ(ppm)=1.65(2H,m),2.07(4H,m),3.31(3H,s),4.04(2H,s),5.13(1H,t),5 .25(1H,m),5.48(1H,t),5.78(1H,m),6.72(1H,m),7.34(1H,m),7.40(1H,m),7.81(1H,m),7.87(1H,m)

[0390] [Synthesis Example 6: Synthesis of monomer (m06)] 27.0 g of (m06-pre1) was dissolved in 135 g of THF, and a mixed solution of 31.6 g of diazabicycloundensene (DBU), 30.8 g of (m01-pre4), and 37.5 g of carbonyldiimidazole (CDI) in 75.1 g of tetrahydrofuran was added dropwise to the solution under ice cooling. After stirring at 60°C for 4 hours, the solvent was removed by distillation, and 200 g of heptane was added to the residue. Impurities were removed by filtration. Subsequently, 30.0 g of monomer (m06) was obtained by purification by column chromatography.

[0391] [ka]

[0392] The 1H-NMR measurement results for monomer (m06) are shown below. 1H-NMR (DMSO-D6, 400MHz): δ(ppm)=1.65(2H,m),2.07(4H,m),3.31(3H,s),4.04(2H,s),5.13(1H,t),5 .25(1H,m),5.48(1H,t),5.78(1H,m),6.72(1H,m),6.87(1H,m),7.17(1H,m),7.66(1H,m),15.2(1H,s)

[0393] [Synthesis Example 7: Synthesis of monomer (m07)] Monomer (m07) was obtained in the same manner as in "Synthesis Example 6: Synthesis of Monomer (m06)" above, except that the raw material 2-hydroxy-5-vinylbenzoic acid was changed to 2-methoxy-5-vinylbenzoic acid.

[0394] [ka]

[0395] The 1H-NMR measurement results for monomer (m07) are shown below. 1H-NMR (DMSO-D6, 400MHz): δ(ppm)=1.65(2H,m),2.07(4H,m),3.31(3H,s),3.90(3H,s),4.04(2H,s),5 .13(1H,t),5.25(1H,m),5.48(1H,t),5.78(1H,m),6.72(1H,m),7.02(1H,m),7.34(1H,m),7.83(1H,m)

[0396] [Synthesis Example 8: Synthesis of monomer (m08)] 50.0 g of (m08-pre1), 120.4 g of cerium chloride heptahydrate, and 500 g of methanol were placed in a three-necked flask and stirred under ice. 13.3 g of sodium borohydride was added to the resulting reaction mixture, and after aging for 3 hours, 500 g of diethyl ether and 500 g of deionized water were added and extracted. The organic layer was washed with deionized water and recovered. The organic layer was concentrated using a rotary evaporator to obtain 40.9 g of (m08-pre2).

[0397] [ka]

[0398] 40.0 g of (m08-pre2), 28.8 g of triethylamine, 2.3 g of N,N-dimethylaminopyridine, and 189 g of dichloromethane were placed in a three-necked flask and stirred. 25.8 g of methacrylate chloride was added and the mixture was stirred for 2 hours. 200.0 g of water was added to terminate the reaction, and the organic layer was concentrated using a rotary evaporator to obtain 38.3 g of (m08-pre3).

[0399] [ka]

[0400] 38.0 g of (m08-pre3), 380 g of methanol, and 114 g of 10 wt% hydrochloric acid were placed in a three-necked flask, stirred, and aged for 3 hours. The reaction was stopped with 5 wt% sodium bicarbonate aqueous solution, the organic layer was washed with deionized water, and the mixture was concentrated to obtain 29.6 g of monomer (m08).

[0401] [ka]

[0402] The 1H-NMR measurement results for monomer (m08) are shown below. 1H-NMR (DMSO-D6, 400MHz): δ(ppm)=1.65(2H,m),1.89(2H,m),2.01(3H,t),2.06(2 H,m),4.20(2H,s),5.13(1H,t),5.48(1H,t),5.56(1H,s),6.40(1H,m),6.48(1H,m)

[0403] [Synthesis Example 9: Synthesis of monomer (m09)] 30.0 g of (m01-pre3), 150 g of THF, and 319.0 g of 12 wt% methylmagnesium bromide THF solution were placed in a three-necked flask and stirred under ice bath for 3 hours. 150 g of dichloromethane and 150 g of saturated ammonium chloride aqueous solution were added to the resulting reaction mixture to stop the reaction, and the organic layer was washed with deionized water. The organic layer was concentrated using a rotary evaporator to obtain 29.1 g of (m09-pre1).

[0404] [ka]

[0405] 28.0 g of (m09-pre1), 27.2 g of triethylamine, 2.2 g of N,N-dimethylaminopyridine, and 196 g of dichloromethane were placed in a three-necked flask and stirred. 24.4 g of methacrylate chloride was added and the mixture was stirred for 2 hours. 200.0 g of water was added to terminate the reaction, and the organic layer was concentrated using a rotary evaporator to obtain 32.0 g of (m09).

[0406] [ka]

[0407] The 1H-NMR measurement results for monomer (m09) are shown below. 1H-NMR (DMSO-D6, 400MHz): δ(ppm)=1.24(3H,s),1.65(2H,m),1.84(2H,m),2.01(3 H,t),2.06(2H,m),3.31(3H,s),4.04(2H,s),5.48(1H,t),6.40(1H,m),6.48(1H,m)

[0408] [Synthesis Example 10: Synthesis of monomer (m10)] 40.0 g of (m10-pre1), 57.0 g of potassium carbonate, 54.0 g of iodomethane, and 200 g of DMF were placed in a three-necked flask and stirred for 3 hours. 200 g of dichloromethane and 200 g of deionized water were added to the resulting reaction mixture and extracted. The organic layer was washed with 5% sodium hydroxide aqueous solution and deionized water, and the organic layer was recovered. The organic layer was concentrated using a rotary evaporator to obtain 35.9 g of (m10-pre2).

[0409] [ka] 34.0 g of (m10-pre2), 110.5 g of cerium chloride heptahydrate, and 340 g of methanol were placed in a three-necked flask and stirred under ice. 12.2 g of sodium borohydride was added to the resulting reaction mixture and aged for 3 hours. Then, 340 g of diethyl ether and 340 g of deionized water were added and extracted. The organic layer was washed with deionized water and recovered. The organic layer was concentrated using a rotary evaporator to obtain 28.6 g of (m10-pre3).

[0410] [ka]

[0411] 27.0 g of (m10-pre3), 28.8 g of triethylamine, 2.32 g of N,N-dimethylaminopyridine, and 189 g of dichloromethane were placed in a three-necked flask and stirred. 25.8 g of methacrylate chloride was added and the mixture was stirred for 2 hours. 200.0 g of water was added to terminate the reaction, and the organic layer was concentrated using a rotary evaporator to obtain 34.8 g of (m10).

[0412] [ka]

[0413] The 1H-NMR measurement results for monomer (m10) are shown below. 1H-NMR (DMSO-D6, 400MHz): δ(ppm)=1.65(2H,m),1.89(2H,m),1.94(2H,m),2.01(3 H,t),3.31(3H,s),4.04(2H,s),5.13(1H,q),5.58(1H,d),6.40(1H,m),6.48(1H,m)

[0414] Using the monomers (m01) to (m10) listed above, the monomers (m101) to (m102) listed below, and the monomers (m201) to (m203) listed below, polymer compounds (A1-1) to (A1-11) and polymer compounds (A2-1) to (A2-3) were produced, respectively, by the synthesis method shown below.

[0415] <Synthesis of polymer compounds> The polymer compounds (A1-1) to (A1-11) and (A2-1) to (A2-3) used in this example were obtained by radical polymerization using the following monomers, which derive the constituent units of each polymer compound, in predetermined molar ratios. 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). The results are shown in Table 1. 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 The results were determined by 13C-NMR. The results are shown in Table 1.

[0416] [ka]

[0417] [ka]

[0418] [ka]

[0419] [Table 1]

[0420] The structures of polymer compounds (A1-1) to (A1-11) and polymer compounds (A2-1) to (A2-3) are shown below. In each formula, l, m, and n indicate the composition ratio of each constituent unit.

[0421] [ka]

[0422] [ka]

[0423] [ka]

[0424] <Preparation of the resist composition> (Examples 1-14, Comparative Examples 1-3) Each of the components shown in Table 2 was mixed and dissolved to prepare the resist compositions for each example.

[0425] [Table 2]

[0426] In Table 2, each abbreviation has the following meaning. The numbers in brackets [ ] represent the amount (parts by mass) of the ingredients. (A)-1 to (A)-11: The above polymer compounds (A1-1) to (A1-11). (A)-12~(A)-14: The above polymer compounds (A2-1)~(A2-3).

[0427] (B)-1: An acid generator consisting of a compound represented by the following chemical formula (B-1). (B)-2: An acid generator consisting of a compound represented by the following chemical formula (B-2). (B)-3: An acid generator consisting of a compound represented by the following chemical formula (B-3).

[0428] [ka]

[0429] (D)-1: An acid diffusion control agent consisting of a compound represented by the following chemical formula (D1-1). (D)-2: An acid diffusion control agent comprising a compound represented by the following chemical formula (D1-2). (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60 / 40 (mass ratio).

[0430] [ka]

[0431] <Rating> Line-and-space resist patterns (LS patterns) were formed using the resist pattern formation method described below, and their sensitivity and resolution were evaluated.

[0432] Formation of a resist pattern Each example of the resist composition was applied to an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS) using a spinner, and a 50 nm thick resist film was formed by pre-baking (PAB) on a hot plate at 110°C for 60 seconds and drying. Next, the resist film was subjected to a drawing (exposure) using an electron beam lithography system JEOL-JBX-9300FS (manufactured by JEOL Ltd.) at an acceleration voltage of 100kV, creating a 1:1 line-and-space pattern (hereinafter referred to as an LS pattern) with a target size of 50nm line width. Subsequently, post-exposure heating (PEB) treatment was performed at 100°C for 60 seconds. Next, alkaline development was performed at 23°C for 60 seconds using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) "NMD-3" (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Afterward, a 15-second rinse was performed using pure water. As a result, in all examples, a 1:1 LS pattern with a line width of 50 nm was formed.

[0433] [Sensitivity evaluation] In the above "Formation of the resist pattern", the optimal exposure amount Eop(μC / cm²) when the LS pattern is formed is... 2 We calculated this as "Eop(μC / cm²)".2 This is shown in Table 3 as follows: A lower sensitivity measurement indicates better sensitivity.

[0434] [Resolution evaluation] The optimal exposure amount Eop(μC / cm²) for forming a target-sized LS pattern through the above-described "resist pattern formation" is used. 2 When forming an LS pattern by gradually increasing the exposure dose from ), the minimum size at which the pattern resolves was determined using a scanning electron microscope S-9380 (Hitachi High-Technologies Corporation). The results are shown in Table 3 as "resolution (nm)". A lower resolution measurement indicates better resolution.

[0435] [Table 3]

[0436] As shown in Table 3, the resist compositions of Examples 1 to 14 to which the present invention was applied exhibited better sensitivity and resolution compared to Comparative Examples 1 to 3, which were outside the scope of the present invention. In a resist composition to which the present invention is applied, Ra 01 The resist compositions of Examples 1 to 14 have "a group having 10 or fewer carbon atoms, wherein at least one of the carbon atoms constituting the carbon-carbon unsaturated bond has one or more selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfo group, an amino group, a phosphoric acid group, an amide group, an ether group, an imino group, and a thioether group," and because they have the aforementioned group having 10 or fewer carbon atoms, the solubility of the deprotecting agent in the developer is enhanced, so it is presumed that the resist compositions of Examples 1 to 14 have better resolution than Comparative Examples 1 to 3.

[0437] Ya 01 Example 6, in which is a phenyl group having a hydroxyl group, 01 Compared to Example 5, in which the phenyl group did not have a hydroxyl group, the sensitivity was superior. C 01 Example 1, in which is a secondary carbon atom, is C 01Compared to Example 9, in which the element is a tertiary carbon atom, the resolution was superior.

Claims

1. A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, It contains a resin component (A1) whose solubility in the developer changes due to the action of acid, The resin component (A1) is a resist composition having a constituent unit (a0) represented by the following general formula (a0-0). 【Chemistry 1】 [In the formula, R ０１ This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, or a hydrogen atom. ０１ This is a divalent linking group or a single bond. Ra ０１ This is an acid-dissociable group selected from the group consisting of 25 acid-dissociable groups represented by the following formula (a0-c2) and 21 acid-dissociable groups represented by the following formula (a0-c3). 【Chemistry 2】 [In the formula, * represents the bond with the oxygen atom (-O-) in formula (a0-0).] 【Transformation 3】 [In the formula, * represents the bond with the oxygen atom (-O-) in formula (a0-0).]

2. The resist composition according to claim 1, wherein the constituent unit (a0) is a constituent unit represented by the following general formula (a0-1). 【Chemistry 4】 [In the formula, Ya ｘ１ is a single bond or a divalent linking group. Wa ｘ１ is an aromatic hydrocarbon group which may have a substituent. R ０１ and Ra ０１ are each the same as R ０１ and Ra ０１ in the formula (a0-0).]

3. A method for forming a resist pattern, comprising the steps of: forming a resist film on a support using the resist composition described in claim 1 or 2; exposing the resist film; and developing the exposed resist film to form a resist pattern.

4. The resist pattern forming method according to claim 3, wherein in the step of exposing the resist film, the resist film is exposed to EUV (extreme ultraviolet) or EB (electron beam).

5. A compound represented by the following general formula (a0-m0). 【Transformation 5】 [In the formula, R ０１ This is an alkyl group having 1 to 5 carbon atoms, an alkyl halide having 1 to 5 carbon atoms, or a hydrogen atom. ０１ This is a divalent linking group or a single bond. Ra ０１ This is an acid-dissociable group selected from the group consisting of 25 acid-dissociable groups represented by the following formula (a0-c2) and 21 acid-dissociable groups represented by the following formula (a0-c3). 【Transformation 6】 [In the formula, * represents the bond with the oxygen atom (-O-) in the formula (a0-m0).] 【Transformation 7】 [In the formula, * represents the bond with the oxygen atom (-O-) in the formula (a0-m0).]

6. The compound according to claim 5, represented by the following general formula (a0-m1). 【Transformation 8】 [In the formula, Ya ｘ１ Wa is a single bond or a divalent linking group. ｘ１ R is an aromatic hydrocarbon group which may have substituents. ０１ and Ra ０１ These are R in the above formula (a0 - m0), respectively. ０１ and Ra ０１ It is identical to [this].

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