Resist composition, resist pattern forming method, compound, and polymer compound

Abstract

To provide a resist composition or the like which is good in sensitivity, roughness and etching resistance.SOLUTION: The resist composition generates an acid upon exposure, changes its solubility in a developer by the action of an acid, and contains a resin component (A1) which changes its solubility in a developer by the action of an acid. The resin component has a constituent unit (a0) derived from a compound represented by general formula (a0-m). [In the formula, W is a polymerizable group-containing group; RAr1 and RAr2 are each independently an optionally substituted aromatic group; L11 is a divalent linking group containing -C(=O)-NH-; L12 is a divalent linking group containing an aromatic ring, or a single bond; and when L12 is a divalent linking group containing an aromatic ring, a carbon atom of a carboxylate ion in the formula is bonded to the aromatic ring.]SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, pattern miniaturization has been rapidly progressing due to the advancement of lithography technology. As a miniaturization technique, generally, the short-wavelength (high-energy) conversion of the exposure light source has been carried out.

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

[0004] In a chemically amplified resist composition, generally, a resin having a plurality of constitutional units is used as the base material component in order to improve lithography characteristics and the like. As the acid generator component, various types have been proposed so far. For example, onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, disulfone-based acid generators, and the like are known.

[0005] In addition, as a resist material, a chemically amplified resist composition having an acid diffusion controller that controls the diffusion of an acid generated from the acid generator component upon exposure has also been proposed.

[0006] In a chemically amplified resist composition, a polymer compound having a structural unit containing an acid generating group that generates an acid upon exposure has been proposed as an acid generator component (see, for example, Patent Document 1). Such a polymer compound has both a function as an acid generator and a function as a base material component.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] As the miniaturization of resist patterns progresses, for example, in lithography using EUV or EB, the formation of fine patterns of several tens of nm is targeted. With such miniaturization of resist patterns, it is required to improve lithography characteristics such as sensitivity and roughness without sacrificing each other. Furthermore, with the thinning of the resist film in fine patterns, a resist composition capable of forming a resist film with high etching resistance is required.

[0009] The present invention has been made in view of the above circumstances, and an object thereof is to provide a resist composition having excellent sensitivity, roughness, and etching resistance, a resist pattern forming method using the resist composition, a polymer compound that can be used in the resist composition, and a compound that can be used in the synthesis of the polymer compound.

Means for Solving the Problems

[0010] In order to solve the above problems, the present invention employs the following configuration. That is, a first aspect of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes by the action of the acid, the resist composition containing a resin component (A1) whose solubility in a developer changes by the action of the acid, wherein the resin component (A1) has a structural unit (a0) derived from a compound represented by the following general formula (a0-m).

[0011] [Chemical formula] [In the formula, W is a polymerizable group-containing group. R Ar1 and R Ar2 are each independently an aromatic group which may have a substituent. L 11 is a divalent linking group containing -C(=O)-NH-. L 12 is a divalent linking group containing an aromatic ring, or a single bond. When L 12 is a divalent linking group containing an aromatic ring, a carbon atom in the carboxylate ion in the formula is bonded to this aromatic ring. M m+ is an m-valent onium cation. m is an integer of 1 or more. ]

[0012] A second aspect of the present invention is a resist pattern forming method having a step of forming a resist film using the resist composition according to the first aspect on a support, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern.

[0013] A third aspect of the present invention is a compound represented by the following general formula (a0-m).

[0014] [Chemical formula] [In the formula, W is a polymerizable group-containing group. R Ar1 and R Ar2 are each independently an aromatic group which may have a substituent. L 11 is a divalent linking group containing -C(=O)-NH-. L 12is a divalent linking group containing an aromatic ring, or a single bond. L 12 When 12 is a divalent linking group containing an aromatic ring, a carbon atom in the carboxylate ion in the formula is bonded to this aromatic ring. M m+ is an m-valent onium cation. m is an integer of 1 or more.]

[0015] A fourth aspect of the present invention is a polymer compound having a structural unit derived from the compound according to the third aspect.

Advantages of the Invention

[0016] According to the present invention, it is possible to provide a resist composition having good sensitivity, roughness, and etching resistance, a resist pattern forming method using the resist composition, a polymer compound that can be used in the resist composition, and a compound that can be used in the synthesis of the polymer compound.

Modes for Carrying Out the Invention

[0017] In this specification and the claims, “aliphatic” is a relative concept with respect to aromatic, and is defined to mean a group, compound, etc. that does not have aromaticity. “Alkyl group” includes linear, branched, and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group. “Alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified. “Halogen atom” includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. “Structural unit” means a monomer unit (monomeric unit) that constitutes a polymer compound (resin, polymer, copolymer). When it is described as “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 all irradiations with radiation.

[0018] The "acid-decomposable group" is a group having acid-decomposability such that 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), and the like. 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).

[0019] The "acid-dissociable group" refers to both (i) a group having acid-dissociability such that 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 constituting the acid-decomposable group needs to be a group having a lower polarity than the polar group generated by the dissociation of the acid-dissociable group. Thereby, when the acid-dissociable group is dissociated by the action of an acid, a polar group having a higher polarity than the acid-dissociable group is generated and the polarity increases. As a result, the polarity of the whole of the component (A1) increases. By the increase in 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.

[0020] "Base material component" refers to an organic compound having film-forming ability. The organic compounds used as base material components are roughly classified into non-polymers and polymers. As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. In the following, when referring to a "low molecular compound", it indicates a non-polymer having a molecular weight of 500 or more and less than 4000. As the polymer, those having a molecular weight of 1000 or more are usually used. In the following, when referring to "resin", "high molecular compound" or "polymer", it indicates a polymer having 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).

[0021] "Derived structural unit" means a structural unit formed by cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond. In "acrylic acid ester", the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. The substituent (R αx ) is an atom or group other than a hydrogen atom. Further, it shall include itaconic acid diester in which the substituent (R αx ) is substituted with a substituent containing an ester bond, and α-hydroxyacrylic ester in which the substituent (R αx ) is substituted with a hydroxyalkyl group or a group obtained by modifying its hydroxyl group. Incidentally, 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 with a substituent may be referred to as an α-substituted acrylic acid ester.

[0022] The term "derivative" refers to a concept that includes those in which the hydrogen atom at the α-position of the target compound is substituted with another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include those in which the hydrogen atom of the hydroxyl group of the target compound, which may have its hydrogen atom at the α-position substituted with a substituent, is substituted with an organic group; those in which a substituent other than a hydroxyl group is bonded to the target compound, which may have its hydrogen atom at the α-position substituted with a substituent, and the like. Herein, the α-position refers to the first carbon atom adjacent to the functional group, unless otherwise specified. Examples of the substituent that substitutes the hydrogen atom at the α-position of hydroxystyrene include R αx the same as those described above.

[0023] In this specification and the claims of this patent, depending on the structure represented by a chemical formula, there may be asymmetric carbons, and enantiomers or diastereomers may exist. In that case, those isomers are represented by one chemical formula. Those isomers may be used alone or as a mixture.

[0024] (Resist composition) The resist composition of this embodiment generates an acid upon exposure and changes its solubility in a developer upon the action of the acid. Such a resist composition contains a base material component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes upon the action of an acid. Component (A) includes a resin component (A1) having a structural unit (a0) described below. In the resist composition of this embodiment, this (A1) component also acts as a quencher that controls the diffusion of the acid generated upon exposure. That is, in the resist composition of this embodiment, the (A1) component described below is a resin that controls the diffusion of the acid generated upon exposure and changes its solubility in a developer upon the action of the acid.

[0025] In the resist composition of the present embodiment, the component (A) may generate an acid whose diffusion is controlled by the structural unit (a0) upon exposure, or an additive component blended separately from the component (A) may generate an acid whose diffusion is controlled by the structural unit (a0) upon exposure. Specifically, the resist composition of the present embodiment may further contain (1) an acid generator component (B) (hereinafter referred to as "component (B)") that generates an acid whose diffusion is controlled by the structural unit (a0) upon exposure; (2) the component (A) may be a component that generates an acid whose diffusion is controlled by the structural unit (a0) upon exposure; or (3) the component (A) may be a component that generates an acid whose diffusion is controlled by the structural unit (a0) upon exposure and further contains the component (B). That is, in the cases of the above (2) and (3), the component (A) becomes a "base material component that generates an acid whose diffusion is controlled by the structural unit (a0) upon exposure and whose solubility in the developer changes due to the action of the acid". When the component (A) is a base material component that generates an acid whose diffusion is controlled by the structural unit (a0) upon exposure and whose solubility in the developer changes due to the action of the acid, it is preferable that the component (A1) described later is a resin that generates an acid whose diffusion is controlled by the structural unit (a0) upon exposure and whose solubility in the developer changes due to the action of the acid. As such a resin, a polymer compound having the structural unit (a0) and a structural unit that generates an acid whose diffusion is controlled by the structural unit (a0) upon exposure can be used. As the structural unit that generates an acid whose diffusion is controlled by the structural unit (a0) upon exposure, the structural unit (a5) described later may be used.

[0026] When a resist film is formed using the resist composition of this embodiment and selective exposure is performed on the resist film, in the exposed portion of the resist film, for example, an acid is generated from the component (B), and the solubility of the component (A) in the developer changes due to the action of the acid. On the other hand, in the unexposed portion of the resist film, the solubility of the component (A) in the developer does not change. Therefore, a difference in solubility in the developer occurs between the exposed portion and the unexposed portion. Therefore, when the resist film is developed, when the resist composition is a positive type, the exposed portion of the resist film is dissolved and removed to form a positive type resist pattern, and when the resist composition is a negative type, the unexposed portion of the resist film is dissolved and removed to form a negative type resist pattern.

[0027] The resist composition of this embodiment may be a positive type resist composition or a negative type resist composition. Further, the resist composition of this embodiment may be for an alkali development process using an alkali developer for the development treatment during resist pattern formation, or may be for a solvent development process using a developer containing an organic solvent (organic-based developer) for the development treatment.

[0028] <Base material component (A)> In the resist composition of this embodiment, as the component (A), it is preferable to use a resin component (A1) (hereinafter also referred to as “component (A1)”) whose solubility in the developer changes due to the action of an acid. By using the component (A1), since the polarity of the base material component changes before and after exposure, good development contrast can be obtained not only in the alkali development process but also in the solvent development process. As the component (A), other high molecular compounds and / or low molecular compounds may be used in combination with the component (A1).

[0029] In the resist composition of this embodiment, the component (A) may be used alone or in combination of two or more.

[0030] ·Regarding the component (A1) (A1) component is a resin component whose solubility in the developer changes due to the action of an acid, and has a structural unit (a0) derived from a compound represented by the general formula (a0-m) described later. As the (A1) component, in addition to the structural unit (a0), it may have other structural units as necessary.

[0031] ≪Structural unit (a0)≫ The structural unit (a0) is a structural unit derived from a compound represented by the following general formula (a0-m) (hereinafter, also referred to as "compound (a0-m)"). In addition, the structural unit (a0) has a photo-disintegrating base site (carboxylate group -C(=O)-O-) that decomposes upon exposure and loses acid diffusion controllability. Further, the structural unit (a0) is also a structural unit that generates an acid upon exposure.

Chemical formula

[0032] {Anion part} In the formula (a0-m), the "polymerizable group" in the polymerizable group-containing group of W is a group that enables a compound having a polymerizable group to polymerize by radical polymerization or the like, and for example, refers to a group containing a multiple bond between carbon atoms such as an ethylenic double bond. Examples of the polymerizable group include vinyl group, allyl group, acryloyl group, methacryloyl group, fluorovinyl group, difluorovinyl group, trifluorovinyl group, difluorotrifluoromethylvinyl group, trifluoroallyl group, perfluoroallyl group, trifluoromethylacryloyl group, nonafluorobutylacryloyl group, vinyl ether group, fluorine-containing vinyl ether group, allyl ether group, fluorine-containing allyl ether group, styryl group, vinylnaphthyl group, fluorine-containing styryl group, fluorine-containing vinylnaphthyl group, norbornyl group, fluorine-containing norbornyl group, silyl group and the like. Among them, the vinyl group is preferable as the polymerizable group.

[0033] The polymerizable group-containing group may be a group composed only of a polymerizable group, or a group composed of a polymerizable group and another group other than the polymerizable group. Examples of the other group other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like. Examples of the polymerizable group-containing group include, for example, a group represented by the formula: C(R X11 )(R X12 )=C(R X13 )-Ya x0 -. In the above formula, R X11 , R X12 and R X13 each independently represent 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 represents a single bond or a divalent linking group. Examples of the divalent linking group in Ya x0 include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like. Examples of the divalent linking group in Ya x0 include an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an ether bond (-O-), -C(=O)-NH-, -NH-C(=O)-, a linear or branched alkylene group, or a combination thereof.

[0034] W in the formula (a0-m) is preferably a polymerizable group-containing group represented by the following general formula (a0-w).

[0035]

Chemical formula

[0036] In the formula (a0-w), the alkyl group having 1 to 5 carbon atoms in R 0 is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. can be mentioned. R 0 The halogenated alkyl group having 1 to 5 carbon atoms in is a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. R 0 Examples of include a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms. From the viewpoint of easy industrial availability, a hydrogen atom, a methyl group, or a trifluoromethyl group is preferable, a hydrogen atom or a methyl group is more preferable, and a hydrogen atom is even more preferable.

[0037] In the formula (a0-w), examples of L 10 include -C(=O)-O-, -C(=O)-NH-, or a single bond, etc., and a single bond is preferable.

[0038] In the formula (a0-m), R Ar1 and R Ar2The aromatic group in [compound] is, independently of each other, a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group). As the aromatic hydrocarbon group, a group obtained by removing two hydrogen atoms from benzene or a group obtained by removing two hydrogen atoms from naphthalene is preferable, and a group obtained by removing two hydrogen atoms from benzene is more preferable.

[0039] R Ar1 and R Ar2 The aromatic groups in [compound] may each independently have a substituent or may not have a substituent. R Ar1 and R Ar2 Examples of the substituent that the aromatic groups in [compound] may each independently have include a hydroxy group, an alkyl group, an alkoxy group, an acyloxy group, an alkylsulfonyloxy group, a halogen atom, an amino group, a nitro group, a cyano group, an alkenyl group, a halogen atom, and a halogenated alkyl group. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable. As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group is more preferable, and a methoxy group or an ethoxy group is even more preferable. As the halogen atom as the substituent, an iodine atom, a fluorine atom, or a bromine atom is preferable, an iodine atom or a bromine atom is more preferable, and an iodine atom is even more preferable. Examples of the halogenated alkyl group as the substituent include a group in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms.

[0040] R Ar1 The aromatic group in R preferably has at least one selected from the group consisting of a hydroxy group, an alkyl group, an alkoxy group, an acyloxy group, an alkylsulfonyloxy group, a halogen atom, an amino group, a nitro group, a cyano group, and an alkenyl group as a substituent, more preferably has at least one selected from the hydroxy group and the halogen atom, even more preferably has at least one selected from the hydroxy group and the iodine atom, and particularly preferably has a hydroxy group. R Ar1 When the aromatic group in R has a substituent, the number of substituents is 1 to 4, preferably 1 to 3, more preferably 1 to 2, and even more preferably 1. R Ar1 The plurality of substituents in R may be the same or different from each other.

[0041] R Ar2 The aromatic group in R preferably has at least one selected from the group consisting of a hydroxy group, an alkyl group, an alkoxy group, an acyloxy group, an alkylsulfonyloxy group, a halogen atom, an amino group, a nitro group, a cyano group, and an alkenyl group as a substituent, more preferably has at least one selected from the alkyl group, the alkoxy group, and the halogen atom, even more preferably has at least one selected from the methyl group, the methoxy group, and the iodine atom, and particularly preferably has an iodine atom. R Ar2 When the aromatic group in R has a substituent, the number of substituents is 1 to 4, preferably 1 to 3, more preferably 1 to 2, and even more preferably 2. R Ar2 The plurality of substituents in R may be the same or different from each other.

[0042] When the aromatic group has an iodine atom as a substituent, R Ar1 and R Ar2 may each independently have an iodine atom, or R Ar1 or R Ar2 may have an iodine atom. From the viewpoint of ease of synthesis, it is preferable that R Ar2 has an iodine atom.

[0043] In the formula (a0-m), L 11 and L 12 As the divalent linking group in, although it is not particularly limited respectively, a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, etc. are mentioned as preferable ones.

[0044] ·Divalent hydrocarbon group which may have a substituent: The divalent hydrocarbon group which may have a substituent may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0045] ··Aliphatic hydrocarbon group The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure.

[0046] ···Linear or branched aliphatic hydrocarbon group The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, examples include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, and other alkylalkylene groups. The alkyl group in the alkylalkylene group preferably has 1 to 5 carbon atoms and is a linear alkyl group.

[0047] The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, a carbonyl group, and the like.

[0048] ···an aliphatic hydrocarbon group containing a ring in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) which may contain a substituent containing a hetero atom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like. 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, more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane and the like.

[0049] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy group, a carbonyl group and the like. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferred, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group. As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and even more preferably a methoxy group or an ethoxy group. As the halogen atom as the substituent, a fluorine atom is preferred. Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a heteroatom. Preferred examples of the substituent containing a heteroatom include -O-, -C(=O)-O-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0050] ··Aromatic hydrocarbon group The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (such as biphenyl, fluorene, etc.); a group in which one hydrogen atom of the group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom from the 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 of 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.

[0051] In the aromatic hydrocarbon group, the hydrogen atoms of the aromatic hydrocarbon group may be 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 the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, etc. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0052] · Divalent linking group containing a heteroatom: Examples of the divalent linking group containing a heteroatom include -O-, -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), -S-, -S(=O)2-, -S(=O)2-O-, general formula -Y 21 -O-Y22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m ”-Y 22 -,-Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 -represented group [wherein, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m” is an integer of 1 to 3.], etc. are exemplified. When the divalent linking group containing the hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)-, the H thereof may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms. General formula -Y 21 -O-Y 22 -,-Y 21 -O-,-Y 21 -C(=O)-O-,-C(=O)-O-Y 21 -,-[Y 21 -C(=O)-O] m ”-Y 22 -,-Y 21 -O-C(=O)-Y 22 - or -Y 21 -S(=O)2-O-Y 22 - Among them, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same ones as described above. Y 21 is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. Y 22As for this, a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkylmethylene group is more preferable. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula -[Y 21 -C(=O)-O] m ”-Y 22 - In the group represented by m ” is an integer from 1 to 3, preferably 1 or 2, and more preferably 1. That is, the formula -[Y21-C(=O)-O] m ”-Y 22 - As the group represented by, the formula -Y 21 -C(=O)-O-Y 22 - The group represented by is particularly preferable. Among them, the formula -(CH2) a ’-C(=O)-O-(CH2) b ’- The group represented by is preferable. Among them, the formula -(CH2) a’ -C(=O)-O-(CH2) b’ - The group represented by is preferable. In the formula, a’ is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, still more preferably 1 or 2, and most preferably 1. b’ is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, still more preferably 1 or 2, and most preferably 1.

[0053] L 11 As for this, it may or may not contain a divalent linking group other than -C(=O)-NH-. L 11 When contains a divalent linking group other than -C(=O)-NH-, the divalent linking group preferably includes an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably includes a linear or branched alkylene group. L 11 As for this, it is preferable not to contain a divalent linking group other than -C(=O)-NH-, and -C(=O)-NH- is RAr1 and R Ar2 The direction of bonding is not limited.

[0054] L 12 is a divalent linking group containing the aromatic ring or a single bond, and a single bond is preferred.

[0055] L 12 When L is a divalent linking group containing the aromatic ring, a carbon atom in the carboxylate ion in the formula is bonded to the aromatic ring, and it may or may not contain a divalent linking group other than the aromatic ring. Examples of the divalent linking group other than the aromatic ring include an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and a linear or branched alkylene group is more preferred.

[0056] L 12 is a single bond, and when the aromatic group in R Ar2 is a group obtained by removing two hydrogen atoms from benzene, the carboxylate ion in the formula bonded to L 12 is bonded to any of the ortho, meta, and para positions, and bonding to the ortho position is preferred.

[0057] The structural unit (a0) is preferably a structural unit derived from a compound (a0-m') represented by the following general formula (a0-m').

Chemical formula

[0058] R in the formula (a0-m') 0 and L 10 are the same as R 0 and L 10 in the formula (a0-w), respectively. R in the formula (a0-m') Ar1 , R Ar2 , M m+ and m are the same as R Ar1 , R Ar2 , M m+ and m in the formula (a0-m), respectively.

[0059] As R in the formula (a0-m'), a hydrogen atom, a methyl group or a trifluoromethyl group is preferable, a hydrogen atom or a methyl group is more preferable, and a hydrogen atom is further preferable. 0 As L in the formula (a0-m'), a single bond is preferable. As the aromatic group in R 10 and R in the formula (a0-m'), a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group) is preferable, a group obtained by removing two hydrogen atoms from benzene or a group obtained by removing two hydrogen atoms from naphthalene is more preferable, and a group obtained by removing two hydrogen atoms from benzene is further preferable. The aromatic group in R Ar1 and R Ar2 in the general formula (a0-m') preferably has a substituent selected from the group consisting of a hydroxy group, an alkyl group, an alkoxy group, an acyloxy group, an alkylsulfonyloxy group, a halogen atom, an amino group, a nitro group, a cyano group and an alkenyl group, more preferably has at least one selected from a hydroxy group and an iodine atom, and particularly preferably has a hydroxy group. When the aromatic group in R Ar1 in the general formula (a0-m') has a substituent, the number of substituents is 1 to 4, preferably 1 to 3, more preferably 1 to 2, and further preferably 1. R Ar1 When the aromatic group in has a substituent, the number of substituents is 1 to 4, preferably 1 to 3, more preferably 1 to 2, and further preferably 1. R Ar1The plurality of substituents in may be the same or different from each other. R in the formula (a0-m') Ar2 The aromatic group in preferably has at least one selected from the group consisting of a hydroxy group, an alkyl group, an alkoxy group, an acyloxy group, an alkylsulfonyloxy group, a halogen atom, an amino group, a nitro group, a cyano group, and an alkenyl group as a substituent, more preferably has at least one selected from an alkyl group, an alkoxy group, and a halogen atom, still more preferably has at least one selected from a methyl group, a methoxy group, and an iodine atom, and particularly preferably has an iodine atom.

[0060] Specific examples of the anion part of the compound (a0-m) are given below, but are not limited thereto.

[0061]

Chemical formula

[0062] {Cation part} M in the above formula m+ is an m-valent onium cation. Preferred cations include a sulfonium cation and an iodonium cation. m is an integer of 1 or more.

[0063] Preferred cation parts ((M m+ )) 1 / m include organic cations represented by the following general formulas (ca-1) to (ca-3), respectively.

[0064]

Chemical formula

[0065] In the above general formulas (ca-1) to (ca-3), R 201 ~R 207 Examples of the aryl group in include unsubstituted aryl groups having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferred. R 201 ~R 207 Examples of the alkyl group in include linear or cyclic alkyl groups, preferably those having 1 to 30 carbon atoms. R 201 ~R 207 Examples of the alkenyl group in preferably have 2 to 10 carbon atoms. R 201 ~R 207 , and examples of the substituent that R 210 may have include, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, a group represented by each of the following general formulas (ca-r-1) to (ca-r-7), etc.

[0066] [Chemical formula] [In the formula, R’ 201 each independently is a hydrogen atom, a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent. ]

[0067] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Further, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0068] R’ 201 The aromatic hydrocarbon group in 201 is a hydrocarbon group having an aromatic ring. The number of carbon atoms of the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R’ 201 Specific examples of the aromatic ring of the aromatic hydrocarbon group in 201 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which a part of the carbon atoms constituting these aromatic rings is substituted with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. R’ 201 Specific examples of the aromatic hydrocarbon group in 201 include a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., such as arylalkyl groups). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0069] R’ 201 The cyclic aliphatic hydrocarbon group in 201 includes an aliphatic hydrocarbon group containing a ring in its structure. Examples of the aliphatic hydrocarbon group containing a ring in this structure include an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group 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, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane, etc. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferred, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, as the polycycloalkane, polycycloalkanes having a crosslinked ring system polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane; polycycloalkanes having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferred.

[0070] Among them, R’ 201 The cyclic aliphatic hydrocarbon group in is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane or a polycycloalkane, more preferably a group obtained by removing one hydrogen atom from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0071] The linear or branched aliphatic hydrocarbon group that may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred, and specifically, a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. can be mentioned. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, etc. can be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0072] Also, the cyclic hydrocarbon group in R’ 201 may contain a hetero atom such as a heterocyclic ring. Specifically, lactone-containing cyclic groups represented by the above general formulas (a2-r-1) to (a2-r-7), -SO2-containing cyclic groups represented by the following general formulas (b5-r-1) to (b5-r-4), and heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16) can be mentioned.

[0073]

Chemical formula

[0074] R’ 201 Examples of the substituent in the cyclic group of R’ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, etc. As the alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable. As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, 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 preferable, and a methoxy group and an ethoxy group are most preferable. As the halogen atom as a substituent, a fluorine atom is preferable. As the halogenated alkyl group as a substituent, a group in which a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group, are substituted with the halogen atom can be mentioned. The carbonyl group as a substituent is a group that substitutes the methylene group (-CH2-) constituting the cyclic hydrocarbon group.

[0075] A chain alkyl group which may have a substituent: R’ 201 As the chain alkyl group of, it may be either linear or branched. As the linear alkyl group, it preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. As the branched alkyl group, it preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 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, 4-methylpentyl group, etc. can be mentioned.

[0076] A chain alkenyl group which may have a substituent: R’ 201The chain alkenyl group may be either 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 the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Among the above, the linear alkenyl group is preferred as the chain alkenyl group, the vinyl group and the propenyl group are more preferred, and the vinyl group is particularly preferred.

[0077] R’ 201 Examples of the substituent in the chain alkyl group or alkenyl group of include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the cyclic group in the above R’ 201 and the like.

[0078] R’ 201 The cyclic group which may have a substituent, the chain alkyl group which may have a substituent, or the chain alkenyl group which may have a substituent may, in addition to those described above, include the same ones as the acid dissociable group represented by the above formula (a1-r-2) as the cyclic group which may have a substituent or the chain alkyl group which may have a substituent.

[0079] Among them, R’ 201 preferably has a cyclic group which may have a substituent, and more preferably is a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane; a lactone-containing cyclic group represented by the general formulas (a2-r-1) to (a2-r-7) respectively; a -SO2-containing cyclic group represented by the general formulas (b5-r-1) to (b5-r-4) described later, etc. are preferred.

[0080] In the above general formulas (ca-1) to (ca-3), R 201 ~R203 , R 206 ~R 207 When combined with each other to form a ring together with the sulfur atom in the formula, they may be bonded via a heteroatom such as a sulfur atom, an oxygen atom, a nitrogen atom, or a functional group such as a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N ). (The R N is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, particularly preferably a 5- to 7-membered ring, including the sulfur atom in the formula in its ring skeleton. Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydrothiophenium ring, tetrahydrothiopyranium ring, and the like.

[0081] R 208 ~R 209 each 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, and when it is an alkyl group, they may be bonded to each other to form a ring.

[0082] R 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO2-containing cyclic group which may have a substituent. R 210 Examples of the aryl group in R include unsubstituted aryl groups having 6 to 20 carbon atoms, preferably a phenyl group and a naphthyl group. 210 Examples of the alkyl group in R include linear or cyclic alkyl groups, preferably those having 1 to 30 carbon atoms. 210 Examples of the alkenyl group in R preferably have 2 to 10 carbon atoms. 210In the case of the -SO2-containing cyclic group, any group can be used without particular limitation. Specifically, groups represented by the following general formulas (b5-r-1) to (b5-r-4) can be mentioned, and a "-SO2-containing polycyclic group" is preferable, and a group represented by the general formula (b5-r-1) is more preferable.

[0083]

Chemical formula

[0084] In the general formulas (b5-r-1) to (b5-r-2), B” is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom. As B”, an alkylene group having 1 to 5 carbon atoms or -O- is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is even more preferable.

[0085] In the general formulas (b5-r-1) to (b5-r-4), Rb’ 51 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR”, -OC(=O)R”, a hydroxyalkyl group or a cyano group, and among them, each is preferably independently a hydrogen atom or a cyano group.

[0086] Specific examples of the groups represented by the general formulas (b5-r-1) to (b5-r-4) are given below. “Ac” in the formula represents an acetyl group.

[0087] [Chemistry]

[0088] [Chemistry]

[0089] [Chemistry]

[0090] Specific examples of the preferred cation represented by the formula (ca-1) include cations represented by the following chemical formulas, respectively.

[0091] [Chemistry]

[0092] [Chemistry]

[0093] [Chemistry] [In the formula, g1, g2, and g3 represent the number of repetitions, g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 0 to 20.]

[0094] [Chemistry]

[0095] [Chemistry]

[0096] [Chemistry] [In the formula, R” 201is a hydrogen atom or a substituent, and examples of the substituent include the aforementioned R 201 ~R 207 , and R 210 ~R 212 are the same as those listed as the substituents that may be possessed.]

[0097]

Chemical formula

[0098] Specific examples of the suitable cation represented by the formula (ca-2) include a diphenyliodonium cation, a bis(4-tert-butylphenyl)iodonium cation, and the like.

[0099] Specific examples of the suitable cation represented by the formula (ca-3) include cations respectively represented by the following formulas (ca-3-1) to (ca-3-6).

[0100]

Chemical formula

[0101] As the cation part ((M m+ )) 1 / m ) in the formula (a0-m), a sulfonium cation is preferable, cations respectively represented by the formulas (ca-1) to (ca-3) are more preferable, the cation represented by the formula (ca-1) is still more preferable, and cations respectively represented by the formulas (ca-1-1) to (ca-1-84) are particularly preferable. From the viewpoint of particularly enhancing the sensitivity, as the suitable cation represented by the formula (ca-1), those having an electron-withdrawing group such as a fluorine atom, a fluorinated alkyl group, or a sulfonyl group as a substituent are preferable. For example, cations selected from the group consisting of cations respectively represented by the above chemical formulas (ca-1-44), (ca-1-71) to (ca-1-84) are particularly preferable.

[0102] Specific examples of the compound (a0-m) are given below, but the compound is not limited thereto.

[0103] [Chem.]

[0104] As the compound (a0-m), those selected from the group consisting of the compounds represented by the above formulas (a0-m-1) to (a0-m-11) are preferable. Alternatively, since the sensitivity is more likely to be improved, those selected from the group consisting of the compounds represented by the above formulas (a0-m-2) to (a0-m-5), (a0-m-7), and (a0-m-9) to (a0-m-11) are preferable, and those selected from the group consisting of the compounds represented by the above formulas (a0-m-2) to (a0-m-4) and (a0-m-11) are more preferable. Alternatively, since the roughness is more likely to be reduced, those selected from the group consisting of the compounds represented by the above formulas (a0-m-2) to (a0-m-5) and (a0-m-9) to (a0-m-11) are preferable, and those selected from the group consisting of the compounds represented by the above formulas (a0-m-2) to (a0-m-4) and (a0-m-10) are more preferable. Alternatively, since the etching resistance is more likely to be improved, those selected from the group consisting of the compounds represented by the above formulas (a0-m-2) to (a0-m-7) and (a0-m-9) to (a0-m-11) are preferable, and those selected from the group consisting of the compounds represented by the above formulas (a0-m-2) to (a0-m-5) are more preferable. Alternatively, from the viewpoint of achieving both high sensitivity, roughness reduction, and improvement of etching resistance, those selected from the group consisting of the compounds represented by the above formulas (a0-m-2) to (a0-m-4) are preferable, and the compound represented by (a0-m-2) is more preferable.

[0105] The structural unit (a0) contained in the component (A1) may be one kind or two or more kinds.

[0106] As the proportion of the structural unit (a0) in the component (A1), 0.5 to 20 mol% is preferable, 1 to 15 mol% is more preferable, 2 to 10 mol% is still more preferable, and 3 to 7 mol% is particularly preferable, based on the total of all the structural units (100 mol%) constituting the component (A1). By setting the proportion of the structural unit (a0) to be not less than the lower limit value of the above-mentioned preferable range, all of sensitivity, roughness, and etching resistance become good. On the other hand, when it is not more than the upper limit value of the above-mentioned preferable range, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0107] ≪Other Structural Units≫ The component (A1) may have other structural units in addition to the above-described structural unit (a0), if necessary. Examples of the other structural units include, for example, the structural unit (a1) described below; the structural unit (a10) represented by the general formula (a10-1) described below; the structural unit (a2) containing a lactone-containing cyclic group; the structural unit (a5) that generates an acid upon exposure; the structural unit (a6) having acid diffusion controllability; the structural unit (a8) derived from a compound represented by the general formula (a8-1) described below, and the like.

[0108] ≪Structural Unit (a1)≫ The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases by the action of an acid.

[0109] Examples of the acid-dissociable group include those proposed as the acid-dissociable group of the base resin for a chemically amplified resist composition so far. Specific examples of those proposed as the acid-dissociable group of the base resin for a chemically amplified resist composition include the "acetal-type acid-dissociable group", "tertiary alkyl ester-type acid-dissociable group", "tertiary alkyloxycarbonyl acid-dissociable group", and "secondary alkyloxycarbonyl acid-dissociable group" described below.

[0110] Acetal-Type Acid-Dissociable Group: Examples of the acid dissociable group that protects the carboxy group or the hydroxy group among the polar groups include an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal type acid dissociable group").

[0111] [Chemical formula] [In the formula, Ra’ 1 , Ra’ 2 is a hydrogen atom or an alkyl group. Ra’ 3 is a hydrocarbon group, and Ra’ 3 may combine with either Ra’ 1 , Ra’ 2 to form a ring.]

[0112] In formula (a1-r-1), it is preferable that at least one of Ra’ 1 and Ra’ 2 is a hydrogen atom, and it is more preferable that both are hydrogen atoms. When Ra’ 1 or Ra’ 2 is an alkyl group, examples of the alkyl group are the same as those of the alkyl group that may be bonded to the α-carbon atom in the description of the above α-substituted acrylic acid ester, and an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a linear or branched alkyl group is preferably mentioned. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. are mentioned, a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.

[0113] In formula (a1-r-1), examples of the hydrocarbon group of Ra’ 3 include a linear or branched alkyl group, or a cyclic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and the like. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0114] The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, and the like, and an isopropyl group is preferred.

[0115] Ra’ 3 When Ra’ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As the aliphatic hydrocarbon group that is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, examples include cyclopentane, cyclohexane, and the like. As the aliphatic hydrocarbon group that is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferred. The polycycloalkane preferably has 7 to 12 carbon atoms, and specifically, examples include adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane, and the like.

[0116] Ra’ 3 When the cyclic hydrocarbon group of Ra’ is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it has a cyclic conjugated system with 4n + 2 π electrons, and it may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms, and the like. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring. Ra’ 3 Specific examples of the aromatic hydrocarbon group in include a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.); a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group (for example, 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 heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0117] Ra’ 3 The cyclic hydrocarbon group in may have a substituent. Examples of this substituent include -RP1, -RP2-O-RP1, -RP2-CO-RP1, -RP2-CO-ORP1, -RP2-O-CO-RP1, -RP2-OH, -RP2-CN, or -RP2-COOH (hereinafter these substituents are also collectively referred to as "Rax5"). Here, R P1 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, RP2 is a single bond, a divalent linear 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 of the linear saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group may be substituted with fluorine atoms. The above aliphatic cyclic hydrocarbon group may have one or more of the above substituents alone, or may have one or more of a plurality of types of the above substituents. Examples of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, and the like. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, a cyclododecyl group; polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0118] Ra’ 3 When Ra’ 1 and Ra’ 2 are bonded to each other to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group, a tetrahydrofuranyl group, and the like.

[0119] Tertiary alkyl ester type acid dissociable group: Among the above polar groups, examples of the acid dissociable group that protects the carboxy group include acid dissociable groups represented by the following general formula (a1-r-2). Among the acid dissociable groups represented by the following formula (a1-r-2), those composed of an alkyl group may be hereinafter referred to as "tertiary alkyl ester type acid dissociable groups" for convenience.

[0120] [Chemical formula] [In the formula, Ra’ 4 ~Ra’ 6 are each a hydrocarbon group, and Ra’ 5 , Ra’ 6 may be bonded to each other to form a ring.]

[0121] Examples of the hydrocarbon group of Ra’ 4 include a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic hydrocarbon group. Examples of the linear or branched alkyl group and cyclic hydrocarbon group (aliphatic hydrocarbon group which is a monocyclic group, aliphatic hydrocarbon group which is a polycyclic group, aromatic hydrocarbon group) in Ra’ 4 are the same as those of the above Ra’ 3 . Examples of the linear or cyclic alkenyl group in Ra’ 4 are preferably alkenyl groups having 2 to 10 carbon atoms. Examples of the hydrocarbon group of Ra’ 5 , Ra’ 6 are the same as those of the above Ra’ 3 .

[0122] When Ra’ 5 and Ra’ 6 are bonded to each other to form a ring, groups represented by the following general formula (a1-r2-1), groups represented by the following general formula (a1-r2-2), and groups represented by the following general formula (a1-r2-3) are preferably exemplified. On the other hand, Ra’ 4 ~Ra’ 6When they are hydrocarbon groups that are not bonded to each other and are independent, the group represented by the following general formula (a1-r2-4) is preferably mentioned.

[0123]

Chemical formula

[0124] In the above formula (a1-r2-1), Ra’ 10 is a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with a halogen atom or a heteroatom-containing group.

[0125] Ra’ 10 In the case of a linear alkyl group, the number of carbon atoms is 1 to 12, preferably 1 to 10, and particularly preferably 1 to 5. Ra’ 10 In the case of a branched alkyl group, examples thereof include the same groups as the above Ra’ 3 The alkyl group in may be partially substituted with a halogen atom or a heteroatom-containing group. For example, a part of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Further, a part of the carbon atoms (such as a methylene group) constituting the alkyl group may be substituted with a heteroatom-containing group.

[0126] Ra’ 10 Examples of the heteroatom herein include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroatom-containing group include (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, -S(=O)2-O-, etc. Examples of the heteroatom herein include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroatom-containing group include (-O-), -C(=O)-O-, -O-C(=O)-, -C(=O)-, -O-C(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, -S(=O)2-O-, etc.

[0127] In formula (a1-r2-1), (the aliphatic cyclic group formed together with the carbon atom to which Ra’ is bonded) is preferably a group exemplified as the monocyclic group or polycyclic group of Ra’ in formula (a1-r-1), which is an aliphatic hydrocarbon group (alicyclic hydrocarbon group). Among them, a monocyclic alicyclic hydrocarbon group is preferable, and specifically, a cyclopentyl group and a cyclohexyl group are more preferable. 11 (Ra’ 10 The cyclic hydrocarbon group formed by Xa and Ya together in formula (a1-r2-2) includes a group obtained by further removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) of Ra’ in formula (a1-r-1). 3 The cyclic hydrocarbon group formed by Xa and Ya together in formula (a1-r2-2) includes a group obtained by further removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) of Ra’ in formula (a1-r-1).

[0128] In formula (a1-r2-2), examples of the cyclic hydrocarbon group formed by Xa and Ya together include a group obtained by further removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) of Ra’ in formula (a1-r-1). 3 In formula (a1-r2-2), examples of the cyclic hydrocarbon group formed by Xa and Ya together include a group obtained by further removing one or more hydrogen atoms from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) of Ra’ in formula (a1-r-1). The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of this substituent include the same groups as those that the cyclic hydrocarbon group in the above Ra’ 3 may optionally have. In formula (a1-r2-2), examples of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in Ra 101 ~Ra 103 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, and the like. Ra 101 ~Ra 103 Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in Ra 2,6 ~Ra 3,7 include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, a cyclododecyl group; polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.0 3,6 .0 2,7 decanyl group, a tricyclo[3.3.1.1 Ra 101 ~Ra 103 Among them, from the viewpoint of ease of synthesis, a hydrogen atom and a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms are preferable, and among them, a hydrogen atom, a methyl group, and an ethyl group are more preferable, and a hydrogen atom is particularly preferable.

[0129] Examples of the substituent of the linear saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by the above Ra 101 ~Ra 103 include, for example, the same groups as those of the above Ra x5 .

[0130] Ra 101 ~Ra 103Examples of the group containing a carbon-carbon double bond formed by the bonding of two or more of them to form a cyclic structure include, for example, a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylideneethenyl group, a cyclohexylideneethenyl group, and the like. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylideneethenyl group are preferable.

[0131] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is the Ra' in formula (a1-r-1) 3 The group mentioned as the aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group is preferable. In formula (a1-r2-3), Ra 104 Examples of the aromatic hydrocarbon group in Ra include a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra 104 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from benzene or naphthalene, and most preferably a group obtained by removing one or more hydrogen atoms from benzene.

[0132] Examples of the substituent that Ra in formula (a1-r2-3) 104 may have include, for example, a methyl group, an ethyl group, a propyl group, a hydroxy group, a carboxy group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), an alkyloxycarbonyl group, and the like.

[0133] In formula (a1-r2-4), Ra' 12 and Ra' 13 are each independently a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Ra' 12 and Ra' 13In the case of a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, examples of the above Ra 101 ~Ra 103 include the same groups as the monovalent linear saturated hydrocarbon groups having 1 to 10 carbon atoms in the above. Some or all of the hydrogen atoms of this linear saturated hydrocarbon group may be substituted. Ra’ 12 and Ra’ 13 Among them, an alkyl group having 1 to 5 carbon atoms is preferable, an alkyl group having 1 to 5 carbon atoms is more preferable, a methyl group and an ethyl group are even more preferable, and a methyl group is particularly preferable. In the above Ra’ 12 and Ra’ 13 when the linear saturated hydrocarbon group represented by is substituted, examples of the substituent include, for example, the same groups as the above Ra x5 .

[0134] In formula (a1-r2-4), Ra’ 14 is a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group in Ra’ 14 include a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0135] Ra’ 14 The linear alkyl group in preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. can be mentioned. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

[0136] Ra’ 14 The branched alkyl group in preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, etc. can be mentioned, and an isopropyl group is preferable.

[0137] Ra’14 When it is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from monocycloalkane is preferable. As the monocycloalkane, those having 3 to 6 carbon atoms are preferable, and specifically, cyclopentane, cyclohexane and the like can be mentioned. As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from polycycloalkane is preferable. As the polycycloalkane, those having 7 to 12 carbon atoms are preferable, and specifically, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane and the like can be mentioned.

[0138] Ra’ 14 Examples of the aromatic hydrocarbon group in Ra’ 104 are the same as those of the aromatic hydrocarbon group in Ra. Among them, Ra’ 14 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from naphthalene or anthracene, and most preferably a group obtained by removing one or more hydrogen atoms from naphthalene. Ra’ 14 Examples of the substituent that Ra’ 104 may have are the same as those of the substituent that Ra

[0139] In formula (a1-r2-4), when Ra’ 14 is a naphthyl group, the position bonded to the tertiary carbon atom in the formula (a1-r2-4) may be either the 1-position or the 2-position of the naphthyl group. In formula (a1-r2-4), Ra’ 14When it is an anthryl group, the position bonding to the tertiary carbon atom in the formula (a1-r2-4) may be any of the 1-position, 2-position or 9-position of the anthryl group.

[0140] Specific examples of the group represented by the formula (a1-r2-1) are given below.

[0141]

Chemical formula

[0142]

Chemical formula

[0143]

Chemical formula

[0144] Specific examples of the group represented by the formula (a1-r2-2) are given below.

[0145]

Chemical formula

[0146]

Chemical formula

[0147]

Chemical formula

[0148] Specific examples of the group represented by the formula (a1-r2-3) are given below.

[0149]

Chemical formula

[0150] Specific examples of the group represented by the formula (a1-r2-4) are given below.

[0151]

Chemical formula

[0152] Tertiary alkyloxycarbonyl acid dissociable group: Among the above polar groups, examples of the acid dissociable group for protecting a hydroxyl group include an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter sometimes referred to as "tertiary alkyloxycarbonyl acid dissociable group" for convenience).

[0153]

Chemical formula

[0154] In formula (a1-r-3), Ra’ 7 ~Ra’ 9 are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms. Also, the total number of carbon atoms of each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0155] Secondary alkyl ester type acid dissociable group: Among the above polar groups, examples of the acid dissociable group for protecting a carboxy group include an acid dissociable group represented by the following general formula (a1-r-4).

[0156]

Chemical formula

[0157] In the formula, Ra’ 10 and Ra’ 12 Examples of the hydrocarbon group in include the same as those of the above Ra’ 3 . In the formula, Ra’ 11a and Ra’ 11b Examples of the alkyl group in include the same as those of the alkyl group in the above Ra’ 1 . In the formula, Ra’ 10 and Ra’ 12 The hydrocarbon group in, and Ra’ 11a and Ra’ 11b The alkyl group in may have a substituent. Examples of this substituent include, for example, the above-mentioned Ra x5 etc.

[0158] Ra’ 10 and Ra’ 11a or Ra’ 11b may combine with each other to form a ring. The ring may be a polycyclic or monocyclic ring, and may be an alicyclic or aromatic ring. The alicyclic and aromatic rings may contain heteroatoms.

[0159] Ra’ 10 and Ra’ 11a or Ra’ 11b Among the above, the rings formed by combining with each other are preferably monocycloalkene, a ring in which some of the carbon atoms of monocycloalkene are substituted with heteroatoms (oxygen atom, sulfur atom, etc.), and monocycloalkadiene, preferably cycloalkene having 3 to 6 carbon atoms, and preferably cyclopentene or cyclohexene.

[0160] Ra’ 10 and Ra’ 11a or Ra’ 11b The ring formed by combining with each other may be a condensed ring. Specific examples of the condensed ring include indane and the like.

[0161] Ra’ 10 and Ra’ 11a or Ra’ 11b The ring formed by combining with each other may have a substituent. Examples of this substituent include, for example, Ra x5 described above and the like.

[0162] Ra’ 11a or Ra’ 11b and Ra’ 12 and Ra’ 10 and Ra’ 11a or Ra’ 11b and may combine with each other to form a ring. Examples of the ring include the same ones as the ring formed by combining Ra’

[0163] Specific examples of the group represented by the formula (a1-r-4) are given below.

[0164]

Chemical formula

[0165] Examples of the constitutional unit (a1) include a constitutional unit derived from an acrylate ester in which a hydrogen atom bonded to an α-position carbon atom may be substituted with a substituent, a constitutional unit derived from acrylamide, and a constitutional unit in which at least a part of the hydrogen atoms in the hydroxyl group of a constitutional unit derived from hydroxystyrene or a hydroxystyrene derivative is protected by a substituent containing the acid-decomposable group, and a constitutional unit in which at least a part of the hydrogen atoms in the -C(=O)-OH of a constitutional unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative is protected by a substituent containing the acid-decomposable group.

[0166] As the constitutional unit (a1), among the above, a constitutional unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent is preferable. Preferable specific examples of such a constitutional unit (a1) include constitutional units represented by the following general formula (a1-1), (a1-2), or (a1-3).

[0167] [Chemical formula] [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 is a divalent hydrocarbon group which may have an ether bond. n a1 is an integer of 0 to 2. Ra 1 is an acid dissociable group represented by the above general formula (a1-r-1), (a1-r-2), or (a1-r-4). Wa 1 is n a2 + a monovalent hydrocarbon group. n a2 is an integer of 1 to 3. Ra 2 is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-3). Ya 001 is a single bond or a divalent linking group. Ya 01 is a single bond or a divalent linking group. Rax 01 is an acid dissociable group represented by the above general formula (a1-r-1), (a1-r-2), or (a1-r-4). Rz 01 is an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxy group, or an alkoxy group. q is an integer of 0 to 3. n is an integer of 0 or more. However, n ≦ q × 2 + 4.]

[0168] In the formulas (a1-1) to (a1-3), the alkyl group having 1 to 5 carbon atoms for R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like. The alkyl halide group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. As 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 preferable, and from the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is most preferable.

[0169] In the formula (a1-1), Va 1 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0170] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated. More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0171] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched-chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched-chain aliphatic hydrocarbon group, a branched-chain alkylene group is preferred. Specifically, alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2- and other alkylalkylene groups can be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferred.

[0172] Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched-chain aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched-chain aliphatic hydrocarbon group. Examples of the linear or branched-chain aliphatic hydrocarbon group are the same as those of the linear aliphatic hydrocarbon group or the branched-chain aliphatic hydrocarbon group described above. 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 polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, cyclopentane, cyclohexane and the like can be mentioned. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane and the like can be mentioned.

[0173] Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring of the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group in which one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, and a 2-naphthylethyl group). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0174] In the formula (a1-1), Ra 1 is preferably an acid dissociable group represented by the above general formula (a1-r-2) or (a1-r-4). Among these, a group represented by the general formula (a1-r2-1) or an acid dissociable group represented by the general formula (a1-r-4) is more preferable.

[0175] In the formula (a1-2), Wa 1 n in a2 The +1-valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a group combining a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in the structure. The above n a2 The +1-valent is preferably divalent to tetravalent, more preferably divalent or trivalent. In the formula (a1-2), Ra 2 is preferably an acid dissociable group represented by the above general formula (a1-r-1).

[0176] In the formula (a1-3), Ya 001 The divalent linking group in is not particularly limited, but examples of suitable ones include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a heteroatom. Ya 001 is preferably an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group or a combination thereof, or a single bond. The number of carbon atoms of the alkylene group is preferably 1 to 10, more preferably 1 to 6, still more preferably 1 to 4, and particularly preferably 1 to 3. Among these, Ya 001As the [bond], a combination of an ester bond [-C(=O)-O-, -O-C(=O)-] and a linear alkylene group, or a single bond is more preferable, and a single bond is even more preferable.

[0177] In the formula (a1-3), Ya 01 The divalent linking group in [the relevant part] is not particularly limited, but examples of suitable ones include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a heteroatom, and the like. Ya 01 Among these, Ya is preferably an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof, or a single bond. Among these, as Ya 01 a combination of an ester bond [-C(=O)-O-, -O-C(=O)-] and a linear alkylene group, or a single bond is more preferable, and a single bond is even more preferable.

[0178] In the formula (a1-3), Rax 01 is preferably an acid dissociable group represented by the above general formula (a1-r-2) or (a1-r-4). Among these, an acid dissociable group represented by the general formula (a1-r-2) is more preferable, and a group represented by the general formula (a1-r2-1) is even more preferable.

[0179] In the formula (a1-3), Rz 01 The alkyl group, halogenated alkyl group, and alkoxy group in [the relevant part] preferably have 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, even more preferably 1 to 3 carbon atoms, and particularly preferably 1 or 2 carbon atoms. The alkyl group, halogenated alkyl group, and alkoxy group may be linear or branched. Rz 01 As the halogen atom in [the relevant part], an iodine atom is preferable. As the halogen atom of the halogenated alkyl group in Rz 01 a fluorine atom, an iodine atom, or a bromine atom is preferable, and a fluorine atom is more preferable. Rz01 is preferably an alkoxy group or a hydroxy group, more preferably a hydroxy group.

[0180] In the formula (a1-3), q is an integer of 0 to 3. When q is 0, it is a benzene structure; when q is 1, it is a naphthalene structure; when q is 2, it is an anthracene structure; when q is 3, it is a tetracene structure. In the formula (a1-3), n is an integer of 0 or more, preferably 0 to 5, more preferably 0 to 3, and still more preferably 1 or 2. When n is an integer of 2 or more, two or more Rz 01 may be the same as or different from each other. In the formula (a1-3), n ≦ q × 2 + 4. For example, when q is 1 and it is a naphthalene structure, all six hydrogen atoms of the naphthalene may be substituted with hydroxy groups. Also, in the naphthalene, Ya 001 , -Ya 01 -C(=O)-O-Ra 01 groups, and the substitution positions of the hydroxy groups are not particularly limited.

[0181] Specific examples of the constitutional unit (a1) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0182]

Chemical formula

[0183]

Chemical formula

[0184]

Chemical formula

[0185]

Chemical formula

[0186] [Chemistry]

[0187] [Chemistry]

[0188] [Chemistry]

[0189] [Chemistry]

[0190] [Chemistry]

[0191] In the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group. Rz represents a hydrogen atom, an alkyl group, a halogen atom, a halogenated alkyl group, a hydroxy group, or an alkoxy group.

[0192] [Chemistry]

[0193] [Chemistry]

[0194] [Chemistry]

[0195] [Chemistry]

[0196] [Chemical formula]

[0197] (A1) component may have one or more than two kinds of structural units (a1). As the structural unit (a1), the structural unit represented by the formula (a1-1) or the structural unit represented by the formula (a1-3) is more preferable because the characteristics (sensitivity, shape, etc.) in lithography by electron beam or EUV can be more easily enhanced. Among them, since it is suitable for enhancing reactivity in EB or EUV, the acid dissociable groups (Ra 1 , Rax 01 ) are preferably acid dissociable groups represented by the above general formulas (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4), respectively. Among them, it is particularly preferable to select those that are cyclic groups.

[0198] Alternatively, as the structural unit (a1), it may include a structural unit represented by the following general formula (a1-1-1).

[0199] [Chemical formula] [In the formula, Ra 1 ” is an acid dissociable group represented by the general formulas (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4). * indicates a bond.]

[0200] In the formula (a1-1-1), R, Va 1 and n a1 are the same as R, Va 1 and n a1 in the formula (a1-1).

[0201] The description of the acid dissociable group represented by the general formula (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4) is as described above. Among them, since it is suitable for enhancing reactivity in EB or EUV, it is preferable to select an acid dissociable group that is a cyclic group.

[0202] The proportion of the structural unit (a1) in the component (A1) is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, still more preferably 30 to 70 mol%, and particularly preferably 40 to 70 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). By setting the proportion of the structural unit (a1) to be equal to or higher than the lower limit value of the above-mentioned preferable range, lithography characteristics such as sensitivity, resolution, and CDU improvement are improved. On the other hand, when it is equal to or lower than the upper limit value of the above-mentioned preferable range, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0203] Structural unit (a10): The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

[0204] [Chemical formula] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms. Ya x1 is a single bond or a divalent linking group. Wa x1 is an aromatic hydrocarbon group which may have a substituent. n ax1 is an integer of 1 or more.]

[0205] In the formula (a10-1), R is the same as R in the general formula (a1-1). As 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 preferable, and a hydrogen atom or a methyl group is particularly preferable from the viewpoint of easy availability in industry.

[0206] In the formula (a10-1), Ya x1is a single bond or a divalent linking group. In the above chemical formula, Ya x1 The divalent linking group in is not particularly limited, but the above L 11 and L 12 Similar ones to those are mentioned as preferred examples.

[0207] Ya x1 As Ya, a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof is preferred, and a single bond, an ester bond [-C(=O)-O-, -O-C(=O)-] is more preferred.

[0208] In the above formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. Wa x1 The aromatic hydrocarbon group in includes a group obtained by removing (n ax1 +1) hydrogen atoms from an aromatic ring which may have a substituent. 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 of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom, etc. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring, a thiophene ring, etc. Also, the aromatic hydrocarbon group in Wa x1 includes a group obtained by removing (n ax1 +1) hydrogen atoms from an aromatic compound (for example, biphenyl, fluorene, etc.) containing an aromatic ring which may have two or more substituents. Among the above, as Wa x1 is benzene, naphthalene, anthracene or biphenyl from (n ax1A group excluding (+1) hydrogen atoms is preferred, and a group excluding (+1) hydrogen atoms from benzene or naphthalene is more preferred, and a group excluding (+1) hydrogen atoms from benzene is even more preferred. ax1 A group excluding (+1) hydrogen atoms is more preferred, and a group excluding (+1) hydrogen atoms from benzene is even more preferred. ax1 A group excluding (+1) hydrogen atoms is even more preferred.

[0209] Wa x1 The aromatic hydrocarbon group in may have a substituent or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, etc. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent are the same as those listed as the substituent of the cyclic aliphatic hydrocarbon group in Ya x1 A linear or branched alkyl group having 1 to 5 carbon atoms is preferred as the substituent, a linear or branched alkyl group having 1 to 3 carbon atoms is more preferred, an ethyl group or a methyl group is even more preferred, and a methyl group is particularly preferred. Wa x1 The aromatic hydrocarbon group in is preferably unsubstituted.

[0210] In the formula (a10-1), n ax1 is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, even more preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0211] Specific examples of the structural unit (a10) represented by the formula (a10-1) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0212]

Chemical formula

[0213]

Chemical formula

[0214] [Chemical]

[0215] (A1) component may have one or more than two kinds of structural units (a10). (A1) component may or may not have the structural unit (a10), but it is preferred to have the structural unit (a10). When (A1) component has the structural unit (a10), the proportion of the structural unit (a10) in (A1) component is preferably 20 - 80 mol%, more preferably 25 - 70 mol%, still more preferably 30 - 60 mol%, and particularly preferably 30 - 50 mol% with respect to the total of all structural units constituting (A1) component (100 mol%). By setting the proportion of the structural unit (a10) to be not less than the lower limit value, the sensitivity is more likely to be enhanced. On the other hand, by setting it to be not more than the upper limit value, it is easier to balance with other structural units.

[0216] Structural unit (a2): (A1) component may or may not have a structural unit (a2) containing a lactone-containing cyclic group (excluding those corresponding to the structural unit (a1)). The lactone-containing cyclic group of the structural unit (a2) is effective in enhancing the adhesion of the resist film to the substrate when (A1) component is used for forming the resist film. Also, by having the structural unit (a2), for example, by appropriately adjusting the acid diffusion length, enhancing the adhesion of the resist film to the substrate, appropriately adjusting the solubility during development, etc., the lithography characteristics and the like become good.

[0217] "Lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -O-C(=O)- in its ring skeleton. Counting the lactone ring as the first ring, in the case of only the lactone ring, it is a monocyclic group, and when it further has other ring structures, regardless of the structure, it is called a polycyclic group. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. As the lactone-containing cyclic group in the structural unit (a2), any group can be used without particular limitation. Specifically, groups represented by the following general formulas (a2-r-1) to (a2-r-7) can be mentioned.

[0218] [Chemical formula] [In the formula, Ra’ 21 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR”, -OC(=O)R”, a hydroxyalkyl group or a cyano group; R” is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group; A” is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom or a sulfur atom, n’ is an integer of 0 to 2, and m’ is 0 or 1. * indicates a bond (the same applies hereinafter).]

[0219] In the general formulas (a2-r-1) to (a2-r-7), the alkyl group in Ra’ 21 is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a hexyl group and the like can be mentioned. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable. The alkoxy group in Ra’ 21 is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, a group in which the alkyl group mentioned as the alkyl group in the above Ra’ 21 is linked to an oxygen atom (-O-) can be mentioned. The halogen atom in Ra’ 21 is preferably a fluorine atom. The halogenated alkyl group in Ra’ 21 is, as the alkyl group in the above Ra’ 21Examples of the group include those in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

[0220] Ra’ 21 In -COOR” and -OC(=O)R” in, R” is each a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. As the alkyl group in R”, any of linear, branched, and cyclic ones may be used, and the number of carbon atoms is preferably 1 to 15. When R” is a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 10, more preferably 1 to 5, and particularly preferably a methyl group or an ethyl group. When R” is a cyclic alkyl group, the number of carbon atoms is preferably 3 to 15, more preferably 4 to 12, and most preferably 5 to 10. Specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane can be exemplified. More specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane and cyclohexane; adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as tetracyclododecane, etc. can be mentioned. Examples of the lactone-containing cyclic group in R” include the same groups as those represented by the general formulas (a2-r-1) to (a2-r-7) respectively. Ra’ 21 As the hydroxyalkyl group in, those having 1 to 6 carbon atoms are preferable, and specifically, the Ra’ 21 Examples of the group include those in which at least one of the hydrogen atoms of the alkyl group in is substituted with a hydroxyl group.

[0221] Ra’ 21 Among them, it is preferably a hydrogen atom or a cyano group, respectively independently.

[0222] In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A” is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropyl group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is interposed at the terminal or between carbon atoms of the alkylene group, and examples thereof include -O-CH2-, -CH2-O-CH2-, -S-CH2-, and -CH2-S-CH2-. A” is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0223] Specific examples of the groups represented by the general formulas (a2-r-1) to (a2-r-7) are given below.

[0224]

Chemical formula

[0225]

Chemical formula

[0226] As the constitutional unit (a2), among others, a constitutional unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent is preferable. Such a constitutional unit (a2) is preferably a constitutional unit represented by the following general formula (a2-1).

[0227]

Chemical formula

[0228] In the formula (a2-1), R is the same as described above. As 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 preferable, and from the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is particularly preferable.

[0229] In the formula (a2-1), Ya 21 The divalent linking group in is not particularly limited, but examples thereof preferably include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like. The divalent linking group in Ya 21 is the same as the divalent linking group in Ya x1 in the general formula (a10-1).

[0230] Ya 21 is preferably a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0231] In the formula (a2-1), Ya 21 is a single bond, and La 21 is preferably -COO- or -OCO-.

[0232] In the formula (a2-1), Ra 21 is a lactone-containing cyclic group. Ra 21Examples of the lactone-containing cyclic group in [the compound] include groups each represented by the aforementioned general formulas (a2-r-1) to (a2-r-7).

[0233] (A1) The structural unit (a2) may be one type or two or more types. The (A1) component may or may not have the structural unit (a2). (A1) When the component has the structural unit (a2), the proportion of the structural unit (a2) is preferably 1 to 20 mol%, more preferably 1 to 15 mol%, and even more preferably 1 to 10 mol% with respect to the total (100 mol%) of all the structural units constituting the (A1) component. When the proportion of the structural unit (a2) is set to be equal to or higher than the preferable lower limit value, the effect of including the structural unit (a2) can be sufficiently obtained due to the aforementioned effect. When it is equal to or lower than the upper limit value, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0234] Structural unit (a5): (A1) The component may or may not have the structural unit (a5) that generates an acid upon exposure. Known structural units (a5) can be used. By having the structural unit (a5), the acid generated upon exposure is likely to be uniformly distributed within the resist film. Examples of the structural unit (a5) include structural units containing the structure described in the later-described (B) component. For example, structural units containing the structure represented by any of the following general formulas (b-1) to (b-3) can be mentioned. Examples of the structural unit (a5) preferably include a structural unit represented by the following general formula (a5-1).

[0235] [Chemical formula] [In the formula, R m is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogen atom, or a hydrogen atom. La50 is a divalent linking group or a single bond. Ra 50 is a divalent hydrocarbon group which may have a substituent. n a5 is an integer of 0 to 2. La 51 is a divalent linking group. Ya 5 is a divalent linking group which may have a heteroatom, or a single bond. Ra 51 and Ra 52 are each independently a hydrogen atom, a fluorine atom or a fluorinated alkyl group. n5 is an integer of 1 to 4. m is an integer of 1 or more, and M’ m+ is an m-valent onium cation.]

[0236] {Anion part} In the formula (a5-1), R m is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a halogen atom or a hydrogen atom. R m The alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. may be mentioned. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. Among the halogen atoms in the halogenated alkyl group, a fluorine atom is particularly preferable. R m 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 from the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is most preferable.

[0237] In the formula (a5-1), La 50 is a divalent linking group or a single bond. La 50The divalent linking group in is not particularly limited, but a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom are preferable, and each of them is the above Ya x1 is the same as the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom exemplified as the divalent linking group in . Among the above, La 50 is preferably an ester bond [-C(=O)-O-, -O-C(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group or a combination thereof, or a single bond. Among these, La 5 is more preferably an ester bond [-C(=O)-O-, -O-C(=O)-] or a single bond, and even more preferably an ester bond [-C(=O)-O-, -O-C(=O)-].

[0238] In the formula (a5-1), Ra 50 is a divalent hydrocarbon group which may have a substituent. Ra 50 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0239] ··Ra 50 The aliphatic hydrocarbon group in The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure.

[0240] ···linear or branched aliphatic hydrocarbon group 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 the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, examples include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, and the like, which are alkylalkylene groups. The alkyl group in the alkylalkylene group preferably is a linear alkyl group having 1 to 5 carbon atoms.

[0241] The above-mentioned linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, a carbonyl group, and the like.

[0242] ···an aliphatic hydrocarbon group containing a ring in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the terminal of a linear or branched aliphatic hydrocarbon group, a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like. 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, more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, cyclopentane, cyclohexane and the like can be mentioned. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane and the like can be mentioned.

[0243] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group and the like. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group and a tert-butyl group are most preferable. As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, 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 preferable, and a methoxy group and an ethoxy group are most preferable. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferred. Examples of the halogenated alkyl group as the substituent include a group in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. Preferred examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, -S(=O)2-, -S(=O)2-O-.

[0244] ··Ra 50 The aromatic hydrocarbon group in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with hetero atoms. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, etc. Specific examples of the aromatic heterocyclic ring include a pyridine ring, a thiophene ring, etc. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (such as biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) is substituted with an alkylene group (for example, a group obtained by further removing one 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 of 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.

[0245] The hydrogen atoms of the aromatic hydrocarbon group may be 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 the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, etc. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atoms of the cyclic aliphatic hydrocarbon group.

[0246] In the formula (a5-1), n a5 is an integer of 0 to 2. Among the above, Ra 50 preferably has an aliphatic hydrocarbon group containing a ring in its structure, more preferably a cyclic aliphatic hydrocarbon group that may contain a substituent containing a heteroatom in the ring structure, and still more preferably an alicyclic hydrocarbon group that may have a substituent and is a polycyclic group or a monocyclic group. Alternatively, among the above, Ra 50 is preferably an aromatic hydrocarbon group.

[0247] n a5 When is 2, the two Ra 50 may each be an alicyclic hydrocarbon group which may have a substituent, may each be an aromatic hydrocarbon group, or may be a combination of an alicyclic hydrocarbon group which may have a substituent and an aromatic hydrocarbon group.

[0248] In the formula (a5-1), La 51 is a divalent linking group. La 51 Examples of the divalent linking group in include non-hydrocarbon oxygen atom-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-O-C(=O)-O-); combinations of such non-hydrocarbon oxygen atom-containing linking groups and an alkylene group, etc. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of such divalent linking groups include linking groups each represented by the following general formulas (L-al-1) to (L-al-8). In the following general formulas (L-al-1) to (L-al-8), Ra 50 in the above formula (a5-1) binds to V’ 101 in the following general formulas (L-al-1) to (L-al-8).

[0249]

Chemical formula

[0250] V’ 102The 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.

[0251] V’ 101 and V’ 102 The alkylene group in and may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferred. V’ 101 and V’ 102 Specific examples of the alkylene group in and include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-; a pentamethylene group [-CH2CH2CH2CH2CH2-], and the like. Also, V’ 101 Or V’ 102 Some of the methylene groups in the alkylene group in or may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group) of Ra’ in the formula (a1-r-1). 3 is preferably a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group) of Ra’ in the formula (a1-r-1), more preferably a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group.

[0252] La 51As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferred, the linking groups represented by the above formulas (L-al-1) to (L-al-5) and (L-al-8) are more preferred, and the linking group represented by (L-al-3) or (L-al-8) is even more preferred.

[0253] In the formula (a5-1), Ya 5 is a divalent linking group which may have a hetero atom or a single bond. Ya 5 The divalent linking group in Ya Ya 5 is not particularly limited, but preferably includes a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like. x1 The divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom in Ya x1 are the same as the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom exemplified as the divalent linking group in Ya x1 above. Among the above, as Ya 5 a linear or branched alkylene group or a single bond is preferred, and a single bond is more preferred.

[0254] In the formula (a5-1), Ra 51 and Ra 52 are each independently a hydrogen atom, a fluorine atom or a fluorinated alkyl group. Ra 51 and Ra 52 As the fluorinated alkyl group in Ra 51 and Ra 52 each, a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms is preferred, and a trifluoromethyl group is more preferred. In the formula (a5-1), SO3 - At least one of Ra 51 and Ra 52 bonded to the carbon atom adjacent to SO3 - is preferably a fluorine atom from the viewpoint of acid strength.

[0255] In the formula (a5-1), n5 is an integer of 1 to 4, and 1, 2 or 3 is preferred.

[0256] {Cation moiety} In the formula (a5-1), M’ m+ represents an m-valent onium cation. Among these, M’ m+ is preferably a sulfonium cation or an iodonium cation. m is an integer of 1 or more.

[0257] Preferred cation moieties ((M’ m+ )) 1 / m include those similar to the organic cations represented by the above general formulas (ca-1) to (ca-3), respectively.

[0258] The cation moiety ((M’ m+ )) 1 / m in the formula (a5-1) is preferably a sulfonium cation, more preferably a cation represented by the above general formulas (ca-1) to (ca-3), still more preferably a cation represented by the formula (ca-1), and particularly preferably a cation represented by the formulas (ca-1-1) to (ca-1-84), respectively. Particularly from the viewpoint of high sensitivity, as a preferred cation represented by the formula (ca-1), those having an electron-withdrawing group such as a fluorine atom, a fluorinated alkyl group, or a sulfonyl group as a substituent are preferable. For example, a cation selected from the group consisting of cations represented by the above chemical formulas (ca-1-44), (ca-1-71) to (ca-1-84) is particularly preferable.

[0259] Preferred specific examples of the structural unit (a5) are shown below. In the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group. m and M’ m+ are the same as m and M m+ in the above general formula (a0-m).

[0260]

Chemical formula

[0261]

Chemical formula

[0262] [Chemical formula]

[0263] The structural unit (a5) contained in the component (A1) may be one kind or two or more kinds. When the component (A1) has the structural unit (a5), the proportion of the structural unit (a5) in the component (A1) is preferably 5 to 25 mol%, more preferably 10 to 20 mol%, and even more preferably 15 to 20 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). When the proportion of the structural unit (a5) is at least the lower limit of the above-mentioned preferred range, it becomes easier to achieve further higher sensitivity and improved resolution. On the other hand, when it is at most the upper limit of the above-mentioned preferred range, it becomes easier to balance with other structural units.

[0264] Structural unit (a6): The structural unit (a6) is a structural unit having acid diffusion controllability. The component (A1) may or may not have the structural unit (a6). Known structural units can be used as the structural unit (a6). Examples of the structural unit (a6) include structural units containing the structures described in the components (D1) and (D2) described below. For example, structural units containing the structures represented by any of the general formulas (d1-1) to (d1-3) described below can be mentioned.

[0265] The structural unit (a6) contained in the component (A1) may be one kind or two or more kinds. When the component (A1) has the structural unit (a6), the proportion of the structural unit (a6) in the component (A1) is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and even more preferably 3 to 10 mol% with respect to the total (100 mol%) of all the structural units constituting the component (A1). The ratio of the constitutional unit (a6) being equal to or higher than the lower limit of the above-mentioned preferable range makes it easier to achieve further higher sensitivity. On the other hand, being equal to or lower than the upper limit of the above-mentioned preferable range makes it easier to balance with other constitutional units.

[0266] Constitutional unit (a8): The constitutional unit (a8) is a constitutional unit derived from a compound represented by the following general formula (a8-1). The component (A1) may or may not have the constitutional unit (a8).

[0267]

Chemical formula

[0268] W 2 The "polymerizable group" in the polymerizable group-containing group of W is a group that enables a compound having a polymerizable group to polymerize by radical polymerization or the like, and for example, refers to a group containing a multiple bond between carbon atoms such as an ethylenic double bond.

[0269] The polymerizable group-containing group may be a group composed only of a polymerizable group, or a group composed of a polymerizable group and another group other than the polymerizable group. Examples of the other group other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like. Examples of the polymerizable group-containing group include, for example, the chemical formula: C(R X11 )(R X12)=C(R X13 )-Ya x0 -represented groups are preferably mentioned. In this chemical formula, R X11 , R X12 and R X13 are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya x0 is a single bond or a divalent linking group.

[0270] Ya x2 and W 2 The condensed ring formed by and is, as the condensed ring formed by the polymerizable group at the W 2 site and Ya x2 , the condensed ring formed by the polymerizable group at the W 2 site and other groups other than the polymerizable group and Ya x2 -formed condensed rings are mentioned. Ya x2 and W 2 The condensed ring formed by and may have a substituent.

[0271] Specific examples of the structural unit (a8) are shown below. In the following formula, R α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0272]

Chemical formula

[0273] Among the above examples, the structural unit (a8) is preferably at least one selected from the group consisting of structural units represented by chemical formulas (a8-1-01) to (a8-1-04), (a8-1-06), (a8-1-08), (a8-1-09), and (a8-1-10), and more preferably at least one selected from the group consisting of structural units represented by chemical formulas (a8-1-01) to (a8-1-04), (a8-1-09).

[0274] (A1) The constituent unit (a8) it has may be one kind or two or more kinds. The (A1) component may or may not have the constituent unit (a8). The proportion of the constituent unit (a8) in the (A1) component is preferably 0 to 50 mol%, more preferably 0 to 30 mol%, based on the total (100 mol%) of all the constituent units constituting the (A1) component.

[0275] As the (A1) component contained in the resist composition, one kind may be used alone, or two or more kinds may be used in combination.

[0276] Examples of the (A1) component include a polymer compound having a constituent unit (a0) and a constituent unit (a1); a polymer compound having a constituent unit (a0), a constituent unit (a1), and a constituent unit (a10), etc. The (A1) component is preferably a polymer compound composed of a constituent unit (a0), a constituent unit (a1), and a constituent unit (a10).

[0277] In the polymer compound composed of a constituent unit (a0), a constituent unit (a1), and a constituent unit (a10), the proportion of the constituent unit (a0) is preferably 0.5 to 20 mol%, more preferably 1 to 15 mol%, still more preferably 2 to 10 mol%, and particularly preferably 3 to 7 mol%, based on the total (100 mol%) of all the constituent units constituting the polymer compound. The proportion of the constituent unit (a1) in the polymer compound is preferably 5 to 80 mol%, more preferably 10 to 75 mol%, still more preferably 30 to 70 mol%, and particularly preferably 40 to 70 mol%, based on the total (100 mol%) of all the constituent units constituting the polymer compound. The proportion of the constituent unit (a10) in the polymer compound is preferably 20 to 80 mol%, more preferably 25 to 70 mol%, still more preferably 30 to 60 mol%, and particularly preferably 30 to 50 mol%, based on the total (100 mol%) of all the constituent units constituting the polymer compound.

[0278] Such component (A1) can be produced by dissolving monomers that induce each structural unit in a polymerization solvent, adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (e.g., V-601, etc.) thereto, and performing polymerization. Alternatively, such component (A1) can be produced by dissolving a monomer that induces structural unit (a0) and a monomer that induces an arbitrary structural unit (e.g., structural unit (a10), structural unit (a1), etc.) in a polymerization solvent, adding the above radical polymerization initiator thereto, performing polymerization, and then performing a deprotection reaction. In addition, 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. Thus, a copolymer into which a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms is introduced is effective for reducing development defects and LER (Line Edge Roughness: non-uniform unevenness on the sidewall of the line).

[0279] The weight average molecular weight (Mw) of component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, and is preferably 1000 to 50000, more preferably 5000 to 40000, and even more preferably 5000 to 30000. When the Mw of component (A1) is below the preferred upper limit of this range, it has sufficient solubility in a resist solvent for use as a resist, and when it is above the preferred lower limit of this range, the dry etching resistance and the cross-sectional shape of the resist pattern are good. The dispersity (Mw / Mn) of component (A1) is not particularly limited, and is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Note that Mn represents the number average molecular weight.

[0280] ·Regarding component (A2) The resist composition of this embodiment may also use, as component (A), a base material component (hereinafter referred to as "(A2) component") that does not correspond to the (A1) component and whose solubility in a developer changes by the action of an acid. The (A2) component is not particularly limited, and it may be arbitrarily selected and used from among many base material components conventionally known as those for chemically amplified resist compositions. As the (A2) component, one kind of a high molecular compound or a low molecular compound may be used alone, or two or more kinds may be used in combination.

[0281] The proportion of the (A1) component in the (A) component is preferably 25% by mass or more, more preferably 50% by mass or more, still more preferably 75% by mass or more, and may even be 100% by mass, based on the total mass of the (A) component. When the proportion is 25% by mass or more, a resist pattern excellent in various lithography characteristics such as high sensitivity, high resolution, CDU improvement, roughness reduction, and etching resistance improvement is likely to be formed.

[0282] In the resist composition of this embodiment, the content of the (A) component may be adjusted according to the resist film thickness to be formed and the like.

[0283] <Acid generator component (B)> The resist composition of this embodiment may contain an acid generator component (B) that generates an acid upon exposure. The (B) component is not particularly limited, and those proposed as acid generators for chemically amplified resist compositions heretofore can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators; diazomethane-based acid generators such as bis-alkyl or bis-aryl sulfonyldiazomethanes and poly(bis-sulfonyl)diazomethanes; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators. The form of containing the (B) component may be in the form of a compound, may be in the form incorporated into the (A1) component as the above-mentioned structural unit (a5), or may be in both of these forms.

[0284] Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "(b-1) component"), a compound represented by the general formula (b-2) (hereinafter also referred to as "(b-2) component"), or a compound represented by the general formula (b-3) (hereinafter also referred to as "(b-3) component").

[0285] Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "(b-1) component"), a compound represented by the general formula (b-2) (hereinafter also referred to as "(b-2) component"), or a compound represented by the general formula (b-3) (hereinafter also referred to as "(b-3) component").

[0286] [Chemical formula] [In the formula, R 101 and R 104 ~R 108 are each independently a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. R 104 and R 105 may be bonded to each other to form a ring structure. R 102 is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y 101 is a divalent linking group containing an oxygen atom or a single bond. V 101 ~V 103 are each independently a single bond, an alkylene group or a fluorinated alkylene group. However, Y 101 and V 101 do not simultaneously become a single bond. L 101 ~L 102 are each independently a single bond or an oxygen atom. L 103 ~L 105 are each independently a single bond, -CO- or -SO2-. m is an integer of 1 or more, and M’ m+ is an m-valent onium cation.]

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

[0288] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Also, the aliphatic hydrocarbon group is preferably saturated.

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

[0290] R 101The cyclic aliphatic hydrocarbon group in [the compound] includes aliphatic hydrocarbon groups containing a ring in their structure. Examples of the aliphatic hydrocarbon group containing a ring in this structure include alicyclic hydrocarbon groups (groups obtained by removing one hydrogen atom 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, groups in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane, and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferred, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, as the polycycloalkane, polycycloalkanes having a cross-linked ring system polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane; and polycycloalkanes having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferred.

[0291] Among them, as the cyclic aliphatic hydrocarbon group in R 101 , a group obtained by removing one or more hydrogen atoms from a monocycloalkane or a polycycloalkane is preferred, a group obtained by removing one hydrogen atom from a polycycloalkane is more preferred, an adamantyl group and a norbornyl group are even more preferred, and an adamantyl group is particularly preferred.

[0292] 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 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. may be mentioned. 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 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2- and other alkylalkylene groups may be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[0293] Also, R 101 The cyclic hydrocarbon group in R may contain a hetero atom such as a heterocyclic ring. Specifically, 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 chemical formulas (r-hr-1) to (r-hr-16) may be mentioned.

[0294] R 101Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, and the like. As the alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferable. As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. As the halogen atom as a substituent, a fluorine atom, a bromine atom, or an iodine atom is preferable. Examples of the halogenated alkyl group as a substituent include a group in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc., are substituted with the above halogen atoms. The carbonyl group as a substituent is a group that substitutes the methylene group (-CH2-) constituting the cyclic hydrocarbon group.

[0295] R 101 The cyclic hydrocarbon group in may be a condensed cyclic group containing a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring are condensed. Examples of the condensed ring include those in which one or more aromatic rings are condensed to a polycycloalkane having a bridged ring system polycyclic skeleton. Specific examples of the bridged ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. As the condensed cyclic group, a group containing a condensed ring in which 2 or 3 aromatic rings are condensed to a bicycloalkane is preferable, and a group containing a condensed ring in which 2 or 3 aromatic rings are condensed to bicyclo[2.2.2]octane is more preferable. R 101 Specific examples of the condensed cyclic group in include those represented by the following formulas (r-br-1) to (r-br-2). In the formula, * represents a bond that binds to Y in the formula (b-1). 101 represents the bond that binds to.

[0296]

Chemical formula

[0297] R 101 Examples of the substituent that the condensed cyclic group in R may optionally have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, and the like. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the condensed cyclic group are the same as those exemplified as the substituent of the cyclic group in the above R 101 and may be the same as those exemplified as the substituent of the cyclic group in R. Examples of the aromatic hydrocarbon group as the substituent of the condensed cyclic group include a group obtained by removing one hydrogen atom from an aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., arylalkyl groups), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6), respectively. Examples of the alicyclic hydrocarbon group as the substituent of the condensed cyclic group include a group obtained by removing one hydrogen atom from a monocycloalkane such as cyclopentane or cyclohexane; a group obtained by removing one hydrogen atom from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane or tetracyclododecane; lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), respectively; -SO2-containing cyclic groups represented by the general formulas (b5-r-1) to (b5-r-4), respectively; and heterocyclic groups represented by the formulas (r-hr-7) to (r-hr-16), respectively.

[0298] Optionally substituted chain alkyl group: R 101 The chain alkyl group of R 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, for example, 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, 4-methylpentyl group, etc. can be mentioned.

[0299] The chain alkenyl group which may have a substituent: R 101 The chain alkenyl group of may be either linear or branched, preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include vinyl group, propenyl group (allyl group), butenyl group, etc. Examples of the branched alkenyl group include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group, etc. Among the above, the linear alkenyl group is preferred as the chain alkenyl group, more preferably vinyl group and propenyl group, and particularly preferably vinyl group.

[0300] R 101 Examples of the substituent in the chain alkyl group or alkenyl group of include alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, carbonyl group, nitro group, amino group, the cyclic group in the above R 101 etc.

[0301] In formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 When is a divalent linking group containing an oxygen atom, the Y 101It may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, nitrogen atoms, and the like. Examples of the divalent linking group containing an oxygen atom include the linking groups represented by the above general formulas (L-al-1) to (L-al-8), respectively. In the following general formulas (L-al-1) to (L-al-8), R in the above formula (b-1) 101 is bonded to V' in the following general formulas (L-al-1) to (L-al-8). 101 That is.

[0302] In formula (b-1), V 101 is a single bond, an alkylene group or a fluorinated alkylene group. Among them, V 101 is preferably a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

[0303] In formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0304] Specific examples of the anion part represented by the formula (b-1) include, for example, when Y 101 is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; when Y 101 is a divalent linking group containing an oxygen atom, anions represented by any of the following formulas (an-1) to (an-3).

[0305]

Chemical formula

[0306] R” 101 , R.” 102 and R.” 103 The aliphatic cyclic group which may have a substituent is represented by R 101 As the substituent, R in the formula (b-1) is preferably a group exemplified as the cyclic aliphatic hydrocarbon group. 101 Examples of the substituents which may substitute the cyclic aliphatic hydrocarbon group in the above formula (1) include the same as those in the above formula (1).

[0307] R” 101 and R.” 103 The aromatic cyclic group which may have a substituent in the formula (b-1) is 101 The substituent is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in the formula (b-1). 101 The substituents which may substitute the aromatic hydrocarbon group in the above formula (I) are the same as those in the above formula (I).

[0308] R” 101 The chain alkyl group which may have a substituent in R may preferably be the group exemplified as the chain alkyl group in the formula (b-1). 101 R” 103 The chain alkenyl group which may have a substituent in R may preferably be the group exemplified as the chain alkenyl group in the formula (b-1). 101

[0309] · Anion in the component (b-2) In the formula (b-2), R 104 and R 105 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each may be the same as R 101 in the formula (b-1). However, R 104 and R 105 may be bonded to each other to form a ring. R 104 and R 105 are preferably a chain alkyl group which may have a substituent, more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The number of carbon atoms of the chain alkyl group is preferably 1 to 10, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms. The number of carbon atoms of the chain alkyl group of R 104 and R 105 is preferably smaller within the above range of the number of carbon atoms for reasons such as good solubility in the resist solvent. Also, R 104 and R 105 ​​In the chain alkyl group, the larger the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid strength, and it is preferable because the transparency to high-energy light or electron beams of 250 nm or less is improved. The ratio of fluorine atoms in the chain alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted by fluorine atoms. In formula (b-2), V 102 , V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and examples thereof are the same as those of V 101 in formula (b-1). In formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0310] · Anion in component (b-3) In formula (b-3), R 106 ~R 108 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof are the same as those of R 101 in formula (b-1). In formula (b-3), L 103 ~L 105 are each independently a single bond, -CO- or -SO2-.

[0311] Among the above, as the anion part of component (B), the anion in component (b-1) is preferable, and the anion represented by the above formula (an-1) is more preferable.

[0312] {Cation part} In the above formulas (b-1), (b-2), and (b-3), M’ m+ represents an m-valent onium cation. Among these, a sulfonium cation and an iodonium cation are preferable. m is an integer of 1 or more.

[0313] As the cationic part of the component (B), a sulfonium cation is preferable, a cation represented by the formula (ca-1) to (ca-3) is more preferable, a cation represented by the formula (ca-1) is still more preferable, and a cation represented by the formula (ca-1-1) to (ca-1-84) is particularly preferable.

[0314] In the resist composition of this embodiment, the component (B) may be used alone or in combination of two or more. When the resist composition contains the component (B), in the resist composition, the content of the component (B) is preferably less than 50 parts by mass, more preferably 5 to 45 parts by mass, and still more preferably 10 to 43 parts by mass with respect to 100 parts by mass of the component (A). By setting the content of the component (B) within the above preferable range, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, and the storage stability as a resist composition is good, which is preferable.

[0315] <Base component (D)> The resist composition of this embodiment may contain, in addition to the component (A), a base component ((D) component) that traps the acid generated by exposure (that is, controls the diffusion of the acid). The component (D) acts as a quencher (acid diffusion controller) that traps the acid generated by exposure in the resist composition. Examples of the component (D) include a photo-dissociable base (D1) that decomposes upon exposure and loses acid diffusion control properties (hereinafter referred to as the "(D1) component"), and a nitrogen-containing organic compound (D2) that does not correspond to the (D1) component (hereinafter referred to as the "(D2) component"). Among these, a photo-dissociable base ((D1) component) is preferable because it is easy to enhance the characteristics of high sensitivity, reduction of roughness, and suppression of the occurrence of coating defects. (D1) component and (D2) component may be in the form of a compound, may be in the form incorporated into the (A1) component as the above-described structural unit (a6), or may be in both of these forms. The compound exemplified as the (D1) component described later may be used as the above-described acid generator component ((B) component) depending on the combination with other compounds.

[0316] ·Regarding the (D1) component The (D1) component is not particularly limited as long as it decomposes upon exposure and loses acid diffusion controllability, and is preferably one or more compounds selected from the group consisting of a compound represented by the following general formula (d1-1) (hereinafter referred to as "(d1-1) component"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "(d1-2) component"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "(d1-3) component"). The (d1-1) to (d1-3) components do not act as a quencher in the exposed portion of the resist film because they decompose and lose acid diffusion controllability (basicity), and act as a quencher in the unexposed portion of the resist film.

[0317] [Chemical formula] [In the formula, Rd 1 ~Rd 4 is a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. However, it is assumed that a fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd 2 in the formula (d1-2). Yd 1 is a single bond or a divalent linking group. m is an integer of 1 or more, and M m+ are each independently an m-valent organic cation.]

[0318] {(d1-1) component} ··Anion part In the formula (d1-1), Rd 1is a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, each of which is the above R’ 201 and the like can be mentioned. Among these, as Rd 1 it is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. As the substituent which these groups may have, a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by the above general formulas (a2-r-1) to (a2-r-8), an ether bond, an ester bond, or a combination thereof can be mentioned. When an ether bond or an ester bond is included as a substituent, it may be via an alkylene group, and as the substituent in this case, a linking group represented by the above formulas (L-al-1) to (L-al-5) is preferable. Note that when the aromatic hydrocarbon group, aliphatic cyclic group, or chain-like alkyl group in Rd 1 has a linking group represented by the above general formulas (L-al-1) to (L-al-7) as a substituent, in the above general formulas (L-al-1) to (L-al-7), the Rd in formula (d3-1) 1 the aromatic hydrocarbon group, aliphatic cyclic group, or chain-like alkyl group in is bonded to the carbon atom constituting the aromatic hydrocarbon group, aliphatic cyclic group, or chain-like alkyl group in Rd 101 is the V’ in the above general formulas (L-al-1) to (L-al-7). As the above aromatic hydrocarbon group, a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure composed of a bicyclooctane skeleton and another ring structure) are preferably mentioned. As the above aliphatic cyclic group, it is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms. Specifically, examples include linear alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, and decyl group; branched-chain alkyl groups such as 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.

[0319] When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the fluorinated alkyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 8 carbon atoms, and even more preferably 1 to 4 carbon atoms. The fluorinated alkyl group may contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0320] Preferred specific examples of the anionic part of the component (d1-1) are shown below.

[0321]

Chemical formula

[0322] ···Cationic part In formula (d1-1), M m+ is an m-valent organic cation. M m+ Examples of the organic cation of M preferably include the same cations as those represented by the general formulas (ca-1) to (ca-3) respectively. The cation represented by the general formula (ca-1) is more preferable, and the cations represented by the formulas (ca-1-1) to (ca-1-84) are even more preferable. The component (d1-1) may be used alone or in combination of two or more.

[0323] {(d1-2) component} ·· Anion part In formula (d1-2), Rd 2 is a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent, and the above R’ 201 is the same as that described above. However, it is assumed that a fluorine atom is not bonded (not fluorine-substituted) to the carbon atom adjacent to the S atom in Rd 2 . As a result, the anion of the (d1-2) component becomes a moderately weak acid anion, and the quenching ability as the (D) component is improved. Rd 2 is preferably a linear alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent, and more preferably an aliphatic cyclic group which may have a substituent.

[0324] The linear alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. Examples of the aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, tetracyclododecane, etc. (which may have a substituent); and groups obtained by removing one or more hydrogen atoms from camphor are more preferred.

[0325] Rd 2 The hydrocarbon group of may have a substituent, and examples of the substituent are the same as those which the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, linear alkyl group) in Rd 1 in formula (d1-1) may have.

[0326] Preferred specific examples of the anion part of the (d1-2) component are shown below.

[0327]

Chemical formula

[0328] ·· Cation part In formula (d1-2), M m+ is an m-valent organic cation, which is the same as M in the above formula (d1-1). m+ The same applies to The component (d1-2) may be used alone or in combination of two or more.

[0329] {(component (d1-3))} ··Anion part In formula (d1-3), Rd 3 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the same as those of the above R'. It is preferably a cyclic group, a chain alkyl group, or a chain alkenyl group containing a fluorine atom. Among them, a fluorinated alkyl group is preferable, and more preferably the same as the fluorinated alkyl group of the above Rd. 201 1

[0330] In formula (d1-3), Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the same as those of the above R'. 201 Among them, it is preferably an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group which may have a substituent. Rd 4 The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, etc. A part of the hydrogen atoms of the alkyl group in Rd may be substituted with a hydroxyl group, a cyano group, or the like. 4 Rd 4 ​​​​The alkoxy group in [the compound] is preferably an alkoxy group having 1 to 5 carbon atoms. Specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Among them, a methoxy group and an ethoxy group are preferred.

[0331] Rd 4 The alkenyl group in [the compound] is the same as the alkenyl group in the above R’ 201 and examples thereof include a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group. These groups may further have, as a substituent, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

[0332] Rd 4 The cyclic group in [the compound] is the same as the cyclic group in the above R’ 201 and examples thereof include an alicyclic group obtained by removing one or more hydrogen atoms from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 decane, and tetracyclododecane, or an aromatic group such as a phenyl group and a naphthyl group. When Rd 4 is an alicyclic group, the resist composition dissolves well in an organic solvent, and thus the lithography characteristics are good. Also, when Rd 4 is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition has excellent light absorption efficiency, and the sensitivity and lithography characteristics are good.

[0333] In formula (d1-3), Yd 1 is a single bond or a divalent linking group. Yd 1 The divalent linking group in [the compound] is not particularly limited, and examples thereof include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a divalent linking group containing a heteroatom, and the like. Each of these is the same as Ya in the above formula (a2-1) 21In the description of the divalent linking group, the same as the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom, which were mentioned, can be given. Yd 1 As, it is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group or a combination thereof. As the alkylene group, a linear or branched alkylene group is more preferable, and a methylene group or an ethylene group is even more preferable.

[0334] The following shows preferable specific examples of the anionic part of the component (d1-3).

[0335]

Chemical formula

[0336]

Chemical formula

[0337] ···Cationic part In formula (d1-3), M m+ is an m-valent organic cation, which is the same as M m+ in the above formula (d1-1). The component (d1-3) may be used alone or in combination of two or more.

[0338] The component (D1) may use only any one of the above components (d1-1) to (d1-3), or may use a combination of two or more. When the resist composition contains the component (D1), the content of the component (D1) in the resist composition is preferably 0.5 to 15 parts by mass, more preferably 1 to 15 parts by mass, and even more preferably 2 to 15 parts by mass with respect to 100 parts by mass of the component (A).

[0339] The component (D1) preferably contains the above component (d1-1). Of the whole (D1) component, the content of the (d1-1) component is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, and the (D1) component may consist only of the compound (d1-1) component.

[0340] Production method of the (D1) component: The production methods of the above-mentioned (d1-1) component and (d1-2) component are not particularly limited and can be produced by known methods. Also, the production method of the (d1-3) component is not particularly limited and is produced, for example, in the same manner as the method described in US2012-0149916. As an example of the base component ((D) component) that traps the acid generated by exposure, the compound of the (D1) component was shown, but the compound of the (D1) component may be used as the (B) component. For example, in the resist composition of the present embodiment, a compound of the (D1) component is used as the (B) component, and a compound that generates an acid with a lower acidity than the acid generated by exposure of the (D1) component compound may be used as the (D) component. Further, in the resist composition of the present embodiment, a compound of the (D1) component may be used as the (B) component, and the (D2) component described later may be used as the (D) component.

[0341] ·Regarding the (D2) component As the (D) component, a nitrogen-containing organic compound component that does not correspond to the above (D1) component (hereinafter referred to as the "(D2) component") may be contained. The (D2) component is not particularly limited as long as it acts as an acid diffusion control agent and does not correspond to the (D1) component, and can be arbitrarily used from known ones. Among them, 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 the aliphatic group preferably has 1 to 12 carbon atoms. Examples of the aliphatic amine include an amine (alkylamine or alkyl alcohol amine) obtained by substituting at least one hydrogen atom of ammonia NH3 with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms, or a cyclic amine. Specific examples of the alkylamine and alkyl alcohol amine 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 alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

[0342] Examples of the cyclic amine include, for example, a heterocyclic compound containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine). Specific examples of the aliphatic monocyclic amine include piperidine, piperazine, and the like. As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable, and specific examples include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, 1,4-diazabicyclo[2.2.2]octane, and the like.

[0343] Examples of 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., and triethanolamine triacetate is preferred.

[0344] Also, as the component (D2), an aromatic amine may be used. Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or their derivatives, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, 2,6-di-tert-butylpyridine, 2,6-di-tert-butylpyridine, etc.

[0345] The component (D2) may be used alone or in combination of two or more. When the resist composition contains the component (D2), the content of the component (D2) in the resist composition is usually in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A). By setting it within the above range, the resist pattern shape, standing stability over time, etc. are improved.

[0346] <At least one compound (E) selected from the group consisting of an organic carboxylic acid, an oxo acid of phosphorus and its derivatives> In the resist composition of this embodiment, for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, standing stability over time, etc., at least one compound (E) (hereinafter referred to as "component (E)") selected from the group consisting of an organic carboxylic acid, an oxo acid of phosphorus and its derivatives can be contained as an optional component. Examples of the organic carboxylic acid include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc. Among them, salicylic acid is preferred. Examples of the oxo acid of phosphorus include phosphoric acid, phosphonic acid, phosphinic acid, etc. Among them, phosphonic acid is particularly preferred.

[0347] In the resist composition of this embodiment, the component (E) may be used alone or in combination of two or more. When the resist composition contains the component (E), the content of the component (E) is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, based on 100 parts by mass of the component (A). By setting it within the above range, the lithography characteristics can be further improved.

[0348] <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. The component (F) is used to impart water repellency to the resist film, and by using it as a resin different from the component (A), the lithography characteristics can be improved. As the component (F), for example, the fluorine-containing polymer compounds described in JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226 can be used. (F) More specifically as the component, polymers having a structural unit (f1) represented by the following general formula (f1-1) can be mentioned. As this polymer, a polymer (homopolymer) consisting only of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1); a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1) is preferable, and a copolymer of the structural unit (f1) and the structural unit (a1) is more preferable. Here, as the structural unit (a1) copolymerized with the structural unit (f1), a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate and a structural unit derived from 1-methyl-1-adamantyl (meth) acrylate are preferable, and a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate is more preferable.

[0349]

Chemical formula

[0350] In formula (f1-1), R bonded to the carbon atom at the α-position is the same as described above. As R, a hydrogen atom or a methyl group is preferable. In formula (f1-1), Rf 102 and Rf 103 As the halogen atom of, a fluorine atom is preferable. Rf 102 and Rf 103 Examples of the alkyl group having 1 to 5 carbon atoms of include the same ones as the alkyl group having 1 to 5 carbon atoms of R above, and a methyl group or an ethyl group is preferable. Rf 102 and Rf103 As the alkyl halide group having 1 to 5 carbon atoms, specifically, a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms can be mentioned. As the halogen atom, a fluorine atom is preferable. Among them, Rf 102 and Rf 103 are preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom. In formula (f1-1), nf 1 is an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0351] In formula (f1-1), Rf 101 is an organic group containing a fluorine atom, preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, preferably having 1 to 20 carbon atoms, more preferably having 1 to 15 carbon atoms, and particularly preferably having 1 to 10 carbon atoms. Further, in the hydrocarbon group containing a fluorine atom, 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 preferably 60% or more are fluorinated because the hydrophobicity of the resist film during immersion exposure increases. Among them, Rf 101 is more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, and particularly preferably a trifluoromethyl group, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, -CH2-CH2-CF2-CF2-CF2-CF3.

[0352] (F) component's weight-average molecular weight (Mw) (in terms of polystyrene conversion standard by gel permeation chromatography) is preferably from 1,000 to 50,000, more preferably from 5,000 to 40,000, and most preferably from 10,000 to 30,000. When it is below the upper limit value of this range, there is sufficient solubility in the resist solvent for use as a resist. When it is above the lower limit value of this range, the water repellency of the resist film is good. (F) component's dispersity (Mw / Mn) is preferably from 1.0 to 5.0, more preferably from 1.0 to 3.0, and most preferably from 1.0 to 2.5.

[0353] In the resist composition of this embodiment, the (F) component may be used alone or in combination of two or more. When the resist composition contains the (F) component, the content of the (F) component is preferably from 0.5 to 10 parts by mass, more preferably from 1 to 10 parts by mass with respect to 100 parts by mass of the (A) component.

[0354] <Organic solvent component (S)> The resist composition of this embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter referred to as the "(S) component"). In the resist composition of this embodiment, the (S) component may be used alone or as a mixed solvent of two or more. Among them, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), γ-butyrolactone, ethyl lactate (EL), and cyclohexanone are preferred.

[0355] Also, as the (S) component, a mixed solvent of PGMEA and a polar solvent is also preferred. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, etc. 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, as the mixing ratio, the mass ratio of the former to the latter is preferably from 70:30 to 95:5. (S) The amount of use is not particularly limited and is appropriately set according to the coating film thickness at a concentration that can be applied to a substrate or the like. Generally, the 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.

[0356] In the resist composition of the present embodiment, after dissolving the above resist material in the component (S), impurities and the like may be removed using a polyimide porous membrane, a polyamideimide 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 polyamideimide porous membrane, a filter made of a polyimide porous membrane and a polyamideimide porous membrane, or the like. Examples of the polyimide porous membrane and the polyamideimide porous membrane include those described in JP-A-2016-155121.

[0357] The resist composition of the present embodiment described above contains a resin component having a structural unit (a0) derived from a compound (a0-m) represented by the general formula (a0-m). By containing the structural unit (a0), the resist composition of the present embodiment exhibits the effect that all of sensitivity, roughness, and etching resistance are good. The reason for such an effect is presumed as follows. In the resist composition of the present embodiment, since the anion part of the structural unit (a0) has an amide bond (-C(=O)-NH-), the rigidity of the resist film is increased, so the roughness during pattern formation is improved, and the remaining film property after etching is improved. In addition, since the anion part of the constitutional unit (a0) has an amide bond (-C(=O)-NH-), the carboxylic acid generated by exposure from the constitutional unit (a0) exhibits an appropriate pKa (acid dissociation constant). Specifically, the pKa of 4-vinylbenzoic acid (a0-m-pKa-1) is 4.292, whereas the pKa of the compound (a0-m-pKa-2) corresponding to the compound (a0-m) is 3.569, and the pKa of the compound (a0-m-pKa-3) in which the amide bond of the compound (a0-m-pKa-2) is changed to an ester bond is 3.297. Thus, since the carboxylic acid generated by exposure from the constitutional unit (a0) exhibits an appropriate pKa, in the resist composition of the present embodiment, the diffusion of the acid generated by exposure is efficiently controlled, so that the roughness and sensitivity are improved. By the above-described respective actions acting synergistically, it is presumed that in the resist composition of the present embodiment, improvements in all of sensitivity, roughness, and etching resistance can be achieved. Here, "pKa (acid dissociation constant)" refers to what is generally used as an index indicating the acid strength of the target substance. Note that the pKa in this specification is a value under the temperature condition of 25°C. Also, the pKa value can be measured and obtained by a known method. Further, a calculated value using known software such as "ACD / Labs" (trade name, manufactured by Advanced Chemistry Development) can also be used.

[0358]

Chemical formula

[0359] (Resist pattern forming method) The resist pattern forming method according to the second aspect of the present invention is a method having a step of forming a resist film on a support using the resist composition according to the first aspect of the present invention described above, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern. As an embodiment of such a resist pattern forming method, for example, a resist pattern forming method performed as follows can be mentioned.

[0360] First, the resist composition of the above-described embodiment is applied onto a support by a spinner or the like, and a baking (post-apply bake (PAB)) treatment is performed at a temperature condition of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film. Next, selective exposure is performed on the resist film by exposure through a mask (mask pattern) having a predetermined pattern formed thereon or by direct irradiation with an electron beam without passing through the mask pattern using an exposure apparatus such as an electron beam lithography apparatus or an ArF exposure apparatus. After that, a baking (post-exposure bake (PEB)) treatment is performed at a temperature condition of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds. Next, the resist film is developed. In the case of an alkali development process, an alkali developer is used, and in the case of a solvent development process, a developer containing an organic solvent (organic-based developer) is used.

[0361] After the development process, preferably a rinsing process is performed. In the case of an alkali development process, water rinsing using pure water is preferable, and in the case of a solvent development process, it is preferable to use a rinsing solution containing an organic solvent. In the case of a solvent development process, after the development process or the rinsing process, a process of removing the developer or the rinsing solution adhering to the pattern with a supercritical fluid may be performed. After the development process or the rinsing process, drying is performed. Also, in some cases, a baking process (post-bake) may be performed after the above-described development process.

[0362] The support is not particularly limited, and conventionally known ones can be used. For example, substrates for electronic components and those having a predetermined wiring pattern formed thereon can be mentioned. More specifically, silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and glass substrates can be mentioned. As materials for the wiring pattern, for example, copper, aluminum, nickel, gold, etc. can be used.

[0363] The wavelength used for exposure is not particularly limited, and it can be performed using radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. The resist pattern forming method of the present embodiment is particularly useful for a method of exposing the resist film to EUV (extreme ultraviolet) or EB (electron beam) in the step of exposing the resist film.

[0364] The exposure method of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be liquid immersion exposure (Liquid Immersion Lithography). Liquid immersion exposure is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is filled with a solvent (liquid immersion medium) having a refractive index larger than that of air in advance, and exposure (immersion exposure) is performed in that state. As the liquid immersion medium, a solvent having a refractive index larger than that of air and smaller than that of the resist film to be exposed is preferable, and examples thereof include water, fluorine-based inert liquids, silicon-based solvents, hydrocarbon-based solvents, and the like. Water is preferably used as the liquid immersion medium.

[0365] Examples of the alkaline developer used for development in the alkaline development process include an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used for development in the solvent development process may be any one that can dissolve the component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specifically, polar solvents such as ketone-based solvents, ester-based solvents, alcohol-based solvents, nitrile-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents are included.

[0366] 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.

[0367] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, butyronitrile, and the like.

[0368] Known additives can be blended into the organic developer as needed. Examples of such additives include surfactants. The surfactant is not particularly limited, and for example, ionic or non-ionic fluorine-based and / or silicon-based surfactants can be used.

[0369] The development process can be carried out by known development methods. For example, a method of immersing the support in the developer for a certain period of time (dip method), a method of raising the developer on the surface of the support by surface tension and allowing it to stand still for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), a method of continuously discharging the developer while scanning a developer discharge nozzle at a constant speed on a support rotating at a constant speed (dynamic dispense method), and the like.

[0370] As the organic solvent contained in the rinse liquid used for the rinse treatment after the development treatment in the solvent development process, for example, among the organic solvents listed as the organic solvents used in the organic-based developer, those that are less likely to dissolve the resist pattern can be appropriately selected and used. Usually, 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 alone or in combination of two or more. Also, they may be used in mixture with organic solvents other than those mentioned above or with water.

[0371] The rinse treatment (cleaning treatment) using the rinse liquid can be carried out by a known rinse method. Examples of the method of this rinse treatment include a method of continuously coating the rinse liquid on a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dip method), a method of spraying the rinse liquid on the surface of the support (spray method), etc.

[0372] According to the resist pattern forming method of the present embodiment described above, since the above-described resist composition is used, a resist pattern having good sensitivity, roughness, and etching resistance can be formed.

[0373] In the resist composition of the above-described embodiment and various materials used in the pattern forming method of the above-described embodiment (for example, resist solvent, developer, rinse liquid, composition for forming an antireflection film, composition for forming a top coat, etc.), it is preferable that they do not contain impurities such as metals, metal salts containing halogens, acids, alkalis, components containing sulfur atoms or phosphorus atoms. Here, examples of the impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. As the content of the impurities contained in these materials, 200 ppb or less is preferable, 1 ppb or less is more preferable, 100 ppt (parts per trillion) or less is still more preferable, 10 ppt or less is particularly preferable, and it is most preferable that they are substantially not contained (below the detection limit of the measuring device).

[0374] (Compound) The compound according to the third aspect of the present invention is a compound represented by the following general formula (a0-m) (hereinafter, also referred to as "compound (a0-m)").

[0375] [Chemical formula] [In the formula, W is a polymerizable group-containing group. R Ar1 and R Ar2 are each independently an aromatic group which may have a substituent. L 11 is a divalent linking group containing -C(=O)-NH-. L 12 is a divalent linking group containing an aromatic ring, or a single bond. When L 12 is a divalent linking group containing an aromatic ring, the carbon atom in the carboxylate ion in the formula is bonded to this aromatic ring. M m+ is an m-valent onium cation. m is an integer of 1 or more.]

[0376] In the formula, W, R Ar1 , R Ar2 , L 11 , L 12 , M m+ and m are the same as W, R Ar1 , R Ar2 , L 11 , L 12 , M m+ and m in the general formula (a0-m) in the above-mentioned <<Constituent Unit (a0)>>.

[0377] The compound (a0-m) is preferably a compound represented by the following general formula (a0-m'). [Chemical formula] [In the formula, R 0 is an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydrogen atom. L 10 is -C(=O)-O-, -C(=O)-NH-, or a single bond. R Ar1 and R Ar2Each is independently an aromatic group which may have a substituent. M m+ is an m-valent onium cation. m is an integer of 1 or more.]

[0378] In the formula, R 0 , L 10 , R Ar1 , R Ar2 , M m+ and m are the same as R 0 , L 10 , R Ar1 , R Ar2 , M m+ and m in the general formula (a0-m’) in the above-mentioned <<Constituent unit (a0)>>.

[0379] The compound of this embodiment is the same as the compound that induces the constituent unit (a0) possessed by the component (A1) of the resist composition according to the first aspect.

[0380] <Method for producing compound> The compound (a0-m) can be produced by appropriately combining known methods as in the <Compound synthesis example> shown in the following [Examples]. The compound (a0-m) can be produced, for example, by the following reactions (I) to (III).

[0381] <<Reaction (I)>> In reaction (I), as raw materials corresponding to the target compound, an acid chloride (-C(=O)Cl) and a primary amine (-NH2) are reacted to obtain a compound forming an amide bond (-C(=O)-NH-) as an intermediate for the target compound. Specifically, in reaction (I), as raw materials corresponding to the target compound, a compound (a0pre1-m) represented by the following general formula (a0pre1-m) and a compound (a0pre2-m) represented by the following general formula (a0pre2-m) are reacted to obtain a compound (a0pre3-m) represented by the following general formula (a0pre3-m) as an intermediate for the target compound.

[0382]

Chemical formula

[0383] L 13 and L 14 As the divalent linking group in, the same as the divalent linking group in L 11 and L 12 in the above-mentioned <<structural unit (a0)>>. L in the formula (a0pre3-m) 11 in, L 15 and L 16 The amide bond (-C(=O)-NH-) formed by the reaction between and may bond to R Ar1 and R Ar2 in any direction.

[0384] The temperature condition of the reaction (I) is not particularly limited, for example, it is about 0 to 50 °C, and the reaction time of the reaction (I) is, for example, 10 minutes or more and 24 hours or less.

[0385] The reaction (I) is carried out in a solvent such as water, dichloromethane, acetonitrile or chloroform. The solvent here may be an organic solvent or a mixed solvent of an organic solvent and water. Examples of the organic solvent include ketone solvents such as cyclohexanone, methyl ethyl ketone, diethyl ketone, and methyl isobutyl ketone; ether solvents such as diethyl ether, t-butyl methyl ether, and diisopropyl ether; halogen solvents such as tetrahydrofuran, 1,3-dioxolane, dichloromethane, 1,2-dichloroethane, and chloroform; ester solvents such as ethyl acetate and propylene glycol monomethyl ether acetate; propionitrile, acetonitrile, or a mixed solvent thereof, etc.

[0386] <<Reaction (II)>> By reacting a compound (a0pre3-m) represented by the following general formula (a0pre3-m) with a compound (S0-1) represented by the following general formula (S0-1), a compound (a0pre4-m) represented by the following general formula (a0pre4-m) is obtained as an intermediate for the target compound.

[0387] [Chemical formula] [In the formula, W, R Ar1 , R Ar2 , L 11 and L 12 are the same as those in the general formula (a0-m) in the above <<Constituent unit (a0)>> respectively. Mp m’+ is a counter cation. m’ is an integer of 1 or more. ]

[0388] In the general formula (S0-1), examples of Mp m’+ include ammonium cations such as tetramethylammonium cation, tetrabutylammonium cation, and triethylammonium cation, and pyridinium cation, etc. As the base compound represented by the general formula (S0-1), tetramethylammonium hydroxide (TMAH) is preferable.

[0389] The temperature condition of reaction (II) is, for example, about 0 to 50°C, and the reaction time of reaction (II) is, for example, 10 minutes or more and 24 hours or less. Examples of the reaction solvent for reaction (II) include the same solvents as those for reaction (I).

[0390] ≪Reaction (III)≫ Compound (a0-m) is obtained by reacting compound (a0pre4-m) represented by the following general formula (a0pre4-m) with compound (S0-2) for salt exchange.

[0391]

Chemical formula

[0392] In the formula (S0-2), X - is preferably a halogen ion, more preferably a chloride ion or a bromide ion, and even more preferably a chloride ion.

[0393] The temperature condition of reaction (III) is, for example, about 0 to 50°C, and the reaction time of reaction (I) is, for example, 10 minutes or more and 24 hours or less. Examples of the reaction solvent for reaction (III) include the same solvents as those for reaction (I).

[0394] In the method for producing the above-described compound (a0-m), after each reaction is completed, the compound in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be appropriately combined and used. The structure of the compound obtained as described above can be identified by general organic analysis methods such as 1H-nuclear magnetic resonance (NMR) spectroscopy and 13C-NMR spectroscopy. As the raw materials used in each step, commercially available ones may be used, or synthesized ones may be used.

[0395] The compound of the present embodiment described above can be used in the production of the resist composition according to the first aspect. Further, the compound of the present embodiment can be used in the production of the polymer compound according to the fourth aspect described later.

[0396] (Polymer compound) The polymer compound according to the fourth aspect of the present invention has a structural unit (a0) derived from the compound represented by the general formula (a0-m). The structural unit (a0) is the same as that described above. The polymer compound of the present embodiment can be used in the production of the resist composition according to the first aspect. By incorporating the polymer compound of the present embodiment into the resist composition, the sensitivity, roughness, and etching resistance can be improved.

Examples

[0397] Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[0398] (Synthesis example of compound) (Synthesis example of compound (a0-m-1)) 82.3 g of compound (a0pre1-m-1), 247.0 g of dichloromethane, 14.7 g of N,N-dimethylaminopyridine, and 66.8 g of triethylamine were placed in a three-necked flask, and a solution of 100.0 g of compound (a0pre2-m-1) in 100.0 g of dichloromethane was added under an ice bath, followed by stirring for 3 hours. 200 g of ion-exchanged water was added to the reaction solution for extraction. The organic layer was washed with a 5% aqueous sodium hydroxide solution, a 5% aqueous hydrochloric acid solution, and ion-exchanged water, and the organic layer was recovered. The organic layer was concentrated using a rotary evaporator. After dissolving the crude product in THF, heptane was added, and the resulting crystals were collected by filtration to obtain 125.1 g of compound (a0pre3-m-1).

[0399]

Chemical Structure

[0400] 100.0 g of compound (a0pre3-m-1) and 682.1 g of a 5% aqueous solution of tetramethylammonium hydroxide were added to a three-necked flask and stirred for 3 hours to obtain an aqueous solution of compound (a0pre4-m-1).

[0401]

Chemical Structure

[0402] The aqueous solution of compound (a0pre4-m-1), 247.0 g of dichloromethane, and 111.8 g of compound (S0-2-1) were placed in a three-necked flask and stirred for 1 hour. Subsequently, the organic layer was concentrated using a rotary evaporator to obtain 157.8 g of compound (a0-m-1).

[0403]

Chemical Structure

[0404] (Synthesis Examples of Compounds (a0-m-2) to (a0-m-8)) Compound (a0pre2-m-1) was changed to compounds (a0pre2-m-2) to (a0pre2-m-8) represented by the following general formulas (a0pre2-m-2) to (a0pre2-m-8) respectively, and compounds (a0-m-2) to (a0-m-8) were synthesized in the same manner as the synthesis of compound (a0-m-1).

[0405]

Chemical formula

[0406] (Synthesis examples of compounds (a0-m-9) to (a0-m-10)) Compound (a0pre1-m-1) was changed to compounds (a0pre1-m-9) to (a0pre1-m-10) represented by the following general formulas (a0pre1-m-9) to (a0pre1-m-10) respectively, and compounds (a0-m-9) to (a0-m-10) were synthesized in the same manner as the synthesis of compound (a0-m-1).

[0407]

Chemical formula

[0408] (Synthesis example of compound (a0-m-11)) Compound (a0-m-11) was synthesized in the same manner as the synthesis of compound (a0-m-1), except that compound (S0-2-1) was changed to compound (S0-2-2) represented by the following general formula (S0-2-2).

[0409]

Chemical formula

[0410] For the obtained compounds (a0-m-1) to (a0-m-11), NMR measurements were performed, and their structures were identified from the analysis results shown below.

[0411] Compound (a0-m-1): 1 H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 5.25 (1H, dd), 5.76 (1H, dd), 6.72 (1H, dd), 6.95 (1H, t), 7.35 (15H, m), 7.52 (2H, d), 7.68 (1H, t), 7.81 (1H, d), 7.95 (2H, d), 7.99 (1H, d), 11.85 (1H, s)

[0412] Compound (a0-m-2): 1 H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 5.25 (1h, dd), 5.76 (1h, dd), 6.72 (1h, dd), 7.35 (15H, m), 7.52 (2H, d), 7.95 (2H, d), 8.28 (1H, s), 8.40 (1H, s), 10.31 (1H, s)

[0413] Compound (a0-m-3): 1 H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 2.48 (3h, s), 5.25 (1h, dd), 5.76 (1h, dd), 6.72 (1H, dd), 6.96 (1H, d), 7.35 (15H, m), 7.52 (2H, d), 7.95 (2H, d), 8.10 (1H, d), 10.31 (1H, s)

[0414] Compound (a0-m-4): 1 H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 3.90 (3H, s), 5.25 (1H, dd), 5.76 (1H, dd), 6.72 (1H, dd), 7.36 (16H, m), 7.52 (2H, d), 7.76 (1H, s), 7.95 (1H, d), 11.85 (1H, s)

[0415] Compound (a0-m-5): 11H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 5.25 (1H, dd), 5.76 (1H, dd), 6.72 (1H, dd), 7.35 (15H, m), 7.52 (2H, d), 7.95 (2H, d), 8.07 (1H, s), 8.36 (1H, s), 10.31 (1H, s)

[0416] Compound (a0-m-6): 1 1H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 5.25 (1H, dd), 5.55 (2H, s), 5.76 (1H, dd), 6.72 (1H, dd), 7.15 (1H, d), 7.35 (15H, m), 7.54 (1H, d), 7.77 (1H, s), 7.95 (2H, d), 11.85 (1H, s)

[0417] Compound (a0-m-7): 1 1H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 3.77 (3H, s), 5.25 (1H, dd), 5.76 (1H, dd), 6.72 (1H, dd), 7.35 (15H, m), 7.45 (1H, s), 7.52 (2H, d), 7.77 (1H, d), 7.95 (2H, d), 8.64 (1H, d), 11.85 (1H, s)

[0418] Compound (a0-m-8): 1 1H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 5.25 (1H, dd), 5.76 (1H, dd), 6.72 (1H, dd), 7.52 (2H, d), 7.55 (1H, d), 7.69 (1H, d), 7.94 (1H, d), 7.95 (2H, d), 8.03 (1H, s), 10.40 (1H, s)

[0419] Compound (a0-m-9): 1H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 5.25 (1H, dd), 5.76 (1H, dd), 6.72 (1H, dd), 6.94 (2H, m), 7.15 (1H, s), 7.69 (2H, m), 7.81 (1H, d), 7.99 (1H, d), 11.11 (1H, s), 11.85 (1H, s)

[0420] Compound (a0-m-10): 1 H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 5.25 (1H, dd), 5.76 (1H, dd), 6.72 (1H, dd), 6.95 (1H, d), 7.14 (1H, s), 7.68 (1H, m), 7.76 (1H, s), 7.81 (1H, d), 7.99 (1H, d), 11.85 (1H, s), 21.38 (1H, s)

[0421] Compound (a0-m-11): 1 H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 5.25 (1H, dd), 5.76 (1H, dd), 6.72 (1H, dd), 6.78 (6H, m), 6.95 (1H, t), 7.35 (5H, m), 7.52 (2H, d), 7.68 (1H, t), 7.81 (1H, d), 7.95 (2H, d), 7.99 (1H, d), 11.85 (1H, s)

[0422] <Production of Polymer Compound> (Synthesis of Polymer Compound (A1-1)) 20.0 g of Compound (a0-m1), 53.8 g of Compound (m10pre-1), 70.0 g of Compound (m1-1), and 6.1 g of 2,2'-Azobis(2-methylpropionitrile) (V-601) as a polymerization initiator were dissolved in 287.0 g of methyl ethyl ketone (MEK), heated to 80 °C under a nitrogen atmosphere, and stirred for 6 hours. Then, 6.7 g of acetic acid and 120 g of methanol were added to the reaction solution, and the mixture was stirred at 30 °C for 18 hours. After completion of the reaction, the obtained reaction solution was precipitated in 360 g of heptane and washed. The obtained white solid was filtered and dried under reduced pressure overnight to obtain 64.7 g of the target polymer compound (A1-1).

[0423] [Chemical formula]

[0424] (Synthesis of Polymer Compounds (A1-2) to (A1-14)) Polymer compounds (A1-2) to (A1-14) were each synthesized in the same manner as the synthesis of polymer compound (A1-1), except that the compounds used in the polymerization reaction were changed.

[0425] Polymer compounds (A1-1) to (A1-14) are shown below. In the following formulas, l, m, and n represent the composition ratios (molar ratios) of the respective structural units.

[0426] [Chemical formula]

[0427] [Chemical formula]

[0428] [Chemical formula]

[0429] (Synthesis of Polymer Compounds (A2-1) to (A2-3) in Comparative Examples) Polymer compounds (A2-1) to (A2-3) were each synthesized in the same manner as the synthesis of polymer compound (A1-1), except that the compounds used in the polymerization reaction were changed.

[0430] Polymer compounds (A2-1) to (A2-3) are shown below. In the following formulas, l, m, and n represent the composition ratios (molar ratios) of the respective structural units.

[0431] [Chemical formula]

[0432] For the obtained polymer compounds (A1-1) to (A1-14) and (A2-1) to (A2-3), the weight-average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) were determined by GPC measurement (in terms of standard polystyrene). Also, for the polymer compounds (A1-1) to (A1-14) and (A2-1) to (A2-3), the copolymer composition ratio (the ratio of each structural unit in the structural formula (molar ratio)) was determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz, 13 C-NMR). The results are shown below.

[0433] Polymer compound (A1-1): Weight-average molecular weight (Mw) 14,600, molecular weight distribution (Mw / Mn) 1.89, l / m / n = 5 / 40 / 55. Polymer compound (A1-2): Weight-average molecular weight (Mw) 15,800, molecular weight distribution (Mw / Mn) 1.76, l / m / n = 5 / 40 / 55. Polymer compound (A1-3): Weight-average molecular weight (Mw) 15,500, molecular weight distribution (Mw / Mn) 1.81, l / m / n = 5 / 40 / 55. Polymer compound (A1-4): Weight-average molecular weight (Mw) 15,700, molecular weight distribution (Mw / Mn) 1.79, l / m / n = 5 / 40 / 55. Polymer compound (A1-5): Weight-average molecular weight (Mw) 15,200, molecular weight distribution (Mw / Mn) 1.83, l / m / n = 5 / 40 / 55. Polymer compound (A1-6): Weight-average molecular weight (Mw) 15,300, molecular weight distribution (Mw / Mn) 1.83, l / m / n = 5 / 40 / 55. Polymer compound (A1-7): Weight-average molecular weight (Mw) 14,900, molecular weight distribution (Mw / Mn) 1.81, l / m / n = 5 / 40 / 55. Polymer compound (A1-8): Weight-average molecular weight (Mw) 15,100, molecular weight distribution (Mw / Mn) 1.86, l / m / n = 5 / 40 / 55. Polymer compound (A1-9): Weight-average molecular weight (Mw) 15,600, molecular weight distribution (Mw / Mn) 1.86, l / m / n = 5 / 40 / 55. Polymer compound (A1-10): weight-average molecular weight (Mw) 15,200, molecular weight dispersity (Mw / Mn) 1.84, l / m / n = 5 / 40 / 55. Polymer compound (A1-11): weight-average molecular weight (Mw) 14,600, molecular weight dispersity (Mw / Mn) 1.89, l / m / n = 5 / 40 / 55. Polymer compound (A1-12): weight-average molecular weight (Mw) 15,100, molecular weight dispersity (Mw / Mn) 1.76, l / m / n = 5 / 40 / 55. Polymer compound (A1-13): weight-average molecular weight (Mw) 15,600, molecular weight dispersity (Mw / Mn) 1.86, l / m / n = 5 / 40 / 55. Polymer compound (A1-14): weight-average molecular weight (Mw) 15,400, molecular weight dispersity (Mw / Mn) 1.79, l / m / n = 5 / 40 / 55. Polymer compound (A2-1): weight-average molecular weight (Mw) 16,300, molecular weight dispersity (Mw / Mn) 1.88, l / m / n = 5 / 40 / 55. Polymer compound (A2-2): weight-average molecular weight (Mw) 7,800, molecular weight dispersity (Mw / Mn) 1.51, l / m = 40 / 60. Polymer compound (A2-3): weight-average molecular weight (Mw) 16,500, molecular weight dispersity (Mw / Mn) 1.89, l / m / n = 5 / 40 / 55.

[0434] <Preparation of resist composition> (Examples 1 to 15, Comparative Examples 1 to 3) The resist compositions of each example were prepared by mixing and dissolving the respective components shown in Table 1.

[0435]

Table 1

[0436] In Table 1, each abbreviation has the following meaning respectively. The numerical values in [ ] are the blending amounts (parts by mass). (A)-1 to (A)-14: the above polymer compounds (A1-1) to (A1-14). (A)-15: the above polymer compound (A2-1). (A)-16: The above polymer compound (A2-2). (A)-17: The above polymer compound (A2-3).

[0437] (B)-1: An acid generator composed of the following compound (B-1). (B)-2: An acid generator composed of the following compound (B-2).

[0438]

Chemical formula

[0439] (D)-1: An acid diffusion control agent composed of a compound represented by the following chemical formula (D1-1).

[0440]

Chemical formula

[0441] (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 60 / 40 (mass ratio).

[0442] <Formation of resist pattern> Step of forming a resist film: On an 8-inch silicon substrate subjected to hexamethyldisilazane (HMDS) treatment, each resist composition was applied using a spinner, and pre-baked (PAB) at a temperature of 110 °C for 60 seconds on a hot plate and dried to form a resist film with a thickness of 50 nm.

[0443] Step of exposing the resist film: Next, using an electron beam lithography apparatus JEOL JBX-9300FS (manufactured by JEOL Ltd.), the resist film was drawn (exposed) at an acceleration voltage of 100 kV with a target size of a 1:1 line and space pattern (hereinafter "LS pattern") with a line width of 50 nm (pitch width of 100 nm). Thereafter, post-exposure bake (PEB) treatment was performed at 100 °C for 60 seconds.

[0444] Step of developing the exposed resist film: Next, at 23°C, using an aqueous solution of 2.38 mass% tetramethylammonium hydroxide (TMAH) "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.), alkali development was performed for 60 seconds. Thereafter, water rinsing was performed for 15 seconds using pure water. As a result, a 1:1 LS pattern with a line width of 50 nm (pitch width of 100 nm) was formed.

[0445] [Evaluation of the optimum exposure dose (Eop)] The optimum exposure dose Eop (μC / cm 2 ) at which the LS pattern of the target size is formed by the above <Formation of resist pattern> was determined. This was shown in Table 2 as "Eop (μC / cm 2 )".

[0446] [Evaluation of LWR (Line Width Roughness)] For the LS pattern formed in the above <Formation of resist pattern>, 3σ, which is a measure indicating LWR, was determined. This was shown in Table 2 as "LWR (nm)". "3σ" indicates three times the standard deviation (σ) value (3σ) (unit: nm) obtained from measuring the line positions 400 times in the longitudinal direction of the line using a scanning electron microscope (acceleration voltage: 800 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). The smaller the value of 3σ, the smaller the roughness of the line sidewall, meaning that an LS pattern with a more uniform width was obtained.

[0447] [Evaluation of etching resistance] On an 8-inch silicon substrate subjected to hexamethyldisilazane (HMDS) treatment, each resist composition was applied using a spinner, and pre-baked (PAB) at a temperature of 110°C for 60 seconds on a hot plate and dried to form a resist film with a thickness of 50 nm. Next, for each resist film, dry etching treatment was performed for 60 seconds using a dry etching apparatus TCA-3822 (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) with CF4 gas. The remaining film amount was determined from the film thickness of the resist film before and after the dry etching treatment. Then, the remaining film amount of the resist film formed using the resist composition of each example was calculated as a relative value when the remaining film amount of the resist film formed using the resist composition of Example 1 was set to 1.00. The results are shown in Table 2 as "etching resistance". The higher the value of this "etching resistance", the higher the etching resistance of the resist film.

[0448] [Table 2]

[0449] As shown in Table 2, it was confirmed that the resist compositions of Examples 1 to 15 were superior in all of sensitivity, roughness, and etching resistance as compared with the resist compositions of Comparative Examples 1 to 3.

Claims

1. A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, containing a resin component (A1) whose solubility in a developer changes due to the action of an acid, wherein the resin component (A1) has a structural unit (a0) derived from a compound represented by the following general formula (a0-m): A resist composition. 【Chemical Formula 1】 [In the formula, W is a polymerizable group-containing group. R Ａｒ１ and R Ａｒ２ are each independently an aromatic group which may have a substituent. L １１ is a divalent linking group containing -C(=O)-NH-. L １２ is a divalent linking group containing an aromatic ring, or a single bond. When L １２ is a divalent linking group containing an aromatic ring, a carbon atom in the carboxylate ion in the formula is bonded to this aromatic ring. M ｍ＋ is an m-valent onium cation. m is an integer of 1 or more. ]

2. R in the general formula (a0-m) Ａｒ２ The resist composition according to claim 1, wherein is an aromatic group having an iodine atom as a substituent.

3. R in the general formula (a0 - m) Ａｒ１ The resist composition according to claim 1, wherein is an aromatic group having a substituent containing at least one selected from the group consisting of a hydroxy group, an alkyl group, an alkoxy group, an acyloxy group, an alkylsulfonyloxy group, a halogen atom, an amino group, a nitro group, a cyano group, and an alkenyl group.

4. A resist pattern forming method, comprising a step of forming a resist film using the resist composition according to any one of Claims 1 to 3 on a support, a step of exposing the resist film, and a step of developing the exposed resist film to form a resist pattern.

5. A compound represented by the following general formula (a0-m). 【Chemical 2】 [In the formula, W is a polymerizable group-containing group. R Ａｒ１ and R Ａｒ２ are each independently an aromatic group which may have a substituent. L １１ is a divalent linking group containing -C(=O)-NH-. L １２ is a divalent linking group containing an aromatic ring, or a single bond. When L １２ is a divalent linking group containing an aromatic ring, a carbon atom in the carboxylate ion in the formula is bonded to this aromatic ring. M ｍ＋ is an m-valent onium cation. m is an integer of 1 or more. ]

6. R in the general formula (a0 - m) Ａｒ２ The compound according to claim 5, wherein R is an aromatic group having an iodine atom as a substituent.

7. R in the general formula (a0-m) Ａｒ１ is an aromatic group having a substituent containing at least one selected from the group consisting of a hydroxy group, an alkyl group, an alkoxy group, an acyloxy group, an alkylsulfonyloxy group, a halogen atom, an amino group, a nitro group, a cyano group, and an alkenyl group, The compound according to claim 5.

8. A polymer compound having a structural unit derived from the compound according to any one of Claims 5 to 7.

Images