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

Abstract

To provide a resist composition which achieves higher sensitivity in forming a resist pattern and can form a resist pattern having reduced LWR and improved etching resistance, a resist pattern forming method using the resist composition, a polymer compound useful for the resist composition, and a compound usable for synthesizing the polymer compound.SOLUTION: The resist composition contains a resin component (A1) containing a constituent unit (a0) represented by general formula (a0) (where R represents a hydrogen atom or the like; X0 represents a hydrogen atom or an alkyl group; and Ar01 represents an optionally substituted arylene group).SELECTED DRAWING: None

Description

[Technical field]

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

[0002] In recent years, advances in lithography technology have led to rapid progress in miniaturization of patterns in the manufacture of semiconductor devices and liquid crystal display devices. A common method of miniaturization is to use shorter wavelengths (higher energy) exposure light sources.

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

[0004] In chemically amplified resist compositions, generally, resins having specific structural units are used in order to improve lithography properties and the like. For example, Patent Document 1 discloses a resist composition that contains a resin component (A1) that has a structural unit (a0) that contains a specific acid-dissociable group that has a carbon atom that constitutes a carbon-carbon unsaturated bond. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-219469 A Summary of the Invention [Problem to be solved by the invention]

[0006] As lithography technology continues to advance and resist patterns become finer, for example, in lithography using EUV (extreme ultraviolet) or EB (electron beam), the goal is to form fine patterns of several tens of nm. As the pattern dimensions become smaller, both high sensitivity to the exposure light source and lithography properties such as dimensional uniformity are required. Furthermore, etching resistance is also required to accommodate the thinner resist film that accompanies the finer resist patterns. However, conventional resist compositions such as those described in Patent Document 1 require further improvement in terms of these required properties.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a resist composition that enables the formation of a resist pattern with high sensitivity, reduced LWR, and improved etching resistance, a method of forming a resist pattern using the resist composition, a polymeric compound useful for the resist composition, and a compound that can be used for synthesizing the polymeric compound. [Means for solving the problem]

[0008] 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 acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition containing a resin component (A1) whose solubility in a developer changes due to the action of an acid, the resin component (A1) containing a structural unit (a0) represented by the following general formula (a0):

[0009] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; X 0 represents a hydrogen atom or an alkyl group; Ar 01 represents an arylene group which may have a substituent; La 01represents a single bond or a divalent linking group; Rpg 0 represents an acid dissociable group.]

[0010] A second aspect of the present invention is a method for forming a resist pattern, comprising the steps of forming a resist film on a support using the resist composition related to the first aspect, exposing the resist film to light, and developing the exposed resist film to form a resist pattern.

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

[0012] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; X 0 represents a hydrogen atom or an alkyl group; Ar 01 represents an arylene group which may have a substituent; La 01 represents a single bond or a divalent linking group; Rpg 0 represents an acid dissociable group.]

[0013] A fourth aspect of the present invention is a polymeric compound having a structural unit derived from the compound according to the third aspect. Effect of the Invention

[0014] ADVANTAGEOUS EFFECTS OF THE DISCLOSURE OF THE DISCLOSURE The present invention is capable of providing a resist composition that enables the formation of a resist pattern with high sensitivity, reduced LWR, and improved etching resistance; a method of forming a resist pattern that uses the resist composition; a polymeric compound useful for the resist composition; and a compound that can be used for synthesizing the polymeric compound. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In this specification and claims, the term "aliphatic" is a relative concept to aromaticity and is defined as meaning a group, compound, etc. that does not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in an alkoxy group. Unless otherwise specified, the term "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups. The "halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The term "structural unit" refers to a monomer unit that constitutes a polymeric compound (resin, polymer, copolymer). The phrase "may have a substituent" includes both the case where a hydrogen atom (-H) is replaced with a monovalent group and the case where a methylene group (-CH2-) is replaced with a divalent group. The term "exposure" is intended to include any concept including irradiation with radiation.

[0016] The term "acid-decomposable group" refers to a group having acid decomposability in which at least a part of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases under the action of an acid include groups that are decomposed by the action of an acid to generate a polar group. Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO3H). More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

[0017] The term "acid dissociable group" refers to both (i) a group having acid dissociability in which the bond between the acid dissociable group and an atom adjacent to the acid dissociable group can be cleaved by the action of an acid, and (ii) a group in which a portion of the bond is cleaved by the action of an acid and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid dissociable group and an atom adjacent to the acid dissociable group. The acid dissociable group constituting the acid decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid dissociable group, and thus, when the acid dissociable group is dissociated by the action of an acid, a polar group with higher polarity than the acid dissociable group is generated, increasing the polarity. As a result, the polarity of the entire (A1) component increases. The increase in polarity relatively changes the solubility in the developer, increasing the solubility when the developer is an alkaline developer, and decreasing the solubility when the developer is an organic developer.

[0018] The "base material component" is an organic compound having a film-forming ability. Organic compounds used as base material components are broadly divided into non-polymers and polymers. As non-polymers, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, the term "low molecular weight compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4000. As polymers, those having a molecular weight of 1000 or more are usually used. Hereinafter, the terms "resin", "polymer compound" and "polymer" refer to a polymer having a molecular weight of 1000 or more. The molecular weight of the polymer is the weight average molecular weight calculated in terms of polystyrene by GPC (gel permeation chromatography).

[0019] The term "derived structural unit" refers to a structural unit formed by cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond. In the "acrylic acid ester", the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. αx ) is an atom or group other than a hydrogen atom. αx Itaconic acid diesters in which the substituent (R αx It also includes α-hydroxyacrylic esters in which the α-position carbon atom of an acrylic ester is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group of the acrylic ester. Unless otherwise specified, the carbon atom at the α-position of an acrylic ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, an acrylic ester in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent will sometimes be referred to as an α-substituted acrylic ester.

[0020] The term "derivative" refers to a concept that includes compounds in which the hydrogen atom at the α-position of the target compound is replaced with other substituents such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include compounds in which the hydrogen atom of the hydroxyl group of a target compound, which may have the hydrogen atom at the α-position replaced with a substituent, is replaced with an organic group; compounds in which the hydrogen atom at the α-position of a target compound, which may have the hydrogen atom at the α-position replaced with a substituent, is bonded with a substituent other than a hydroxyl group, and the like. The α-position refers to the first carbon atom adjacent to the functional group, unless otherwise specified. The substituent that replaces the hydrogen atom at the α-position of hydroxystyrene is R αx The same can be mentioned.

[0021] In the present specification and claims, some structures represented by chemical formulas may have asymmetric carbons, and may have enantiomers or diastereomers. In such cases, a single chemical formula represents all of the isomers. These isomers may be used alone or as a mixture.

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

[0023] In the resist composition of this embodiment, the component (A) may generate an acid upon exposure, or an additive component that is formulated separately from the component (A) may generate an acid upon exposure. Specifically, the resist composition of this embodiment may be one that further contains (1) an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “component (B)”); (2) the component (A) may be a component that generates an acid upon exposure; or (3) the component (A) may be a component that generates an acid upon exposure, and may further contain component (B). That is, in the above cases of (2) and (3), the component (A) is a "base component that generates an acid upon exposure and changes its solubility in a developer by the action of the acid." When the component (A) is a base component that generates an acid upon exposure and changes its solubility in a developer by the action of the acid, the component (A1) described below is preferably a resin that generates an acid upon exposure and changes its solubility in a developer by the action of the acid. As such a resin, a polymer compound having a structural unit that generates an acid upon exposure can be used. As the structural unit that generates an acid upon exposure, a known one can be used.

[0024] Of the above, the resist composition of this embodiment is preferably the above-mentioned case (1). That is, the resist composition of this embodiment preferably contains the component (A) and the component (B).

[0025] When a resist film is formed using the resist composition of this embodiment and the resist film is selectively exposed, for example, an acid is generated from the component (B) in the exposed portion of the resist film, and the solubility of the component (A) in the developer changes due to the action of the acid, whereas the solubility of the component (A) in the developer does not change in the unexposed portion of the resist film, so that a difference in solubility in the developer occurs between the exposed portion and the unexposed portion. Therefore, when the resist film is developed, if 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 if 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.

[0026] The resist composition of the present embodiment may be a positive resist composition or a negative resist composition. The resist composition of the present embodiment may be for an alkaline development process in which an alkaline developer is used in the development treatment during resist pattern formation, or may be for a solvent development process in which a developer containing an organic solvent (organic developer) is used in the development treatment.

[0027] <Component (A)> In the resist composition of this embodiment, the component (A) contains a resin component (A1) (hereafter, also referred to as “component (A1)”) whose solubility in a developer changes under the action of an acid. By using the component (A1), the polarity of the base components changes before and after exposure, making it possible to obtain good development contrast not only in an alkaline development process but also in a solvent development process. As the component (A), other polymeric compounds and / or low molecular weight compounds may be used in combination with the component (A1).

[0028] In the resist composition of this embodiment, the component (A) may use either a single type, or a combination of two or more types.

[0029] Regarding component (A1) The component (A1) is a resin component whose solubility in a developer changes under the action of an acid.

[0030] <Structural unit (a0)> The component (A1) has a structural unit (a0) derived from a compound represented by the following general formula (a0).

[0031] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; X 0 represents a hydrogen atom or an alkyl group; Ar 01 represents an arylene group which may have a substituent; La 01represents a single bond or a divalent linking group; Rpg 0 represents an acid dissociable group.]

[0032] In the general formula (a0), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 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, 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, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms for R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. In the general formula (a0), R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, is more preferably a hydrogen atom, a methyl group, or a trifluoromethyl group, is further preferably a hydrogen atom or a methyl group, and is particularly preferably a methyl group.

[0033] In the general formula (a0), X 0 represents a hydrogen atom or an alkyl group, and the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group. In the general formula (a0), X 0 Among the above, is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

[0034] In the general formula (a0), Ar 01 represents an arylene group which may have a substituent, and examples of the arylene group include a phenylene group and a naphthalene-diyl group. Among them, Ar 01is preferably an o-phenylene group, an m-phenylene group, or a p-phenylene group, and more preferably an o-phenylene group or a p-phenylene group. 01 N and La in 01 This represents the relationship between the substitution positions.

[0035] In the general formula (a0), Ar 01 Examples of the substituent in include 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, or a butoxy group), and an alkyloxycarbonyl group.

[0036] In the general formula (a0), Ar 01 Among the above, from the viewpoint of improving LWR, it is preferably an unsubstituted arylene group, and from the viewpoint of improving sensitivity and etching rate, it is preferably an arylene group having an iodine atom. The number of iodine atoms in the arylene group having an iodine atom is preferably 1 to 5, more preferably 1 to 3, and further preferably 1 or 2.

[0037] In the general formula (a0), La 01 represents a single bond or a divalent linking group, and examples of the divalent linking group include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0038] Optionally substituted divalent hydrocarbon group: The hydrocarbon group in the divalent hydrocarbon group which may have a substituent may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0039] Aliphatic hydrocarbon groups 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 linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0040] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably has 1 to 6 carbon atoms, further preferably has 1 to 4 carbon atoms, and most preferably has 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific 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-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0041] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, which may include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group.

[0042] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed 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 end of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0043] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, 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 further preferably a methoxy group or an ethoxy group. The halogen atom as the substituent is preferably a fluorine atom. Examples of the halogenated alkyl group as the substituent include the alkyl groups in which some or all of the hydrogen atoms of the alkyl groups 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, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0044] Aromatic hydrocarbon groups The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further 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 heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., a group in which one hydrogen atom has been further removed 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, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0045] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom and halogenated alkyl group as the substituent include those exemplified as the substituent substituting a hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0046] Divalent linking groups containing heteroatoms: Preferred divalent linking groups containing a heteroatom include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)2-, -S(=O)2-O-, and groups represented by the general formula -Y 21 -OY22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 -, wherein Y 21 and Y 22 each independently represents a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 0 to 3. When the divalent linking group containing a hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group, acyl, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. General formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O)2-OY 22 -Medium, Y 21 and Y 22 are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same ones as those (divalent hydrocarbon groups which may have a substituent) mentioned above in the explanation of the divalent linking group. Y 21As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferable, a straight-chain alkylene group is more preferable, a straight-chain alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or ethylene group is particularly preferable. Y 22 is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula − [Y 21 -C(=O)-O] m” -Y 22 In the group represented by -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The group represented by the formula -Y 21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH2) a’ -C(=O)-O-(CH2) b’ In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.

[0047] In the general formula (a0), La 01 Among the above, it is preferable that is a single bond.

[0048] In the general formula (a0), Rpg 0 represents an acid dissociable group, and specific examples thereof include an "acetal-type acid dissociable group," a "tertiary alkyl ester-type acid dissociable group," and a "secondary alkyl ester-type acid dissociable group," which will be described below.

[0049] Acetal type acid dissociable group: Rpg 0 Examples of the acid dissociable group in the formula (a0-r-1) include acid dissociable groups represented by the following general formula (a0-r-1) (hereinafter sometimes referred to as "acetal-type acid dissociable group").

[0050] [ka] [In formula (a0-r-1), Ra 01 and Ra 02 Each of Ra is independently a hydrogen atom or an alkyl group. 03 is a hydrocarbon group, and Ra 01 Or Ra 02 may be bonded to any one of the following to form a ring. * indicates a bond.]

[0051] In formula (a0-r-1), Ra 01 and Ra 02 are each independently a hydrogen atom or an alkyl group. In formula (a0-r-1), Ra 01 and Ra 02 At least one of the groups is preferably a hydrogen atom, and both of the groups are more preferably hydrogen atoms. Ra 01 Or Ra 02 When is an alkyl group, the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms. Specifically, preferred examples include linear or branched alkyl groups. More specifically, preferred examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups, with methyl and ethyl groups being more preferred, and methyl being particularly preferred. In formula (a0-r-1), Ra 01 and Ra 02 Among the above, each of the is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom or a methyl group.

[0052] In formula (a0-r-1), Ra 03Examples of the hydrocarbon group include a linear or branched alkyl group, and a cyclic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably has 1 to 4 carbon atoms, and further preferably has 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. 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.

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

[0054] Ra 03 When 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. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0055] Ra 03 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Ra 03 Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0056] Ra 03 The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (hereinafter, these substituents are collectively referred to as "Ra x5" Also known as ".) 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. P2 is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P1 and R P2 Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the alicyclic saturated hydrocarbon group and the aromatic hydrocarbon group may be substituted with fluorine atoms. The alicyclic hydrocarbon group may have one or more of the above-mentioned substituents or may have one or more of each of the above-mentioned substituents. Examples of the monovalent chain 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, and a decyl group. 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, and a cyclododecyl group; and 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 in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.

[0057] Ra 03 But, Ra 01 , Ra 02When it is bonded to any one of the above 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, etc.

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

[0059] [ka]

[0060] Tertiary alkyl ester type acid-labile group: Rpg 0 Examples of the acid dissociable group in the formula (a0-r-2) include acid dissociable groups represented by the following general formula (a0-r-2). Among the acid dissociable groups represented by the following formula (a0-r-2), those constituted by an alkyl group may be referred to as "tertiary alkyl ester-type acid dissociable groups" hereinafter for the sake of convenience.

[0061] [ka] [In formula (a0-r-2), Ra 04 ~Ra 06 are each independently a hydrocarbon group; Ra 05 and Ra 06 may be bonded to each other to form a ring. * indicates a bond.]

[0062] Ra 04 Examples of the hydrocarbon group include a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic hydrocarbon group. Ra 04 The linear or branched alkyl group and the cyclic hydrocarbon group (the monocyclic aliphatic hydrocarbon group, the polycyclic aliphatic hydrocarbon group, and the aromatic hydrocarbon group) in 03 The same can be mentioned. Ra 04The chain or cyclic alkenyl group in is preferably an alkenyl group having 2 to 10 carbon atoms. Ra 05 , Ra 06 As the hydrocarbon group of Ra 03 The same can be mentioned.

[0063] Ra 05 and Ra 06 and (a0-r2-03) are preferably used. When these are bonded to each other to form a ring, suitable examples of such a ring include a group represented by general formula (a0-r2-01) below, a group represented by general formula (a0-r2-02) below, and a group represented by general formula (a0-r2-03) below. On the other hand, Ra 04 ~Ra 06 When are not bonded to each other and are independent hydrocarbon groups, suitable examples include groups represented by the following general formula (a0-r2-04).

[0064] [ka] [In formula (a0-r2-01), Ra 001 is an optionally substituted straight or branched alkyl group. 0 is a carbon atom. 0 Yaa 0 It is a group which forms a cyclic hydrocarbon group together with. Some or all of the hydrogen atoms of this cyclic hydrocarbon group may be substituted, and some of the carbon atoms constituting the ring may be substituted with heteroatoms. * indicates a bond. In formula (a0-r2-02), Yab 0 is a carbon atom. 0 Yab 0 A part or all of the hydrogen atoms of the cyclic hydrocarbon group may be substituted, and a part of the carbon atoms constituting the ring may be substituted with a hetero atom. 002 ~Ra 004are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. 002 ~Ra 004 Two or more of may be bonded to each other to form a cyclic structure. * indicates a bond. In formula (a0-r2-03), Yac 0 is a carbon atom. 0 Yac 0 A part or all of the hydrogen atoms of the cyclic hydrocarbon group may be substituted, and a part of the carbon atoms constituting the ring may be substituted with a hetero atom. 005 is an aromatic hydrocarbon group. Some or all of the hydrogen atoms of this aromatic hydrocarbon group may be substituted, and some of the carbon atoms constituting the ring may be substituted with heteroatoms. * indicates a bond. In formula (a0-r2-04), Ra 006 and Ra 007 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms of this chain saturated hydrocarbon group may be substituted. 008 is a hydrocarbon group which may have a substituent. * indicates a bond.]

[0065] In formula (a0-r2-01), Ra 001 is an optionally substituted straight-chain or branched-chain alkyl group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably has 1 to 4 carbon atoms, and even more preferably has 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, Ra 001 is preferably a methyl group, an ethyl group or an n-butyl group, more preferably a methyl group or an ethyl group.

[0066] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably has 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group.

[0067] Ra 001 Examples of the substituent that the linear or branched alkyl group in x5 Examples include:

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

[0069] In formula (a0-r2-01), Yaa 0 is a carbon atom, and Xaa 0 Yaa 0 This group forms a cyclic hydrocarbon group together with the above group. The cyclic hydrocarbon group may be an aliphatic hydrocarbon group or a condensed cyclic hydrocarbon group of an aliphatic hydrocarbon group and an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.

[0070] The monocyclic aliphatic hydrocarbon group is preferably a group in which two or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, more preferably 5 or 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which two or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0071] The aromatic hydrocarbon group in the condensed cyclic hydrocarbon group of an aliphatic hydrocarbon group and an aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.

[0072] Specific examples of the condensed cyclic hydrocarbon group of an aliphatic hydrocarbon group and an aromatic hydrocarbon group are shown below.

[0073] [ka]

[0074] Some or all of the hydrogen atoms in the cyclic hydrocarbon group may be substituted, and some of the carbon atoms constituting the ring may be substituted with heteroatoms. Specific examples of the substituents that substitute a part or all of the hydrogen atoms of the cyclic hydrocarbon group include the above-mentioned Ra x5 When some of the carbon atoms constituting the ring are substituted with a heteroatom, examples of the heteroatom include an oxygen atom, a sulfur atom and a nitrogen atom.

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

[0076] In formula (a0-r2-02), Yab 0 is a carbon atom, and Xab 0 Yab 0 The cyclic hydrocarbon group is a group that, together with the above Xaa 0 And, Yaa 0 and the like.

[0077] In formula (a0-r2-02), Ra 002 ~Ra 004 are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms.

[0078] Ra 002 ~Ra 004 In the above formula, examples of the monovalent chain 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, and a decyl group. Ra 002 ~Ra 004 In the above formula, 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, and a cyclododecyl group; 2,6 ]decanyl group, tricyclo[3.3.1.1 3,7 ]decanyl group, tetracyclo[6.2.1.1 3,6 .0 2,7]A dodecanyl group, an adamantyl group, and other polycyclic aliphatic saturated hydrocarbon groups are also included.

[0079] Ra 002 ~Ra 004 In the above, some or all of the hydrogen atoms in the chain saturated hydrocarbon group and the alicyclic saturated hydrocarbon group may be substituted. Specific examples of the substituents that substitute some or all of the hydrogen atoms in the chain saturated hydrocarbon group and the alicyclic saturated hydrocarbon group include the above-mentioned Ra x5 When some of the carbon atoms constituting the ring are substituted with a heteroatom, examples of the heteroatom include an oxygen atom, a sulfur atom and a nitrogen atom.

[0080] Ra 002 ~Ra 004 Examples of groups containing a carbon-carbon double bond formed by two or more of the above being bonded to each other to form a cyclic structure include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylidene-ethenyl group, a cyclohexylidene-ethenyl group, etc. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylidene-ethenyl group are preferred.

[0081] In formula (a0-r2-02), Ra 002 ~Ra 004 Among the above, each independently is preferably a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom.

[0082] In formula (a0-r2-03), Yac 0 is a carbon atom, and Xac 0 Yac 0 The cyclic hydrocarbon group is a group that, together with the above Xaa 0 And, Yaa 0 and the like.

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

[0084] Some or all of the hydrogen atoms in the aromatic hydrocarbon group may be substituted, and some of the carbon atoms constituting the ring may be substituted with heteroatoms. Specific examples of the substituents that substitute a part or all of the hydrogen atoms of the aromatic hydrocarbon group include the above-mentioned Ra x5 When some of the carbon atoms constituting the ring are substituted with a heteroatom, examples of the heteroatom include an oxygen atom, a sulfur atom and a nitrogen atom.

[0085] In formula (a0-r2-04), Ra 006 and Ra 007 are each independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms. Ra 006 and Ra 007 In the formula, the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms includes the above-mentioned Ra 002 ~Ra 004 Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms are the same as those in the above formula.

[0086] In formula (a0-r2-04), Ra 006 and Ra 007 Among the above, an alkyl group having 1 to 5 carbon atoms is preferable, a methyl group or an ethyl group is more preferable, and a methyl group is even more preferable. Ra 006 and Ra 007 In the case where the chain saturated hydrocarbon group represented by the formula (I) is substituted, examples of the substituent include the above-mentioned Ra x5 The same groups as those shown below can be mentioned.

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

[0088] Ra 008 The linear alkyl group in the formula (I) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. 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.

[0089] Ra 008 The branched alkyl group in the above formula (I) preferably has a carbon number of 3 to 10, and more preferably 3 to 5. Specific examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and is preferably an isopropyl group.

[0090] Ra 008 When 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. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0091] Ra 008 As the aromatic hydrocarbon group in 005Among them, the aromatic hydrocarbon group Ra 008 is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene. Ra 008 Examples of the substituent that may be possessed by Ra include 005 The substituents include the same ones as those which may be possessed by the group.

[0092] Ra in formula (a0-r2-04) 008 When is a naphthyl group, the position at which it is bonded to the tertiary carbon atom in the above formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. Ra in formula (a0-r2-04) 008 When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the above formula (a0-r2-04) may be any one of the 1-position, 2-position, or 9-position of the anthryl group.

[0093] In formula (a0-r2-04), Ra 008 Among the above, an alkyl group having 1 to 5 carbon atoms is preferable, a methyl group or an ethyl group is more preferable, and a methyl group is even more preferable.

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

[0095] [ka]

[0096] [ka]

[0097] [ka]

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

[0099] [ka]

[0100] [ka]

[0101] [ka]

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

[0103] [ka]

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

[0105] [ka]

[0106] Secondary alkyl ester type acid-labile group: Rpg 0 Examples of the acid dissociable group in the formula (a0-r-3) include acid dissociable groups represented by the following general formula (a0-r-3).

[0107] [ka] [In formula (a0-r-3), Ra 07 is a hydrocarbon group.08a and Ra 08b are each independently a hydrogen atom, a halogen atom or an alkyl group. 09 is a hydrogen atom or a hydrocarbon group. 07 and Ra 08a Or Ra 08b may be bonded to each other to form a ring. 08a Or Ra 08b And, Ra 09 may be bonded to each other to form a ring. * represents a bond to the oxygen atom (-O-) in the general formula (a0).

[0108] In the formula, Ra 07 and Ra 09 As the hydrocarbon group in Ra 01 The same can be mentioned. In the formula, Ra 08a and Ra 08b As the alkyl group in the above, 01 The alkyl groups in the above formula (I) are the same as those in the above formula (I). In the formula, Ra 07 and Ra 09 The hydrocarbon group in 08a and Ra 08b The alkyl group in may have a substituent. Examples of the substituent include the above-mentioned Ra x5 etc.

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

[0110] Ra 07 and Ra 08a Or Ra 08band are bonded to each other to form a ring. Among the above, preferred are monocycloalkenes, rings in which some of the carbon atoms of a monocycloalkene are substituted with heteroatoms (oxygen atoms, sulfur atoms, etc.), and monocycloalkadiene, more preferred are cycloalkenes having 3 to 6 carbon atoms, and more preferred are cyclopentene or cyclohexene.

[0111] Ra 07 and Ra 08a Or Ra 08b The ring formed by bonding with each other may be a condensed ring. Specific examples of the condensed ring include indan.

[0112] Ra 07 and Ra 08a Or Ra 08b The ring formed by bonding with each other may have a substituent. Examples of the substituent include the above-mentioned Ra x5 etc.

[0113] Ra 08a Or Ra 08b And, Ra 09 may be bonded to each other to form a ring, and the ring may be 07 and Ra 08a Or Ra 08b and the like are similar to the ring formed by bonding with each other.

[0114] In the above formula (a0-r-3), Ra 07 and Ra 08a Or Ra 08b Among the above, it is preferable that they are bonded to each other to form a ring, it is more preferable that they are bonded to each other to form a monocyclic ring, and it is further preferable that they are bonded to each other to form a monocyclic alicyclic ring. In that case, Ra 09 is preferably a hydrogen atom. Also, Ra 07 and Ra 08a Or Ra 08bThe ring formed by bonding with each other may have a substituent, and the substituent is preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group or an ethyl group.

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

[0116] [ka]

[0117] In the above formula (a0), Rpg 0 The acid dissociable group in is preferably a tertiary alkyl ester type acid dissociable group or a secondary alkyl ester type acid dissociable group, and from the viewpoint of improving the LWR, it is more preferably a chain-like tertiary alkyl ester type acid dissociable group or a chain-like secondary alkyl ester type acid dissociable group, and from the viewpoint of improving the sensitivity and etching rate, it is more preferably a cyclic tertiary alkyl ester type acid dissociable group or a cyclic secondary alkyl ester type acid dissociable group. Specifically, the cyclic tertiary alkyl ester-type acid dissociable group is preferably an acid dissociable group represented by the above general formula (a0-r2-01), an acid dissociable group represented by the above general formula (a0-r2-02), or an acid dissociable group represented by the above general formula (a0-r2-03), and more preferably an acid dissociable group represented by the above general formula (a0-r2-02) or an acid dissociable group represented by the above general formula (a0-r2-03). Specifically, the cyclic secondary alkyl ester type acid-dissociable group is preferably an acid-dissociable group represented by the above general formula (a0-r-3).

[0118] Specific examples of the structural unit (a0) are shown below: In each of the following formulas, Rα represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0119] [ka]

[0120] From the standpoint of improving LWR, the structural unit (a0) in the resist composition of this embodiment is preferably a structural unit represented by general formula (a01-1a-5) above. As the structural unit (a0), from the viewpoint of improving sensitivity and etching rate, structural units represented by any one of the above general formulas (a01-1a-1) to (a01-1a-4), (a01-1a-6) to (a01-1a-10) are preferred, and structural units represented by the above general formula (a01-1a-6) or (a01-1a-7) are more preferred.

[0121] The structural unit (a0) contained in the component (A1) may be of one type, or two or more types. The proportion of the structural unit (a0) in the component (A1) is preferably 30 mol % or more, more preferably 40 mol % or more, and even more preferably 50 mol % or more, based on the total (100 mol %) of all structural units constituting the component (A1). The proportion of the structural unit (a0) in the component (A1) is preferably no greater than 90 mol%, more preferably no greater than 80 mol%, and even more preferably no greater than 70 mol%, based on the total (100 mol%) of all structural units constituting the component (A1).

[0122] By ensuring that the proportion of the structural unit (a0) is at least as large as the above-mentioned preferable lower limit, sensitivity can be improved when forming a resist pattern, the LWR can be further reduced, and a resist pattern with improved etching resistance can be formed. By ensuring that the proportion of the structural unit (a0) is equal to or less than the aforementioned preferred upper limit, it becomes easier to achieve a balance with the other structural units. For example, the proportion of the structural unit (a0) in the component (A1) relative to the total (100 mol%) of all structural units constituting the component (A1), is preferably from 30 mol% to 90 mol%, more preferably from 40 mol% to 80 mol%, and even more preferably from 50 mol% to 70 mol%.

[0123] Other structural units The component (A1) may contain other structural units, in addition to the structural unit (a0) described above, as necessary. Examples of other structural units include structural units (a1) containing an acid-decomposable group whose polarity increases by the action of acid (excluding those corresponding to structural unit (a0)); structural units (a10) represented by general formula (a10-1) described below; structural units (a2) containing a lactone-containing cyclic group; structural units (a5) that generate acid upon exposure; and structural units (a8) derived from a compound represented by general formula (a8-1) described below.

[0124] Regarding the structural unit (a1): The structural unit (a1) is a structural unit that contains an acid-decomposable group whose polarity increases when acted upon by an acid, with the proviso that structural units that fall under the category of the structural unit (a0) are excluded from the structural unit (a1).

[0125] Examples of the structural unit (a1) include structural units represented by the following general formula (a1-1), (a1-2) or (a1-3).

[0126] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 1 is a divalent hydrocarbon group which may have an ether bond. a1 is an integer from 0 to 2. 1 is an acid dissociable group represented by the above general formula (a0-r-1), (a0-r-2) or (a0-r-3). 1 is a2 +1-valent hydrocarbon group, n a2 is an integer from 1 to 3, and Ra 2 is an acid-dissociable group represented by the above general formula (a0-r-1) or the following general formula (a1-r-3). 001 is a single bond or a divalent linking group. 01 is a single bond or a divalent linking group. 01is an acid dissociable group represented by the above general formula (a0-r-1), (a0-r-2) or (a0-r-3). q is an integer of 0 to 3. n is an integer of 0 or more, provided that n≦q×2+4.]

[0127] [ka] [In the formula, Ra' 7 ~Ra' 9 are each an alkyl group.

[0128] Specific examples of the structural unit (a1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0129] [ka]

[0130] [ka]

[0131] [ka]

[0132] [ka]

[0133] [ka]

[0134] [ka]

[0135] [ka]

[0136] [ka]

[0137] [ka]

[0138] [ka]

[0139] [ka]

[0140] [ka]

[0141] [ka]

[0142] [ka]

[0143] The structural unit (a1) contained in the component (A1) may be of one type, or two or more types. As the structural unit (a1), a structural unit represented by the above formula (a1-1) or a structural unit represented by the above formula (a1-3) is more preferable, since these structural units are capable of more easily improving the characteristics (sensitivity, shape, etc.) in electron beam or EUV lithography.

[0144] When the component (A1) contains the structural unit (a1), the proportion of the structural unit (a1) in the component (A1) is preferably 1 to 30 mol %, more preferably 1 to 20 mol %, and even more preferably 1 to 10 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a1) is at least as large as the lower limit of the aforementioned preferred range, lithography properties such as sensitivity, resolution, and roughness can be improved. On the other hand, by ensuring that the proportion is at most the upper limit of the aforementioned preferred range, a balance with other structural units can be achieved, resulting in various favorable lithography properties. In this embodiment, the component (A1) may or may not contain the structural unit (a1), but it is preferable that it does not contain the structural unit (a1).

[0145] Building block (a10): The structural unit (a10) is a structural unit represented by general formula (a10-1) shown below.

[0146] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. x1 is a single bond or a divalent linking group. x1 is an aromatic hydrocarbon group which may have a substituent. ax1 is an integer greater than or equal to 1.]

[0147] In the formula (a10-1), R is the same as R in the general formula (a1-1). R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferable.

[0148] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group. In the above chemical formula, Ya x1The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0149] Ya x1 is preferably a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a single bond or an ester bond [-C(=O)-O-, -OC(=O)-].

[0150] In the formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. Wa x1 The aromatic hydrocarbon group in the formula (n) is an aromatic ring which may have a substituent. ax1 4n+1) hydrogen atoms are removed. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles 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 heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Also, Wa x1 The aromatic hydrocarbon group in the formula (n) may be an aromatic compound having an aromatic ring which may have two or more substituents (e.g., biphenyl, fluorene, etc.). ax1 +1) hydrogen atoms may also be removed. Among the above, Wa x1 As the aryl group, benzene, naphthalene, anthracene, or biphenyl (n ax1 A group in which (n +1) hydrogen atoms have been removed is preferred, and a group in which (n ax1A group in which (n +1) hydrogen atoms have been removed from benzene is more preferable. ax1 A group in which +1) hydrogen atoms have been removed is more preferred.

[0151] Wa x1 The aromatic hydrocarbon group in may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. Examples of the alkyl group, the alkoxy group, the halogen atom, and the halogenated alkyl group as the substituent include Ya x1 The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, further preferably an ethyl group or a methyl group, and particularly preferably a methyl group. x1 The aromatic hydrocarbon group in the formula (I) preferably does not have a substituent.

[0152] 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, further preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0153] Specific examples of the structural unit (a10) represented by the aforementioned formula (a10-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0154] [ka]

[0155] [ka]

[0156] [ka]

[0157] The structural unit (a10) contained in the component (A1) may be of one type, or two or more types. The component (A1) may or may not contain the structural unit (a10), but it preferably contains the structural unit (a10). When the component (A1) contains the structural unit (a10), the proportion of the structural unit (a10) in the component (A1) is preferably at least 10 mol %, more preferably at least 20 mol %, and even more preferably at least 30 mol %, based on the combined total (100 mol %) of all structural units constituting the component (A1). The proportion of the structural unit (a10) in the component (A1) is preferably no greater than 70 mol %, more preferably no greater than 60 mol %, and even more preferably no greater than 50 mol %, based on the total (100 mol %) of all structural units constituting the component (A1).

[0158] By ensuring that the proportion of the structural unit (a10) is at least as large as the aforementioned preferable lower limit, it becomes easier to further increase the sensitivity. By ensuring that the proportion of the structural unit (a10) is no more than the aforementioned preferred upper limit, it becomes easier to achieve a balance with the other structural units. For example, the proportion of the structural unit (a10) in the component (A1) relative to the total (100 mol%) of all structural units constituting the component (A1), is preferably from 10 mol% to 70 mol%, more preferably from 20 mol% to 60 mol%, and even more preferably from 30 mol% to 50 mol%.

[0159] Building block (a2): The component (A1) may have a structural unit (a2) that contains a lactone-containing cyclic group (provided that this does not include those that correspond to the structural units (a0) and (a1)). The lactone-containing cyclic group of the structural unit (a2) is effective in increasing the adhesion of the resist film to the substrate when the component (A1) is used to form a resist film. In addition, the structural unit (a2) has the effects of, for example, appropriately adjusting the acid diffusion length, increasing the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development, thereby improving the lithography properties, etc.

[0160] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -OC(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and when there is only a lactone ring, it is called a monocyclic group, and when there is further a ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. The lactone-containing cyclic group in the structural unit (a2) is not particularly limited and any suitable group can be used. Specific examples include the groups represented by the following general formulae (a2-r-1) to (a2-r-7).

[0161] [ka] [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. * represents a bond (the same applies hereinafter).]

[0162] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples 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 a hexyl group. Among these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred. Ra' 21 The alkoxy group in the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. 21 Examples of the alkyl group include those groups in which the alkyl groups mentioned above are linked to an oxygen atom (-O-). Ra' 21 As the halogen atom in, a fluorine atom is preferable. Ra' 21 As the halogenated alkyl group in the above, Ra' 21 and groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the above halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0163] Ra' 21 In -COOR" and -OC(=O)R", R" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group. The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably has 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane. More specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples of the lactone-containing cyclic group in R″ include the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7) above. Ra' 21 The hydroxyalkyl group in Ra' is preferably one having 1 to 6 carbon atoms. 21 In the above formula, at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0164] Ra' 21 Among the above, it is preferable that each of them independently is a hydrogen atom or a cyano group.

[0165] In the general formulae (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 isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between the 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.

[0166] Specific examples of the groups represented by general formulas (a2-r-1) to (a2-r-7) are listed below.

[0167] [ka]

[0168] [ka]

[0169] Of the various possibilities, the structural unit (a2) is preferably a structural 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. The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0170] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 21 is a single bond or a divalent linking group. 21is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. 21 If -O-, Ya 21 does not become -CO-. Ra 21 is a lactone-containing cyclic group.

[0171] In the formula (a2-1), R is the same as defined above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferable.

[0172] In the formula (a2-1), Ya 21 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. 21 As the divalent linking group, Ya in the above general formula (a10-1) is x1 The divalent linking group may be the same as the divalent linking group in the above formula.

[0173] 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.

[0174] In the formula (a2-1), Ya 21 is a single bond, La 21 is preferably -COO- or -OCO-.

[0175] In the above formula (a2-1), Ra 21 is a lactone-containing cyclic group. Ra 21 Suitable examples of the lactone-containing cyclic group in include the groups represented by the above-mentioned general formulae (a2-r-1) to (a2-r-7), respectively.

[0176] The structural unit (a2) contained in the component (A1) may be of one type, or may be of two or more types. The component (A1) may or may not have the structural unit (a2). When the component (A1) contains the structural unit (a2), the proportion of the structural unit (a2) relative to the total (100 mol %) of all structural units constituting the component (A1), is preferably 1 to 20 mol %, more preferably 1 to 15 mol %, and even more preferably 1 to 10 mol %. When the proportion of the structural unit (a2) is at least as large as the preferred lower limit, the effects achieved by including the structural unit (a2) as described above can be fully obtained. When the proportion of the structural unit (a2) is at most the upper limit, a balance with other structural units can be achieved, and various lithography properties become favorable.

[0177] Building block (A5): In this embodiment, the structural unit (a5) is a structural unit that generates an acid upon exposure, and any known structural unit can be used. By including the structural unit (a5), the acid generated upon exposure tends to be distributed uniformly within the resist film. Suitable examples of the structural unit (a5) include structural units represented by general formula (a5-1) shown below.

[0178] [ka] [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. 1 is a divalent linking group or a single bond. 050 is a divalent hydrocarbon group which may have a substituent. a5 is an integer from 0 to 2. 0 is a divalent linking group. 0 is a divalent linking group which may have a heteroatom, or a single bond. 051 and Ra 052 are each independently a hydrogen atom, a fluorine atom or a fluorinated alkyl group. n0 is an integer of 1 to 4. m is an integer of 1 or more, and M'm+ is an onium cation with a valence of m.

[0179] {anion part} In the above formula (a5-1), R m represents 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 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, and a neopentyl group. 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. As the halogen atom in the halogenated alkyl group, a fluorine atom is particularly preferred. 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 industrial availability, a hydrogen atom or a methyl group is most preferable.

[0180] In the above formula (a5-1), La 1 is a divalent linking group or a single bond. La 1 The divalent linking group in the formula (I) 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. x1 The divalent linking groups are the same as the divalent hydrocarbon groups which may have a substituent and the divalent linking groups containing a hetero atom exemplified in the above. Among the above, La 1 is preferably an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, an aromatic hydrocarbon group, or a combination thereof, or a single bond.1 is preferably an ester bond [-C(=O)-O-, -OC(=O)-] or a single bond, and more preferably an ester bond [-C(=O)-O-, -OC(=O)-].

[0181] In the above formula (a5-1), Ra 050 is a divalent hydrocarbon group which may have a substituent. Ra 050 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0182] ··Ra 050 Aliphatic hydrocarbon groups 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 linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0183] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably contains 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 straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific 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-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0184] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, which may include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group.

[0185] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed 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 end of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0186] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, 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 most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being 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, and the heteroatom-containing substituent is preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0187] ··Ra 050 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, 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 heterocycles 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 heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group (arylene group or heteroarylene group) obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle; a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) in which one hydrogen atom is substituted with an alkylene group (e.g., a group obtained by further removing one hydrogen atom from an 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, or a 2-naphthylethyl group). 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 carbon atom.

[0188] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom and halogenated alkyl group as the substituent include those exemplified as the substituent substituting a hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0189] n a5 is an integer from 0 to 2. Among the above, Ra 050 is preferably an aliphatic hydrocarbon group containing a ring in its structure, more preferably a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure, and further preferably an alicyclic hydrocarbon group which is a polycyclic group or a monocyclic group and which may have a substituent. Or, among the above, Ra 050 is preferably an aromatic hydrocarbon group.

[0190] n a5 If is 2, then two Ra 050 may all be alicyclic hydrocarbon groups which may have a substituent, may all be aromatic hydrocarbon groups, or may be a combination of alicyclic hydrocarbon groups and aromatic hydrocarbon groups which may have a substituent.

[0191] In the above formula (a5-1), La 0 is a divalent linking group. La 0 Examples of the divalent linking group in the formula (I) include non-hydrocarbon oxygen-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-OC(=O)-O-); and combinations of such non-hydrocarbon oxygen-containing linking groups with alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of such a divalent linking group include linking groups 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 in the above formula (a5-1) 050 The bond to V' in the following general formulas (L-al-1) to (L-al-8) is 101 It is.

[0192] [ka] [In the formula, V' 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' 102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0193] V' 102 The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0194] V' 101 and V' 102 The alkylene group in may be a straight-chain alkylene group or a branched-chain alkylene group, and is preferably a straight-chain alkylene group. V' 101 and V' 102Specific examples of the alkylene group in the formula (I) include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2 -, etc.; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-]. Also, V' 101 or V' 102 In the above formula (a1-r-1), some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by Ra' in the above formula (a1-r-1). 3 A divalent group in which one hydrogen atom has been further removed from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group, a polycyclic aliphatic hydrocarbon group) such as those mentioned above is preferred, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferred.

[0195] La 0 is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, more preferably a linking group represented by each of the above formulas (L-al-1) to (L-al-5) and (L-al-8), and further preferably a linking group represented by (L-al-3) or (L-al-8).

[0196] In the formula (a5-1), Ya 0 represents a divalent linking group which may have a heteroatom, or a single bond. Ya 0The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Ya 0 The divalent hydrocarbon group which may have a substituent and the divalent linking group which contains a hetero atom in x1 The divalent linking groups are the same as the divalent hydrocarbon groups which may have a substituent and the divalent linking groups containing a hetero atom exemplified in the above. Among the above, Ya 0 is preferably a linear or branched alkylene group or a single bond, and more preferably a single bond.

[0197] In the above formula (a5-1), Ra 051 and Ra 052 each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group. Ra 051 and Ra 052 The fluorinated alkyl group in each of the above is preferably a linear or branched fluorinated alkyl group having 1 to 5 carbon atoms, and more preferably a trifluoromethyl group. In the above formula (a5-1), SO3 - Ra bonded to the carbon atom adjacent to 051 and Ra 052 From the viewpoint of acid strength, it is preferable that at least one of the groups is a fluorine atom.

[0198] In the formula (a5-1), n0 represents an integer of 1 to 4, and is preferably 1, 2 or 3.

[0199] {cationic part} In the above formula (a5-1), M' m+ represents an onium cation having a valence of m. Among these, M' m+ is preferably a sulfonium cation or an iodonium cation, and m is an integer of 1 or more.

[0200] Preferred cationic moieties ((M' m+ ) 1 / m) include organic cations represented by the following general formulas (ca-1) to (ca-3), respectively.

[0201] [ka] [In the formula, R 201 ~R 207 R each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. 201 ~R 203 , R 206 ~R 207 may be bonded to each other to form a ring together with the sulfur atom in the formula. 208 ~R 209 R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. 210 L is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. 201 represents -C(=O)- or -C(=O)-O-.

[0202] In the above general formulas (ca-1) to (ca-3), R 201 ~R 207 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 , and R 210Examples of the substituent that may be possessed by the group include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulas (ca-r-1) to (ca-r-7).

[0203] [ka] [In the formula, R' 201 are each independently a hydrogen atom, 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.

[0204] Optionally substituted cyclic groups: 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 that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0205] R' 201 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, further preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. 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 the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R' 201Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0206] R' 201 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is present in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically, cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.; or a polycycloalkane having a polycyclic skeleton of a condensed ring system such as a cyclic group having a steroid skeleton.

[0207] Among them, R' 201The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, particularly preferably an adamantyl group or a norbornyl group, and most preferably an adamantyl group.

[0208] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific 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-], etc. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0209] Also, R' 201The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include lactone-containing cyclic groups represented by the above general formulae (a2-r-1) to (a2-r-7), -SO2--containing cyclic groups represented by the following general formulae (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by the following chemical formulae (r-hr-1) to (r-hr-16). In the formula, * represents Y in formula (b-1). 101 Represents a bond that bonds to .

[0210] [ka] [In the formula, 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; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group or a -SO2- containing cyclic group; B" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n' is an integer of 0 to 2. * represents a bond.]

[0211] In the general formulae (b5-r-1) and (b5-r-2) above, 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. B" 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 even more preferably a methylene group.

[0212] In the general formulae (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 these, they are preferably each independently a hydrogen atom or a cyano group.

[0213] Specific examples of the groups represented by general formulas (b5-r-1) to (b5-r-4) are shown below, in which "Ac" represents an acetyl group.

[0214] [ka]

[0215] [ka]

[0216] [ka]

[0217] [ka]

[0218] R' 201 Examples 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, and a nitro group. The alkyl group as a substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, 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 most preferably a methoxy group or an ethoxy group. As the halogen atom as a substituent, a fluorine atom is preferred. Examples of halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0219] A chain alkyl group which may have a substituent: R' 201 The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and most preferably has 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably has 3 to 15 carbon atoms, and most preferably has 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0220] An optionally substituted chain alkenyl group: R' 201 The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, further 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 butynyl 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. Of the above chain alkenyl groups, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0221] R' 201Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, the above R' 201 and the like.

[0222] R' 201 In addition to those mentioned above, the optionally substituted cyclic group, the optionally substituted chain alkyl group, or the optionally substituted chain alkenyl group also includes the same as the acid-dissociable group represented by formula (a1-r-2) above as the optionally substituted cyclic group or the optionally substituted chain alkyl group.

[0223] Among them, R' 201 is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7), and an -SO2--containing cyclic group represented by each of the general formulae (b5-r-1) to (b5-r-4) are preferred.

[0224] In the above general formulas (ca-1) to (ca-3), R 201 ~R 203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they do not include a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(the R Nis an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, in which a ring containing a sulfur atom in the ring skeleton in the formula is a 3- to 10-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0225] 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 they are alkyl groups they may be bonded to each other to form a ring.

[0226] R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 210 As the -SO2- containing cyclic group which may have a substituent in the formula (b5-r-1), a "-SO2- containing polycyclic group" is preferable, and a group represented by the above general formula (b5-r-1) is more preferable.

[0227] Specific examples of the cation represented by the formula (ca-1) are shown below.

[0228] Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following chemical formulas.

[0229] [ka]

[0230] [ka]

[0231] [ka] [In the formula, g1, g2, and g3 each represent a repeating number, where g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.]

[0232] [ka]

[0233] [ka]

[0234] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the above-mentioned R 201 ~R 207 , and R 210 ~R 212 The substituents are the same as those exemplified as the substituents that may be possessed by the

[0235] [ka]

[0236] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0237] Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

[0238] [ka]

[0239] The cation moiety ((M' m+ ) 1 / m ) is preferably a sulfonium cation, more preferably a cation represented by each of the formulas (ca-1) to (ca-3), still more preferably a cation represented by the formula (ca-1), and particularly preferably a cation represented by each of the formulas (ca-1-1) to (ca-1-83).

[0240] Preferred specific examples of the structural unit (a5) are shown below. In the following formula, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group. m+ represents m and M' in the above general formula (a5-1). m+ is the same as:

[0241] [ka]

[0242] [ka]

[0243] [ka]

[0244] The structural unit (a5) contained in the component (A1) may be of one type, or two or more types. When the component (A1) contains 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 12 to 20 mol %, based on the combined total (100 mol %) of all 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 even higher sensitivity and improved resolution, while when the proportion is at most the upper limit of the above-mentioned preferred range, it becomes easier to achieve a balance with other structural units.

[0245] Building block (A8): The structural unit (a8) is a structural unit derived from a compound represented by general formula (a8-1) shown below.

[0246] [ka] [In the formula, W 2 is a polymerizable group-containing group. x2 is a single bond or (n ax2 +1)valent linking group. x2 and W 2 R may form a condensed ring. 1 R is a fluorinated alkyl group having 1 to 12 carbon atoms. 2 R is a hydrogen atom or an organic group having 1 to 12 carbon atoms which may have a fluorine atom. 2 and Ya x2 may be bonded to each other to form a ring structure. ax2 is an integer from 1 to 3.

[0247] W 2 The "polymerizable group" in the polymerizable group-containing group is a group that enables a compound having a polymerizable group to be polymerized by radical polymerization or the like, and refers to a group that contains a multiple bond between carbon atoms, such as an ethylenic double bond.

[0248] The polymerizable group-containing group may be a group composed only of a polymerizable group, or may be a group composed of a polymerizable group and a group other than the polymerizable group. Examples of the group other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom. Examples of the polymerizable group-containing group include those represented by the chemical formula: C(R X11 )(R X12 )=C(R X13 )-Ya x0 A preferred example is a group represented by the formula: 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; x0 is a single bond or a divalent linking group.

[0249] Ya x2 and W 2 The condensed ring formed by 2 Polymerizable group of the site and Ya x2 and W 2 Other groups than the polymerizable group at the Ya site x2 and Ya x2 and W 2 The condensed ring formed by these may have a substituent.

[0250] 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.

[0251] [ka]

[0252] 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) and (a8-1-09).

[0253] The structural unit (a8) contained in the component (A1) may be of one type, or may be of two or more types. The component (A1) may or may not have the structural unit (a8). The amount of the structural unit (a8) in the component (A1) relative to the total amount (100 mol %) of all structural units constituting the component (A1), is preferably 0 to 50 mol %, and more preferably 0 to 30 mol %.

[0254] The component (A1) contained in the resist composition may use either a single type of compound, or a combination of two or more types of compounds.

[0255] The component (A1) is preferably a polymeric compound having a repeating structure of the structural unit (a0), and more preferably a polymeric compound having a repeating structure of the structural unit (a0) and a repeating structure of the structural unit (a10). More specifically, the component (A1) is preferably a polymeric compound consisting only of repeating units of the structural unit (a0); or a polymeric compound consisting only of repeating units of the structural unit (a0) and repeating units of the structural unit (a10).

[0256] In a polymer compound consisting of a repeating structure of the structural unit (a0) and a repeating structure of the structural unit (a10), the proportion of the structural unit (a0) relative to the total (100 mol%) of all structural units constituting the polymer compound is preferably 30 mol% or more and 90 mol% or less, more preferably 40 mol% or more and 80 mol% or less, and even more preferably 50 mol% or more and 70 mol% or less. Furthermore, the proportion of the structural unit (a10) in the polymer compound is preferably 10 mol % or more and 70 mol % or less, more preferably 20 mol % or more and 60 mol % or less, and even more preferably 30 mol % or more and 50 mol % or less, relative to the total (100 mol %) of all structural units constituting the polymer compound.

[0257] The (A1) component can be produced by dissolving monomers that derive each structural unit in a polymerization solvent, and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the solution and polymerizing the resulting mixture. Alternatively, the (A1) component can be produced by dissolving a monomer that derives the structural unit (a0) and, if necessary, a monomer that derives other structural units (for example, a compound in which the hydroxyl group of the monomer that derives the structural unit (a10) is protected) in a polymerization solvent, adding a radical polymerization initiator such as those described above to polymerize, and then, if necessary, carrying out 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 to the end. In this way, a copolymer having a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms is introduced, which is effective in reducing development defects and LER (line edge roughness: unevenness of the line sidewall).

[0258] The weight average molecular weight (Mw) of the component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and even more preferably 5,000 to 30,000. When the Mw of the component (A1) is no more than the preferred upper limit of this range, the compound has sufficient solubility in a resist solvent for use as a resist, and when it is no less than the preferred lower limit of this range, the dry etching resistance and cross-sectional shape of the resist pattern are excellent. The dispersity (Mw / Mn) of the component (A1) is not particularly limited, but is preferably from 1.0 to 4.0, more preferably from 1.0 to 3.0, and particularly preferably from 1.0 to 2.0, where Mn represents the number average molecular weight.

[0259] Regarding component (A2) The resist composition of this embodiment may use, in combination with the component (A), a base component (hereafter referred to as “component (A2)”) that does not fall under the category of the component (A1) above and whose solubility in a developer changes under the action of an acid. There are no particular restrictions on the component (A2), and it may be selected from the many conventional base components for chemically amplified resist compositions. The component (A2) may be a polymeric compound or a low molecular weight compound, and may be used either alone or in combination of two or more.

[0260] The proportion of the (A1) component in the (A) component is preferably 25% by mass or more, more preferably 50% by mass or more, and even more preferably 75% by mass or more, and may 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 that is excellent in various lithography properties such as high sensitivity, resolution, and improved roughness is easily formed.

[0261] The amount of the component (A) in the resist composition of this embodiment may be adjusted depending on factors such as the thickness of the resist film to be formed.

[0262] <Acid generator component (B)> The resist composition of this embodiment preferably further contains an acid generator component (B) that generates an acid upon exposure. There are no particular limitations on the component (B), and any of the compounds that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes, nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0263] Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0264] Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0265] [ka] [In the formula, R 101 and R 104 ~R 108 R each independently represents 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. 104 and R 105 R may be bonded to each other to form a ring structure. 102 Y is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 101 is a divalent linking group containing an oxygen atom or a single bond. 101 ~V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group. 101 and V 101 cannot be a single bond at the same time. 101 ~L102 Each of L is independently a single bond or an oxygen atom. 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 onium cation with a valence of m.

[0266] {anion part} Anion in component (b-1) In formula (b-1), R 101 represents 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.

[0267] Optionally substituted cyclic groups: 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. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. In addition, the aliphatic hydrocarbon group is preferably saturated.

[0268] R 101 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, further 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 the above formula include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R 101Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, etc.), etc. The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0269] R 101 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is present in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically, cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.; or a polycycloalkane having a polycyclic skeleton of a condensed ring system such as a cyclic group having a steroid skeleton.

[0270] Among them, R 101The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, further preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0271] 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, further preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specific 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 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, further 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 specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0272] Also, R 101The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include the lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above, the -SO2-containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) above, and the heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) above.

[0273] R 101 Examples 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, and a nitro group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms. The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, 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 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 preferred. Examples of the halogenated alkyl group as a substituent include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0274] R 101The cyclic hydrocarbon group in may be a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused. Examples of the fused ring include a polycycloalkane having a polycyclic skeleton of a bridged ring system to which one or more aromatic rings are fused. Specific examples of the bridged ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, and more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane. 101 Specific examples of the fused cyclic group in the formula (b-1) include those represented by the following formulas (r-br-1) to (r-br-2). 101 Represents a bond that bonds to .

[0275] [ka]

[0276] R 101 Examples of the substituent that the fused cyclic group in the formula (I) may 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, and an alicyclic hydrocarbon group. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the fused ring group are defined as R 101 Examples of the substituents of the cyclic group in the above formula (I) include the same as those exemplified as the substituents of the cyclic group in the above formula (I). Examples of the aromatic hydrocarbon group as the substituent of the fused ring group include a group in which one hydrogen atom has been removed from an aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.), and the heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of the alicyclic hydrocarbon group as a substituent of the fused cyclic group include groups obtained by removing one hydrogen atom from a monocycloalkane such as cyclopentane or cyclohexane; groups obtained by removing one hydrogen atom from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane; lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above; -SO2- containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) above; and heterocyclic groups represented by the formulae (r-hr-7) to (r-hr-16) above.

[0277] A chain alkyl group which may have a substituent: R 101 The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0278] An optionally substituted chain alkenyl group: R 101 The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, further preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl 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. Of the above chain alkenyl groups, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0279] R 101 Examples of the substituent in the chain alkyl or alkenyl group 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 above-mentioned R 101 Examples of the cyclic groups include the cyclic groups shown in the formula:

[0280] In formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 When Y is a divalent linking group containing an oxygen atom, 101 may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of the divalent linking group containing an oxygen atom include the linking groups represented by the following general formulas (y-al-1) to (y-al-7). In the following general formulas (y-al-1) to (y-al-7), R 101 The bond to V' in the following general formulas (y-al-1) to (y-al-7) is 101 It is.

[0281] [ka] [In the formula, V' 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' 102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0282] V' 102 The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0283] V'101 and V' 102 The alkylene group in may be a straight-chain alkylene group or a branched-chain alkylene group, and is preferably a straight-chain alkylene group. V' 101 and V' 102 Specific examples of the alkylene group in the formula (I) include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2 -, etc.; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-]. Also, V' 101 or V' 102 In the above formula (a1-r-1), some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by Ra' in the above formula (a1-r-1). 3 A divalent group in which one hydrogen atom has been further removed from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group, a polycyclic aliphatic hydrocarbon group) such as those mentioned above is preferred, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferred.

[0284] In formula (b-1), V 101 is a single bond, an alkylene group, or a fluorinated alkylene group. 101 is preferably a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

[0285] In formula (b-1), R 102R is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0286] Specific examples of the anion moiety represented by the formula (b-1) include, for example, Y 101 When Y is a single bond, examples of the anion include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; 101 When is a divalent linking group containing an oxygen atom, examples of the anions include those represented by any of the following formulas (an-1) to (an-3).

[0287] [ka] [In the formula, R” 101 R" is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by the above chemical formulas (r-hr-1) to (r-hr-6), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a chain alkyl group which may have a substituent, or an aromatic cyclic group which may have a substituent. 102 R" is an aliphatic cyclic group which may have a substituent, a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1), (a2-r-3) to (a2-r-7), or an -SO2- containing cyclic group represented by each of the above general formulas (b5-r-1) to (b5-r-4). 103 V" is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. 101 R is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Each v" is independently an integer of 0 to 3, each q" is independently an integer of 0 to 20, and n" is 0 or 1.

[0288] 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).

[0289] 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).

[0290] R” 101 The chain alkyl group which may have a substituent in the formula (b-1) is R 101 The alkyl group is preferably one of the groups exemplified as the chain alkyl group in the above formula (I). R” 103 The chain alkenyl group which may have a substituent is represented by R 101 Preferably, it is a group exemplified as the chain alkenyl group in the above formula.

[0291] Anion in component (b-2) In formula (b-2), R 104 , R 105 each independently represents 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 represents R 101 However, R 104 , R 105 may be bonded to each other to form a ring. R 104 , R 105is preferably a chain alkyl group which may have a substituent, and more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and even more preferably 1 to 3 carbon atoms. 104 , R 105 The number of carbon atoms in the chain-like alkyl group of R is preferably as small as possible within the above range of carbon atoms, for reasons such as good solubility in a resist solvent. 104 , R 105 In the chain alkyl group, the more hydrogen atoms substituted with fluorine atoms, the stronger the acid strength becomes, and the more the transparency to high-energy light of 250 nm or less and electron beams improves, which is preferable. The ratio of fluorine atoms in the chain alkyl group, i.e., 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 with fluorine atoms. In formula (b-2), V 102 , V 103 each independently represents a single bond, an alkylene group, or a fluorinated alkylene group, and each represents V in formula (b-1). 101 The same can be mentioned. In formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0292] Anion in component (b-3) In formula (b-3), R 106 ~R 108 each independently represents 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 represents R 101 The same can be mentioned. In formula (b-3), L 103 ~L 105 are each independently a single bond, -CO- or -SO2-.

[0293] Among the above, the anion moiety of the component (B) is preferably the anion in the component (b-1), and more preferably the anion represented by the above formula (an-1).

[0294] {cationic part} In the above formula (b-1), formula (b-2), and formula (b-3), M' m+ represents an onium cation having a valence of m. Among these, a sulfonium cation and an iodonium cation are preferable. m is an integer of 1 or more. M' in the above formula (b-1), formula (b-2) and formula (b-3) m+ As the group, M' in the formula (a5-1) m+ is the same as:

[0295] Among the above, the cation portion of the (B) component is preferably a sulfonium cation, more preferably the cations represented by the formulas (ca-1) to (ca-3) above, still more preferably the cation represented by the formula (ca-1), and particularly preferably the cations represented by the formulas (ca-1-1) to (ca-1-83) above.

[0296] Of the above, from the standpoint of improving sensitivity and etching rate, the component (B) of the resist composition of this embodiment is preferably a compound represented by general formula (b0) below.

[0297] [ka] [In the formula, X 0 is a bromine atom or an iodine atom. m is a hydroxy group, an alkyl group, a fluorine atom, or a chlorine atom. nb1 is an integer of 1 to 5, and nb2 is an integer of 0 to 4, and 1≦nb1+nb2≦5. Yb 0 is a divalent linking group or a single bond. 0 R is a single bond, an alkylene group, or a fluorinated alkylene group. 0 is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom.m+ represents an organic cation having a valence of m, where m is an integer of 1 or more.

[0298] In the above general formula (b0), X 0 is a bromine atom or an iodine atom, and is preferably an iodine atom.

[0299] In the above general formula (b0), R m R is a hydroxy group, an alkyl group, a fluorine atom, or a chlorine atom. m The alkyl group in is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group. In the above general formula (b0), R m Among the above, is preferably a hydroxy group.

[0300] In the above general formula (b0), nb1 is an integer of 1 to 5, nb2 is an integer of 0 to 4, and 1≦nb1+nb2≦5. nb1 is preferably an integer of 1 to 3, more preferably 2 or 3, and even more preferably 3. nb2 is preferably an integer of 0 to 3, more preferably 0 or 1, and even more preferably 0.

[0301] In the above general formula (b0), Yb 0 is a divalent linking group or a single bond. 0 The divalent linking group in is preferably a divalent linking group containing an oxygen atom. Yb 0 When Yb is a divalent linking group containing an oxygen atom, 0 may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of divalent linking groups containing an oxygen atom include non-hydrocarbon oxygen-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-OC(=O)-O-); and combinations of the non-hydrocarbon oxygen-containing linking groups with alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination. Yb 0 Among the above, is preferably an ester bond (-C(=O)-O-).

[0302] In the above general formula (b0), Vb 0 represents an alkylene group, a fluorinated alkylene group, or a single bond. Vb 0 The alkylene group and the fluorinated alkylene group in Vb each preferably have 1 to 4 carbon atoms, and more preferably have 1 to 3 carbon atoms. 0 The fluorinated alkylene group in the above formula includes alkylene groups in which some or all of the hydrogen atoms have been substituted with fluorine atoms. Vb 0 Among the above, is preferably an alkylene group having 1 to 4 carbon atoms, a fluorinated alkylene group having 1 to 4 carbon atoms, or a single bond, and more preferably an alkylene group having 1 to 3 carbon atoms.

[0303] In the formula (b0), R 0 R is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. 0 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, more preferably a fluorine atom.

[0304] Specific examples of the compound represented by general formula (b0) include, but are not limited to, the following.

[0305] [ka]

[0306] In the resist composition of this embodiment, the component (B) may use either a single type, or a combination of two or more types. In the resist composition, the amount of the component (B) is preferably less than 50 parts by mass, and more preferably 10 to 40 parts by mass, per 100 parts by mass of the component (A). By setting the content of the component (B) within the above-mentioned preferred range, sufficient pattern formation can be achieved. Furthermore, when each component of the resist composition is dissolved in an organic solvent, a homogeneous solution is easily obtained, and the storage stability of the resist composition is also favorable.

[0307] When the component (A1) has a repeating structure of the structural unit (a5), the amount of the component (B) in the resist composition is preferably less than 50 parts by mass, more preferably 0 to 40 parts by mass, and even more preferably 0 to 30 parts by mass, per 100 parts by mass of the component (A).

[0308] <Base component (D)> The resist composition of this embodiment may contain, in addition to the component (A), a base component (component (D)) that traps acid generated upon exposure (i.e., controls the diffusion of acid). The component (D) acts as a quencher (acid diffusion controller) that traps acid generated in the resist composition upon exposure. Examples of the component (D) include a photodegradable base (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure to light and loses its acid diffusion controllability, and a nitrogen-containing organic compound (D2) (hereinafter referred to as "component (D2)") that does not fall under the category of component (D1). Among these, the photodegradable base (component (D1)) is preferred because it is likely to enhance all of the properties of high sensitivity, reduced roughness, and suppression of the occurrence of coating defects.

[0309] Regarding component (D1) The component (D1) is not particularly limited as long as it decomposes upon exposure to light and loses its 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 "component (d1-1)"), a compound represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"), and a compound represented by the following general formula (d1-3) (hereinafter referred to as "component (d1-3)"): The components (d1-1) to (d1-3) do not act as quenchers in the exposed areas of the resist film because they decompose and lose their acid diffusion control ability (basicity), but they act as quenchers in the unexposed areas of the resist film.

[0310] [ka] [In the formula, Rd 1 ~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. 2 In the formula, no fluorine atom is bonded to the carbon atom adjacent to the S atom. 1 is a single bond or a divalent linking group; m is an integer of 1 or more; M m+ are each independently an m-valent organic cation.

[0311] {(d1-1) component} Anion part In formula (d1-1), Rd 1 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, each of which is represented by the R' 201 The same can be mentioned. Among these, Rd 1is 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. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, an iodine atom, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1) to (a2-r-8), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is contained as a substituent, it may be via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the above formulas (y-al-1) to (y-al-5). Note that Rd 1 In the case where the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group in the formula (d3-1) has a linking group represented by the above general formulas (y-al-1) to (y-al-7) as a substituent, in the above general formulas (y-al-1) to (y-al-7), Rd 1 The carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group in the above formula (y-al-1) to (y-al-7) is bonded to V' 101 It is. Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and another ring structure). The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms. Specific examples of the chain alkyl group include linear alkyl groups such as 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 nonyl group, and a decyl group; and branched alkyl groups such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0312] When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and further preferably 1 to 4. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of the atom other than a fluorine atom include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0313] In formula (d1-1), Rd 1 Among the above, from the viewpoint of improving the sensitivity and etching rate, a cyclic group which may have a substituent is preferable, a cyclic group having at least an iodine atom is more preferable, an aromatic hydrocarbon group having at least an iodine atom is further preferable, and an aromatic hydrocarbon group having an iodine atom and a hydroxyl group is particularly preferable.

[0314] Preferred specific examples of the anion moiety of the component (d1-1) are shown below.

[0315] [ka]

[0316] ··Cation part In formula (d1-1), M m+ is an m-valent organic cation. M m+Suitable organic cations include those similar to those represented by the general formulas (ca-1) to (ca-3) above, with the cation represented by the general formula (ca-1) above being more preferred, and the cations represented by the general formulas (ca-1-1) to (ca-1-83) above being even more preferred. The component (d1-1) may be used alone or in combination of two or more.

[0317] {Component (d1-2)} Anion part In formula (d1-2), Rd 2 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 the R' 201 The same can be mentioned. However, Rd 2 In the above, the carbon atom adjacent to the S atom does not have a fluorine atom bonded thereto (is not substituted with fluorine), and this makes the anion of the (d1-2) component an appropriate weak acid anion, thereby improving the quenching ability of the (D) component. Rd 2 As the alkyl group, a chain alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent is preferable, and an aliphatic cyclic group which may have a substituent is more preferable.

[0318] The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably has 3 to 10 carbon atoms. The aliphatic cyclic group is preferably a group (which may have a substituent) in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like; or a group in which one or more hydrogen atoms have been removed from camphor.

[0319] Rd 2 The hydrocarbon group may have a substituent, and examples of the substituent include Rd 1Examples of the substituent include the same as the substituents that may be possessed by the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0320] Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

[0321] [ka]

[0322] ··Cation part In formula (d1-2), M m+ is an m-valent organic cation, and M in the formula (d1-1) m+ is the same as: The component (d1-2) may be used alone or in combination of two or more.

[0323] {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 R' 201 The Rd is preferably a fluorine atom-containing cyclic group, a chain alkyl group, or a chain alkenyl group. Among these, a fluorinated alkyl group is preferred, and the Rd 1 More preferred are the same fluorinated alkyl groups as those mentioned above.

[0324] 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 the R' 201 The same can be mentioned. Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group, which may have a substituent, is preferable. Rd 4The 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, and a neopentyl group. 4 A part of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, or the like. Rd 4 The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and 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. Of these, a methoxy group and an ethoxy group are preferred.

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

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

[0327] In formula (d1-3), Yd 1 is a single bond or a divalent linking group. Yd 1 The divalent linking group in is not particularly limited, but examples thereof include divalent hydrocarbon groups (aliphatic hydrocarbon groups, aromatic hydrocarbon groups) which may have a substituent, and divalent linking groups containing a hetero atom. Yd 1 is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and further preferably a methylene group or an ethylene group.

[0328] Preferred specific examples of the anion moiety of the component (d1-3) are shown below.

[0329] [ka]

[0330] [ka]

[0331] ··Cation part In formula (d1-3), M m+ is an m-valent organic cation, and M in the formula (d1-1) m+ is the same as: The component (d1-3) may be used alone or in combination of two or more.

[0332] The component (D1) may be any one of the above components (d1-1) to (d1-3), or a combination of two or more of them. When the resist composition contains the component (D1), the amount of the component (D1) in the resist composition is preferably 0.5 to 15 parts by mass, more preferably 1 to 12 parts by mass, and even more preferably 2 to 10 parts by mass, relative to 100 parts by mass of the component (A).

[0333] The component (D1) preferably contains the above-mentioned component (d1-1). Of the entire (D1) component, the content of the (d1-1) component is preferably 50 mass% or more, preferably 70 mass% or more, and more preferably 90 mass% or more. The (D1) component may consist solely of the compound (d1-1) component.

[0334] Manufacturing method of component (D1): The method for producing the components (d1-1) and (d1-2) is not particularly limited, and they can be produced by known methods. The method for producing the component (d1-3) is not particularly limited, and it can be produced, for example, in a manner similar to that described in US2012-0149916.

[0335] Regarding component (D2) The component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not fall under the category of the above component (D1). The component (D2) is not particularly limited as long as it acts as an acid diffusion control agent and does not fall under the category of component (D1), and any known component may be used. Among these, aliphatic amines are preferred, and among these, secondary aliphatic amines and tertiary aliphatic amines are more preferred. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. Examples of aliphatic amines include amines in which at least one hydrogen atom of ammonia NH3 has been substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines), or cyclic amines. Specific examples of alkylamines and alkyl alcohol amines 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 preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0336] Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a heteroatom. The heterocyclic compounds may be monocyclic (aliphatic monocyclic amines) or polycyclic (aliphatic polycyclic amines). Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. The aliphatic polycyclic amine is preferably one having 6 to 10 carbon atoms, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0337] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, and the like, with triethanolamine triacetate being preferred.

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

[0339] The component (D2) may be used alone or in combination of two or more types. When the resist composition contains the component (D2), the amount of the component (D2) in the resist composition is usually within the range of 0.01 to 5 parts by mass relative to 100 parts by mass of the component (A). By ensuring that the amount is within this range, the resist pattern shape, the storage stability over time, and the like are improved.

[0340] <At least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxoacids and derivatives thereof> The resist composition of this embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids, and phosphorus oxoacids and derivatives thereof (hereafter referred to as "component (E)") for the purposes of preventing deterioration of sensitivity and improving the resist pattern shape and stability over time after exposure. Specific examples of the organic carboxylic acid include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, and among these, salicylic acid is preferred. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred.

[0341] In the resist composition of this embodiment, the component (E) may use either a single type, or a combination of two or more types. When the resist composition contains the component (E), the amount of the component (E) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass, per 100 parts by mass of the component (A). By setting the amount in this range, the lithography properties are further improved.

[0342] <Fluorine additive component (F)> The resist composition of this embodiment may contain a fluorine additive component (hereafter referred to as "component (F)") as a hydrophobic resin. The component (F) is used to impart water repellency to the resist film, and when used as a resin separate from the component (A), it can improve lithography properties. As the component (F), for example, fluorine-containing polymeric 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. More specifically, the component (F) may be a polymer having a structural unit (f1) represented by the following general formula (f1-1). The polymer may be a polymer (homopolymer) consisting of only 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), and more preferably a copolymer of the structural unit (f1) and the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, or a structural unit derived from 1-methyl-1-adamantyl (meth)acrylate, and more preferably a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate.

[0343] [ka] [In the formula, R is the same as above, and Rf 102 and Rf 103 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Rf 102 and Rf 103 may be the same or different. 1 is an integer from 0 to 5, and Rf 101 is an organic group containing a fluorine atom.

[0344] In formula (f1-1), R bonded to the carbon atom at the α-position is the same as defined above. R is preferably a hydrogen atom or a methyl group. In formula (f1-1), Rf 102 and Rf 103 The halogen atom in Rf is preferably a fluorine atom. 102 and Rf 103 Examples of the alkyl group having 1 to 5 carbon atoms in R include the same alkyl groups having 1 to 5 carbon atoms as those in R, and a methyl group or an ethyl group is preferred. 102 and Rf103 Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms include groups in which part or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is preferred. Among these, Rf 102 and Rf 103 is 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 further preferably a hydrogen atom. In formula (f1-1), nf 1 represents an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0345] In formula (f1-1), Rf 101 is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom. The fluorine atom-containing hydrocarbon group may be linear, branched or cyclic and preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and particularly preferably has 1 to 10 carbon atoms. Furthermore, in the hydrocarbon group containing fluorine atoms, preferably 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more, and particularly preferably 60% or more are fluorinated, as this enhances the hydrophobicity of the resist film during immersion exposure. 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, or -CH2-CH2-CF2-CF2-CF2-CF3.

[0346] The weight average molecular weight (Mw) of component (F) (based on polystyrene conversion by gel permeation chromatography) is preferably 1000 to 50000, more preferably 5000 to 40000, and most preferably 10000 to 30000. When it is below the upper limit of this range, the compound has sufficient solubility in a resist solvent for use as a resist, and when it is above the lower limit of this range, the resist film has good water repellency. The dispersity (Mw / Mn) of the component (F) 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.

[0347] In the resist composition of this embodiment, the component (F) may use either a single type, or a combination of two or more types. When the resist composition contains the component (F), the amount of the component (F) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the component (A).

[0348] <Organic solvent component (S)> The resist composition of this embodiment can be produced by dissolving the resist materials in an organic solvent component (hereafter referred to as “component (S)”). In the resist composition of this embodiment, the component (S) may be used alone or as a mixed solvent of two or more kinds. Of these, PGMEA, PGME, γ-butyrolactone, EL, cyclohexanone, and diacetone alcohol are preferred.

[0349] As the component (S), a mixed solvent of PGMEA and a polar solvent is also preferred. The blending ratio (mass ratio) may be appropriately determined taking into consideration the compatibility between PGMEA and the polar solvent, etc. As the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferred. In this case, the mixing ratio of the former to the latter is preferably 70:30 to 95:5 by mass. The amount of the component (S) used is not particularly limited, and is set appropriately depending on the coating film thickness at a concentration that allows application to a substrate, etc. In general, the component (S) is used so that the solids concentration of the resist composition falls within the range of 0.1 to 20 mass %, and preferably 0.2 to 15 mass %.

[0350] In the resist composition of this embodiment, after dissolving the resist material in the component (S), impurities and the like may be removed using a polyimide porous film, a polyamideimide porous film, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous film, a filter made of a polyamideimide porous film, or a filter made of a polyimide porous film and a polyamideimide porous film. Examples of the polyimide porous film and the polyamideimide porous film include those described in JP 2016-155121 A.

[0351] The resist composition of the present embodiment explained above contains a resin component (A1) that has a structural unit (a0) derived from a compound represented by general formula (a0). The structural unit (a0) has an amide group on the side chain, which increases the dissolution rate of the exposed areas of the resist film in a developer, thereby improving sensitivity. In addition, the structural unit (a0) has an amide group in the side chain, so that the diffusion of the acid can be controlled. In addition, the structural unit (a0) has a hydrophilic amide group and a hydrophobic arylene group in the side chain, so that the solubility in the developer can be appropriately adjusted. Therefore, the dissolution contrast in the developer of the exposed and unexposed parts of the resist film is improved. Furthermore, the structural unit (a0) improves etching resistance due to the formation of hydrogen bonds via the amide groups. Therefore, according to the resist composition of this embodiment, it is possible to achieve high sensitivity when forming a resist pattern, and it is possible to form a resist pattern with reduced LWR and improved etching resistance.

[0352] (Method of forming resist pattern) A method for forming a resist pattern according to a second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition according to the first aspect of the present invention, exposing the resist film to light, and developing the exposed resist film to form a resist pattern. One embodiment of the resist pattern forming method is, for example, a resist pattern forming method carried out as follows.

[0353] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and then baked (post-applied bake (PAB)) at a temperature of, for example, 80 to 150° C. for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film. Next, the resist film is selectively exposed using an exposure device such as an electron beam lithography device or an ArF exposure device, either through a mask (mask pattern) on which a predetermined pattern has been formed, or by lithography using direct irradiation with an electron beam without using a mask pattern, and then baked (post-exposure bake (PEB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150°C. Next, the resist film is developed using an alkaline developer in the case of an alkaline development process, or a developer containing an organic solvent (organic developer) in the case of a solvent development process.

[0354] After the development process, a rinse process is preferably carried out. In the case of an alkaline development process, the rinse process is preferably a water rinse using pure water, and in the case of a solvent development process, a rinse liquid containing an organic solvent is preferably used. In the case of a solvent development process, after the development treatment or rinsing treatment, a treatment may be carried out in which the developer or rinsing liquid adhering to the pattern is removed by using a supercritical fluid. After the development treatment or rinsing treatment, drying is performed. In some cases, a baking treatment (post-baking) may be performed after the development treatment.

[0355] The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and substrates on which a predetermined wiring pattern is formed. More specifically, the support includes silicon wafers, substrates made of metals such as copper, chromium, iron, and aluminum, and glass substrates. Materials for the wiring pattern include, for example, copper, aluminum, nickel, and gold.

[0356] The wavelength used for exposure is not particularly limited, and radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays can be used.

[0357] The exposure method for the resist film may be a normal exposure method (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography. Immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure tool is filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. The immersion medium is preferably a solvent having a refractive index greater than that of air and less than that of the resist film to be exposed, and examples of such a solvent include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent. As the liquid immersion medium, water is preferably used.

[0358] An example of an alkaline developer used in the development treatment in the alkaline development process is a 0.1 to 10 mass % aqueous solution of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used in the development treatment in the solvent development process may be any organic solvent capable of dissolving the component (A) (the component (A) before exposure), and may be appropriately selected from known organic solvents. Specific examples of the organic solvent include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, and hydrocarbon solvents.

[0359] Examples of ester-based 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.

[0360] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0361] The organic developer may contain known additives as necessary. Examples of such additives include surfactants. The surfactants are not particularly limited, but may include, for example, ionic or nonionic fluorine-based and / or silicon-based surfactants.

[0362] The development process can be carried out by a known development method, such as a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it there for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), and a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0363] The organic solvent contained in the rinse solution used in the rinsing treatment after the development treatment in the solvent development process can be appropriately selected from the organic solvents listed above as the organic solvents used in the organic developer, which do not easily dissolve the resist pattern. Usually, at least one solvent selected from the group consisting of 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 thereof, and may be used in combination with other organic solvents or water.

[0364] The rinse treatment (cleaning treatment) using a rinse liquid can be carried out by a known rinse method, such as a method of continuously applying the rinse liquid onto 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), or a method of spraying the rinse liquid onto the surface of the support (spray method).

[0365] According to the method of forming a resist pattern of the present embodiment as described above, since the above-mentioned resist composition is used, it is possible to achieve high sensitivity when forming a resist pattern, reduce LWR, and form a resist pattern with improved etching resistance.

[0366] The resist composition of the above-mentioned embodiment and various materials used in the pattern forming method of the above-mentioned embodiment (for example, resist solvent, developer, rinse solution, anti-reflective film forming composition, top coat forming composition, etc.) preferably do not contain impurities such as metals, metal salts containing halogens, acids, alkalis, and components containing sulfur atoms or phosphorus atoms. Here, examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The content of impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device).

[0367] (compound) The compound according to the third aspect of the present invention is a compound represented by the following general formula (m0) (hereinafter also referred to as "compound (m0)").

[0368] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; X 0 represents a hydrogen atom or an alkyl group; Ar 01 represents an arylene group which may have a substituent; La 01 represents a single bond or a divalent linking group; Rpg 0 represents an acid dissociable group.]

[0369] In the general formula (m0), R and X 0 , Ar 01 , La 01 , and RPG 0 R and X in the general formula (a0) described above in the section "Structural Unit (a0)" 0 , Ar 01 , La 01 , and RPG 0 are identical to

[0370] Preferable specific examples of the compound (m0) are shown below: In each of the following formulae, Rα represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0371] [ka]

[0372] [Method of manufacturing compound] The compound of this embodiment can be produced, for example, by an esterification reaction between a compound represented by the following general formula (C-1) and a compound represented by the following general formula (Al-1).

[0373] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; X 0 represents a hydrogen atom or an alkyl group; Ar 01 represents an arylene group which may have a substituent; La 01 represents a single bond or a divalent linking group; Rpg 0 represents an acid dissociable group.]

[0374] The temperature condition for the esterification reaction is not particularly limited, and is, for example, -10 to 40°C. The reaction time for the esterification reaction is not particularly limited and is, for example, 1 to 24 hours.

[0375] Examples of reaction solvents used in the above esterification reaction include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide, and dimethylsulfoxide.

[0376] In the esterification reaction, a condensing agent and a basic catalyst may be used. Specific examples of the condensing agent include 1,3-diisopropylcarbodiimide (DIC), N,N'-dicyclohexylcarbodiimide, N,N'-1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, carbonyldiimidazole (CDI), and the like. Specific examples of the basic catalyst include tertiary amines such as dimethylaminopyridine (DMAP), trimethylamine, triethylamine, and tributylamine; aromatic amines such as pyridine and pyrrolidinopyridine; diazabicyclononene (DBN); and diazabicycloundecene (DBU).

[0377] After completion of the reaction, the compound represented by general formula (m0) in the reaction mixture may be isolated and purified. For isolation and purification, a conventionally known method can be used, for example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc., which can be used alone or in combination of two or more of these. The structure of the compound obtained as above is 1 H-nuclear magnetic resonance (NMR) spectroscopy, 13 C-NMR spectroscopy, 19 This can be confirmed by common organic analysis methods such as F-NMR spectroscopy, infrared absorption (IR) spectroscopy, mass spectrometry (MS), elemental analysis, and X-ray crystal diffraction.

[0378] The compound represented by the general formula (C-1) may be commercially available or may be synthesized. For example, a compound represented by the general formula (C-1) can be synthesized by reacting an aromatic compound having an amino group and a carboxy group with methacrylic acid chloride.

[0379] The compound of this embodiment is useful for producing a polymer compound having the structural unit (a0).

[0380] (polymer compound) The polymer compound related to the fourth aspect of the present invention is as explained in the above resin component (A1). EXAMPLES

[0381] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0382] [Synthesis Example 1: Synthesis of compound (m0-1)] 40.0g of 4-aminobenzoic acid and 88.5g of triethylamine were stirred in 239.4g of dichloromethane (DCM) at 0°C, and 79.3g of methacrylic acid chloride was added thereto. After stirring at room temperature for 4 hours, 239.4g of ultrapure water was added and stirred. After stirring, the aqueous layer was removed, and 239.4g of ammonia water was added and stirred. After stirring, the aqueous layer was removed, and the solvent was distilled off. Then, 239.4g of MeOH was added to the residue, and impurities were removed by filtration. Then, the compound (C1-1) was obtained by purifying it by column chromatography. Next, 28.6g of 1-methylcyclopentanol (Al1-1), 45.0g of compound (C1-1), 6.3g of 4-dimethylaminopyridine (DMAP), and 252.1g of dichloromethane (DCM) were stirred at 0°C, and 33.2g of 1,3-diisopropylcarbodiimide (DIC) was added thereto. After stirring at room temperature for 3 hours, the solvent was distilled off, 252.1g of heptane was added to the residue, and impurities were removed by filtration. Then, the compound (m0-1) was obtained by purifying it by column chromatography.

[0383] The obtained compound (m0-1) was subjected to NMR measurement, and its structure was identified from the following results. 1 H NMR (DMSO-d6,400MHz): 1.39(3H,s), 1.61-1.77(6H,m), 1.96-2.02(5H,m), 5.72(1H,s), 5.79(1H,s), 7.82-7.88(4H,m), 9.54(1H,s)

[0384] [ka]

[0385] [Synthesis Examples 2 to 10: Synthesis of Compounds (m0-2) to (m0-10)] Compounds (m0-2) to (m0-10) were synthesized by a method similar to that for synthesizing compound (m0-1).

[0386] The obtained compound (m0-2) was subjected to NMR measurement, and its structure was identified from the following results. 1 H NMR (DMSO-d6,400MHz): 0.90(3H,t), 1.61-1.77(8H,m), 1.96-2.02(5H,m), 5.72(1H,s), 5.79(1H,s), 7.82-7.88(4H,m), 9.54(1H,s)

[0387] The obtained compound (m0-3) was subjected to NMR measurement, and its structure was identified from the following results. 1 H NMR(DMSO-d6,400MHz):1.39(3H,s), 1.61-1.77(6H,m), 1.96-2.02(5H,m), 5 .72(1H,s), 5.79(1H,s), 7.53(1H,d), 7.89(1H,d), 8.47(1H,s), 10.08(1H,s)

[0388] The obtained compound (m0-4) was subjected to NMR measurement, and its structure was identified from the following results. 1 H NMR(DMSO-d6,400MHz):1.39(3H,s), 1.42-1.55(6H,m), 1.75(2H,t), 1.96-2.02(5H ,m), 5.72(1H,s), 5.79(1H,s), 7.53(1H,d), 7.89(1H,d), 8.47(1H,s), 10.08(1H,s)

[0389] The obtained compound (m0-5) was subjected to NMR measurement, and its structure was identified from the following results. 1H NMR (DMSO-d6,400MHz): 1.42(9H,s), 1.98(3H,s), 5.72(1H,s), 5.79(1H,s), 7.53(1H,d), 7.89(1H,d), 8.47(1H,s), 10.08(1H,s)

[0390] The obtained compound (m0-6) was subjected to NMR measurement, and its structure was identified from the following results. 1 H NMR(DMSO-d6,400MHz):1.61-1.82(6H,m), 1.96-2.07(5H,m), 5.26-5.31(2H ,m), 5.70-5.91(3H,m), 7.53(1H,d), 7.89(1H,d), 8.47(1H,s), 10.08(1H,s)

[0391] The obtained compound (m0-7) was subjected to NMR measurement, and its structure was identified from the following results. 1 H NMR (DMSO-d6,400MHz):1.58-1.72(6H,m), 1.82-2.00(5H,m), 2.19(1H,t), 5.13(1H,q), 5 .37(1H,d), 5.72(1H,s), 5.79(1H,s), 7.53(1H,d), 7.87(1H,d), 8.45(1H,s), 10.08(1H,s)

[0392] The obtained compound (m0-8) was subjected to NMR measurement, and its structure was identified from the following results. 1 H NMR(DMSO-d6,400MHz):1.39(3H,s), 1.61-1.77(6H,m), 1.96-2.02(5H,m), 5.72(1H ,s), 5.79(1H,s), 7.24(1H,t), 7.60(1H,t), 7.73(1H,d), 7.95(1H,d), 10.08(1H,s)

[0393] The obtained compound (m0-9) was subjected to NMR measurement, and its structure was identified from the following results. 1H NMR(DMSO-d6,400MHz):1.39(3H,s), 1.61-1.77(6H,m), 1.96-2.02(5H,m), 5 .72(1H,s), 5.79(1H,s), 7.53(1H,d), 7.84(1H,d), 8.47(1H,s), 10.08(1H,s)

[0394] The obtained compound (m0-10) was subjected to NMR measurement, and its structure was identified from the following results. 1 H NMR (DMSO-d6,400MHz): 1.39(3H,s), 1.61-1.77(6H,m), 1.96-2.02(5H,m), 5.72(1H,s), 5.79(1H,s), 8.32(1H,s), 8.46(1H,s), 10.08(1H,s)

[0395] [ka]

[0396] <Examples of polymer compound production> The polymer compounds (A1-1) to (A1-10) and (A2-1) to (A2-3) were each obtained by radical polymerization of monomers that derive the structural units constituting each polymer compound in a predetermined molar ratio, followed by a deprotection reaction. The weight average molecular weight (Mw) and the molecular weight dispersity (Mw / Mn) of each of the obtained polymer compounds were determined by GPC measurement (converted into standard polystyrene). The results are shown in Tables 1 and 2. The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) of each obtained polymer compound was measured by carbon-13 nuclear magnetic resonance spectroscopy (600 MHz, 13 The results are shown in Tables 1 and 2.

[0397] [Table 1]

[0398] [Table 2]

[0399] [ka]

[0400] [ka]

[0401] [ka]

[0402] [ka]

[0403] <Preparation of resist composition> (Examples 1 to 12, Comparative Examples 1 to 3) The components shown in Tables 3 and 4 were mixed and dissolved to prepare resist compositions of each example.

[0404] [Table 3]

[0405] [Table 4]

[0406] In Tables 3 and 4, the abbreviations have the following meanings. The numbers in brackets [ ] are the blend amounts (parts by mass).

[0407] (A1)-1 to (A1)-10: the above-mentioned polymer compounds (A1-1) to (A1-10). (A2)-1 to (A2)-3: The above-mentioned polymer compounds (A2-1) to (A2-3).

[0408] (B1)-1, (B1)-2: an acid generator comprising the following compound (B1-1) or (B1-2).

[0409] [ka]

[0410] (D1)-1, (D1)-2: An acid diffusion controller comprising the following compound (D1-1) or (D1-2).

[0411] [ka]

[0412] (S)-1: propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether=60 / 40

[0413] <Formation of Resist Pattern> Each resist composition of the examples was applied to an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS) using a spinner, and pre-baked (PAB) was performed on a hot plate at a temperature of 110° C. for 60 seconds, followed by drying to form a resist film with a thickness of 50 nm. Next, the resist film was subjected to drawing (exposure) at an acceleration voltage of 100 kV using an electron beam lithography device JEOL JBX-9300FS (manufactured by JEOL Ltd.) to form a 1:1 line and space pattern (hereinafter referred to as "LS pattern") with a target size of a line width of 50 nm. Then, post-exposure bake (PEB) was performed at 100° C. for 60 seconds. Next, alkaline development was performed for 60 seconds at 23° C. using a 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). Then, water rinsing was performed using pure water for 15 seconds. As a result, a 1:1 LS pattern with a line width of 50 nm was formed.

[0414] [Evaluation of optimal exposure (Eop)] The optimum exposure dose Eop (μC / cm) at which a LS pattern of the target size is formed by the above resist pattern forming method. 2 The results were recorded as "Eop (μC / cm 2 ) are shown in Tables 5 and 6.

[0415] [Evaluation of LWR (Line Width Roughness)] For the LS pattern formed in the above <Formation of Resist Pattern>, 3σ, which is a scale indicating LWR, was obtained. "3σ" indicates three times the standard deviation (σ) (unit: nm) obtained by measuring 400 line positions in the longitudinal direction of the line using a scanning electron microscope (accelerating voltage 800 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). The smaller the 3σ value, the less rough the line sidewall is, meaning that a LS pattern with a more uniform width is obtained. The results are shown in Tables 5 and 6 as "LWR (nm)".

[0416] [Evaluation of etching resistance] Each resist composition of the example was applied using a spinner onto an 8-inch silicon substrate that had been treated with hexamethyldisilazane (HMDS), and then pre-baked (PAB) on a hot plate at 110°C for 60 seconds, followed by drying to form a resist film with a thickness of 50 nm. Next, each resist film was subjected to dry etching treatment with CF4 gas for 60 seconds using a dry etching apparatus TCA-3822 (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). From the resist film after the dry etching treatment, the remaining film amount was obtained. Then, from the remaining film amount of the resist film formed using the resist composition of each example, a relative value was obtained when the remaining film amount of the resist film formed using the resist composition of Comparative Example 1 was set to 1.00. The larger this relative value, the greater the remaining film amount is, and the more the film loss is suppressed, which means that the etching resistance is high. The results are shown in Tables 5 and 6 as "etching rate."

[0417] [Table 5]

[0418] [Table 6]

[0419] As shown in Tables 5 and 6, the resist compositions of the Examples were superior in both sensitivity and LWR compared to the resist compositions of the Comparative Examples. Furthermore, the resist compositions of the Examples also had superior etching resistance.

Claims

1. A resist composition which generates an acid upon exposure and changes its solubility in a developer by the action of the acid, Contains a resin component (A1) whose solubility in a developer changes under the action of an acid, The resist composition, wherein the resin component (A1) includes a structural unit (a0) represented by the following general formula (a0): 【Chemistry 1】 [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; X ０ represents a hydrogen atom or an alkyl group; Ar ０１ represents an arylene group which may have a substituent; La ０１ represents a single bond or a divalent linking group; ０ represents an acid dissociable group.

2. The Ar ０１ The resist composition according to claim 1 , wherein: is an arylene group having an iodine atom.

3. The Ar ０１ The resist composition according to claim 1 , wherein: is an unsubstituted arylene group.

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

5. A compound represented by the following general formula (m0): 【Chemistry 2】 [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; X ０ represents a hydrogen atom or an alkyl group; Ar ０１ represents an arylene group which may have a substituent; La ０１ represents a single bond or a divalent linking group; ０ represents an acid dissociable group.

6. A polymeric compound having a structural unit derived from the compound according to claim 5.

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