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 enhances lithographic characteristics such as dimensional uniformity, 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 base component having a constituent unit derived from a compound represented by general formula (a0-1). In the formula (a0-1), W01 represents a polymerizable group-containing group; La01 represents a divalent linking group or a single bond; I represents an iodine atom; Ra02 represents a substituent other than an iodine atom; Ya01 represents a divalent linking group or a single bond; Va01 represents a single bond, an alkylene group or a fluorinated alkylene group; Ra01 represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group; and Mm+ represents an m-valent cation.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. 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.

[0003] In chemically amplified resist compositions, a resin having a plurality of structural units is generally used as the base material component in order to improve lithography properties, etc. A wide variety of acid generator components have been proposed so far. For example, onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, diazomethane acid generators, nitrobenzylsulfonate acid generators, iminosulfonate acid generators, disulfone acid generators, etc. are known.

[0004] Furthermore, in a chemically amplified resist composition, a polymeric compound has been proposed in which a structural unit containing an acid generating group that generates acid upon exposure has been introduced as an acid generator component (see, for example, Patent Document 1). Such a polymeric compound functions both as an acid generator and as a base component. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-197168 A Summary of the Invention [Problem to be solved by the invention]

[0006] As lithography technology continues to advance and resist patterns become finer, the goal is to form fine patterns of several tens of nm in lithography using, for example, EUV (extreme ultraviolet) or EB (electron beam). As the pattern dimensions become smaller, both high sensitivity to the exposure light source and lithography characteristics such as uniformity of pattern dimensions are required. 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 view of the above circumstances, and an object of the present invention is to provide a resist composition that enables high sensitivity when forming a resist pattern, and improves lithography properties such as dimensional uniformity, 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 in the synthesis of the polymeric compound. [Means for solving the problem]

[0008] The present invention includes the following aspects. 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) having a structural unit (a0) derived from a compound represented by the following general formula (a0-1):

[0009] [ka] [In the formula, W 01 represents a polymerizable group-containing group. 01represents a divalent linking group or a single bond. I represents an iodine atom. n i is an integer from 1 to 6. 02 represents a substituent other than an iodine atom. a2 is an integer from 0 to 5. a2 If is 2 or more, multiple Ra 02 may be the same or different. 1≦n i +n a2 ≦6. 01 represents a divalent linking group or a single bond. 01 represents a single bond, an alkylene group, or a fluorinated alkylene group. 01 and Va 01 Both of Ra cannot be single bonds. 01 represents a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms. m+ is a cation with a valence of m, where m is an integer of 1 or more.

[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 (a0-1):

[0012] [ka] [In the formula, W 01 represents a polymerizable group-containing group. 01 represents a divalent linking group or a single bond. I represents an iodine atom. n i is an integer from 1 to 6. 02 represents a substituent other than an iodine atom. a2 is an integer from 0 to 5. a2 If is 2 or more, multiple Ra 02 may be the same or different. 1≦n i +na2 ≦6. 01 represents a divalent linking group or a single bond. 01 represents a single bond, an alkylene group, or a fluorinated alkylene group. 01 and Va 01 Both of Ra cannot be single bonds. 01 represents a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms. m+ is a cation with a valence of m, where m is an integer of 1 or more.

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

[0014] Effect of the Invention The present invention is able to provide a resist composition that enables high sensitivity when forming a resist pattern, and improves lithography properties such as dimensional uniformity, 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 in the synthesis of 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 classified 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 referred to as "low molecular weight compounds"). As the molecular weight of polymers, the weight average molecular weight calculated in terms of polystyrene by GPC (gel permeation chromatography) is used.

[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. This 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. In the resist composition of this embodiment, the component (A) contains a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer changes under the action of an acid. The component (A1) has a structural unit (a0) derived from a compound represented by the general formula described below.

[0023] When a resist film is formed using the resist composition of this embodiment and the resist film is selectively exposed, an acid is generated from the component (A) 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, while 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 of the resist film. 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.

[0024] 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 using an alkaline developer in the development treatment during resist pattern formation, or may be for a solvent development process using a developer containing an organic solvent (organic developer) in the development treatment.

[0025] Furthermore, the resist composition of this embodiment may further contain other components in addition to the component (A). Examples of other components include the below-described components (B), (D), (E), (F), and (S).

[0026] 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.

[0027] 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.

[0028] <Component (A)> In the resist composition of this embodiment, by using the component (A1), the polarity of the base component changes between before and after exposure, and therefore a favorable development contrast can be obtained not only in an alkali 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).

[0029] In the resist composition of this embodiment, the component (A) may use either a single type, or a combination of two or more types.

[0030] Regarding component (A1) The component (A1) is a resin component whose solubility in a developer changes under the action of an acid. The component (A1) has a structural unit (a0) derived from a compound represented by general formula (a0-1) described below. The component (A1) may contain other structural units in addition to the structural unit (a0), as necessary.

[0031] <Structural unit (a0)> The structural unit (a0) is a structural unit derived from a compound represented by general formula (a0-1) shown below.

[0032] [ka] [In the formula, W 01 represents a polymerizable group-containing group. 01 represents a divalent linking group or a single bond. I represents an iodine atom. n i is an integer from 1 to 6. 02 represents a substituent other than an iodine atom. a2 is an integer from 0 to 5. a2 If is 2 or more, multiple Ra 02 may be the same or different. 1≦n i +n a2 ≦6. 01 represents a divalent linking group or a single bond. 01 represents a single bond, an alkylene group, or a fluorinated alkylene group. 01 and Va 01 Both of Ra cannot be single bonds. 01represents a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms. m+ is a cation with a valence of m, where m is an integer of 1 or more.

[0033] In the formula (a0-1), W 01 is a polymerizable group-containing group. W 01 The "polymerizable group" in the above formula 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. In the structural unit (a0), the multiple bond in the polymerizable group is cleaved to form the main chain.

[0034] W 01 Examples of the polymerizable group in the formula (I) include a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a fluorovinyl group, a difluorovinyl group, a trifluorovinyl group, a difluorotrifluoromethylvinyl group, a trifluoroallyl group, a perfluoroallyl group, a trifluoromethylacryloyl group, a nonylfluorobutylacryloyl group, a vinyl ether group, a fluorine-containing vinyl ether group, an allyl ether group, a fluorine-containing allyl ether group, a styryl group, a vinyl naphthyl group, a fluorine-containing styryl group, a fluorine-containing vinyl naphthyl group, a norbornyl group, a fluorine-containing norbornyl group, and a silyl group.

[0035] W 01 The "polymerizable group-containing group" in the above formula may be a group composed only of polymerizable groups. W 01 Examples of the compound include the compound represented by the chemical formula: C(R X11 )(R X12 )=C(R X13 In this chemical formula, C(R X13 ) is La 01 and combine. 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.

[0036] R X11 , R X12 and R X13 The alkyl group having 1 to 5 carbon atoms in the formula (I) 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. As the halogen atom, a fluorine atom is particularly preferable. Among these, R X11 and R X12 are 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, are more preferably a hydrogen atom or a methyl group, and are particularly preferably a hydrogen atom. Also, R X13 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, more preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability, and particularly preferably a hydrogen atom.

[0037] In the formula (a0-1), La 01 Examples of the divalent linking group in 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: La 01 When is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0039] ··La 01 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated. 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 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.

[0041] The linear or branched 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 or an iodine 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.

[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 in which two hydrogen atoms have been removed 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 in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] 2,6 ]decane, tetracyclododecane, and the like.

[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 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. 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-.

[0044] ··La 01 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. However, 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.

[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 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.

[0046] Divalent linking groups containing heteroatoms: When the group other than the polymerizable group is a divalent linking group containing a heteroatom, preferred examples of the linking group include -O-, -C(=O)-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 a divalent linking group containing a heteroatom. 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 -, 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 -, -Y21 -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 21 As 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] La 01 Among the above, is preferably an ester bond [-C(=O)-O-, -OC(=O)-], an aromatic hydrocarbon group, or a combination thereof.

[0048] W 01 -La 01 - is a compound having the chemical formula: C(R X11 )(R X12 )=C(R X13 )-Ya x0 In this chemical formula, R X11 , R X12 and R X13 is W 01 R in X11 , R X12 and R X13 is the same as: Ya x0 The divalent linking group in is not particularly limited, but preferred examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom, and each of them is represented by La 01 The examples of the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom are the same as those given in the above.

[0049] n i is preferably 2 or more, and more preferably 3 or more.

[0050] Ra 02 Examples of the alkyl group include an alkyl group, an alkoxy group, a halogen atom other than an iodine atom, a halogenated alkyl group, and a hydroxyl group, and an alkoxy group is preferred. Ra 02When is an alkyl group, the alkyl group 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. Ra 02 When is an alkoxy group, the alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, or tert-butoxy group, further preferably a methoxy group or ethoxy group, and particularly preferably a methoxy group. Ra 02 When is a halogen atom other than an iodine atom, examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. Ra 02 When is a halogenated alkyl group, examples of the halogenated alkyl group include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

[0051] n a2 may be 1 or more, preferably 3 or less, and more preferably 2 or less.

[0052] n i +n a2 is more preferably 2 or more, further preferably 3 or more, and particularly preferably 4 or more.

[0053] Ya 01 An example of the divalent linking group in the formula (I) is a divalent linking group containing an oxygen atom. Ya 01 When Ya is a divalent linking group containing an oxygen atom, 01 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. 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-8). In the following general formulae (y-al-1) to (y-al-8), the V' in the following general formulae (y-al-1) to (y-al-8) is bonded to the naphthalene ring in the above general formula (a0-1). 101 It is.

[0054] [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.

[0055] 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.

[0056] 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 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-].

[0057] Also, V' 101 or V' 102 Some methylene groups in the alkylene group in the above formula may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably 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). The monocyclic alicyclic 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 alicyclic hydrocarbon group which is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane. The polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 ]decane, tetracyclododecane, and the like. Among these, the aliphatic cyclic group is preferably a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group.

[0058] Ya 01 As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable, the linking groups represented by the above formulas (y-al-1) to (y-al-6) are more preferable, and the linking groups represented by the above formulas (y-al-1), (y-al-3), and (y-al-6) are further preferable.

[0059] In the formula (a0-1), Va 01 is a single bond, an alkylene group or a fluorinated alkylene group. 01 The alkylene group and fluorinated alkylene group in the formula (Va) preferably have 1 to 4 carbon atoms. 01 The fluorinated alkylene group in 01 and groups in which some or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms. Among them, Va 01 is preferably a linear alkylene group having 1 to 4 carbon atoms, a linear fluorinated alkylene group having 1 to 4 carbon atoms, or a single bond, and more preferably a methylene group (-CH2-), an ethylene group (-CH2CH2-), or a linear fluorinated alkylene group having 1 to 3 carbon atoms. In the formula (a0-1), Ya 01 and Va 01 cannot simultaneously be a single bond.

[0060] In the formula (a0-1), Ra 01 is preferably a fluorine atom or a fluorinated alkyl group, more preferably a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms, and further preferably a fluorine atom.

[0061] Preferred specific examples of the anion moiety of the structural unit (a0) are shown below.

[0062] [ka]

[0063] [ka]

[0064] [ka]

[0065] The anion moiety of the structural unit (a0) is preferably an anion represented by any one of the above formulas (a0-an-2) to (a0-an-7), (a0-an-9), (a0-an-11) to (a0-an-16), and more preferably an anion represented by any of the above formulas (a0-an-3) to (a0-an-4), (a0-an-11) to (a0-an-12).

[0066] In the formula (a0-1), M m+ is an onium cation having a valence of m, where m is an integer of 1 or more. m+ The onium cation in the formula (I) is preferably a sulfonium cation or an iodonium cation. Preferred cationic moieties ((M m+ ) 1 / m ) include onium cations represented by the following general formulas (ca-1) to (ca-3), respectively.

[0067] [ka] [In the formula, R 201 ~R 207 R each independently represents an aryl group, an alkyl group, 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-.

[0068] 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 210 Examples 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), respectively.

[0069] [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.

[0070] 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.

[0071] R' 201The 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' 201 Specific 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.

[0072] 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 in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among these, the polycycloalkane is preferably adamantane, norbornane, isobornane, tricyclo[5.2.1.0], or the like. 2,6 More preferred are polycycloalkanes having a polycyclic skeleton of a bridged ring system, such as tetracyclodecane and tetracyclododecane; and polycycloalkanes having a polycyclic skeleton of a condensed ring system, such as a cyclic group having a steroid skeleton.

[0073] Among them, R' 201 The 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.

[0074] 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.

[0075] Also, R' 201 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle, etc. Examples include lactone-containing cyclic groups, -SO2--containing cyclic groups, and other heterocyclic groups represented by the following chemical formulas (r-hr-1) to (r-hr-16), respectively.

[0076] [ka]

[0077] 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.

[0078] 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.

[0079] 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.

[0080] R' 201 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, the above R' 201 and the like.

[0081] 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.

[0082] 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, an -SO2- containing cyclic group, etc. are preferred.

[0083] 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.

[0084] 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.

[0085] 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 In the above, the optionally substituted -SO2- containing cyclic group is preferably an "-SO2- containing polycyclic group".

[0086] Specific examples of suitable cations represented by the above formula (ca-1) include cations represented by the following chemical formulas (ca-1-1) to (ca-1-75), respectively.

[0087] [ka]

[0088] [ka]

[0089] [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.]

[0090] [ka]

[0091] [ka]

[0092] [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

[0093] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0094] 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).

[0095] [ka]

[0096] Among the above, M m+ As the cation, the cation represented by the above formula (ca-1) is preferable. Also, M m+ From the viewpoint of increasing sensitivity, an m-valent onium cation having a fluorine atom is preferred. m+ As the cation, a cation represented by the following formula (ca-1-1) is preferable.

[0097] [ka] [In the formula, Rf 201 ~Rf 203 Rf 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 ~Rf 203 may be bonded to each other to form a ring together with the sulfur atom in the formula. 201 ~Rf 203 At least one of contains at least one fluorine atom.

[0098] Rf in the above formula (ca-1-1) 201 ~Rf 203 is R in the above formula (ca-1). 201 ~R 203 However, Rf 201 ~Rf 203 At least one of the formula (ca-1-1) contains at least one fluorine atom. The cation represented by formula (ca-1-1) preferably contains three or more fluorine atoms, more preferably contains four or more fluorine atoms, further preferably contains five or more fluorine atoms, and particularly preferably contains six or more fluorine atoms. Rf 201 ~Rf 203 may have three or more fluorine atoms, and Rf 201 ~Rf 203 may contain three or more fluorine atoms in total.

[0099] Specific examples of the structural unit (a0) include, but are not limited to, the following.

[0100] [ka]

[0101] [ka]

[0102] [ka]

[0103] [ka]

[0104] Examples of the structural unit (a0) include structural units represented by any of the above formulas (a0-u1) to (a0-u9). A structural unit represented by any of the above formulas (a0-u2) to (a0-9) is more preferable. A structural unit represented by any of the above formulas (a0-u3), (a0-u4), (a0-u6) to (a0-u9) is even more preferable. A structural unit represented by the above formula (a0-u9) is particularly preferable.

[0105] 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) relative to the total (100 mol %) of all structural units constituting the component (A1), is preferably 1 to 30 mol %, more preferably 5 to 25 mol %, and even more preferably 10 to 20 mol %.

[0106] 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 that fall under the structural unit (a0)); structural units (a10) represented by general formula (a10-1) described below; structural units (a5) that generate acid upon exposure (excluding those that fall under the structural unit (a0)); structural units (a2) containing a lactone-containing cyclic group; and structural units (a8) derived from a compound represented by general formula (a8-1) described below.

[0107] <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.

[0108] Examples of the acid-dissociable group include those that have been proposed as acid-dissociable groups in base resins for chemically amplified resist compositions. Specific examples of the acid dissociable group that have been proposed for the base resin of the chemically amplified resist composition include the "acetal type acid dissociable group," "tertiary alkyl ester type acid dissociable group," "tertiary alkyloxycarbonyl acid dissociable group," and "secondary alkyloxycarbonyl acid dissociable group," which are explained below.

[0109] Acetal type acid dissociable group: Among the polar groups, examples of the acid-dissociable group that protects a carboxy group or a hydroxyl group include an acid-dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid-dissociable group").

[0110] [ka] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Ra' 3 Is, Ra' 1 , Ra' 2 may be bonded to any one of the following to form a ring.

[0111] In formula (a1-r-1), Ra' 1 and Ra' 2 At least one of these is preferably a hydrogen atom, and both are more preferably hydrogen atoms. Ra' 1 Or Ra' 2 When is an alkyl group, the alkyl group may be the same as the alkyl group exemplified as the substituent that may be bonded to the carbon atom at the α-position in the explanation of the α-substituted acrylic acid ester above, and an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a linear or branched alkyl group is preferable. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like are preferable, and a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.

[0112] In formula (a1-r-1), Ra' 3 Examples 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 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.

[0113] 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.

[0114] Ra' 3When is a cyclic hydrocarbon group, the hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic alicyclic 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 alicyclic hydrocarbon group which is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane. The polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 ]decane, tetracyclododecane, and the like.

[0115] Ra' 3 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' 3Specific 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.

[0116] Ra' 3 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 aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P1 and R P2Some 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; 2,6 ]decanyl group, tricyclo[3.3.1.1 3,7 ]decanyl group, tetracyclo[6.2.1.1 3,6 .0 2,7 ]A polycyclic aliphatic saturated hydrocarbon group such as a dodecanyl group or an adamantyl group is exemplified. 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, and phenanthrene.

[0117] Ra' 3 But Ra' 1 , Ra' 2 When 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.

[0118] Tertiary alkyl ester type acid-labile group: Among the above polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2). Among the acid-dissociable groups represented by the following formula (a1-r-2), those constituted by an alkyl group may be referred to as "tertiary alkyl ester-type acid-dissociable groups" hereinafter for the sake of convenience.

[0119] [ka] [In the formula, Ra' 4 ~Ra' 6 are each a hydrocarbon group, and Ra' 5 , Ra' 6 may be bonded to each other to form a ring.

[0120] Ra' 4 Examples of the hydrocarbon group include a linear or branched alkyl group, a linear or cyclic alkenyl group, a linear alkynyl group, and a cyclic hydrocarbon group. Ra' 4 The linear or branched alkyl group and the cyclic hydrocarbon group (the alicyclic hydrocarbon group which is a monocyclic group, the alicyclic hydrocarbon group which is a polycyclic group, and the aromatic hydrocarbon group) in the formula Ra' 3 The same can be mentioned. Ra' 4 The chain or cyclic alkenyl group in is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 As the hydrocarbon group of Ra' 3 The same can be mentioned.

[0121] Ra' 5 and Ra' 6 and (a1-r2-3) are preferably used. On the other hand, Ra' 4 ~Ra' 6 When are not bonded to each other and are independent hydrocarbon groups, preferred examples include groups represented by the following general formula (a1-r2-4).

[0122] [ka] [In formula (a1-r2-1), Ra' 10 Ra' represents a linear or branched alkyl group having 1 to 12 carbon atoms, some of which may be substituted with a halogen atom or a heteroatom-containing group. 11 Is Ra' 10 In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra 101 ~Ra 103 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. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. 101 ~Ra 103 Two or more of may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group which forms an aliphatic cyclic group together with Yaa. Ra 104 In formula (a1-r2-4), Ra' is an aromatic hydrocarbon group which may have a substituent. 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group which may have a substituent. * indicates a bond (hereinafter the same).

[0123] In the above formula (a1-r2-1), Ra' 10 represents a linear or branched alkyl group having 1 to 12 carbon atoms which may be partially substituted with a halogen atom or a heteroatom-containing group.

[0124] Ra' 10In the formula, the linear alkyl group has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra' 10 As the branched alkyl group in the formula (I), 3 The same can be mentioned.

[0125] Ra' 10 The alkyl group in may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. In addition, some of the carbon atoms (e.g., methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. The heteroatom includes an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heteroatom-containing group include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0126] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed together with the carbon atom to which is bonded) is Ra' in formula (a1-r-1). 3 Among them, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl and cyclohexyl groups are more preferred.

[0127] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes Ra' in the formula (a1-r-1). 3 Examples of such groups include groups in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (alicyclic hydrocarbon group) in the above formula. The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of the substituent include the above-mentioned Ra' 3Examples of the substituents include those similar to those that the cyclic hydrocarbon group in the above may have. In formula (a1-r2-2), Ra 101 ~Ra 103 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 101 ~Ra 103 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. Ra 101 ~Ra 103 Among these, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms is preferable, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferable, and a hydrogen atom is particularly preferable.

[0128] The above Ra 101 ~Ra 103 Examples of the substituents of the chain saturated hydrocarbon group or the cyclic saturated aliphatic hydrocarbon group represented by the formula x5 The same groups as those shown below can be mentioned.

[0129] Ra 101 ~Ra 103Examples 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.

[0130] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is represented by Ra' in formula (a1-r-1). 3 The groups mentioned above as the alicyclic hydrocarbon group are preferably monocyclic or polycyclic groups of the above formula. In formula (a1-r2-3), Ra 104 Examples of the aromatic hydrocarbon group in the formula include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. 104 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 benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.

[0131] Ra in formula (a1-r2-3) 104 Examples of the substituent that may be possessed by the group include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl 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.

[0132] In formula (a1-r2-4), Ra' 12 and Ra' 13 Each of Ra' is independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms. 12 and Ra' 13In the above, the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is 101 ~Ra 103 Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in the above formula are the same as those in the above formula. Some or all of the hydrogen atoms in the chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, an alkyl group having 1 to 5 carbon atoms is preferable, an alkyl group having 1 to 5 carbon atoms is more preferable, a methyl group or an ethyl group is further preferable, and a methyl group is particularly preferable. The above Ra' 12 and Ra' 13 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.

[0133] In formula (a1-r2-4), Ra' 14 Ra' is a hydrocarbon group which may have a substituent. 14 The hydrocarbon group in the formula (I) includes a linear or branched alkyl group, or a cyclic hydrocarbon group.

[0134] Ra' 14 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.

[0135] Ra' 14 The branched alkyl group in the above formula (I) 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.

[0136] Ra'14 When is a cyclic hydrocarbon group, the hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic alicyclic 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 alicyclic hydrocarbon group which is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane. The polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 ]decane, tetracyclododecane, and the like.

[0137] Ra' 14 As the aromatic hydrocarbon group in 104 Among them, the aromatic hydrocarbon group Ra' is the same as that in 14 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' 14 Examples of the substituent that may be possessed by Ra include 104 The substituents may be the same as those which may be possessed by the group.

[0138] Ra' in formula (a1-r2-4) 14 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 (a1-r2-4) 14When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the above formula (a1-r2-4) may be any one of the 1-position, 2-position, or 9-position of the anthryl group.

[0139] Specific examples of the group represented by formula (a1-r2-1) are shown below.

[0140] [ka]

[0141] [ka]

[0142] [ka]

[0143] Specific examples of the group represented by formula (a1-r2-2) are shown below.

[0144] [ka]

[0145] [ka]

[0146] [ka]

[0147] Specific examples of the group represented by formula (a1-r2-3) are shown below.

[0148] [ka]

[0149] Specific examples of the group represented by formula (a1-r2-4) are shown below.

[0150] [ka]

[0151] Tertiary alkyloxycarbonyl acid dissociating group: Among the polar groups, examples of the acid dissociable group that protects the hydroxyl group include acid dissociable groups represented by the following general formula (a1-r-3) (hereinafter, for convenience, may be referred to as "tertiary alkyloxycarbonyl acid dissociable group").

[0152] [ka] [In the formula, Ra' 7 ~Ra' 9 are each an alkyl group.

[0153] In formula (a1-r-3), Ra' 7 ~Ra' 9 Each of the groups is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. The total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0154] Secondary alkyl ester type acid-labile group: Among the above polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-4).

[0155] [ka] [In the formula, Ra' 10 is a hydrocarbon group. 11a and Ra' 11b Each of Ra' independently represents a hydrogen atom, a halogen atom, or an alkyl group. 12is a hydrogen atom or a hydrocarbon group. 10 and Ra' 11a Or Ra' 11b and may be bonded to each other to form a ring. 11a Or Ra' 11b And, Ra' 12 may be bonded to each other to form a ring.

[0156] In the formula, Ra' 10 and Ra' 12 As the hydrocarbon group in Ra', 3 The same can be mentioned. In the formula, Ra' 11a and Ra' 11b As the alkyl group in the above, Ra' 1 The alkyl groups in the above formula (I) are the same as those in the above formula (I). In the formula, Ra' 10 and Ra' 12 The hydrocarbon group in 11a and Ra' 11b The alkyl group in may have a substituent. Examples of the substituent include the above-mentioned Ra x5 etc.

[0157] Ra' 10 and Ra' 11a Or Ra' 11b 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.

[0158] Ra' 10 and Ra' 11a Or Ra' 11b and are bonded to each other to form a ring. Among the above, a monocycloalkene, a ring in which a portion of the carbon atoms of a monocycloalkene is substituted with a heteroatom (such as an oxygen atom or a sulfur atom), or a monocycloalkadiene is preferable, a cycloalkene having 3 to 6 carbon atoms is preferable, and cyclopentene or cyclohexene is preferable.

[0159] Ra' 10 and Ra' 11a Or Ra' 11b The ring formed by bonding with each other may be a condensed ring. Specific examples of the condensed ring include indan.

[0160] Ra' 10 and Ra' 11a Or Ra' 11b The ring formed by bonding with each other may have a substituent. Examples of the substituent include the above-mentioned Ra x5 etc.

[0161] Ra' 11a Or Ra' 11b And, Ra' 12 and may be bonded to each other to form a ring, and the ring may include Ra' 10 and Ra' 11a Or Ra' 11b and the like are similar to the ring formed by bonding with each other.

[0162] Specific examples of the group represented by formula (a1-r-4) are shown below.

[0163] [ka]

[0164] Examples of the structural unit (a1) include 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, a structural unit derived from an acrylamide, a structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least a portion of the hydrogen atoms in the hydroxyl groups are protected with a substituent containing the above-mentioned acid-decomposable group, and a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative in which at least a portion of the hydrogen atoms in -C(═O)-OH are protected with a substituent containing the above-mentioned acid-decomposable group.

[0165] Of the above, the structural unit (a1) 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. Preferred specific examples of the structural unit (a1) include structural units represented by the following general formula (a1-1) or (a1-2).

[0166] [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 (a1-r-1), (a1-r-2) or (a1-r-4). 1 is a2 +1 valent hydrocarbon group. n a2 is an integer from 1 to 3. 2 is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-3). 001 is a single bond or a divalent linking group. 01 is a single bond or a divalent linking group. 01 is an acid dissociable group represented by the above general formula (a1-r-1), (a1-r-2) or (a1-r-4). q is an integer of 0 to 3. n is an integer of 1 or more, provided that n≦q×2+4.]

[0167] In the formulas (a1-1) to (a1-3), the alkyl group of R 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. As the halogen atom, a fluorine atom is particularly preferable. 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 most preferable.

[0168] In the formula (a1-1), Va 1 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0169] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure.

[0170] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the 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.

[0171] Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, etc. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear aliphatic hydrocarbon group or the branched 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 polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed 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 in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0], etc. 2,6 ]decane, tetracyclododecane, and the like.

[0172] Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (aryl group) has been substituted with an alkylene group (for example, 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 (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0173] In the formula (a1-1), Ra 1 is preferably an acid dissociable group represented by the above general formula (a1-r-2) or (a1-r-4), and among these, a group represented by general formula (a1-r2-1) or an acid dissociable group represented by general formula (a1-r-4) is more preferable.

[0174] In the formula (a1-2), Wa 1 n in a2 The +1-valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. The aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group that combines a straight-chain or branched-chain aliphatic hydrocarbon group with an aliphatic hydrocarbon group containing a ring in its structure. The above n a2 The +1 valency is preferably 2 to 4, more preferably 2 or 3. In the formula (a1-2), Ra 2 is preferably an acid dissociable group represented by the above general formula (a1-r-1).

[0175] In the formula (a1-3), Ya 001 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. Ya 001 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. The alkylene 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. Among these, Ya 001is preferably a combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group, or a single bond, and more preferably a single bond.

[0176] In the formula (a1-3), Ya 01 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. Ya 01 Among the above, Ya 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. 01 is preferably a combination of an ester bond [-C(=O)-O-, -OC(=O)-] and a linear alkylene group, or a single bond, and more preferably a single bond.

[0177] In the formula (a1-3), Rax 01 is preferably an acid dissociable group represented by the above general formula (a1-r-2) or (a1-r-4), and among these, an acid dissociable group represented by general formula (a1-r-2) is more preferable, and a group represented by general formula (a1-r2-1) is even more preferable.

[0178] In the formula (a1-3), q is an integer of 0 to 3. When q is 0, the structure is a benzene structure, when q is 1, the structure is a naphthalene structure, when q is 2, the structure is an anthracene structure, and when q is 3, the structure is a tetracene structure. In the above formula (a1-3), n is an integer of 1 or more, preferably 1 to 5, more preferably 1 to 3, and even more preferably 1 or 2. In the formula (a1-3), n≦q×2+4. For example, when q is 1 and the naphthalene structure is a naphthalene structure, all six hydrogen atoms of the naphthalene may be substituted with hydroxy groups. 001 , -Ya 01 -C(=O)-O-Ra01 The substitution positions of the group and the hydroxy group are not particularly limited.

[0179] 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.

[0180] [ka]

[0181] [ka]

[0182] [ka]

[0183] [ka]

[0184] [ka]

[0185] [ka]

[0186] [ka]

[0187] [ka]

[0188] [ka]

[0189] [ka]

[0190] [ka]

[0191] [ka]

[0192] [ka]

[0193] [ka]

[0194] 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. Among these, the acid dissociable group (Ra 1 , Rax 01 ) are preferably acid dissociable groups represented by the following general formula (a1-r2-1), (a1-r2-3), (a1-r2-4) or (a1-r-4), respectively, and more preferably acid dissociable groups represented by the following general formula (a1-r2-1) or (a1-r-4). Alternatively, it is particularly preferable to select the acid-dissociable group as a cyclic group.

[0195] Alternatively, the structural unit (a1) may include a structural unit represented by the following general formula (a1-1-1):

[0196] [ka] [In the formula, Ra 1 " is an acid-dissociable group represented by general formula (a1-r2-1), (a1-r2-3), (a1-r2-4), or (a1-r-4). * represents a bond.

[0197] In the formula (a1-1-1), R and Va 1 and n a1 R and Va in the formula (a1-1) 1 and n a1 is the same as:

[0198] The proportion of the structural unit (a1) in the component (A1) relative to the total (100 mol %) of all structural units constituting the component (A1), is preferably 10 to 80 mol %, even more preferably 30 to 75 mol %, and particularly preferably 40 to 70 mol %. By ensuring that the proportion of the structural unit (a1) is at least the lower limit of the preferred range described above, it becomes easier to improve lithography properties such as high sensitivity and dimensional uniformity. On the other hand, by ensuring that the proportion is at most the upper limit of the preferred range described above, a balance with other structural units can be achieved, resulting in various improved lithography properties.

[0199] Regarding the structural unit (a10): The structural unit (a10) is a structural unit represented by general formula (a10-1) below (however, this does not include those that correspond to the structural unit (a1)).

[0200] [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.]

[0201] 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, more preferably a hydrogen atom, a methyl group, or a trifluoromethyl group, still more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

[0202] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group. In the above chemical formula, Ya x1 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0203] Optionally substituted divalent hydrocarbon group: The divalent hydrocarbon group which may have a substituent may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0204] 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.

[0205] 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.

[0206] 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.

[0207] 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 in which two hydrogen atoms have been removed 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 in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] 2,6 ]decane, tetracyclododecane, and the like.

[0208] 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-.

[0209] 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 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. 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 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.

[0210] 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.

[0211] Divalent linking groups containing heteroatoms: Examples of the divalent linking group containing a hetero atom 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 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, an acyl group, 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 as those described above. Y 21 As 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 22is 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.

[0212] 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)-].

[0213] 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. ax14n+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 ax1 A 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.

[0214] 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 substituents are preferably linear or branched alkyl groups having 1 to 5 carbon atoms, more preferably linear or branched alkyl groups having 1 to 3 carbon atoms, further preferably an ethyl group or a methyl group, and particularly preferably a methyl group. x1The aromatic hydrocarbon group in the formula (I) preferably does not have a substituent.

[0215] 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.

[0216] 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.

[0217] [ka]

[0218] [ka]

[0219] [ka]

[0220] The structural unit (a10) that the component (A1) can have 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 10 to 60 mol %, more preferably 15 to 50 mol %, and even more preferably 20 to 40 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a10) is at least as large as the lower limit of the above range, it is possible to further increase the sensitivity, whereas by ensuring that the proportion is at most the upper limit of the above range, it is easier to achieve a balance with other structural units.

[0221] Building block (A5): In this embodiment, the structural unit (a5) is a structural unit that generates an acid upon exposure, and a known structural unit can be used. The structural unit (a5) does not include those that correspond to the structural unit (a0). By including the structural unit (a5), the acid generated upon exposure tends to be uniformly distributed within the resist film. Suitable examples of the structural unit (a5) include structural units represented by general formula (a5-1) shown below.

[0222] [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.

[0223] {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.

[0224] 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)-].

[0225] 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.

[0226] ··Ra 050Aliphatic 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.

[0227] 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.

[0228] 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.

[0229] 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 in which two hydrogen atoms have been removed 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 in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.0] 2,6 ]decane, tetracyclododecane, and the like.

[0230] 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-.

[0231] ··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.

[0232] 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.

[0233] 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, Ra050 is preferably an aromatic hydrocarbon group.

[0234] 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.

[0235] 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.

[0236] [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.

[0237] V' 102The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0238] 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.

[0239] La 0is 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).

[0240] In the formula (a5-1), Ya 0 represents a divalent linking group which may have a heteroatom, or a single bond. Ya 0 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. 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.

[0241] 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.

[0242] In the formula (a5-1), n0 represents an integer of 1 to 4, and is preferably 1, 2 or 3.

[0243] {cationic part} In the above formula (a5-1), M' m+ represents an onium cation having a valence of m. m+ represents m and M in the general formula (a0-1). m+ is the same as:

[0244] 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:

[0245] [ka]

[0246] [ka]

[0247] [ka]

[0248] 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 15 to 20 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). When the proportion of the structural unit (a5) is at least as large as the lower limit of the above-mentioned preferred range, it becomes easier to achieve even higher sensitivity and reduced roughness, 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.

[0249] Regarding the structural unit (a2): The component (A1) may further include a structural unit (a2) that includes a lactone-containing cyclic group (provided that this does not fall under the category of the structural unit (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 (A1) component 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.

[0250] 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).

[0251] [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).]

[0252] 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.

[0253] 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; adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 ] decane, tetracyclododecane, and other polycycloalkanes in which one or more hydrogen atoms have been removed. 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.

[0254] Ra' 21 Among the above, it is preferable that each of them independently is a hydrogen atom or a cyano group.

[0255] 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.

[0256] Specific examples of the groups represented by general formulas (a2-r-1) to (a2-r-7) are listed below.

[0257] [ka]

[0258] [ka]

[0259] 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).

[0260] [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.

[0261] 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.

[0262] 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. Ya 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.

[0263] 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.

[0264] In the formula (a2-1), Ya 21 is a single bond, La 21 is preferably -COO- or -OCO-.

[0265] 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.

[0266] The structural unit (a2) that the component (A1) can have may be of one type, or two or more types. The component (A1) may or may not contain 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 2 to 15 mol %, and even more preferably 5 to 15 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.

[0267] Regarding the structural unit (a8): The structural unit (a8) is a structural unit derived from a compound represented by general formula (a8-1) shown below.

[0268] [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.

[0269] 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.

[0270] 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.

[0271] Ya x2 and W 2 The condensed ring formed by the above is W 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.

[0272] 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.

[0273] [ka]

[0274] 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).

[0275] The structural unit (a8) that the component (A1) can have may be of one type, or two or more types. The component (A1) may or may not contain the structural unit (a8). When the component (A1) contains the structural unit (a8), the proportion of the structural unit (a8) in the component (A1) is preferably 30 mol % or less, more preferably 0 to 20 mol %, and even more preferably 0 to 10 mol %, relative to the total (100 mol %) of all structural units constituting the component (A1).

[0276] 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.

[0277] Of the above, the component (A1) is preferably a polymeric compound having a repeating structure of the structural unit (a0), the structural unit (a10), and the structural unit (a1), and more preferably a polymeric compound consisting only of repeating structures of the structural unit (a0), the structural unit (a10), and the structural unit (a1).

[0278] In a polymeric compound having a repeating structure of the structural unit (a0), the structural unit (a10), and the structural unit (a1), the proportion of the structural unit (a0) relative to the total (100 mol%) of all structural units constituting the polymeric compound is preferably 1 to 30 mol%, more preferably 5 to 25 mol%, and even more preferably 10 to 20 mol%. Furthermore, the proportion of the structural unit (a10) in the polymer compound is preferably 10 to 60 mol %, more preferably 15 to 50 mol %, and even more preferably 20 to 40 mol %, based on the total (100 mol %) of all structural units constituting the polymer compound. Furthermore, the proportion of the structural unit (a1) in the polymer compound is more preferably 10 to 80 mol %, further preferably 30 to 75 mol %, and particularly preferably 40 to 70 mol %, based on the total (100 mol %) of all structural units constituting the polymer compound. However, the total amount of the structural units (a0), (a10) and (a1) does not exceed 100 mol %.

[0279] 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. For example, the component (A1) can be produced by dissolving a monomer that derives the structural unit (a0) and a monomer that derives the structural unit (a10) in a polymerization solvent, adding the above-mentioned radical polymerization initiator to the solution, polymerizing the resulting solution, and then 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).

[0280] 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 40,000, more preferably 2,000 to 20,000, and even more preferably 5,000 to 10,000. 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 molecular weight 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.

[0281] 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 a combination of two or more of these.

[0282] 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 uniformity of pattern dimensions is easily formed.

[0283] 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.

[0284] <Other ingredients> The resist composition of this embodiment may further contain other components in addition to the above-mentioned component (A). Examples of other components include the following components (B), (D), (E), (F), and (S).

[0285] <Acid generator component (B)> The resist composition of this embodiment may further contain 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.

[0286] <Base component (D)> In addition to the component (A), the resist composition of this embodiment preferably further contains a base component (hereinafter also referred to as "component (D)") that traps the acid generated upon exposure (i.e., controls the diffusion of the acid). The component (D) acts as a quencher (acid diffusion controller) that traps the 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 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 improve the uniformity of pattern dimensions and reduce roughness. In addition, by including component (D1), it is likely to improve both the properties of high sensitivity and suppression of the occurrence of coating defects.

[0287] Regarding component (D1) By using a resist composition that contains the component (D1), the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. 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.

[0288] [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 onium cation having a valence of m.

[0289] {(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, 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-7), 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-6). 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-8) as a substituent, in the above general formulas (y-al-1) to (y-al-8), 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-8) 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 includes adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 ]decane, tetracyclododecane, or another polycycloalkane having one or more hydrogen atoms removed therefrom is more preferred. 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.

[0290] 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.

[0291] Preferred specific examples of the anion moiety of the component (d1-1) are shown below.

[0292] [ka]

[0293] ··Cation part In formula (d1-1), M m+ is an onium cation with a valence of m. M m+ Suitable onium cations include those similar to those represented by the general formulas (ca-1) to (ca-3), more preferably those represented by the general formula (ca-1), and even more preferably those represented by the general formulas (ca-1-1) to (ca-1-75). The component (d1-1) may be used alone or in combination of two or more.

[0294] {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.

[0295] The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably has 3 to 10 carbon atoms. The aliphatic cyclic group includes adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 ]decane, tetracyclododecane, or the like (which may have a substituent); more preferably a group in which one or more hydrogen atoms have been removed from camphor.

[0296] Rd 2 The hydrocarbon group may have a substituent, and examples of the substituent include Rd 1 Examples 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.

[0297] Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

[0298] [ka]

[0299] ··Cation part In formula (d1-2), M m+ is an onium cation having a valence of m, 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.

[0300] {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.

[0301] 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 4 The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, 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 4The 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.

[0302] 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.

[0303] Rd 4 The cyclic group in R' 201 Examples of the cyclic groups include cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclo[5.2.1.0 2,6 ] is preferably an alicyclic group obtained by removing one or more hydrogen atoms from a cycloalkane such as decane or tetracyclododecane, or an aromatic group such as a phenyl group or 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.

[0304] 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 a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, and a divalent linking group containing a hetero atom. 01Examples of the divalent linking group include the same divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom as mentioned in the description of the divalent linking group in the above. 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.

[0305] Preferred specific examples of the anion moiety of the component (d1-3) are shown below.

[0306] [ka]

[0307] [ka]

[0308] ··Cation part In formula (d1-3), M m+ is an onium cation having a valence of m, 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.

[0309] 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. In the resist composition of this embodiment, the component (D1) preferably includes the above-mentioned component (d1-1). 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 10 parts by mass, and even more preferably 2 to 9 parts by mass, relative to 100 parts by mass of the component (A1). When the amount of the component (D1) is at least as large as the preferred lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained, while when it is no more than the upper limit, good sensitivity can be maintained and excellent throughput is also achieved.

[0310] In the resist composition of this embodiment, the content of the component (d1-1) in the entire component (D) is preferably 50 mass % or more, more preferably 70 mass % or more, and even more preferably 90 mass % or more. The component (D) may consist solely of the compound (d1-1).

[0311] 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.

[0312] 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-mentioned 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.

[0313] 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.

[0314] 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.

[0315] 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.

[0316] Of the above, the component (D2) is preferably an alkylamine, and more preferably a trialkylamine having 6 to 30 carbon atoms.

[0317] 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 preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.5 to 5 parts by mass, relative to 100 parts by mass of the component (A1). When the amount of the component (D2) is at least as large as the preferred lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained, while when it is no more than the upper limit, good sensitivity can be maintained and excellent throughput is also achieved.

[0318] <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.

[0319] 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) per 100 parts by mass of the component (A1) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass. By setting the amount in this range, the lithography properties are further improved.

[0320] <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 (A1), 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.

[0321] [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.

[0322] 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.

[0323] 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.

[0324] 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 molecular weight 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.

[0325] 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 (A1).

[0326] <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, and cyclohexanone are preferred.

[0327] 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 %.

[0328] 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.

[0329] The resist composition of the present embodiment described above contains a resin component (A1) having a structural unit (a0) represented by the above general formula (a0-1). This makes it possible to achieve high sensitivity and further improve lithography properties such as uniformity of pattern dimensions. The reason for this effect is presumed to be as follows. In the structural unit (a0), an anion portion, which is an acid generating group, is incorporated into the resin component (A1). This allows the acid generating group to be distributed uniformly throughout the resist film, so that the acid generated by exposure acts uniformly on the acid decomposable sites in the resist film. The anion portion of the structural unit (a0) has a naphthalene structure, and the naphthalene structure has an iodine atom as a substituent. The structural unit (a0) has a naphthalene structure, which enhances its solubility in the developer. In addition, iodine atoms easily absorb EUV, so the structural unit (a0) easily generates secondary electrons during exposure. The secondary electrons generated from the structural unit (a0) upon exposure transfer their energy to a component that generates acid upon exposure, accelerating the decomposition of resin components whose solubility in the developer changes due to the action of the acid. It is believed that the above-mentioned actions work synergistically to achieve higher sensitivity and further improvements in lithography properties such as uniformity of pattern dimensions.

[0330] (Method of forming a 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.

[0331] 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 subjected to selective exposure using an exposure device such as an electron beam lithography device or an EUV exposure device, either through a mask (mask pattern) on which a predetermined pattern is formed, or by lithography using direct irradiation with an electron beam without using a mask pattern. Thereafter, baking (post-exposure baking (PEB)) treatment is performed, for example, at a temperature of 80 to 150° C. for 40 to 120 seconds, preferably 60 to 90 seconds. 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.

[0332] 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.

[0333] The support is not particularly limited, and may be a conventionally known support, such as a substrate for electronic components or a substrate on which a predetermined wiring pattern is formed. More specifically, it may be a silicon wafer, a substrate made of metal such as copper, chromium, iron, or aluminum, or a glass substrate. As the material for the wiring pattern, for example, copper, aluminum, nickel, or gold may be used.

[0334] 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. The method for forming a resist pattern of this embodiment is useful for exposing the resist film to EUV (extreme ultraviolet) or EB (electron beam) in the step of exposing the resist film.

[0335] 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.

[0336] 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 (A1) (the component (A1) 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.

[0337] 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.

[0338] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0339] 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.

[0340] 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).

[0341] 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.

[0342] 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).

[0343] According to the method of forming a resist pattern of the present embodiment as described above, the resist composition described above is used, so that high sensitivity can be achieved and a resist pattern with excellent lithography properties such as uniformity of pattern dimensions can be formed.

[0344] 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).

[0345] (compound) The compound according to the third aspect of the present invention is a compound represented by the following formula (a0-1) (hereinafter also referred to as "compound (a0)"). This compound (a0) is the compound represented by formula (a0-1) in the first aspect of the present invention.

[0346] [ka] [In the formula, W 01 represents a polymerizable group-containing group. 01 represents a divalent linking group or a single bond. I represents an iodine atom. n i is an integer from 1 to 6. 02 represents a substituent other than an iodine atom. a2 is an integer from 0 to 5. a2 If is 2 or more, multiple Ra 02 may be the same or different. 1≦n i +n a2 ≦6. 01 represents a divalent linking group or a single bond. 01 represents a single bond, an alkylene group, or a fluorinated alkylene group. 01 and Va 01Both of Ra cannot be single bonds. 01 represents a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms. m+ is a cation with a valence of m, where m is an integer of 1 or more.

[0347] Specific examples of the compound (a0) are shown below, but the compound (a0) is not limited thereto. M m+ is an onium cation having a valence of m, and is preferably a cation represented by the above general formula (ca-1).

[0348] [ka]

[0349] [ka]

[0350] [ka]

[0351] [Method for producing compound (a0)] The compound (a0) of this embodiment can be produced by combining known methods.

[0352] The compound of this embodiment can be used as a raw material monomer for a polymer compound according to the fourth aspect described below.

[0353] (polymer compound) A fourth aspect of the present invention is a polymeric compound having a structural unit derived from a compound represented by the general formula (a0-1). The structural unit derived from the compound represented by the general formula (a0-1) is the same as the structural unit (a0) described above.

[0354] The polymer compound according to the fourth aspect preferably has, in addition to the structural unit (a0), a structural unit (a1) containing an acid-decomposable group whose polarity increases under the action of an acid as described above, and a structural unit represented by the general formula (a10-1). The structural unit represented by the general formula (a10-1) is the same as the structural unit (a10) described above. The polymer compound according to the fourth aspect is similar to the above-mentioned explanation of the component (A1). The polymer compound related to the fourth aspect can be used as a base component of the resist composition related to the first aspect. Furthermore, a polymer compound having the structural unit (a0), the structural unit (a1), and the structural unit represented by general formula (a10-1) is particularly useful as a resist material for lithography using exposure to EUV or EB. EXAMPLES

[0355] The present invention will be described below with reference to examples, but the present invention is not limited to the following examples.

[0356] <Synthesis examples of compounds> [Synthesis Example 1: Synthesis of compound (m01)] 100g of 3-hydroxy-4-iodo-2-naphthoic acid, 53.9g of methacrylic acid chloride, and 55.7g of triethylamine (Et3N) were dissolved in 800g of THF and stirred for 6 hours. The reaction solution was then washed with 200g of 10% aqueous sodium bicarbonate solution and 10% aqueous ammonium chloride solution, and the organic layer was concentrated to obtain a mixture of compound (m01-pre1). Then, compound (m01-pre1), 1,1-difluoro-2-hydroxyethanesulfonic acid-trimethylbenzylamine salt, diisopropylcarbodiimide (DIC), dimethylaminopyridine (DMAP), and 337g of dichloromethane (DCM) were added and stirred at room temperature for 2 hours. The precipitate was filtered, and t-butyl methyl ether was added to the eluate to precipitate compound (m01-pre2), and the solvent was removed by vacuum drying to obtain 120g of compound (m01-pre2).

[0357] [ka]

[0358] 100 g of compound (m01-pre2) was dissolved in 800 g of dichloromethane, 51.3 g of compound (C1-1) and 800 g of ultrapure water were added, and the mixture was stirred at room temperature for 1 hour. After removing the aqueous layer, the organic layer was washed three times with 800 g of ultrapure water. The solvent was distilled off from the organic layer to obtain 105 g of compound (m01).

[0359] [ka]

[0360] The obtained compound (m01-pre2) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR(DMSO-d6,400MHz):δ(ppm)=8.65(s,Ar-H,1H),7.7-7.1(m,Ar-H,7H),3 .30(s,-CH3,9H),5.30-5.0(t,-CH2,2H),4.55(s,-CH2,2H),2.22(s,-CH3,3H)

[0361] The obtained compound (m01) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR (DMSO-d6,400MHz): δ(ppm)=8.30(s,Ar-H,1H),8.00-7.0(m,Ar-H,19H),6.58-6.0(m,=CH2,2H),5.18(t,-CH2,2H),2.01(s,-CH3,3H)

[0362] [Synthesis Example 2: Synthesis of compound (m02)] 100g of 2,6-dihydroxynaphthalene and 180g of N-iodosuccinimide (NIS) were dissolved in 800g of tetrahydrofuran (THF) and stirred for 24 hours to synthesize compound (m02-pre1). Next, 53.9g of methacrylic acid chloride and 337g of triethylamine were added and stirred at room temperature for 2 hours. Next, the reaction solution was concentrated and purified by column chromatography to obtain 110g of compound (m02-pre2). Compound (m02-pre2) was dissolved in 1500g of dichloromethane (DCM), and 98g of DIC, 12g of DMAP, and 110g of 2,2-difluoro-2-sulfoacetic acid-trimethylbenzylamine salt were added and stirred for 5 hours. Next, the reaction solution was filtered to remove the solids, and the eluate was washed three times with pure water, then concentrated and dried, and the solvent was distilled off to obtain 139g of compound (m02-pre3).

[0363] [ka]

[0364] Compound (m02) was obtained in the same manner as in Synthesis example 1 using compound (m02-pre3) and compound (C1-1).

[0365] [ka]

[0366] The obtained compound (m02-pre3) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR (DMSO-d6,400MHz): δ(ppm)=8.22(m,Ar-H,2H),7.3-7.1(m,Ar-H,5H),6.6-6.1(m,Ar-H ,=CH2,4H),4.53(s,-CH2-,2H),3.30(s,-CH3,9H),5.30-5.0(t,-CH2,2H),2.22(s,-CH3,3H)

[0367] The obtained compound (m02) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR (DMSO-d6,400MHz):δ(ppm)=8.20-8.0(m,Ar-H,2H),8.00-7.70(m,Ar-H,12H),6.45(m,=CH2,2H),2.21(s,=CH3,3H)

[0368] [Synthesis Example 3: Synthesis of compound (m03)] 100g of 3-hydroxy-7-methoxynaphthoic acid, 150g of iodine chloride (ICl), and 900g of acetic acid (AcOH) were added, heated to 80°C, and stirred for 2 hours. After the reaction, the mixture was cooled to room temperature, and the precipitate was collected by filtration, washed with hexane, and then the solvent was removed by vacuum drying to obtain 160g of compound (m03-pre1). Next, 100g of compound (m03-pre1), 55.7g of methacrylic acid chloride, 60g of Et3N, and 1000g of THF were added, and the mixture was stirred for 6 hours. Subsequently, the reaction solution was washed with a 10% aqueous solution of sodium bicarbonate and pure water, and the solvent was distilled off to obtain 134g of compound (m03-pre2). The obtained compound (m03-pre2) was dissolved in 1300g of dichloromethane (DCM), and 121g of 1,1-difluoro-2-hydroxyethanesulfonic acid-trimethylbenzylamine salt, 132g of DIC, and 20g of DMAP were added and stirred for 5 hours. The reaction solution was then filtered to remove the solids, and the eluate was washed three times with pure water, then concentrated to dryness, and the solvent was distilled off to obtain 110g of compound (m03-pre3).

[0369] [ka]

[0370] Compound (m03) was obtained in the same manner as in Synthesis example 1 using compound (m03-pre3) and compound (C1-1).

[0371] [ka]

[0372] The obtained compound (m03-pre3) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR (DMSO-d6,400MHz): δ(ppm)=8.72(m,Ar-H,1H),8.21(s,Ar-H,1H),7.6-7.1(m,Ar-H,5H),6.6-6.1(m ,Ar-H,2H),5.23(t,-CH2,2H),4.33(s,-CH2-,2H),3.80(s,-CH3,9H),3.30(s,-CH3,9H),2.0(s,-CH3,3H)

[0373] The obtained compound (m03) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR (DMSO-d6,400MHz): δ(ppm)=8.67(s,Ar-H,1H),8.10(s,Ar-H,1H),7.35-7.20(m, Ar-H,15H),6.28(m,=CH2,2H),5.72(t,-CH2,2H),3.67(s,-CH3,3H),2.21(s,-CH3-,9H)

[0374] [Synthesis Example 4: Synthesis of compound (m04)] 100g of 3-hydroxy-7-methoxynaphthoic acid, 150g of iodine chloride (ICl), and 900g of acetic acid (AcOH) were added, heated to 80°C, and stirred for 2 hours. After the reaction, the mixture was cooled to room temperature, and the precipitate was collected by filtration, washed with hexane, and then the solvent was removed by vacuum drying to obtain 60g of compound (m03-pre1). Next, 60g of compound (m03-pre1), 85g of 4-benzoyl chloride, 90g of Et3N, and 1500g of THF were added, and stirred for 6 hours. The reaction solution was then washed with a 10% aqueous sodium bicarbonate solution and pure water, and the solvent was distilled off to obtain 179g of compound (m04-pre1). The obtained compound (m04-pre1) was dissolved in 1800g of dichloromethane (DCM), and 120g of 1,1-difluoro-2-hydroxyethanesulfonic acid-trimethylbenzylamine salt, 150g of DIC, and 30g of DMAP were added and stirred for 5 hours. The reaction solution was then filtered to remove the solids, and the eluate was washed three times with pure water, then concentrated to dryness, and the solvent was distilled off to obtain 132g of compound (m04-pre2).

[0375] [ka]

[0376] Compound (m04) was obtained in the same manner as in Synthesis example 1 using compound (m04-pre2) and compound (C1-1).

[0377] [ka]

[0378] The obtained compound (m04-pre2) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR (DMSO-d6,400MHz): δ(ppm)=8.72(d,Ar-H,1H),7.90-8.0(m,Ar-H,10H),6.46(m,=CH ,1H),6.0-5.2(m,=CH2,-CH2,4H),4.50(s,-CH2-,2H),3.66(s,-CH3,3H),3.33(s,-CH3,9H)

[0379] The obtained compound (m04) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR(DMSO-d6,400MHz):δ(ppm)=8.67(s,Ar-H,1H),8.11(s,Ar-H,1H),7.80-7.1 0(m,Ar-H,17H),6.77(m,=CH,1H),5.50-5.0(m,-CH2,=CH2,4H),3.67(s,-CH3,3H)

[0380] [Synthesis Example 5: Synthesis of compound (m05)] 100 g of 4-ethenyl-2,6-diiodophenol and 125 g of iodine chloride were dissolved in 600 g of acetic acid and stirred at 60°C for 6 hours. The reaction solution was then cooled with ice water, and the precipitate was filtered to obtain 210 g of a mixture of compounds (m05-pre1). The mixture of compounds (m05-pre1) was then dissolved in 1050 g of THF, and 114 g of Et3N and 50 g of acrylic acid chloride were added and stirred at room temperature for 2 hours. The reaction solution was then purified by column chromatography to obtain 170 g of compound (m05-pre2). The obtained compound (m05-pre2) was dissolved in 1800 g of dichloromethane (DCM), and 120 g of 1,1-difluoro-2-hydroxyethanesulfonic acid-trimethylbenzylamine salt, 150 g of DIC, and 30 g of DMAP were added and stirred for 5 hours. Next, the reaction liquid was filtered to remove the solids, and the filtrate was washed three times with pure water, then concentrated to dryness, and the solvent was distilled off to obtain 121 g of compound (m05-pre3).

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[0382] Compound (m05) was obtained in the same manner as in Synthesis example 1 using compound (m05-pre3) and compound (C1-1).

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[0384] The obtained compound (m05-pre3) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR (DMSO-d6,400MHz): δ(ppm)=8.72(d,Ar-H,1H),8.33-8.0(m,Ar-H,3H),7.6-7.1(m,Ar -H,5H),6.4-5.5(m,=CH2,=CH,3H),5.23(t,-CH2,2H),4.50(s,-CH2-,2H),3.46(s,-CH3,9H)

[0385] The obtained compound (m05) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR (DMSO-d6,400MHz):δ(ppm)=8.80(s,Ar-H,1H),8.20-7.90(m,Ar-H,3H),7.40-7.10(m,Ar-H,15H),6.40-5.90(m,=CH2,=CH,3H),5.13(t,-CH2,2H)

[0386] [Synthesis Examples 6 to 9: Synthesis of Compounds (m06) to (m09)] Compounds (m06) to (m09) were obtained in the same manner as in Synthesis example 1 using the compound (m03-pre3) and the following compounds (C1-2) to (C1-5).

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[0388] [ka]

[0389] The obtained compound (m06) was subjected to NMR measurement, and its structure was identified from the following results. 1H-NMR(DMSO-d6,400MHz):δ(ppm)=8.67(s,Ar-H,1H),8.11(s,Ar-H,1H),7.80-7.10 (m,Ar-H,13H),5.50-5.0(m,-CH2,=CH2,4H),3.67(s,-CH3,3H),2.21(s,-CH3-,3H)

[0390] [ka]

[0391] The obtained compound (m07) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR(DMSO-d6,400MHz):δ(ppm)=8.67(s,Ar-H,1H),8.11(s,Ar-H,1H),7.80-7.10 (m,Ar-H,11H),5.50-5.0(m,-CH2,=CH2,4H),3.67(s,-CH3,3H),2.21(s,-CH3-,3H)

[0392] [ka]

[0393] The obtained compound (m08) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR(DMSO-d6,400MHz):δ(ppm)=8.67(s,Ar-H,1H),8.11(s,Ar-H,1H),7.80-7.10 (m,Ar-H,12H),5.50-5.0(m,-CH2,=CH2,4H),3.67(s,-CH3,3H),2.21(s,-CH3-,3H)

[0394] [ka]

[0395] The obtained compound (m09) was subjected to NMR measurement, and its structure was identified from the following results. 1 H-NMR(DMSO-d6,400MHz):δ(ppm)=8.67(s,Ar-H,1H),8.11(s,Ar-H,1H),7.70-7.0 (m,Ar-H,9H),5.50-5.0(m,-CH2,=CH2,4H),3.67(s,-CH3,3H),2.21(s,-CH3-,3H)

[0396] <Synthesis example of polymer compound> Polymer compounds (A1-1) to (A1-11), and polymer compounds (A2-1) to (A2-2) were produced by the synthesis methods described below using the above-mentioned monomers (m01) to (m09), the following monomers (m101), (m201), (m301), and (m302), and the following monomers (m21) to (m22).

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[0398] [ka]

[0399] [Synthesis Example of Polymer Compound (A1-1)] 16.2 g of compound (m301), 10.0 g of compound (m101), 11.0 g of compound (m01), and 12.6 g of dimethyl azobis(isobutyrate) (V-601) as a polymerization initiator were dissolved in 100 g of MEK (methyl ethyl ketone), and stirred at 77° C. for 5 hours under a nitrogen atmosphere. The reaction solution was then cooled to room temperature. Next, 3.0 g of acetic acid and 60 g of methanol were added to the obtained polymerization solution, and a deprotection reaction was carried out at 30° C. for 8 hours. After the reaction was completed, the obtained reaction solution was precipitated in 1200 g of a mixed solvent of methanol and water, and washed. The obtained white solid was filtered and dried under reduced pressure overnight to obtain the target polymer compound (A1-1).

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[0401] [Synthesis of polymer compounds (A1-2) to (A1-11) and polymer compounds (A2-1) to (A2-2)] Polymer compound (A1-2) to polymer compound (A1-11), and polymer compound (A2-1) to polymer compound (A2-2) were obtained by using the corresponding raw material monomers and the same synthesis method (radical polymerization, deprotection reaction) as in the above-mentioned [Synthesis of polymer compound (A1-1)].

[0402] The structures of the corresponding raw material monomers and the resulting polymer compounds are shown below. In each formula, l, m, and n represent the composition ratio of each structural unit.

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[0408] For each of the obtained polymer compounds, 13The copolymer composition ratio of the polymer compound (the ratio (molar ratio) of the constitutional units derived from each monomer compound) determined by C-NMR, and the weight average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) calculated in terms of standard polystyrene determined by GPC measurement are also shown in Table 1.

[0409] [Table 1]

[0410] <Preparation of resist composition> (Examples 1 to 12, Comparative Examples 1 to 2) The components shown in Table 2 were mixed and dissolved to prepare resist compositions of each example.

[0411] [Table 2]

[0412] In Table 2, the abbreviations have the following meanings. The numbers in brackets [ ] indicate the blend amount (parts by mass). (A)-1 to (A)-11: The above-mentioned polymer compounds (A1-1) to (A1-11). (A)-21 to (A)-22: The above-mentioned polymer compounds (A2-1) to (A2-2).

[0413] (D)-1: An acid diffusion controller comprising a compound represented by the following chemical formula (D1-1). (D)-2: An acid diffusion controller comprising a compound represented by the following chemical formula (D1-2). (S)-1: a mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 6 / 4 (mass ratio).

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[0415] <Formation of Resist Pattern> Steps for forming a resist film: 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.

[0416] Step of exposing the resist film: Next, the resist film was exposed to light using an electron beam lithography system JEOL-JBX-9300FS (manufactured by JEOL Ltd.) at an acceleration voltage of 100 kV to form a contact hole pattern (CH pattern) with a target size of 46 nm pitch width / 23 nm hole width, followed by post-exposure baking (PEB) at 90° C. for 60 seconds.

[0417] A process for developing the exposed resist film: Next, alkaline development was performed for 60 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C, and then a water rinsing treatment was performed for 15 seconds using pure water. As a result, a CH pattern with a pitch width of 46 nm / hole width of 23 nm was formed.

[0418] [Evaluation of optimal exposure (Eop)] The optimum exposure dose Eop (μC / cm) for forming a CH pattern of the target size by the above <Formation of resist pattern> 2 The result was called "Eop(μC / cm 2 )" in Table 3.

[0419] [Evaluation of Pattern Dimension Uniformity (CDU)] The CDU (dimensional variation 3σ) was calculated for the CH pattern formed in the above <Formation of resist pattern>. "3σ" was calculated by measuring the dimensions of 50 holes using a scanning electron microscope (accelerating voltage 800V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation), and calculating three times the standard deviation (σ) (unit: nm) obtained from the measurement results. The results are shown in Table 3 as "CDU (nm)". The smaller the value of 3σ thus determined, the higher the uniformity of the dimensions (CD) of the multiple holes formed in the resist film.

[0420] [Table 3]

[0421] From the results shown in Table 3, it can be seen that the resist compositions of Examples 1 to 12 have improved sensitivity and good CDU, compared to the resist compositions of Comparative Examples 1 and 2.

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 resin component (A1) has a structural unit (a0) derived from a compound represented by the following general formula (a0-1): Resist composition. 【Chemistry 1】 [In the formula, W ０１ represents a polymerizable group-containing group. ０１ represents a divalent linking group or a single bond. I represents an iodine atom. ｉ is an integer from 1 to 6. ０２ represents a substituent other than an iodine atom. ａ２ is an integer from 0 to 5. ａ２ When Ra is 2 or more, multiple Ra ０２ may be the same or different. ｉ +n ａ２ ≦6. ０１ represents a divalent linking group or a single bond. ０１ represents a single bond, an alkylene group, or a fluorinated alkylene group. ０１ and Va ０１ are not both single bonds. ０１ represents a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms. ｍ＋ is a cation having a valence of m, and m is an integer of 1 or more.

2. In the general formula (a0-1), n ｉ The resist composition according to claim 1 , wherein is 3 or more.

3. 3. 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.

4. A compound represented by the following general formula (a0-1): 【Chemistry 2】 [In the formula, W ０１ represents a polymerizable group-containing group. ０１ represents a divalent linking group or a single bond. I represents an iodine atom. ｉ is an integer from 1 to 6. ０２ represents a substituent other than an iodine atom. ａ２ is an integer from 0 to 5. ａ２ When Ra is 2 or more, multiple Ra ０２ may be the same or different. ｉ +n ａ２ ≦6. ０１ represents a divalent linking group or a single bond. ０１ represents a single bond, an alkylene group, or a fluorinated alkylene group. ０１ and Va ０１ are not both single bonds. ０１ represents a hydrogen atom, a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms. ｍ＋ is a cation having a valence of m, and m is an integer of 1 or more.

5. In the general formula (a0-1), n ｉ The compound according to claim 4, wherein is 3 or more.

6. A polymer compound having a structural unit derived from the compound according to claim 4 or 5.

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