Resist composition, method of forming a resist pattern, compound, and acid generator

Abstract

To provide a resist composition capable of forming a resist pattern which achieves higher sensitivity and exhibits good roughness reduction.SOLUTION: The resist composition contains a base component (A) and a compound (B0) represented by general formula (b0). In the formula, Ar0 represents an arylene group or a heteroarylene group; Rm1 and Rm2 represent substituents other than an iodine atom; L01 represents a divalent linking group or a single bond; L02 represents a divalent linking group; Vb0 represents a single bond or the like; R0 represents a hydrogen atom or the like; nb1 represents an integer of 2-4; nb2 represents an integer of 1-3; nb3 represents an integer of 0-2; nb4 represents an integer of 0 or more; nb5 represents an integer of 1 or more; Mm+ represents an m-valent organic cation; and m represents an integer of 1 or more.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In recent years, advances in lithography technology have led to rapid advances in the miniaturization of patterns in the manufacturing of semiconductor devices and liquid crystal display devices. A common method for achieving this miniaturization is to shorten the wavelength (increase the energy) of the exposure light source.

[0003] Resist materials are required to have lithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with minute dimensions. To satisfy these requirements, a chemically amplified resist composition has been used, which 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.

[0004] For example, Patent Document 1 discloses a resist composition containing a resin component having three specific structural units and a known onium salt-based acid generator. It is disclosed that this resist composition can control acid diffusion, improve affinity with a developer, and improve sensitivity, roughness reduction, and resolution. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-085916 Summary of the Invention [Problem to be solved by the invention]

[0006] With the further advancement of lithography technology and the expansion of its application fields, patterns are rapidly becoming finer. Accordingly, when manufacturing semiconductor devices and the like, there is a demand for technology that can form fine patterns with good shapes. However, in order to meet such demands, the conventional resist composition described in Patent Document 1 does not necessarily provide a sufficient balance between sensitivity and roughness reduction in resist pattern formation, and a higher level of both is required. Furthermore, from the viewpoint of further improving sensitivity and reducing roughness, there is room for further investigation of the acid generator component.

[0007] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a resist composition that enables the formation of a resist pattern that has high sensitivity and favorable roughness reduction properties, a method of forming a resist pattern that uses the resist composition, a novel compound that is useful as an acid generator for the resist composition, and an acid generator that uses the compound. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention employs the following configuration. That is, a first aspect of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition comprising: a base component (A) whose solubility in a developer changes due to the action of the acid; and an acid generator component (B) that generates an acid upon exposure, wherein the acid generator component (B) contains a compound (B0) represented by the following general formula (b0):

[0009] [ka] [In the formula, Ar 0 is an arylene group or a heteroarylene group. m1 and R m2 are each independently a substituent other than an iodine atom. 01 is a divalent linking group or a single bond.02 is a divalent linking group. 0 is a single bond, an alkylene group, or a fluorinated alkylene group. 0 is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 2 to 4, nb2 is an integer of 1 to 3, and nb3 is an integer of 0 to 2. nb4 is an integer of 0 or more, and nb5 is an integer of 1 or more. M m+ represents an m-valent organic cation, where m is an integer of 1 or greater.

[0010] A second aspect of the present invention is a method of forming a resist pattern, comprising the steps of forming a resist film on a support using the resist composition according 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 above general formula (b0).

[0012] A fourth aspect of the present invention is an acid generator comprising the compound according to the third aspect of the present invention. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a resist composition that can achieve high sensitivity and form a resist pattern that exhibits excellent roughness reduction, a method of forming a resist pattern that uses this resist composition, a novel compound that is useful as an acid generator for this resist composition, and an acid generator that uses this compound. DETAILED DESCRIPTION OF THE INVENTION

[0014] In this specification and claims, the term "aliphatic" is defined as a relative concept to aromatic, and refers to groups, compounds, etc. that do not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups in alkoxy groups. 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 a general concept that includes irradiation with radiation.

[0015] The term "acid-decomposable group" refers to a group having acid decomposability in which at least some 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 decompose under the action of an acid to generate a polar group. Examples of polar groups 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).

[0016] The term "acid-dissociable group" refers to either (i) a group having acid dissociability such that 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, or (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. Therefore, when the acid-dissociable group dissociates due to 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 component (A1) 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.

[0017] A "base component" is an organic compound that has film-forming ability. Organic compounds used as base components are broadly divided into non-polymers and polymers. Non-polymers typically have a molecular weight of 500 or more and less than 4000. Hereinafter, the term "low molecular weight compound" refers to a non-polymer with a molecular weight of 500 or more and less than 4000. Polymers typically have a molecular weight of 1000 or more. Hereinafter, the terms "resin," "high molecular weight compound," or "polymer" refer to a polymer with a molecular weight of 1000 or more. The molecular weight of a polymer is determined by the weight average molecular weight converted into polystyrene by GPC (gel permeation chromatography).

[0018] The term "derived structural unit" refers to a structural unit formed by cleavage of a multiple bond between carbon atoms, such as 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 ) is substituted with a substituent containing an ester bond, or αx This also includes α-hydroxyacrylic esters in which the hydroxyl group is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group. Unless otherwise specified, the α-carbon atom 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 may be referred to as an α-substituted acrylic ester.

[0019] The term "derivative" encompasses compounds in which the hydrogen atom at the α-position of the target compound is substituted with another substituent, such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include compounds in which the hydrogen atom of a hydroxyl group of a target compound, which may have the hydrogen atom at the α-position substituted with a substituent, is substituted with an organic group; and compounds in which a substituent other than a hydroxyl group is bonded to a target compound, which may have the hydrogen atom at the α-position substituted with a substituent. Unless otherwise specified, the α-position refers to the first carbon atom adjacent to the functional group. The substituents that replace the hydrogen atom at the α-position of hydroxystyrene include R αx The same can be mentioned.

[0020] In this specification and claims, some structures represented by chemical formulas may have asymmetric carbon atoms, and may exist as enantiomers or diastereomers. In such cases, a single chemical formula represents all isomers. These isomers may be used alone or as a mixture.

[0021] (Resist composition) The resist composition of this embodiment generates an acid upon exposure, and the solubility in a developer changes due to the action of the acid. Such a resist composition contains a base component (A) (hereinafter also referred to as “component (A)”) whose solubility in a developer changes under the action of acid, and an acid generator component (B) that generates acid upon exposure.

[0022] When a resist film is formed using the resist composition of this embodiment and then subjected to selective exposure, an acid is generated from component (B) in the exposed areas of the resist film, and the solubility of component (A) in a developer changes due to the action of the acid, whereas the solubility of component (A) in a developer does not change in the unexposed areas of the resist film, resulting in a difference in solubility in a developer between the exposed and unexposed areas. Therefore, when the resist film is developed, if the resist composition is positive, the exposed areas of the resist film are dissolved and removed, forming a positive resist pattern, whereas if the resist composition is negative, the unexposed areas of the resist film are dissolved and removed, forming a negative resist pattern.

[0023] The resist composition of this embodiment may be a positive resist composition or a negative resist composition. Furthermore, the resist composition of this 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.

[0024] <Component (A)> In the resist composition of this embodiment, the component (A) preferably includes a resin component (A1) (hereafter also referred to as “component (A1)”) whose solubility in a developer changes under the action of acid. By using the component (A1), the polarity of the base component changes before and after exposure, making it possible to obtain good development contrast not only in an alkaline development process but also in a solvent development process. As the component (A), other polymeric compounds and / or low molecular weight compounds may be used in combination with the component (A1). The component (A) may be a "base component that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid." When the component (A) is a base component that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, the component (A1) is preferably a resin that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid. Such a resin can be a polymer compound having a structural unit that generates an acid upon exposure. Known structural units that generate an acid upon exposure can be used.

[0025] In the resist composition of this embodiment, the component (A) may use either a single type of compound, or a combination of two or more types of compounds.

[0026] About component (A1) The component (A1) is a resin component whose solubility in a developer changes under the action of an acid. The component (A1) preferably has a structural unit (a1) that includes an acid-decomposable group whose polarity increases upon the action of an acid. The component (A1) may contain other structural units in addition to the structural unit (a1), as necessary.

[0027] <Constituent unit (a1)> The structural unit (a1) is a structural unit that contains an acid-decomposable group whose polarity increases upon the action of an acid.

[0028] Examples of the acid-dissociable group include those that have been proposed as acid-dissociable groups for base resins used in chemically amplified resist compositions. Specific examples of acid-dissociable groups that have been proposed for use in base resins for chemically amplified resist compositions include the "acetal-type acid-dissociable groups," "tertiary alkyl ester-type acid-dissociable groups," "tertiary alkyloxycarbonyl acid-dissociable groups," and "secondary alkyloxycarbonyl acid-dissociable groups," which are explained below.

[0029] 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 acid-dissociable groups represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as "acetal-type acid-dissociable groups").

[0030] [ka] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Ra' 3 Ra' 1 , Ra' 2 may be bonded to any one of the following to form a ring.]

[0031] 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, examples of the alkyl group include the same alkyl groups as those exemplified as the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylic acid ester above, and an alkyl group having 1 to 5 carbon atoms is preferred. Specific examples include linear or branched alkyl groups. More specific examples include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, and neopentyl groups, with methyl and ethyl groups being more preferred, and methyl being particularly preferred.

[0032] 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. Of 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.

[0033] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 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, with an isopropyl group being preferred.

[0034] Ra' 3 When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0035] 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 some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include pyridine rings and thiophene rings. Ra' 3 Specific examples of the aromatic hydrocarbon group in the formula (I) include a group (aryl group or heteroaryl group) in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle; 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 alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0036] Ra' 3 The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include the above-mentioned Ra x5 etc.

[0037] Ra' 3 But Ra' 1 , Ra' 2 When the cyclic group is bonded to any of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

[0038] Tertiary alkyl ester-type acid-labile group: Among the 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 convenience.

[0039] [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.

[0040] Ra' 4 Examples of the hydrocarbon group include a linear or branched alkyl group, a linear or cyclic alkenyl group, and a cyclic hydrocarbon group. Ra' 4 The linear or branched alkyl group and the cyclic hydrocarbon group (the monocyclic aliphatic hydrocarbon group, the polycyclic aliphatic hydrocarbon group, and the aromatic hydrocarbon group) in 3 The same can be mentioned. Ra' 4 The chain or cyclic alkenyl group in the formula (I) is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 The hydrocarbon group of Ra' 3 The same can be mentioned.

[0041] Ra' 5 and Ra' 6 and (a1-r2-3) are preferably substituted or unsubstituted by the alkyl group. 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).

[0042] [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 Ra' 10 represents a group that forms an aliphatic cyclic group together with the carbon atom to which Ya is bonded. 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 these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group 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 or a hydrogen atom. 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 (the same applies hereinafter).

[0043] In the above formula (a1-r2-1), Ra' 10 is 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.

[0044] Ra' 10The linear alkyl group in the formula (I) has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra' 10 In the formula (I), the branched alkyl group is the above-mentioned Ra' 3 The same can be mentioned.

[0045] 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. Furthermore, some of the carbon atoms (e.g., methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. Examples of heteroatoms include oxygen, sulfur, and nitrogen atoms. Examples of heteroatom-containing groups include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O)2-, and -S(=O)2-O-.

[0046] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed together with the carbon atom to which the carbon atom is bonded is represented by Ra' in formula (a1-r-1). 3 Among these, monocyclic alicyclic hydrocarbon groups are preferred, and specifically, cyclopentyl and cyclohexyl groups are more preferred.

[0047] 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 (aliphatic hydrocarbon group) shown above. The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. The substituent may be any of the above-mentioned Ra' 3Examples of the substituents include the same as those that the cyclic hydrocarbon group in the above may have. In formula (a1-r2-2), Ra 101 ~Ra 103 In the 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 formula (I), 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, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, and cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, tricyclo[5.2.1.02,6]decanyl group, tricyclo[3.3.1.13,7]decanyl group, tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and adamantyl group. Ra 101 ~Ra 103 Among these, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is preferred, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferred, with a hydrogen atom being particularly preferred.

[0048] The above Ra 101 ~Ra 103 Examples of the substituents that the chain saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by the formula: x5 The same groups as those shown below can be mentioned.

[0049] Ra 101 ~Ra 103Examples of the group 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.

[0050] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is Ra' in formula (a1-r-1). 3 The groups mentioned above as the aliphatic hydrocarbon group are preferably monocyclic or polycyclic groups. 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.

[0051] Ra in formula (a1-r2-3) 104 Examples of the substituent that may be possessed by 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.

[0052] In formula (a1-r2-4), Ra' 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. 12 and Ra' 13In the formula, the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms includes the above-mentioned Ra 101 ~Ra 103 Examples include the same monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms as in the chain saturated hydrocarbon group in the above. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, a hydrogen atom or an alkyl group having 1 to 5 carbon atoms is preferred, an alkyl group having 1 to 5 carbon atoms is more preferred, a methyl group or an ethyl group is even more preferred, and a methyl group is particularly preferred. The above Ra' 12 and Ra' 13 When the chain saturated hydrocarbon group represented by the formula: is substituted, examples of the substituent include the above-mentioned Ra x5 The same groups as those shown below can be mentioned.

[0053] 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.

[0054] 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, an n-pentyl group, etc. 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.

[0055] Ra' 14 The branched alkyl group in the formula (I) preferably has 3 to 10 carbon atoms, more preferably 3 to 5. 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, with an isopropyl group being preferred.

[0056] Ra'14 When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0057] Ra' 14 As the aromatic hydrocarbon group in 104 Among them, the aromatic hydrocarbon groups Ra' are the same as those 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 Examples of the substituents include the same as those that may be possessed by the group.

[0058] 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 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 formula (a1-r2-4) may be any one of the 1st, 2nd, or 9th position of the anthryl group.

[0059] Specific examples of the group represented by the formula (a1-r2-1) are listed below.

[0060] [ka]

[0061] [ka]

[0062] [ka]

[0063] Specific examples of the group represented by the formula (a1-r2-2) are listed below.

[0064] [ka]

[0065] [ka]

[0066] [ka]

[0067] Specific examples of the group represented by the formula (a1-r2-3) are listed below.

[0068] [ka]

[0069] Specific examples of the group represented by the formula (a1-r2-4) are listed below.

[0070] [ka]

[0071] 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").

[0072] [ka] [In the formula, Ra' 7 ~Ra' 9 are each alkyl groups.

[0073] In formula (a1-r-3), Ra' 7 ~Ra' 9 are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms. 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.

[0074] Secondary alkyl ester-type acid-labile group: Among the 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).

[0075] [ka] [In the formula, Ra' 10 is a hydrocarbon group. 11a and Ra' 11b are each independently a hydrogen atom, a halogen atom or an alkyl group. 12is a hydrogen atom or a hydrocarbon group. 10 and Ra' 11a or Ra' 11b 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.

[0076] In the formula, Ra' 10 and Ra' 12 The hydrocarbon group in Ra' 3 The same can be mentioned. In the formula, Ra' 11a and Ra' 11b The alkyl group in Ra' is 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.

[0077] Ra' 10 and Ra' 11a or Ra' 11b may be bonded to each other to form a ring, which may be a polycyclic ring, a monocyclic ring, an alicyclic ring, or an aromatic ring. The alicyclic and aromatic rings may contain heteroatoms.

[0078] Ra' 10 and Ra' 11a or Ra' 11b Among the above, the ring formed by bonding to each other is preferably a monocycloalkene, a ring in which some of the carbon atoms of a monocycloalkene are substituted with heteroatoms (oxygen atoms, sulfur atoms, etc.), or a monocycloalkadiene, more preferably a cycloalkene having 3 to 6 carbon atoms, and more preferably cyclopentene or cyclohexene.

[0079] Ra' 10 and Ra' 11a or Ra' 11b The ring formed by bonding these may be a fused ring. Specific examples of such fused rings include indan.

[0080] Ra' 10 and Ra' 11a or Ra' 11b The ring formed by bonding together may have a substituent. Examples of the substituent include the above-mentioned Ra x5 etc.

[0081] 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 ring formed by bonding with each other are exemplified.

[0082] Specific examples of the group represented by the formula (a1-r-4) are listed below.

[0083] [ka]

[0084] 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 acrylamide; a structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least some 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 some of the hydrogen atoms in -C(═O)-OH are protected with a substituent containing the above-mentioned acid-decomposable group.

[0085] Specific examples of the structural unit (a1) are shown below. In each of the following formulas, R αrepresents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0086] [ka]

[0087] [ka]

[0088] [ka]

[0089] [ka]

[0090] [ka]

[0091] [ka]

[0092] [ka]

[0093] [ka]

[0094] [ka]

[0095] The structural unit (a1) contained in the component (A1) may be of one type, or may be of two or more types. As the structural unit (a1), a structural unit represented by the above formula (a1-1) is more preferred, as it is more likely to further improve the properties (sensitivity, shape, etc.) in lithography using electron beams or EUV. Among these, as the structural unit (a1), a structural unit represented by the following general formula (a1-1-1) or a structural unit represented by the following general formula (a1-1-2) is particularly preferred.

[0096] [ka] [In the formula, Ra 1 " is an acid-dissociable group represented by general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4). * represents a bond.

[0097] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.] 001 represents a single bond or a divalent linking group. 01 is a single bond or a divalent linking group. 01 represents an acid-dissociable group represented by the above general formula (a1-r2-1), (a1-r2-3), or (a1-r2-4). q is an integer of 0 to 3. n is an integer of 1 or more, provided that n≦q×2+4.

[0098] In the formula (a1-1-1), R, Va 1 and n a1 represents R and Va in the formula (a1-1). 1 and n a1 is the same as:

[0099] In the formula (a1-1-2), Ya 001 and Ya 01 is preferably a single bond.

[0100] The acid-dissociable groups represented by general formula (a1-r2-1), (a1-r2-3), or (a1-r2-4) are as described above. Among these, the acid-dissociable groups represented by general formula (a1-r2-1) or (a1-r2-4) are preferred because they are suitable for use with EB or EUV and can enhance reactivity. The acid-dissociable group in the formula (a1-1-1) is more preferably an acid-dissociable group represented by the general formula (a1-r2-1).

[0101] The proportion of the structural unit (a1) in the component (A1) is preferably 5 to 95 mol %, more preferably 10 to 90 mol %, even more preferably 30 to 70 mol %, and particularly preferably 40 to 60 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a1) is at least as large as the lower limit of the aforementioned preferred range, lithography properties such as sensitivity, CDU, resolution, and roughness can be improved. On the other hand, by ensuring that the proportion is at most the upper limit of the aforementioned preferred range, a balance with other structural units can be achieved, resulting in various favorable lithography properties.

[0102] Other structural units The component (A1) may contain other structural units in addition to the structural unit (a1) described above, as necessary. Examples of other structural units include the structural unit (a10) represented by the general formula (a10-1) described below; the structural unit (a2) containing a lactone-containing cyclic group; and the structural unit (a8) derived from a compound represented by the general formula (a8-1) described below.

[0103] Regarding the structural unit (a10): The structural unit (a10) is a structural unit represented by the following general formula (a10-1) (however, this does not include structural units that correspond to the structural unit (a1)).

[0104] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.] 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.]

[0105] In the formula (a10-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 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.

[0106] 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.

[0107] 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)-].

[0108] 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. ax1Examples of the aromatic ring include groups in which 4n+1) hydrogen atoms have been 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, even more 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 some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of heteroatoms in aromatic heterocycles include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of aromatic heterocycles include pyridine rings and thiophene rings. Also, Wa x1 The aromatic hydrocarbon group in the formula (n) may be selected from aromatic compounds containing 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 benzene, naphthalene, anthracene or biphenyl (n ax1 A group in which (n +1) hydrogen atoms have been removed from benzene or naphthalene is preferred, ax1 A group obtained by removing (n +1) hydrogen atoms from benzene is more preferred. ax1 A group in which +1) hydrogen atoms have been removed is more preferred.

[0109] 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, alkoxy group, halogen atom, and halogenated alkyl group as the substituent include Ya x1 Examples of the substituent include the same as those exemplified as the substituent of the cyclic aliphatic hydrocarbon group in Wa. The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, further preferably an ethyl group or a methyl group, and particularly preferably a methyl group. x1The aromatic hydrocarbon group in the formula (I) preferably has no substituent.

[0110] 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.

[0111] Specific examples of the structural unit (a10) represented by the 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.

[0112] [ka]

[0113] [ka]

[0114] [ka]

[0115] The structural unit (a10) contained in the component (A1) may be of one type, or may be of two or more types. When the component (A1) contains the structural unit (a10), the proportion of the structural unit (a10) in the component (A1) is preferably 20 to 80 mol %, more preferably 30 to 70 mol %, and even more preferably 30 to 60 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, sensitivity can be further improved, while by ensuring that the proportion is at most the upper limit, it is easier to achieve a balance with other structural units.

[0116] 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 structural unit (a1)). The lactone-containing cyclic group of the structural unit (a2) is effective in improving the adhesion of the resist film to the substrate when the component (A1) is used to form a resist film. Furthermore, the presence of the structural unit (a2) results in favorable lithography properties, for example, by appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0117] A "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -OC(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and a group consisting of only a lactone ring is called a monocyclic group. If a group further contains other ring structures, 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 groups represented by the following general formulae (a2-r-1) to (a2-r-7).

[0118] [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).

[0119] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21The alkyl group in the formula (I) 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 alkoxy group in the formula (1) is preferably linear or branched. 21 Examples of the alkyl group include a group in which the alkyl groups mentioned above are linked to an oxygen atom (—O—). Ra' 21 The halogen atom in is preferably a fluorine atom. Ra' 21 The halogenated alkyl group in the formula Ra' is 21 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. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0120] Ra' 21 In the -COOR" and -OC(=O)R" groups, 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 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; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane. More specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples of the lactone-containing cyclic group in R″ include the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7) above. Ra' 21 The hydroxyalkyl group in the formula (I) preferably has 1 to 6 carbon atoms, and specifically, the hydroxyalkyl group in the formula (I) is preferably a hydroxyalkyl group having 1 to 6 carbon atoms. 21 and a group in which at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0121] Ra' 21 Among the above, each of the groups is preferably independently a hydrogen atom or a cyano group.

[0122] In the general formulae (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms for A" is preferably a straight-chain or branched-chain 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 carbon atoms of the alkylene group, such as -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.

[0123] Specific examples of the groups represented by the general formulae (a2-r-1) to (a2-r-7) are listed below.

[0124] [ka]

[0125] [ka]

[0126] Of the structural units (a2), structural units derived from acrylate esters in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent are particularly preferred. Such a structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0127] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.] 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.

[0128] 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 preferred.

[0129] 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.

[0130] 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.

[0131] In the formula (a2-1), Ya 21 is a single bond, and La 21 is preferably —COO— or —OCO—.

[0132] 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 the formula (a2-r-1) include the groups represented by the general formulae (a2-r-1) to (a2-r-7) described above.

[0133] The structural unit (a2) contained in the component (A1) may be of one type, or may be of two or more types. When the component (A1) contains the structural unit (a2), the proportion of the structural unit (a2) relative to the total (100 mol%) of all structural units constituting the component (A1) is preferably 1 to 20 mol%, more preferably 1 to 15 mol%, and even more preferably 1 to 10 mol%. When the proportion of the structural unit (a2) is at least as great as the preferred lower limit, the effects achieved by including the structural unit (a2) can be fully obtained due to the effects described above. 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.

[0134] Regarding the structural unit (a8): The structural unit (a8) is a structural unit derived from a compound represented by the following general formula (a8-1). However, those that fall under the structural unit (a0) are excluded.

[0135] [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 between 1 and 3.

[0136] 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.

[0137] The polymerizable group-containing group may be a group consisting of only a polymerizable group, or may be a group consisting 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 heteroatom. Examples of the polymerizable group-containing group include a group represented by the chemical formula: C(R X11 )(R X12 )=C(R X13 )-Ya x0 A group represented by the formula - is preferred. In this chemical formula, R X11 , R X12 and R X13 are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya x0 is a single bond or a divalent linking group.

[0138] Ya x2 and W 2 The fused ring formed by 2 Polymerizable group of the site and Ya x2 and the fused ring formed by W 2 Other groups than the polymerizable group at the Ya site x2 and a fused ring formed by Ya x2 and W 2 The fused ring formed by these may have a substituent.

[0139] 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.

[0140] [ka]

[0141] 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).

[0142] The structural unit (a8) contained in the component (A1) may be of one type, or may be of two or more types. The amount of the structural unit (a8) in the component (A1) is preferably no more than 50 mol %, and more preferably 0 to 30 mol %, relative to the total amount (100 mol %) of all structural units constituting the component (A1).

[0143] 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. In the resist composition of this embodiment, the component (A1) can be a polymeric compound having a repeating structure of the structural unit (a1). Of the above, suitable examples of the component (A1) include polymeric compounds that contain a repeating structure of the structural unit (a1) and the structural unit (a10).

[0144] In polymeric compounds having a repeating structure of the structural unit (a1) and the structural unit (a10), the proportion of the structural unit (a1) relative to the total (100 mol%) of all structural units constituting the polymeric compound is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%. Furthermore, the proportion of the structural unit (a10) in the polymer compound is preferably 10 to 90 mol %, more preferably 20 to 80 mol %, even more preferably 30 to 70 mol %, and particularly preferably 40 to 60 mol %, based on the total (100 mol %) of all structural units constituting the polymer compound.

[0145] The component (A1) can be produced by dissolving the monomers that derive the respective structural units in a polymerization solvent, and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the solution and polymerizing the resulting mixture. Alternatively, the component (A1) can be produced by dissolving a monomer that derives the structural unit (a1) and, if necessary, a monomer that derives a structural unit other than the structural unit (a1) (for example, the structural unit (a10)) in a polymerization solvent, adding a radical polymerization initiator such as those described above to the solution to polymerize, and then carrying out a deprotection reaction. 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 terminal. Copolymers incorporating hydroxyalkyl groups in which some of the alkyl group's hydrogen atoms have been substituted with fluorine atoms are effective in reducing development defects and LER (line edge roughness: unevenness on the line sidewalls).

[0146] The weight average molecular weight (Mw) of the component (A1) (based on polystyrene standards measured by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and even more preferably 3,000 to 20,000. When the Mw of the component (A1) is less than or equal to 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 at least the preferred lower limit of this range, the compound exhibits good dry etching resistance and the cross-sectional shape of the resist pattern. The dispersity (Mw / Mn) of the component (A1) is not particularly limited, but is preferably from 1.0 to 4.0, more preferably from 1.0 to 3.0, and particularly preferably from 1.0 to 2.0, where Mn represents the number average molecular weight.

[0147] About ingredient (A2) The resist composition of this embodiment may also use, as the component (A), a base component (hereafter referred to as “component (A2)”) that does not fall under the category of the component (A1) and whose solubility in a developer changes upon the action of an acid. There are no particular restrictions on the component (A2), and it can be selected from the many conventional base components for chemically amplified resist compositions. The component (A2) may be a high molecular weight compound or a low molecular weight compound, and may be used alone or in combination of two or more types.

[0148] The proportion of the component (A1) within the component (A), relative to the total mass of the component (A), is preferably 25 mass% or more, more preferably 50 mass% or more, even more preferably 75 mass% or more, and may even be 100 mass%. When this proportion is 25 mass% or more, a resist pattern that is excellent in various lithography properties, such as high sensitivity, resolution, and improved roughness, is more likely to be formed.

[0149] 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.

[0150] <Acid generator component (B)> The component (B) in the resist composition of this embodiment includes a compound (B0) (hereafter also referred to as “component (B0)”) represented by the following general formula (b0):

[0151] ≪Compound (B0)≫ The component (B0) is a compound represented by the following general formula (b0).

[0152] [ka] [In the formula, Ar 0 is an arylene group or a heteroarylene group. m1 and R m2 are each independently a substituent other than an iodine atom. 01 is a divalent linking group or a single bond. 02 is a divalent linking group.0 is a single bond, an alkylene group, or a fluorinated alkylene group. 0 is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 2 to 4, nb2 is an integer of 1 to 3, and nb3 is an integer of 0 to 2. nb4 is an integer of 0 or more, and nb5 is an integer of 1 or more. M m+ represents an m-valent organic cation, where m is an integer of 1 or greater.

[0153] {Anion portion of component (B0)} In the above general formula (b0), Ar 0 is an arylene group or a heteroarylene group. Ar 0 The arylene group in the formula (I) is a group in which two hydrogen atoms have been removed from an aromatic ring, such as benzene, naphthalene, anthracene, or phenanthrene. Ar 0 Specifically, the aryl group in the formula (I) is preferably a phenylene group.

[0154] Ar 0 The heteroarylene group in the above formula (I) includes a group in which two hydrogen atoms have been removed from an aromatic heterocycle, such as a pyridine ring or a thiophene ring.

[0155] In the above general formula (b0), Ar 0 Among the above, is preferably an arylene group, more preferably a phenylene group.

[0156] In the above general formula (b0), R m1 and R m2 are each independently a substituent other than an iodine atom. Examples of the substituent include a hydroxy group, an alkyl group, a fluorinated alkyl group, a fluorine atom, and a chlorine atom. The alkyl group and the alkyl group in the fluorinated alkyl group are preferably alkyl groups having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group.

[0157] In the above general formula (b0), R m1 and R m2 Among the above, it is preferable that each of the is independently an alkyl group, a fluorinated alkyl group, or a fluorine atom.

[0158] In the above general formula (b0), L 01 is a divalent linking group or a single bond, and L 02 is a divalent linking group. L 01 and L 02 The divalent linking group in the formula (I) is preferably a divalent linking group containing an oxygen atom. L 01 and L 02 is a divalent linking group containing an oxygen atom, 01 and L 02 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 (-O-C(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-O-C(=O)-O-); and combinations of such non-hydrocarbon oxygen-containing linking groups with alkylene groups. A sulfonyl group (-SO-) may be further linked to this combination.

[0159] L 01 and L 02 More specifically, the divalent linking group in a )-C(=O)-, -N(R a )-, -C(R a )(R a )-N(R a )-, -C(R a )(N(R a )(R a ))-, or -C(=O)-N(R a)- etc. R a are each independently a hydrogen atom or an alkyl group.

[0160] In the above general formula (b0), L 01 Among the above, is preferably a divalent linking group, more preferably a divalent linking group containing an oxygen atom, such as -OCO-, -COO-, or -C(=O)-N(R a )- is more preferred, and -OCO- or -COO- is particularly preferred.

[0161] In the above general formula (b0), L 02 Among the above, is preferably a divalent linking group, more preferably a divalent linking group containing an oxygen atom, such as -OCO-, -COO-, or -C(=O)-N(R a )-, and particularly preferably -OCO-, -COO-, or -C(=O)-NH-.

[0162] In the above general formula (b0), Vb 0 is a single bond, an alkylene group, or a fluorinated alkylene group. Vb 0 The alkylene group and fluorinated alkylene group in each of the above preferably have 1 to 4 carbon atoms, and more preferably have 1 to 3 carbon atoms. Vb 0 The fluorinated alkylene group in the formula (I) includes a group in which some or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.

[0163] In the above general formula (b0), Vb 0 Among the above, is preferably an alkylene group or a fluorinated alkylene group, more preferably an alkylene group having 1 to 4 carbon atoms or a fluorinated alkylene group having 1 to 4 carbon atoms, further preferably a methylene group, -CH(CF3)-, -CH2CH2CF2-, or -CH2CH2CHF-, and particularly preferably -CH(CF3)-, -CH2CH2CF2-, or -CH2CH2CHF-.

[0164] In the above general formula (b0), R 0 is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. R 0 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0165] In the above general formula (b0), nb1 and nb5 represent the number of iodine atoms (I). nb1 is an integer of 2 to 4. nb5 is an integer of 1 or more, and is preferably an integer of 2 to 5. The total number of nb1 and nb5 is preferably an integer of 4 to 9, more preferably 5 or 6, and even more preferably 5.

[0166] In the above general formula (b0), nb2 is an integer of 1 to 3, and is preferably 1 or 2. In the above general formula (b0), when nb2 is 2 or 3, a plurality of nb4, nb5, Ar 0 , and L 02 may be the same or different.

[0167] In the above general formula (b0), nb3 is an integer of 0 to 2, preferably 0 or 1, and more preferably 0. In the above general formula (b0), when nb3 is 2, a plurality of R m2 may be the same or different.

[0168] In the above general formula (b0), nb4 is an integer of 0 or more, preferably 0 or 1, and more preferably 0. In the above general formula (b0), when nb4 is 2 or more, a plurality of R m1 may be the same or different.

[0169] Specific examples of preferred anion moieties of component (B0) are shown below.

[0170]

change

[0171]

change

[0172]

change

[0173]

change

[0174]

change

[0175]

change

[0176]

change

[0177]

change

[0178]

change

[0179] The anion portion of the (B0) component is preferably an anion represented by any one of the above chemical formulas (b0-an-001), (b0-an-009), (b0-an-010), (b0-an-011), (b0-an-013), (b0-an-015), (b0-an-020), (b0-an-023), (b0-an-025) to (b0-an-027), (b0-an-030) to (b0-an-032), (b0-an-045), and (b0-an-094) to (b0-an-097), and is preferably an anion represented by any one of the above chemical formulas (b0-an-009), (b0-an-010), It is more preferable that the anion is an anion represented by any one of the following chemical formulas: (b0-an-011), (b0-an-013), (b0-an-015), (b0-an-020), (b0-an-023), (b0-an-025) to (b0-an-027), (b0-an-030) to (b0-an-032), (b0-an-045), (b0-an-094) to (b0-an-097), and it is even more preferable that the anion is an anion represented by any one of the above chemical formulas (b0-an-011), (b0-an-023), (b0-an-030), (b0-an-095) to (b0-an-097).

[0180] {Cation moiety of component (B0)} In the above general formula (b0), M m+ represents an organic cation with a valence of m. Among these, sulfonium cations and iodonium cations are preferred. m is an integer of 1 or greater.

[0181] Preferred cationic moieties ((M m+ ) 1 / m ) includes organic cations represented by the following general formulas (ca-1) to (ca-3), respectively.

[0182] [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 ~R203 , 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 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-.]

[0183] In the above general formulas (ca-1) to (ca-3), R 201 ~R 207 The aryl group in the formula (I) includes 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 the formula (I) 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 formulae (ca-r-1) to (ca-r-7).

[0184] [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.

[0185] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0186] R' 201 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, this number of carbon atoms does not include the number of carbon atoms in the substituent. R' 201 Specific examples of the aromatic ring contained in 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. 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 include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

[0187] 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 interposed 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 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 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 more preferably a polycycloalkane having a bridged ring polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a fused ring polycyclic skeleton, such as a cyclic group having a steroid skeleton.

[0188] 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 a 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.

[0189] 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, still more 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 preferred, and specific examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; 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.

[0190] Also, R' 201 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle, etc. Specific examples include the lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above, the —SO2-containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) above, and other heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) above.

[0191] 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.

[0192] A chain alkyl group which may have a substituent: R' 201 The chain alkyl group may be either a straight chain or a branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. 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.

[0193] An optionally substituted chain alkenyl group: R' 201The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, even more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a 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 chain alkenyl groups mentioned above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0194] 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-mentioned R' 201 Examples of the cyclic groups include the cyclic groups shown in the formula:

[0195] 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.

[0196] Among them, R' 201 is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7), or an —SO2- containing cyclic group represented by each of the general formulae (b5-r-1) to (b5-r-4) is preferred.

[0197] In the above general formulas (ca-1) to (ca-3), R 201 ~R203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they may not contain a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, or a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(the R N is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-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.

[0198] 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.

[0199] 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) includes 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 the formula (I) 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 210As the -SO2- containing cyclic group which may have a substituent in the formula (b5-r-1), an "-SO2- containing polycyclic group" is preferred, and a group represented by the above general formula (b5-r-1) is more preferred.

[0200] Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following chemical formulas (ca-1-1) to (ca-1-70).

[0201] [ka]

[0202] [ka]

[0203] [ka] [In the formula, g1, g2, and g3 represent the number of repeating units, 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.]

[0204] [ka]

[0205] [ka]

[0206] [ka] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the same as 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 group

[0207] Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

[0208] 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).

[0209] [ka]

[0210] Specific preferred examples of the component (B0) are shown below.

[0211] [ka]

[0212] [ka]

[0213] [ka]

[0214] Of the above, the component (B0) is preferably a compound represented by any one of the above chemical formulas (B0-02) to (B0-22), more preferably a compound represented by any one of the above chemical formulas (B0-04), (B0-05), (B0-08), (B0-09), (B0-14), (B0-15), and (B0-17) to (B0-22), and even more preferably a compound represented by any one of the above chemical formulas (B0-04), (B0-08), (B0-14), and (B0-17) to (B0-22).

[0215] In the resist composition of this embodiment, the component (B0) may be used alone, or in combination of two or more different compounds.

[0216] In the resist composition of this embodiment, as the component (B0), one type of compound may be used alone, or two or more types may be used in combination. In the resist composition of this embodiment, the amount of the component (B0) relative to 100 parts by mass of the component (A) is preferably 15 to 50 parts by mass, more preferably 20 to 50 parts by mass, and even more preferably 20 to 45 parts by mass. When the amount of component (B0) is at least as large as the lower limit of the above-mentioned preferred range, lithography properties such as sensitivity and reduced LWR (line width roughness) are further improved during resist pattern formation. On the other hand, when the amount is at most the upper limit of the preferred range, a homogeneous solution is more easily obtained when the components of the resist composition are dissolved in an organic solvent, and the storage stability of the resist composition is further improved.

[0217] In the resist composition of this embodiment, the proportion of the component (B0) relative to the entire component (B) is, for example, 50 mass % or more, preferably 70 mass % or more, and even more preferably 95 mass % or more, and may even be 100 mass %.

[0218] The component (B) in the resist composition of this embodiment may also contain an acid generator component (B1) (hereinafter also referred to as “component (B1)”) other than the above-mentioned component (B0).

[0219] ≪(B1) Component≫ Examples of the component (B1) include various types of acid generators, such as 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 bisaryl sulfonyl diazomethanes and poly(bissulfonyl) diazomethanes; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0220] Examples of the onium salt acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0221] Examples of the onium salt acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0222] [ka] [In the formula, R 101 and R 104 ~R 108 R each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 104 and R 105 R may be bonded to each other to form a ring structure. 102 is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. 101 is a divalent linking group containing an oxygen atom or a single bond. 101 ~V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group. 101 ~L 102 are each independently a single bond or an oxygen atom. 103 ~L 105 are each independently a single bond, —CO— or —SO2—; m is an integer of 1 or more; and M' m+ is an m-valent onium cation.

[0223] {anion part} Anion in component (b-1) In formula (b-1), R 101represents 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.

[0224] Optionally substituted cyclic groups: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. Furthermore, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0225] R 101 The aromatic hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R 101 Specific examples of the aromatic ring contained in 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. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. R 101 Specific examples of the aromatic hydrocarbon group in the formula (I) include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0226] R 101The 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 interposed 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 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 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 more preferably a polycycloalkane having a bridged ring polycyclic skeleton, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a fused ring polycyclic skeleton, such as a cyclic group having a steroid skeleton.

[0227] Among them, R 101 The cyclic aliphatic hydrocarbon group in is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, further preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0228] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, even more preferably 1 to 4, and most preferably 1 to 3. The linear aliphatic hydrocarbon group is preferably a linear alkylene group, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], and a pentamethylene group [-(CH2)5-]. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, even more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. The branched aliphatic hydrocarbon group is preferably a branched alkylene group, and specific examples thereof include alkyl alkylene groups such as alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, and -C(CH2CH3)2-CH2-; 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.

[0229] Also, R 101 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specific examples include lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above, -SO2- containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) below, and other heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) below. In the formula, * represents Y in formula (b-1). 101 represents a bond bonded to

[0230] [ka] [In the formula, Rb' 51 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or an -SO2- containing cyclic group; B" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, and n' is an integer of 0 to 2. * represents a bond.

[0231] In the general formulae (b5-r-1) and (b5-r-2), B″ represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom. B" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and even more preferably a methylene group.

[0232] In the general formulae (b5-r-1) to (b5-r-4), Rb' 51 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group, and among these, are preferably each independently a hydrogen atom or a cyano group.

[0233] Specific examples of the groups represented by general formulae (b5-r-1) to (b5-r-4) are listed below, in which "Ac" represents an acetyl group.

[0234] [ka]

[0235] [ka]

[0236] [ka]

[0237] [ka]

[0238] R 101 Examples of the substituent in the cyclic group include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group. The alkyl group as 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. Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being 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.

[0239] R 101The cyclic hydrocarbon group in may be a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused. Examples of the fused ring include a polycycloalkane having a polycyclic skeleton of a bridged ring system to which one or more aromatic rings are fused. Specific examples of the bridged ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, and more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane. 101 Specific examples of the fused cyclic group in the formula (b-1) include those represented by the following formulas (r-br-1) to (r-br-2). 101 represents a bond bonded to

[0240] [ka]

[0241] R 101 Examples of the substituent that the fused cyclic group in the formula (I) may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group. The alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the fused cyclic group are the same as those described above in R 101 Examples of the substituents for the cyclic group in the formula (I) include the same as those listed above. Examples of the aromatic hydrocarbon group as the substituent of the fused ring group include a group in which one hydrogen atom has been removed from an aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.), and heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of the alicyclic hydrocarbon group as a substituent of the fused cyclic group include groups in which one hydrogen atom has been removed from a monocycloalkane such as cyclopentane or cyclohexane; groups in which one hydrogen atom has been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane; lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above; —SO2- containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) above; and heterocyclic groups represented by the formulae (r-hr-7) to (r-hr-16) above.

[0242] A chain alkyl group which may have a substituent: R 101 The chain alkyl group may be either a straight chain or a branched chain. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0243] An optionally substituted chain alkenyl group: R 101 The chain alkenyl group may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the chain alkenyl groups mentioned above, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0244] R 101 Examples of the substituent in the chain alkyl or alkenyl group include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the above-mentioned R 101 Examples of the cyclic groups include the cyclic groups shown in the formula:

[0245] Among the above, R 101 is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, the cyclic hydrocarbon group is preferably a phenyl group, a naphthyl group, or a group in which one or more hydrogen atoms have been removed from a polycycloalkane; a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7); or an —SO2- containing cyclic group represented by each of the general formulae (b5-r-1) to (b5-r-4), more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane, and even more preferably an adamantyl group.

[0246] In formula (b-1), Y 101 is a single bond or a divalent linking group containing an oxygen atom. Y 101 is a divalent linking group containing an oxygen atom, 101 may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms. Examples of the divalent linking group containing an oxygen atom include non-hydrocarbon oxygen-atom-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-O-C(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-O-C(=O)-O-); and combinations of such non-hydrocarbon oxygen-atom-containing linking groups with alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of such divalent linking groups containing an oxygen atom include linking groups represented by the following general formulae (y-al-1) to (y-al-7). In the following general formulae (y-al-1) to (y-al-7), R in the above formula (b-1) 101 The bond to V' in the following general formulas (y-al-1) to (y-al-7) is 101 is.

[0247] [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.

[0248] 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.

[0249] V' 101 and V' 102 The alkylene group in may be a straight-chain alkylene group or a branched-chain alkylene group, and is preferably a straight-chain alkylene group. V' 101 and V' 102Specific examples of the alkylene group in the formula (I) include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, and -CH(CH2CH3)CH2 -, etc.; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-]. Also, V' 101 or V' 102 In the 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 formula (a1-r-1). 3 A divalent group obtained by removing one more hydrogen atom from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group or a polycyclic aliphatic hydrocarbon group) of the above is preferred, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferred.

[0250] Y 101 As the linking group, a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferred, and the linking groups represented by the above formulas (y-al-1) to (y-al-5) are more preferred.

[0251] In formula (b-1), V 101 is a single bond, an alkylene group, or a fluorinated alkylene group. 101 The alkylene group and fluorinated alkylene group in the formula (V) preferably have 1 to 4 carbon atoms. 101 The fluorinated alkylene group in 101In particular, groups in which some or all of the hydrogen atoms of the alkylene group in the formula (I) are substituted with fluorine atoms are preferred. 101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0252] In formula (b-1), R 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. 102 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and more preferably a fluorine atom.

[0253] Specific examples of the anion moiety represented by the formula (b-1) include, for example, Y 101 When Y is a single bond, examples of the anion include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; 101 When is a divalent linking group containing an oxygen atom, examples of the anions include those represented by any of the following formulae (an-1) to (an-3).

[0254] [ka] [In the formula, R” 101 R" is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by each of the above chemical formulas (r-hr-1) to (r-hr-6), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a chain alkyl group which may have a substituent, or an aromatic cyclic group which may have a substituent. 102 R" is an aliphatic cyclic group which may have a substituent, a fused cyclic group represented by the formula (r-br-1) or (r-br-2) above, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1), (a2-r-3) to (a2-r-7) above, or an -SO2- containing cyclic group represented by each of the general formulae (b5-r-1) to (b5-r-4) above. 103 V" is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. 101is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102 is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms; each v" is independently an integer of 0 to 3, each q" is independently an integer of 0 to 20, and n" is 0 or 1.

[0255] R” 101 , R” 102 and R” 103 The aliphatic cyclic group which may have a substituent is represented by R 101 The substituent is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in the formula (b-1). 101 Examples of the substituents that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1) include the same as those that may be substituted on the cyclic aliphatic hydrocarbon group in the above formula (1).

[0256] R” 101 and R” 103 The aromatic cyclic group which may have a substituent in the formula (b-1) is R 101 The substituent is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in the formula (b-1). 101 Examples of the substituents that may substitute the aromatic hydrocarbon group in the above formula (1) include the same as those in the above formula (1).

[0257] R” 101 The chain alkyl group which may have a substituent in the formula (b-1) is R 101 The alkyl group is preferably one of the groups exemplified as the chain alkyl group in the above formula. R” 103 The chain alkenyl group which may have a substituent is R 101 Preferably, it is a group exemplified as the chain alkenyl group in the above formula.

[0258] Anion in component (b-2) In formula (b-2), R 104 , R 105are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each is represented by R 101 However, R 104 , R 105 may be bonded to each other to form a ring. R 104 , R 105 is preferably a chain alkyl group which may have a substituent, more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and even more preferably 1 to 3 carbon atoms. 104 , R 105 The number of carbon atoms in the chain alkyl group of R is preferably as small as possible within the above range of carbon atoms, for reasons such as good solubility in resist solvents. 104 , R 105 In the chain alkyl group, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength and the improved transparency to high-energy light of 250 nm or less and electron beams, which is preferable. The proportion of fluorine atoms in the chain alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms. In formula (b-2), V 102 , V 103 are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each represents V in formula (b-1). 101 The same can be mentioned. In formula (b-2), L 101 , L 102 are each independently a single bond or an oxygen atom.

[0259] Anion in component (b-3) In formula (b-3), R 106 ~R 108are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and each is represented by R 101 The same can be mentioned. In formula (b-3), L 103 ~L 105 are each independently a single bond, —CO— or —SO2—.

[0260] {cation part} In the formula (b-1), formula (b-2), and formula (b-3), M' m+ represents an m-valent onium cation. Among these, sulfonium cation and iodonium cation are preferred. m is an integer of 1 or greater.

[0261] Preferred cationic moieties ((M' m+ ) 1 / m ) includes organic cations represented by the above general formulas (ca-1) to (ca-3), respectively.

[0262] In the resist composition of this embodiment, the component (B1) may be used either as a single type, or in combination of two or more types. The amount of the component (B1) is preferably no more than 20 parts by mass, more preferably no more than 10 parts by mass, and even more preferably no more than 5 parts by mass, per 100 parts by mass of the component (A). The resist composition of this embodiment preferably contains only the component (B0) as the acid generator.

[0263] <Other ingredients> The resist composition of this embodiment may further contain other components in addition to the above-described components (A) and (B). Examples of other components include the following components (D), (E), (F), and (S).

[0264] <Base component (D)> 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 enhance the roughness reduction properties. Furthermore, the inclusion of component (D1) makes it easier to improve both the sensitivity and the suppression of coating defects.

[0265] 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 properties (basicity), but act as quenchers in the unexposed areas of the resist film.

[0266] [ka] [In the formula, Rd 1 ~Rd 4is 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 this case, no fluorine atom is bonded to the carbon atom adjacent to the S atom. 1 is a single bond or a divalent linking group; m is an integer of 1 or more; M m+ are each independently an m-valent organic cation.

[0267] {(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, and each of the R' 201 The same can be mentioned. Among these, Rd 1 is preferably an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent. 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 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 the above formulas (y-al-1) to (y-al-5). Note that Rd 1 When 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 general formulas (y-al-1) to (y-al-7) as a substituent, in the general formulas (y-al-1) to (y-al-7), Rd 1 The carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain alkyl group in the formula (y-al-1) to (y-al-7) is bonded to V' 101 is. Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure consisting of a bicyclooctane skeleton and another ring structure). The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof include straight-chain 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-chain 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.

[0268] When the chain-like 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 even more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine atoms. Examples of atoms other than fluorine atoms include oxygen atoms, sulfur atoms, and nitrogen atoms.

[0269] Preferred examples of the anion moiety of the component (d1-1) are shown below.

[0270] [ka]

[0271] Cation part In formula (d1-1), M m+ is an m-valent organic cation. M m+Suitable organic cations include those similar to those represented by the general formulae (ca-1) to (ca-3), with the cation represented by the general formula (ca-1) being more preferred, and the cations represented by the general formulae (ca-1-1) to (ca-1-113) being even more preferred. The component (d1-1) may be used alone or in combination of two or more.

[0272] {(d1-2) component} 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 R' 201 The same can be mentioned. However, Rd 2 In this case, the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not fluorinated), which makes the anion of component (d1-2) an appropriately weak acid anion, thereby improving the quenching ability of component (D). Road 2 The alkyl group is preferably a chain alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent, and more preferably an aliphatic cyclic group which may have a substituent.

[0273] The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. The aliphatic cyclic group is preferably a group (which may have a substituent) in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like; or a group in which one or more hydrogen atoms have been removed from camphor.

[0274] Road 2 The hydrocarbon group may have a substituent, and the substituent may be Rd 1Examples of the substituents include the same as those that may be contained in the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0275] Preferred examples of the anion moiety of the component (d1-2) are shown below.

[0276] [ka]

[0277] Cation part In formula (d1-2), M m+ is an m-valent organic cation, and M in the formula (d1-1) m+ is the same as: The component (d1-2) may be used alone or in combination of two or more.

[0278] {(d1-3) component} 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 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 The same fluorinated alkyl groups as those mentioned above are more preferred.

[0279] 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 R' 201 The same can be mentioned. Among these, alkyl groups, alkoxy groups, alkenyl groups and cyclic groups which may have a substituent are preferred. Road 4The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. 4 A portion of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, or the like. Road 4 The alkoxy group in is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferred.

[0280] Road 4 The alkenyl group in R' 201 Examples include the same alkenyl groups as those in the above, and vinyl, propenyl (allyl), 1-methylpropenyl, and 2-methylpropenyl groups 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.

[0281] Road 4 The cyclic group in the formula (I) is the same as the R' 201 Examples of the cyclic group include the same as the cyclic group in the above, and preferred are alicyclic groups obtained by removing one or more hydrogen atoms from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, or aromatic groups such as a phenyl group or a naphthyl group. 4 When Rd is an alicyclic group, the resist composition dissolves well in an organic solvent, resulting in excellent lithography properties. 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.

[0282] 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. 21 Examples of the divalent linking group include the same divalent hydrocarbon groups which may have a substituent and divalent linking groups containing a hetero atom as those 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.

[0283] Preferred examples of the anion moiety of the component (d1-3) are shown below.

[0284] [ka]

[0285] [ka]

[0286] Cation part In formula (d1-3), M m+ is an m-valent organic cation, and M in the formula (d1-1) m+ is the same as: The component (d1-3) may be used alone or in combination of two or more.

[0287] The component (D1) may be any one of the components (d1-1) to (d1-3) above, or a combination of two or more of them. When the resist composition contains the component (D1), the amount of the component (D1) within the resist composition relative to 100 parts by mass of the component (A) is preferably 0.5 to 15 parts by mass, more preferably 1 to 10 parts by mass, and even more preferably 2 to 8 parts by mass. 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 at most the upper limit, good sensitivity can be maintained and excellent throughput can be achieved.

[0288] In the resist composition of this embodiment, the component (D1) preferably includes the component (d1-1) above. Within the resist composition of this embodiment, the amount of the component (d1-1) in the component (D) as a whole 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 component (d1-1).

[0289] 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 component (d1-3) is not particularly limited, and it can be produced, for example, in a manner similar to that described in US2012-0149916.

[0290] 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 component (D1) described above. The component (D2) is not particularly limited as long as it acts as an acid diffusion controller 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 particularly preferred. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 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), and cyclic amines. Specific examples of alkylamines and alkyl alcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 5 to 10 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0291] 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.

[0292] 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, and triethanolamine triacetate, with triethanolamine triacetate being preferred.

[0293] 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, and 2,6-di-tert-butylpyridine.

[0294] Of the above, the component (D2) is preferably an alkylamine, and more preferably a trialkylamine having 5 to 10 carbon atoms.

[0295] The component (D2) may be used alone or in combination of two or more. When the resist composition contains the component (D2), the amount of the component (D2) within 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 (A). 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 at most the upper limit, good sensitivity can be maintained and throughput is also excellent.

[0296] <<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 oxo acids and derivatives thereof (hereafter referred to as "component (E)") for the purposes of preventing sensitivity degradation and improving the resist pattern shape and stability over time after exposure. Specific examples of organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid, with salicylic acid being preferred. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred.

[0297] In the resist composition of this embodiment, the component (E) may be used either as a single type, or in 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 (A) is preferably 0.01 to 5 parts by mass, and more preferably 0.05 to 3 parts by mass. By setting the amount within this range, lithography properties are further improved.

[0298] <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. Component (F) is used to impart water repellency to the resist film, and when used as a resin separate from component (A), it can improve lithography properties. As the component (F), for example, the fluorine-containing polymer compounds described in JP-A Nos. 2010-002870, 2010-032994, 2010-277043, 2011-13569, and 2011-128226 can be used. More specifically, component (F) may be a polymer having a structural unit (f1) represented by the following general formula (f1-1): This polymer is preferably a polymer (homopolymer) consisting solely of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) with the structural unit (a1); or a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1), with the structural unit (f1) being more preferred. 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, with the structural unit derived from 1-ethyl-1-cyclooctyl(meth)acrylate being more preferred.

[0299] [ka] [wherein R is the same as defined 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.

[0300] 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 Rf 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 some 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 even more preferably a hydrogen atom. In formula (f1-1), nf 1 is an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0301] 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 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. Furthermore, in the fluorine atom-containing hydrocarbon group, 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, because this increases 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.

[0302] The weight-average molecular weight (Mw) of component (F) (based on polystyrene standards measured by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. When the Mw is below the upper limit of this range, the component has sufficient solubility in a resist solvent for use as a resist, and when the Mw is above the lower limit of this range, the resulting resist film has good water repellency. The dispersity (Mw / Mn) of the component (F) is preferably from 1.0 to 5.0, more preferably from 1.0 to 3.0, and most preferably from 1.0 to 2.5.

[0303] In the resist composition of this embodiment, the component (F) may be used either as a single type, or in combination of two or more types. When the resist composition contains the component (F), the amount of the component (F) is preferably 0.5 to 10 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the component (A).

[0304] <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)”). The component (S) can be any solvent that is capable of dissolving the individual components used and forming a homogeneous solution, and any solvent that is appropriately selected from among those known to be conventionally used as solvents for chemically amplified resist compositions can be used. Examples of the component (S) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate; and compounds having an ether bond such as monoalkyl ethers or monophenyl ethers of the above polyhydric alcohols or compounds having an ester bond, such as monomethyl ether, monoethyl ether, monopropyl ether, and monobutyl ether. Examples of suitable solvents include derivatives of polyhydric alcohols (among which, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred); cyclic ethers such as dioxane, and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). In the resist composition of this embodiment, the component (S) may be used either alone or as a mixed solvent of two or more different solvents. Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0305] A mixed solvent of PGMEA and a polar solvent is also preferred as component (S). The blending ratio (mass ratio) may be determined appropriately taking into consideration the compatibility of PGMEA with the polar solvent, but is preferably within the range of 1:9 to 9:1, and more preferably 2:8 to 8:2. More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. When PGME is blended as the polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred. Another preferred component (S) is a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone, in which the mass ratio of the former to the latter is preferably 70:30 to 95:5. There are no particular restrictions on the amount of component (S) used, and it is set appropriately depending on the coating film thickness so as to provide a concentration that allows application to a substrate, etc. Generally, 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 %.

[0306] The resist composition of this embodiment may be prepared by dissolving the resist material in component (S) and then removing impurities 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 such polyimide porous films and polyamideimide porous films include those described in JP 2016-155121 A.

[0307] The resist composition of the present embodiment described above contains a base component (A) and an acid generator component (B), and the acid generator component (B) contains a compound (B0) represented by general formula (b0). The compound (B0) has a plurality of iodine atoms, and therefore has high absorption efficiency of EUV (extreme ultraviolet) and EB (electron beam). Furthermore, since the compound (B0) has a phenylene group having two or more iodine atoms and an arylene group or heteroarylene group having one or more iodine atoms, the diffusion length of the acid is appropriately reduced. Furthermore, since the compound (B0) has a phenylene group having two or more iodine atoms at positions relatively close to the sulfonate anion, the acidity of the acid generated from the compound (B0) is increased. Due to these synergistic effects, compound (B0) can generate more acid in the exposed areas of the resist film than conventional acid generators, and can also reduce the amount of acid that diffuses from the exposed areas to the unexposed areas of the resist film. Therefore, it is presumed that the resist composition of this embodiment, which contains compound (B0), can achieve high sensitivity and form a resist pattern with favorable roughness reduction.

[0308] (Method for 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.

[0309] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and then baked (post-apply bake (PAB)) at a temperature of, for example, 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film. Next, the resist film is selectively exposed using an exposure device such as an electron beam lithography device or an ArF exposure device, either through a mask (mask pattern) on which a predetermined pattern has been formed, or by direct irradiation with an electron beam without using a mask pattern, and then baked (post-exposure bake (PEB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150°C. Next, the resist film is developed using an alkaline developer in the case of an alkaline development process, or a developer containing an organic solvent (organic developer) in the case of a solvent development process.

[0310] 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, it is preferable to use a rinse solution containing an organic solvent. In the case of a solvent development process, the developing treatment or rinsing treatment may be followed by a treatment of removing the developing solution or rinsing solution adhering to the pattern using a supercritical fluid. After the development treatment or rinsing treatment, the film is dried. In some cases, a baking treatment (post-baking) may be performed after the development treatment. In this manner, a resist pattern can be formed.

[0311] The support is not particularly limited, and conventionally known supports can be used, such as substrates for electronic components and those on which a predetermined wiring pattern is formed. More specifically, examples include silicon wafers, substrates made of metals such as copper, chromium, iron, and aluminum, and glass substrates. Materials that can be used for the wiring pattern include copper, aluminum, nickel, and gold.

[0312] The wavelength used for exposure is not particularly limited, and radiation such as an ArF excimer laser, a KrF excimer laser, an F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, or soft X-rays can be used. The resist composition is highly useful for KrF excimer lasers, ArF excimer lasers, EB, or EUV, more useful for ArF excimer lasers, EB, or EUV, and particularly useful for EB or EUV. That is, the method of forming a resist pattern according to this embodiment is particularly useful when the step of exposing the resist film includes exposing the resist film to EUV (extreme ultraviolet) or EB (electron beam).

[0313] The exposure method for the resist film may be a normal exposure (dry exposure) carried out 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 device 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, such as water, a fluorine-based inert liquid, a silicon-based solvent, or a hydrocarbon-based solvent. As the immersion medium, water is preferably used.

[0314] The alkaline developer used in the development treatment in the alkaline development process may be, for example, 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 component (A) (component (A) before exposure), and may be appropriately selected from known organic solvents. Specific examples include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, as well as hydrocarbon solvents.

[0315] 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.

[0316] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0317] Known additives can be blended into the organic developer as needed. Examples of such additives include surfactants. The surfactant is not particularly limited, but examples include ionic or nonionic fluorine-based and / or silicon-based surfactants. Nonionic surfactants are preferred, and nonionic fluorine-based surfactants or nonionic silicon-based surfactants are more preferred. When a surfactant is added, the amount added is usually 0.001 to 5 mass %, preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %, based on the total amount of the organic developer.

[0318] 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 standing for a certain period of time (puddle method), a method of spraying the developer onto the surface of the support (spray method), or 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).

[0319] The organic solvent contained in the rinse solution used in the rinsing treatment after development in the solvent development process can be appropriately selected from the organic solvents listed above as organic solvents used in the organic developer, and can be one that does not easily dissolve the resist pattern. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. Among these, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and amide solvents is preferred, at least one solvent selected from alcohol solvents and ester solvents is more preferred, and alcohol solvents are particularly preferred. The alcohol-based solvent used in the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched, or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. Of these, 1-hexanol, 2-heptanol, and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred. These organic solvents may be used alone or in combination of two or more. They may also be used in combination with other organic solvents or water. However, taking into consideration the development characteristics, the amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3% by mass or less, based on the total amount of the rinse solution. The rinse solution may contain known additives as needed. Examples of such additives include surfactants. Examples of surfactants include those described above, with nonionic surfactants being preferred, and nonionic fluorine-based surfactants or nonionic silicone-based surfactants being more preferred. When a surfactant is added, the amount added is usually 0.001 to 5 mass %, preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %, based on the total amount of the rinse liquid.

[0320] The rinse treatment (cleaning treatment) using a rinse solution can be carried out by a known rinse method, such as a method of continuously applying the rinse solution onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse solution for a certain period of time (dipping method), or a method of spraying the rinse solution onto the surface of the support (spray method).

[0321] According to the method of forming a resist pattern of the present embodiment described above, the resist composition described above is used, thereby enabling the formation of a resist pattern with high sensitivity and favorable roughness reduction.

[0322] The resist composition of the above-described embodiment and the various materials used in the pattern formation method of the above-described embodiment (e.g., resist solvent, developer, rinse, anti-reflective coating composition, top coat composition, etc.) preferably do not contain impurities such as metals, halogen-containing metal salts, acids, alkalis, or components containing sulfur or phosphorus atoms. Examples of metal-containing impurities include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, and 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).

[0323] (compound) The compound according to the third aspect of the present invention is a compound represented by the following general formula (b0).

[0324] [ka] [In the formula, Ar 0 is an arylene group or a heteroarylene group. m1 and R m2 are each independently a substituent other than an iodine atom. 01 is a divalent linking group or a single bond. 02 is a divalent linking group. 0 is a single bond, an alkylene group, or a fluorinated alkylene group. 0 is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 2 to 4, nb2 is an integer of 1 to 3, and nb3 is an integer of 0 to 2. nb4 is an integer of 0 or more, and nb5 is an integer of 1 or more. M m+ represents an m-valent organic cation, where m is an integer of 1 or greater.

[0325] The compound represented by the above general formula (b0) is the same as the component (B0) in the resist composition according to the first aspect of the present invention.

[0326] [Method for producing the compound represented by general formula (b0)] The component (B0) can be produced using a known method. For example, the component (B0) can be obtained by carrying out a salt exchange reaction between a precursor Bpre represented by the following general formula (Bpre) and a compound S0 represented by the following general formula (S-0).

[0327] [ka] [In the formula, Ar 0 is an arylene group or a heteroarylene group. m1 and R m2 is a hydroxy group, an alkyl group, a fluorinated alkyl group, a fluorine atom, or a chlorine atom. 01 is a divalent linking group or a single bond. 02 is a divalent linking group. 0 is a single bond, an alkylene group, or a fluorinated alkylene group. 0is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 2 to 4, nb2 is an integer of 1 to 3, and nb3 is an integer of 0 to 2. nb4 is an integer of 0 or more, and nb5 is an integer of 1 or more. (M1" m+ ) 1 / m is an ammonium cation. - is a non-nucleophilic ion. m+ represents an m-valent organic cation, where m is an integer of 1 or greater.

[0328] More specifically, the salt exchange reaction is a step of reacting precursor Bpre with compound S0 for salt exchange in a solvent such as water, dichloromethane, acetonitrile, or chloroform to exchange the cation of precursor Bpre with the cation of compound S0, thereby obtaining component (B0).

[0329] In the above formula, (M1" m+ ) 1 / m is an ammonium cation, and the ammonium cation may be an ammonium cation derived from an aliphatic amine or an ammonium cation derived from an aromatic amine.

[0330] In the above formula, Z - Examples of the ions include those that can become acids with lower acidity than the precursor Bpre, specifically halogen ions such as bromide ions and chloride ions, BF4 - , AsF6 - , SbF6 - , PF6 - , ClO4 - etc.

[0331] The reaction temperature is, for example, 0 to 100° C., and the reaction time is, for example, 10 minutes to 24 hours.

[0332] After the salt exchange reaction is completed, the compound in the reaction mixture may be isolated and purified by a conventional method, for example, a suitable combination of concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. The structure of the compound obtained as above is 1 H-nuclear magnetic resonance (NMR) spectroscopy, 13 C-NMR spectroscopy, 19 Identification can be achieved by common organic analysis methods such as F-NMR spectroscopy, infrared absorption (IR) spectroscopy, mass spectrometry (MS), elemental analysis, and X-ray crystal diffraction.

[0333] The raw materials used in each step may be commercially available or synthesized. For example, examples of the method for producing precursor Bpre include the following methods for producing precursor Bpre 1 and 2.

[0334] [Precursor Bpre Production Method 1] The method 1 for producing precursor Bpre includes a step (first step) of reacting a compound represented by the following general formula (CA-0) (hereinafter referred to as "compound (CA0)") with a compound represented by the following general formula (I-0) (hereinafter referred to as "compound (I0)") to obtain a compound represented by the following general formula (Y-0) (hereinafter referred to as "compound (Y0)"), and a step (second step) of reacting a compound represented by the following general formula (Y-0) with a compound represented by the following general formula (X-0) (hereinafter referred to as "compound (X0)") to obtain precursor Bpre represented by the following general formula (Bpre).

[0335] [ka] [In the formula, Ar 0 is an arylene group or a heteroarylene group. m1 and R m2 is a hydroxy group, an alkyl group, a fluorinated alkyl group, a fluorine atom, or a chlorine atom. 01 is a divalent linking group or a single bond. 02 is a divalent linking group. 0 is a single bond, an alkylene group, or a fluorinated alkylene group. 0is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 2 to 4, nb2 is an integer of 1 to 3, and nb3 is an integer of 0 to 2. nb4 is an integer of 0 or more, and nb5 is an integer of 1 or more. (M1" m+ ) 1 / m is an ammonium cation. a1 and b1 react to form L 01 a2 and b2 are groups that form L 02 is a group that forms

[0336] 1st step: The first step is, for example, a step of reacting compound (CA0) with compound (I0) in an organic solvent (acetonitrile, etc.) to obtain compound (Y0).

[0337] In the first step, a condensing agent, a basic catalyst, etc. may be used. Specific examples of the condensing agent include N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and carbonyldiimidazole (CDI). Specific examples of the basic catalyst include tertiary amines such as trimethylamine, triethylamine, and tributylamine; aromatic amines such as pyridine, dimethylaminopyridine (DMAP), and pyrrolidinopyridine; diazabicyclononene (DBN); and diazabicycloundecene (DBU).

[0338] The reaction temperature in the first step is, for example, 0 to 50°C, and the reaction time is, for example, 10 minutes to 24 hours.

[0339] a1 and b1 react to form L 01 is a group that forms L 01 is an ester bond, one of a1 and b1 is a hydroxy group and the other is a carboxy group.

[0340] a2 and b2 react to form L 02is a group that forms L 02 is an ester bond, one of a2 and b2 is a hydroxy group and the other is a carboxy group.

[0341] Second step: The second step is, for example, a step of reacting the compound (Y0) with the compound (X0) in an organic solvent (acetonitrile, etc.) to obtain a precursor Bpre.

[0342] In the second step, a condensing agent, a basic catalyst, etc. may be used, as in the first step. The reaction temperature in the second step is, for example, 0 to 50°C, and the reaction time is, for example, 10 minutes to 24 hours.

[0343] [Precursor Bpre Production Method 2] The method for producing precursor Bpre 1 includes a step (step A) of reacting a compound represented by the following general formula (CA-00) (hereinafter referred to as "compound (CA00)") with a compound represented by the following general formula (X-00) (hereinafter referred to as "compound (X00)") to obtain a compound represented by the following general formula (Y-00) (hereinafter referred to as "compound (Y00)"), and a step (step B) of reacting a compound represented by the following general formula (Y-00) with a compound represented by the following general formula (Al-00) (hereinafter referred to as "compound (Al00)") to obtain precursor Bpre' represented by the following general formula (Bpre'). The precursor Bpre' is a compound used to obtain the compound (B0), and is represented by L in the general formula (b0). 01 and L 02 However, it is limited to ester bonds.

[0344] [ka] [In the formula, Ar 0 is an arylene group or a heteroarylene group. m1 and R m2 is a hydroxy group, an alkyl group, a fluorinated alkyl group, a fluorine atom, or a chlorine atom.0 is a single bond, an alkylene group, or a fluorinated alkylene group. 0 is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 2 to 4, nb2 is an integer of 1 to 3, and nb3 is an integer of 0 to 2. nb4 is an integer of 0 or more, and nb5 is an integer of 1 or more. (M1" m+ ) 1 / m is the ammonium cation.

[0345] Process A: Step A is a step in which, for example, compound (CA00) and compound (X00) are dissolved in an organic solvent (THF, hexane, etc.) and reacted in the presence of a base to obtain compound (Y00).

[0346] Specific examples of the base include sodium hydride, K2CO3, Cs2CO3, lithium diisopropylamide (LDA), triethylamine, 4-dimethylaminopyridine, and the like. The reaction temperature is, for example, 0 to 50° C., and the reaction time is, for example, 10 minutes to 24 hours.

[0347] Process B: Step B is a step in which, for example, compound (Y00) and compound (Al00) are reacted in an organic solvent (dichloromethane, etc.) to obtain a precursor Bpre'.

[0348] In step B, a condensing agent, a basic catalyst, etc. may be used. Specific examples of the condensing agent include N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and carbonyldiimidazole (CDI). Specific examples of the basic catalyst include tertiary amines such as trimethylamine, triethylamine, and tributylamine; aromatic amines such as pyridine, dimethylaminopyridine (DMAP), and pyrrolidinopyridine; diazabicyclononene (DBN); and diazabicycloundecene (DBU).

[0349] The reaction temperature in step B is, for example, 0 to 50° C., and the reaction time is, for example, 10 minutes to 24 hours.

[0350] The compound related to the third aspect of the present invention explained above is a compound that is useful as an acid generator in the resist composition related to the first aspect of the present invention.

[0351] (acid generator) An acid generator according to a fourth aspect of the present invention comprises the compound according to the third aspect described above. Such an acid generator is useful as an acid generator component for a chemically amplified resist composition. By using such an acid generator component in a chemically amplified resist composition, high sensitivity can be achieved and roughness can be further reduced in resist pattern formation. By using such an acid generator component, high sensitivity can be achieved and roughness can be further reduced, particularly in resist pattern formation using an EB or EUV light source. [Example]

[0352] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0353] <Examples of compound synthesis> [Synthesis example of intermediate] Synthesis of intermediate 1 A 300 mL three-neck flask was charged with 1,1'-carbonyldiimidazole (CDI) (4.60 g, 28.4 mmol) and acetonitrile (20 g), followed by dropwise addition of 3,5-diiodosalicylic acid (CA1) (10.0 g, 25.5 mmol) dissolved in acetonitrile (20 g) over 30 minutes and the reaction was allowed to proceed for 1 hour. Compound (I-1) (9.5 g, 30.6 mmol) was then added and the reaction was allowed to proceed for 3 hours at 65°C. After cooling, ultrapure water (250 g) was added and the mixture was stirred for 30 minutes. The precipitated solid was then filtered. The filtered residue was again dissolved in methanol (100 g) and added dropwise to MTBE (500 g), and the precipitated solid was filtered. The filtered residue was dried under reduced pressure to obtain intermediate 1.

[0354] [ka]

[0355] Synthesis of intermediates 2-6 Intermediates 2 to 6 were synthesized in the same manner as in the synthesis example for Intermediate 1, except that 3,5-diiodosalicylic acid (CA1) (10.0 g, 25.5 mmol) was replaced with an equimolar amount of any of the following carboxylic acids CA2 to CA6.

[0356] [ka]

[0357] [ka]

[0358] Synthesis of intermediate 7 A 500 mL three-neck flask was charged with a 1.06 M THF / hexane solution (87 mL, 92.3 mmol) of lithium diisopropylamide (LDA). After cooling to 5°C, 4-iodophenol (10.1 g, 46.0 mmol) dissolved in THF (30 g) was added and the mixture was allowed to react for 2 hours at 5°C or below. Tetraiodophthalic anhydride (15.0 g, 23.0 mmol) dissolved in THF (150 g) was then added and the mixture was allowed to react for 2 hours at 5°C or below. The reaction solution was poured into ultrapure water (205 g) over 30 minutes, followed by the addition of heptane (205 g). After stirring for 30 minutes, the organic layer was removed. The aqueous layer was washed three times with heptane (100 g), then MTBE (150 g) and 10% aqueous citric acid solution (86.5, 45.0 mmol) were added, and the mixture was stirred for 30 minutes. The aqueous layer was then removed. The collected organic layer was washed three times with ultrapure water (150 g), and the organic layer was concentrated using a rotary evaporator. The concentrate was recrystallized with ethyl acetate to obtain intermediate 7.

[0359] [ka]

[0360] Synthesis of intermediate 8 Intermediate 8 was obtained in the same manner as in the synthesis example of Intermediate 7, except that 4-iodophenol (10.1 g, 46.0 mmol) was changed to 3,5-diiodophenol (15.9 g, 25.5 mmol).

[0361] [ka]

[0362] Synthesis of intermediate 9 Intermediate 9 was obtained in the same manner as in the synthesis example of Intermediate 7, except that 4-iodophenol (10.1 g, 46.0 mmol) was changed to 2,4,6-triiodophenol (21.7 g, 25.5 mmol).

[0363] [ka]

[0364] Synthesis of intermediate 10 Intermediate 10 was obtained in the same manner as in the synthesis example of Intermediate 1, except that compound (I-1) (9.5 g, 30.6 mmol) was changed to compound (I-2) (11.6 g, 30.6 mmol).

[0365] [ka]

[0366] Synthesis of intermediate 11 Intermediate 11 was obtained in the same manner as in the synthesis example of Intermediate 1, except that 3,5-diiodosalicylic acid (10.0 g, 25.6 mmol) was changed to 2,5-diiodosalicylic acid (10.0 g, 25.5 mmol) and compound (I-1) (9.5 g, 30.6 mmol) was changed to compound (I-3) (11.5 g, 30.6 mmol).

[0367] [ka]

[0368] Synthesis of intermediate 12 Intermediate 12 was obtained in the same manner as in the synthesis example of Intermediate 1, except that 3,5-diiodosalicylic acid (10.0 g, 25.6 mmol) was changed to 2,5-diiodosalicylic acid (10.0 g, 25.5 mmol) and compound (I-1) (9.5 g, 30.6 mmol) was changed to compound (I-4) (11.0 g, 30.6 mmol).

[0369] [ka]

[0370] [Precursor synthesis example] Synthesis of precursor (Bpre-01) 4-Iodobenzoic acid (CA7) (4.0 g, 16.1 mmol), intermediate 1 (9.9 g, 14.5 mmol), and dichloromethane (180 g) were added to a 300 mL three-neck flask and stirred at room temperature to dissolve. Next, diisopropylcarbodiimide (DIC) (3.1 g, 24.2 mmol) and dimethylaminopyridine (0.2 g, 1.6 mmol) were added and reacted at room temperature for 5 hours. The reaction solution was filtered, and the filtrate was concentrated using a rotary evaporator. The concentrate was dissolved in acetonitrile (30 g) and then added dropwise to MTBE (180 g). The precipitated solid was filtered. The filtered residue was again dissolved in acetonitrile (60 g) and added dropwise to MTBE (400 g). The precipitated solid was filtered. This procedure was repeated twice, and the filtered residue was dried under reduced pressure to obtain precursor (Bpre-01).

[0371] [ka]

[0372] Synthesis of precursors (Bpre-02) to (Bpre-13), (Bpre-17) to (Bpre-19) Precursors (Bpre-02) to (Bpre-13) and (Bpre-17) to (Bpre-19) were synthesized in the same manner as in the synthesis example of precursor (Bpre-01), except that the combination of carboxylic acid and intermediate was changed. The combinations of carboxylic acids and intermediates used to obtain each precursor are shown in Table 1.

[0373] [ka]

[0374] [ka]

[0375] [ka]

[0376] [Table 1]

[0377] Synthesis of precursor (Bpre-14) Intermediate 7 (10.4 g, 12.1 mmol), compound (I-1) (3.4 g, 10.9 mmol), and dichloromethane (180 g) were added to a 300 mL three-neck flask and dissolved by stirring at room temperature. Next, diisopropylcarbodiimide (DIC) (2.3 g, 18.2 mmol) and dimethylaminopyridine (0.2 g, 1.6 mmol) were added and reacted at room temperature for 5 hours. The reaction solution was filtered, and the filtrate was concentrated using a rotary evaporator. The concentrate was dissolved in acetonitrile (30 g) and then added dropwise to MTBE (180 g). The precipitated solid was filtered. The residue was again dissolved in acetonitrile (60 g) and added dropwise to MTBE (400 g). The precipitated solid was filtered. This procedure was repeated twice, and the residue was dried under reduced pressure to obtain precursor (Bpre-14).

[0378] [ka]

[0379] Synthesis of precursor (Bpre-15) and precursor (Bpre-16) Precursor (Bpre-15) was obtained in the same manner as in the synthesis example of precursor (Bpre-14), except that intermediate 7 (10.4 g, 12.1 mmol) was changed to an equimolar amount of intermediate 8. Furthermore, precursors (Bpre-15) and (Bpre-16) were obtained in the same manner as in the synthesis example of precursor (Bpre-14), except that intermediate 7 (10.4 g, 12.1 mmol) was replaced with an equimolar amount of intermediate 9.

[0380] [ka]

[0381] [Synthesis example of compound (B0)] Synthesis of compound (B0-1) The precursor (Bpre-01) (10.0 g, 10.9 mmol) and salt-exchange compound A (3.93 g, 11.5 mmol) were dissolved in dichloromethane (120 g), and ultrapure water (120 g) was added. The mixture was allowed to react at room temperature for 30 minutes. After the reaction was completed, the aqueous phase was removed, and the organic phase was washed four times with ultrapure water (120 g). The organic phase was concentrated to dryness using a rotary evaporator to obtain compound (B0-1).

[0382] [ka]

[0383] Synthesis of compounds (B0-2) to (B0-22) Compounds (B0-2) to (B0-22) were obtained in the same manner as in the above "Synthesis example of compound (B0-1)," except that the combinations of the above precursors (Bpre-01) to (Bpre-19) and the following salt-exchange compounds A to D were changed. NMR measurements were carried out on each of the obtained compounds, and their structures were identified from the following analytical results.

[0384] [ka]

[0385] [ka]

[0386] [ka]

[0387] [ka]

[0388] Compound (B0-1): A combination of precursor (Bpre-01) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=7.99(d,I-ArH,1H),7.73-7.90(m,ArH,I-ArH,20H),4.81-4.88(m,CF2CH2,2H)

[0389] Compound (B0-2): A combination of precursor (Bpre-02) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.05(d,I-ArH,1H),7.74-7.90(m,ArH,I-ArH,19H),4.81-4.88(m,CF2CH2,2H)

[0390] Compound (B0-3): A combination of precursor (Bpre-03) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.05(d,I-ArH,1H),7.74-7.90(m,ArH,I-ArH,19H),4.81-4.88(m,CF2CH2,2H)

[0391] Compound (B0-4): A combination of precursor (Bpre-04) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.34(d,I-ArH,1H),7.99(d,I-ArH,1H),7.74-7.90(m,ArH,I-ArH,17H),4.81-4.88(m,CF2CH2,2H)

[0392] Compound (B0-5): A combination of precursor (Bpre-05) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.05(d,I-ArH,1H),7.74-7.90(m,ArH,I-ArH,17H),4.81-4.88(m,CF2CH2,2H)

[0393] Compound (B0-6): A combination of precursor (Bpre-06) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=7.99(d,I-ArH,1H),7.74-7.90(m,ArH,I-ArH.16H),4.81-4.88(m,CF2CH2,2H)

[0394] Compound (B0-7): A combination of precursor (Bpre-07) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.12(d,I-ArH,1H),7.73-7.90(m,ArH,I-ArH,19H),4.81-4.88(m,CF2CH2,2H)

[0395] Compound (B0-8): A combination of precursor (Bpre-08) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.12(d,I-ArH,1H),8.05(d,I-ArH,1H),7.74-7.90(m,ArH,I-ArH,17H),4.81-4.88(m,CF2CH2,2H)

[0396] Compound (B0-9): A combination of precursor (Bpre-09) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.34(d,I-ArH,1H),8.12(d,I-ArH,1H),7.74-7.90(m,ArH,I-ArH,16H),4.81-4.88(m,CF2CH2,2H)

[0397] Compound (B0-10): A combination of precursor (Bpre-10) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.12(d,I-ArH,1H),8.05(d,I-ArH,1H),7.74-7.90(m,ArH,15H),4.81-4.88(m,CF2CH2,2H)

[0398] Compound (B0-11): A combination of precursor (Bpre-11) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.12(d,I-ArH,1H),7.74-7.90(m,ArH,15H),4.81-4.88(m,CF2CH2,2H)

[0399] Compound (B0-12): A combination of precursor (Bpre-12) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=9.48(s,NH,1H),8.35(d,I-ArH,1H),7.74-7.90(m,ArH,15H),4.81-4.88(m,CF2CH2,2H)

[0400] Compound (B0-13): A combination of precursor (Bpre-13) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=9.48(s,NH,2H),7.74-7.90(m,ArH,I-ArH19H),4.81-4.88(m,CF2CH2,2H)

[0401] Compound (B0-14): A combination of precursor (Bpre-14) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=7.74-7.90(m,ArH,15H),7.57(d,I-ArH,2H),6.73(d,I-ArH,2H),4.81-4.88(m,CF2CH2,2H)

[0402] Compound (B0-15): A combination of precursor (Bpre-15) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.05(d,I-ArH,1H),7.74-7.90(m,ArH,15H),6.84(d,I-ArH,2H),4.81-4.88(m,CF2CH2,2H)

[0403] Compound (B0-16): A combination of precursor (Bpre-16) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=7.99(d,I-ArH,2H),7.74-7.90(m,ArH,15H),4.81-4.88(m,CF2CH2,2H)

[0404] Compound (B0-17): A combination of precursor (Bpre-17) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.34(d,I-ArH,1H),7.99(d,I-ArH,1H),7.74-7.90(m,ArH,I-ArH,17H),5.93(m,CFCH,1H)

[0405] Compound (B0-18): A combination of precursor (Bpre-18) and salt-exchanging compound A 1H-NMR (DMSO, 400MHz): δ(ppm)=8.34(d,I-ArH1H),7.74-7.90(m,ArH,I-ArH,18H),4.05-4.25(m,COO-“CH2”CH2-,2H),2.63-2.73(m,COOCH2“CH2”,2H)

[0406] Compound (B0-19): A combination of precursor (Bpre-19) and salt-exchanging compound A 1 H-NMR(DMSO,400MHz):δ(ppm)=8.34(d,I-ArH1H),7.74-7.90(m,ArH,I-ArH,18H),4.91-5.20(m,CFCH,1 H),3.95-4.20(m,COO-“CH2”CH2-,2H),2.30-2.45(m,COOCH2“CH2”,1H),1.61-1.72(m,COOCH2“CH2”,1H)

[0407] Compound (B0-20): A combination of precursor (Bpre-17) and salt-exchanging compound B 1 H-NMR(DMSO,400MHz):δ(ppm)=8.34(d,I-ArH,1H),7.70-8.22(m,ArH,I-ArH,17H),5.93(m,CFCH,1H),3.30-3.45(m,SO2CH,1H),1.09-1.90(m,Cyclohexyl,10H)

[0408] Compound (B0-21): A combination of precursor (Bpre-17) and salt-exchanging compound C 1 H-NMR(DMSO,400MHz):δ(ppm)=8.34(d,I-ArH,1H),7.99(d,I-ArH,1H),7.77-7.98(m,ArH,I-ArH13H),5.93(m,CFCH,1H)

[0409] Compound (B0-22): A combination of precursor (Bpre-17) and salt-exchange compound D 1H-NMR(DMSO,400MHz):δ(ppm)=8.50(d,ArH,2H),8.37(d,ArH,2H),8.34(d,I-ArH,1H),7.99(d,I-ArH,1 H),7.93(t,ArH,2H),7.84(d,I-ArH,1H),7.76(d,I-ArH,1H),7.55-7.75(m,ArH,7H),5.93(m,CFCH,1H)

[0410] <Preparation of Resist Composition> (Examples 1 to 27, Comparative Examples 1 to 5) The components shown in Tables 2 to 6 were mixed and dissolved to prepare the resist compositions of the respective examples.

[0411] [Table 2]

[0412] [Table 3]

[0413] [Table 4]

[0414] [Table 5]

[0415] [Table 6]

[0416] In Tables 2 to 6, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass).

[0417] (A)-1: A polymer compound represented by the following chemical formula (A-1): The weight average molecular weight (Mw) of this polymer compound (A-1) calculated in terms of standard polystyrene by GPC measurement was 6100, and the molecular weight dispersity (Mw / Mn) was 1.65. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50.

[0418] (A)-2: A polymer compound represented by the following chemical formula (A-2): The weight average molecular weight (Mw) of this polymer compound (A-2) calculated in terms of standard polystyrene by GPC measurement was 6,300, and the molecular weight dispersity (Mw / Mn) was 1.67. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50.

[0419] (A)-3: Polymer compound represented by the following chemical formula (A-3): For this polymer compound (A-3), the weight average molecular weight (Mw) calculated in terms of standard polystyrene, as determined by GPC measurement, is 6100, and the molecular weight dispersity (Mw / Mn) is 1.69. 13 The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m = 50 / 50.

[0420] [ka]

[0421] (B0)-1 to (B0)-22: Acid generators each consisting of the above-mentioned compounds (B0-1) to (B0-22).

[0422] (B1)-1: An acid generator comprising the following compound (B-1): (B1)-2: An acid generator comprising the following compound (B-2): (B1)-3: An acid generator comprising the following compound (B-3): (D)-1: An acid diffusion controller consisting of the following compound (D-1): (S)-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether=60 / 40 (mass ratio).

[0423] [ka]

[0424] <Formation of Resist Pattern> Each resist composition of each example was applied using a spinner onto an 8-inch silicon substrate that had been treated with hexamethyldisilazane (HMDS), and then pre-baked (PAB) on a hot plate at 110°C for 60 seconds, followed by drying to form a resist film with a thickness of 50 nm. Next, the resist film was subjected to exposure to light using an electron beam lithography system JEOL-JBX-9300FS (manufactured by JEOL Ltd.) at an acceleration voltage of 100 kV, resulting in a 1:1 line and space pattern (hereinafter referred to as "LS pattern") with a target size of 35 nm line width. This was followed by a post-exposure bake (PEB) treatment at 110°C for 60 seconds. Subsequently, alkaline development was performed for 60 seconds at 23°C using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.). After that, the substrate was rinsed with pure water for 15 seconds, resulting in the formation of a 1:1 LS pattern with a line width of 35 nm and a pitch of 70 nm.

[0425] [Evaluation of optimal exposure (Eop)] The optimum exposure dose Eop (μC / cm) for forming a target size LS pattern by the above <Resist pattern formation> 2 This is called "Eop (μC / cm 2 )" are shown in Tables 7 to 10.

[0426] [Evaluation of LWR (Line Width Roughness)] For the LS patterns formed in the above <Formation of Resist Pattern>, 3σ, which is a measure of LWR, was determined. This is shown as "LWR (nm)" in Tables 7 to 10 of the lithography evaluation results. "3σ" indicates three times the standard deviation (σ) (unit: nm) obtained from the measurement results of measuring 400 line positions in the longitudinal direction of the line using a scanning electron microscope (accelerating voltage 800 V, product name: S-9380, manufactured by Hitachi High-Technologies Corporation). The smaller the 3σ value, the less rough the line sidewalls are, meaning that an LS pattern with a more uniform width is obtained.

[0427] [Table 7]

[0428] [Table 8]

[0429] [Table 9]

[0430] [Table 10]

[0431] As shown in Tables 7 to 10, it was confirmed that the resist compositions of the examples were able to achieve a better balance between sensitivity and LWR reduction during resist pattern formation than the resist compositions of the comparative examples.

[0432] Comparison of Example 1 with Comparative Examples 1 and 2 When the resist composition of Example 1 containing compound (B0-1) was compared with the resist composition of Comparative Example 1 containing compound (B-1) having three iodine atoms but only one aromatic ring, the resist composition of Example 1 had a significantly lower LWR value and better roughness reduction properties. Furthermore, when the resist composition of Example 1 containing compound (B0-1) was compared with the resist composition of Comparative Example 2 containing compound (B-2) which had three iodine atoms and two aromatic rings, but one of the aromatic rings did not contain an iodine atom, the resist composition of Example 1 had a significantly lower LWR value and better roughness reduction properties. This is presumably because compound (B0-1) has two aromatic rings each having an iodine atom, and therefore has good acid diffusion controllability and excellent roughness reduction properties.

[0433] Comparison of Example 17 and Comparative Example 3 Comparing the resist composition of Example 17, which contains compound (B0-17), with the resist composition of Comparative Example 3, which contains compound (B-3), which has two aromatic rings each containing an iodine atom, but has only one iodine atom in the aromatic ring closer to the sulfonate anion, the resist composition of Example 17 had significantly lower Eop and LWR values, higher sensitivity, and better roughness reduction properties. This is presumably because compound (B0-17) has two iodine atoms in the aromatic ring closer to the sulfonate anion, and therefore the acid strength of the acid generated by exposure is moderate.

Claims

1. A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, a base component (A) whose solubility in a developer changes under the action of an acid; and an acid generator component (B) that generates an acid upon exposure to light, The resist composition, wherein the acid generator component (B) includes a compound (B0) represented by the following general formula (b0): 【Chemistry 1】 [In the formula, Ar ０ is an arylene group or a heteroarylene group. ｍ１ and R ｍ２ are each independently a substituent other than an iodine atom. ０１ is a divalent linking group or a single bond. ０２ is a divalent linking group. ０ is a single bond, an alkylene group, or a fluorinated alkylene group. ０ is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 2 to 4, nb2 is an integer of 1 to 3, and nb3 is an integer of 0 to 2. nb4 is an integer of 0 or more, and nb5 is an integer of 1 or more. M ｍ＋ represents an m-valent organic cation, where m is an integer of 1 or more.

2. 2. The resist composition according to claim 1, wherein the total number of said nb1 and said nb5 is an integer of 4 to 9.

3. The Ar ０ 3. The resist composition according to claim 1, wherein is a phenylene group.

4. 4. The resist composition according to claim 1, wherein the content of the acid generator component (B) is 15 to 50 parts by mass relative to 100 parts by mass of the base component (A).

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

6. 6. The method for forming a resist pattern according to claim 5, wherein in the step of exposing the resist film, the resist film is exposed to EUV (extreme ultraviolet) or EB (electron beam).

7. A compound represented by the following general formula (b0): 【Chemistry 2】 [In the formula, Ar ０ is an arylene group or a heteroarylene group. ｍ１ and R ｍ２ are each independently a substituent other than an iodine atom. ０１ is a divalent linking group or a single bond. ０２ is a divalent linking group. ０ is a single bond, an alkylene group, or a fluorinated alkylene group. ０ is a hydrogen atom, a fluorinated alkyl group having 1 to 5 carbon atoms, or a fluorine atom. nb1 is an integer of 2 to 4, nb2 is an integer of 1 to 3, and nb3 is an integer of 0 to 2. nb4 is an integer of 0 or more, and nb5 is an integer of 1 or more. M ｍ＋ represents an m-valent organic cation, where m is an integer of 1 or more.

8. An acid generator comprising the compound of claim 7 .

Images