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

Abstract

To provide a compound, an acid generator, a resist composition, and a resist pattern forming method which reduce an environmental load, achieve higher sensitivity, and can form a resist pattern excellent in lithographic characteristics.SOLUTION: The resist composition, which generates an acid upon exposure and whose solubility in a developer changes by the action of an acid, contains: a base component (A) whose solubility in a developer changes by the action of an acid; an acid generator component (B) which generates an acid upon exposure; and an acid diffusion controller component (D). The acid generator component (B) contains a compound represented by general formula (b1-1) described in the specification.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 lithography, for example, a process is performed in which a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed to light, and a developing process is performed to form a resist pattern of a predetermined shape on the resist film. A resist material in which the exposed portion of the resist film changes to a property that makes it soluble in a developer is called a positive type, and a resist material in which the exposed portion changes to a property that makes it insoluble in a developer is called a negative type. 2. Description of the Related Art In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, advances in lithography technology have led to rapid progress in miniaturization of patterns. In general, miniaturization techniques involve shortening the wavelength (increasing the energy) of the exposure light source. Specifically, ultraviolet rays such as g-line and i-line have been used in the past, but currently mass production of semiconductor elements using KrF excimer lasers and ArF excimer lasers has begun. In addition, EUV (extreme ultraviolet), EB (electron beam), X-rays, and other light sources with shorter wavelengths (higher energy) than these excimer lasers are also being investigated. In this situation, resist materials are required to have lithography properties such as sensitivity to these exposure light sources or energy sources, and resolution capable of reproducing patterns with fine dimensions.

[0003] As a resist material that satisfies such requirements, a chemically amplified resist composition that contains an acid generator component that generates acid upon exposure and a base component whose solubility in a developer changes due to the action of acid has conventionally been used.

[0004] For example, Patent Document 1 discusses a resist composition and a method for forming a resist pattern that can achieve high sensitivity and excellent lithography properties. Patent Document 1 also describes a resist composition that uses multiple types of acid generator components having a specific structure, employs a polymer compound having multiple constitutional units having a specific structure, and improves dissociation performance against acid. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 065207 Summary of the Invention [Problem to be solved by the invention]

[0006] As lithography technology continues to advance and resist patterns become increasingly finer, resist compositions are required to have high sensitivity to the exposure light source and good lithography properties such as reduced roughness. Furthermore, in recent years, from the viewpoint of environmental protection, there has been a demand for reducing the use of organic fluorine compounds. However, when fluorine atoms are removed from a fluorine-containing compound used as an acid generator, a good pattern shape can be obtained, but the sensitivity tends to deteriorate, and there is a trade-off between the pattern shape and the sensitivity.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a compound, an acid generator, a resist composition, and a method of forming a resist pattern that reduce the environmental load, achieve high sensitivity, and are capable of forming a resist pattern that has excellent lithography properties. [Means for solving the problem]

[0008] As a result of intensive investigations aimed at solving the above-mentioned problems, the present inventors have found that, by configuring as follows, it is possible to obtain a compound, an acid generator, a resist composition, and a method of forming a resist pattern that reduce the environmental impact, achieve high sensitivity, and are capable of forming a resist pattern that has excellent lithography properties, and have thus completed the present invention.

[0009] That is, the present invention is as follows. A resist composition according to an embodiment of the present invention is a resist composition that generates an acid upon exposure and changes its solubility in a developer by the action of the acid, The composition contains a base component (A) whose solubility in a developer changes under the action of an acid, an acid generator component (B) that generates an acid upon exposure to light, and an acid diffusion controller component (D), The acid generator component (B) includes a compound represented by the following general formula (b1-1).

[0010] [ka]

[0011] [In general formula (b1-1), X 1 and Y 1 each independently represents a halogen atom other than a fluorine atom, a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group, an electron-withdrawing group, a selenol group, a pentafluorosulfanyl group, a mercapto group, a thiocarboxylic acid group, or a dithiocarboxylic acid group. 1 and Y 1 may be bonded to each other to form a ring. n1 represents an integer of 1 to 10. m represents an integer of 1 or more, and M m+ represents an organic cation having a valence of m.

[0012] A method for forming a resist pattern according to a second embodiment of the present invention is a method for forming a resist pattern including the steps of forming a resist film on a support using a resist composition according to an embodiment of the present invention, exposing the resist film to light, and developing the resist film to form a resist pattern.

[0013] The compound according to the third embodiment of the present invention is represented by the above general formula (b1-1).

[0014] Moreover, the acid generator according to the fourth embodiment of the present invention contains the compound represented by the above general formula (b1-1). Effect of the Invention

[0015] The present invention is capable of providing a compound, an acid generator, a resist composition, and a method of forming a resist pattern that reduce the environmental impact, achieves high sensitivity, and is capable of forming a resist pattern that has excellent lithography properties. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the preferred embodiments. However, the present invention is not limited to the preferred embodiments described below.

[0017] In the present disclosure, the term "aliphatic" is a relative concept to aromaticity and is defined as meaning a group, compound, etc. that does not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in an alkoxy group. The term "alkylene group" includes, unless otherwise specified, linear, branched and cyclic divalent saturated hydrocarbon groups. The term "halogenated alkyl group" refers to an alkyl group in which some or all of the hydrogen atoms have been substituted with halogen atoms, and examples of the halogen atoms include fluorine, chlorine, bromine and iodine atoms. The term "fluorinated alkyl group" or "fluorinated alkylene group" refers to an alkyl group or alkylene group in which some or all of the hydrogen atoms have been substituted with fluorine atoms. The term "structural unit" refers to a monomer unit that constitutes a polymeric compound (resin, polymer, copolymer). The term "optionally substituted" refers to the case where a hydrogen atom (-H) is replaced with a monovalent group, or the case where a methylene group (-CH 2 -) is replaced with a divalent group. The term "exposure" is intended to include any concept including irradiation with radiation.

[0018] The term "structural unit derived from an acrylate ester" refers to a structural unit formed by cleavage of the ethylenic double bond of an acrylate ester. "Acrylic acid ester" is acrylic acid (CH 2 It is a compound in which the hydrogen atom at the end of the carboxy group of benzenediamine (=CH-COOH) is replaced with an organic group. In the acrylic acid ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. α0 ) is an atom or group other than a hydrogen atom, and examples thereof include an alkyl group having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms. In addition, the acrylic acid ester has a substituent (R α0 Itaconic acid diesters in which the substituent (R α0 It also includes α-hydroxyacrylic esters in which the α-position carbon atom of an acrylic ester is substituted with a hydroxyalkyl group or a group that modifies the hydroxyl group of the acrylic ester. Unless otherwise specified, the carbon atom at the α-position of an acrylic ester refers to the carbon atom to which the carbonyl group of the acrylic ester is bonded. Hereinafter, an acrylic ester in which the hydrogen atom bonded to the carbon atom at the α-position is replaced with a substituent may be referred to as an α-substituted acrylic ester. In addition, acrylic esters and α-substituted acrylic esters may be collectively referred to as "(α-substituted) acrylic esters."

[0019] The term "structural unit derived from hydroxystyrene" refers to a structural unit formed by cleavage of the ethylenic double bond of hydroxystyrene. The term "structural unit derived from a hydroxystyrene derivative" refers to a structural unit formed by cleavage of the ethylenic double bond of a hydroxystyrene derivative. The term "hydroxystyrene derivative" refers to a concept including hydroxystyrene in which the hydrogen atom at the α-position is replaced by another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include hydroxystyrene in which the hydrogen atom at the α-position may be replaced by a substituent, in which the hydrogen atom of the hydroxyl group is replaced by an organic group; and hydroxystyrene in which the hydrogen atom at the α-position may be replaced by a substituent, in which a substituent other than a hydroxyl group is bonded to the benzene ring. The α-position (the carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified. Examples of the substituent that substitutes the hydrogen atom at the α-position of the hydroxystyrene include the same as those exemplified as the substituent at the α-position in the above-mentioned α-substituted acrylic ester.

[0020] The term "structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative" refers to a structural unit formed by cleavage of the ethylenic double bond of vinylbenzoic acid or a vinylbenzoic acid derivative. The term "vinyl benzoic acid derivative" refers to a concept including vinyl benzoic acid in which the hydrogen atom at the α-position is replaced by another substituent such as an alkyl group or a halogenated alkyl group, as well as derivatives thereof. Examples of such derivatives include vinyl benzoic acid in which the hydrogen atom at the α-position may be replaced by a substituent, the hydrogen atom of the carboxyl group of the vinyl benzoic acid in which the hydrogen atom at the α-position may be replaced by a substituent, and vinyl benzoic acid in which the hydrogen atom at the α-position may be replaced by a substituent, and in which a substituent other than a hydroxyl group or a carboxyl group is bonded to the benzene ring. The α-position (the carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified.

[0021] The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, and specific examples thereof include alkyl groups having 1 to 5 carbon atoms (such as 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). Specific examples of the halogenated alkyl group as the substituent at the α-position include groups in which some or all of the hydrogen atoms of the above-mentioned "alkyl group as the substituent at the α-position" are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferred. Specific examples of the hydroxyalkyl group as the substituent at the α-position include the above-mentioned "alkyl group as the substituent at the α-position" in which some or all of the hydrogen atoms have been substituted with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

[0022] In the present disclosure, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. Furthermore, in the present disclosure, when a plurality of substances corresponding to each component are present in the composition, the amount of each component in the composition means the total amount of the corresponding substances present in the composition, unless otherwise specified. Furthermore, chemical structural formulas in this disclosure may be described as simplified structural formulas in which hydrogen atoms are omitted. In the present disclosure, some structures represented by chemical formulas may have asymmetric carbons, and may have enantiomers or diastereomers. In such cases, a single chemical formula represents all of the isomers. These isomers may be used alone or as a mixture. In the present disclosure, "mass %" and "weight %" are synonymous, and "parts by mass" and "parts by weight" are synonymous.

[0023] [Resist Composition] A resist composition according to an embodiment of the present invention is a resist composition that generates an acid upon exposure and changes its solubility in a developer by the action of the acid, The photoresist contains a base component (A) (hereinafter also referred to as "component (A)") whose solubility in a developer changes due to the action of an acid, an acid generator component (B) (hereinafter also referred to as "component (B)") that generates an acid upon exposure to light, and an acid diffusion controller component (D) (hereinafter also referred to as "component (D)"), and the acid generator component (B) contains a compound represented by general formula (b1-1).

[0024] When a resist film is formed using the resist composition of this embodiment and the resist film is selectively exposed, an acid is generated in the exposed portion of the resist film, and the solubility of the component (A) in the developer changes due to the action of the acid, while the solubility of the component (A) in the developer does not change in the unexposed portion of the resist film, so that a difference in solubility in the developer occurs between the exposed portion and the unexposed portion of the resist film. Therefore, when the resist film is developed, if the resist composition is a positive type, the exposed portion of the resist film is dissolved and removed to form a positive type resist pattern, and if the resist composition is a negative type, the unexposed portion of the resist film is dissolved and removed to form a negative type resist pattern.

[0025] In the present disclosure, a resist composition that forms a positive resist pattern by dissolving and removing exposed portions of the resist film is referred to as a positive resist composition, and a resist composition that forms a negative resist pattern by dissolving and removing unexposed portions of the resist film is referred to as a negative resist composition. The resist composition of this embodiment may be a positive resist composition or a negative resist composition. Furthermore, the resist composition of the present embodiment may be for an alkaline developing process in which an alkaline developer is used in the developing treatment during resist pattern formation, or may be for a solvent developing process in which a developer containing an organic solvent (organic developer) is used in the developing treatment. In other words, the resist composition of this embodiment is a "positive resist composition for an alkaline developing process" that forms a positive resist pattern in an alkaline developing process, and a "negative resist composition for a solvent developing process" that forms a negative resist pattern in a solvent developing process.

[0026] The resist composition of the present embodiment is a resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, and contains a base component (A) whose solubility in a developer changes due to the action of the acid, an acid generator component (B) that generates acid upon exposure, and an acid diffusion controller component (D).

[0027] The component (A) may generate an acid upon exposure, in which case 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." 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) described below is preferably a polymeric compound that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid. As such a polymeric compound, a copolymer having a structural unit that generates an acid upon exposure can be used. As a structural unit that generates an acid upon exposure, for example, known ones can be mentioned.

[0028] The resist composition according to an embodiment of the present invention contains a compound represented by general formula (b1-1) described below as an acid generator component (B).

[0029] In conventional resist processes, the fluorine-containing PAG anion, which is generally used as an acid generator, segregates on the surface of the resist pattern, causing a problem of poor rectangularity in the pattern shape. However, removing the fluorine from the fluorine-containing PAG anion improves the rectangularity of the pattern shape, but the sensitivity is also significantly reduced.

[0030] The compound represented by general formula (b1-1) according to the embodiment of the present invention contains a sulfonate anion having a chain carboxylic acid, and the hydrogen of the carboxylic acid acts as a hydrogen bond donor site, interacting with the sulfonic acid to stabilize the anion, resulting in a lower pKa and high sensitivity. Furthermore, the compound represented by general formula (b1-1) does not contain a fluorine atom, and therefore not only can it reduce the burden on the environment, but it is also believed that the segregation of PAG anion on the resist pattern surface can be eliminated, resulting in the formation of a resist pattern with a good shape.

[0031] Component (A) In the resist composition of this embodiment, the component (A) is a base component whose solubility in a developer changes under the action of an acid, and the component (A) preferably contains a resin component (A1) (hereinafter also referred to as "component (A1)") whose solubility in a developer changes under the action of an acid. The component (A) may be one whose solubility in a developer increases under the action of an acid, or one whose solubility in a developer decreases under the action of an acid. By using the component (A1), the polarity of the base component (A) changes before and after exposure, so that good development contrast can be obtained not only in an alkaline development process but also in a solvent development process. As the component (A), at least the component (A1) is used, and other polymeric compounds and / or low molecular weight compounds may be used in combination with the component (A1).

[0032] When an alkaline development process is applied, the base material component (A) containing the component (A1) is poorly soluble in an alkaline developer before exposure, and when an acid is generated from the component (B) by exposure, the polarity of the base material component (A) increases due to the action of the acid, and the solubility in an alkaline developer increases. Therefore, in forming a resist pattern, when a resist film obtained by applying the resist composition on a support is selectively exposed, the exposed part of the resist film changes from poorly soluble in an alkaline developer to soluble, while the unexposed part of the resist film remains poorly soluble in an alkaline developer, and a positive resist pattern is formed by alkaline development.

[0033] On the other hand, when a solvent development process is applied, the base material component (A) containing the component (A1) is highly soluble in an organic developer before exposure, and when an acid is generated from the component (B) by exposure, the polarity of the base material component (A) increases due to the action of the acid, and the solubility in an organic developer decreases. Therefore, in forming a resist pattern, when a resist film obtained by applying the resist composition on a support is selectively exposed, the exposed part of the resist film changes from soluble to poorly soluble in an organic developer, while the unexposed part of the resist film remains soluble, and therefore, by developing with an organic developer, a contrast can be created between the exposed part and the unexposed part, and a negative resist pattern is formed.

[0034] The component (A) preferably contains a polymeric compound (A1) (hereinafter also referred to as "component (A1)") having a structural unit (a1) that contains an acid-decomposable group whose polarity increases under the action of acid. The component (A1) may include, in addition to the structural unit (a1), a lactone-containing cyclic group, -SO 2 It is preferable to use a polymeric compound having a structural unit (a2) that contains a -containing cyclic group or a carbonate-containing cyclic group.

[0035] In the resist composition according to an embodiment of the present invention, the component (A) may use either a single type, or a combination of two or more types.

[0036] The component (A) is preferably a polymer compound that does not fall under PFAS (Per- and Polyfluoroalkyl Substances). In other words, the component (A1) is preferably a compound that does not fall under PFAS. When the component (A) contains other components other than the component (A1), it is preferable that the other components are also compounds that do not fall under PFAS. "PFAS" refers to a compound that has a trifluoromethyl group (-CF 3 ) and compounds containing a difluoromethylene group (-CF 2 -) is a compound containing

[0037] <Constituent unit (a1)> The structural unit (a1) is a structural unit that contains an acid-decomposable group whose polarity increases when acted upon by an acid. The term "acid-decomposable group" refers to a group having acid decomposability in which at least a part of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases under the action of an acid include groups that are decomposed by the action of an acid to generate a polar group. Examples of polar groups include carboxyl groups, hydroxyl groups, amino groups, and sulfo groups (-SO 3 Among these, polar groups containing -OH in the structure (hereinafter sometimes referred to as "OH-containing polar groups") are preferred, with a carboxy group or a hydroxyl group being more preferred, and a carboxy group being particularly preferred. 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). The term "acid dissociable group" as used herein refers to both (i) a group having acid dissociability in which the bond between the acid dissociable group and an atom adjacent to the acid dissociable group can be cleaved by the action of an acid, and (ii) a group in which a portion of the bond is cleaved by the action of an acid and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid dissociable group and an atom adjacent to the acid dissociable group. The acid dissociable group constituting the acid decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid dissociable group, and thus, when the acid dissociable group is dissociated by the action of an acid, a polar group with higher polarity than the acid dissociable group is generated, increasing the polarity. As a result, the polarity of the entire (A1) component increases. The increase in polarity relatively changes the solubility in the developer, increasing the solubility when the developer is an alkaline developer, and decreasing the solubility when the developer is an organic developer.

[0038] The structural unit (a1) preferably contains an acid-decomposable group having an alicyclic hydrocarbon group, and more preferably contains an acid-decomposable group having a monocyclic alicyclic hydrocarbon group. The acid-decomposable group (acid-dissociable group) in the structural unit (a1) has an appropriate bulkiness, making it possible to appropriately adjust the acid diffusion control and the solubility in a developer, and thereby reducing roughness when forming a resist pattern. Examples of the acid-dissociable group within the structural unit (a1) include those that have been proposed as acid-dissociable groups in base resins for chemically amplified resists. Specific examples of the acid dissociable group that have been proposed for the base resin of a chemically amplified resist composition include an “acetal type acid dissociable group,” a “tertiary alkyl ester type acid dissociable group,” and a “tertiary alkyloxycarbonyl acid dissociable group.”

[0039] Acetal type acid dissociable group: Among the polar groups, examples of the acid-dissociable group that protects a carboxy group or a hydroxyl group include an acid-dissociable group represented by the following formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid-dissociable group").

[0040] [ka]

[0041] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Ra' 3 Is, Ra' 1 , Ra' 2 may be bonded to any one of the following to form a ring.

[0042] 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' 2When is an alkyl group, the alkyl group may be the same as the alkyl group exemplified as the substituent that may be bonded to the carbon atom at the α-position in the explanation of the α-substituted acrylic acid ester above, and an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a linear or branched alkyl group is preferable. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like are preferable, and a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.

[0043] 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 has 1 to 4 carbon atoms, and further preferably has 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0044] The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably has 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and is preferably an isopropyl group.

[0045] 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 thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0046] Ra' 3 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Ra' 3 Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); and a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle has been substituted with an alkylene group (e.g., arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0047] Ra' 3The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (hereinafter, these substituents are collectively referred to as "Ra 05 " Also known as ".) Here, R P1 is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P2 is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P1 and R P2 Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the alicyclic saturated hydrocarbon group and the aromatic hydrocarbon group may be substituted with fluorine atoms. The alicyclic hydrocarbon group may have one or more of the above-mentioned substituents or may have one or more of each of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group; polycyclic aliphatic saturated hydrocarbon groups such as 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, adamantyl group and the like. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene and the like.

[0048] Ra’ 3 is Ra’ 1 or Ra’ 2 When bonding to any of them to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include tetrahydropyranyl group, tetrahydrofuranyl group and the like.

[0049] Tertiary alkyl ester type acid dissociable group: Among the above polar groups, examples of the acid dissociable group for protecting a carboxy group include acid dissociable groups represented by the following general formula (a1-r-2). Among the acid dissociable groups represented by the following formula (a1-r-2), those composed of an alkyl group may be hereinafter referred to as "tertiary alkyl ester type acid dissociable group" for convenience.

[0050]

Chemical formula

[0051] [In the formula, Ra’ 4 to Ra’ 6 each represents a hydrocarbon group, and Ra’ 5 and Ra’ 6 may be bonded to each other to form a ring.]

[0052] Ra' 4 Examples of the hydrocarbon group represented by the formula (I) 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 Examples of the alkyl group include the linear or branched alkyl group and the cyclic hydrocarbon group in the above. Ra' 4 The chain or cyclic alkenyl group in is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 As the hydrocarbon group of Ra' 3 The hydrocarbon groups are the same as those in the above.

[0053] Ra' 5 and Ra' 6 and (a1-r-2) are bonded to each other to form a ring, suitable examples of the acid-dissociable group represented by formula (a1-r-2) above include a group represented by formula (a1-r2-1) below, a group represented by formula (a1-r2-2) below, and a group represented by formula (a1-r2-3) below. On the other hand, Ra' 4 ~Ra' 6 When the are not bonded to each other and are independent hydrocarbon groups, suitable examples of the acid-dissociable group represented by formula (a1-r-2) above include groups represented by formula (a1-r2-4) below.

[0054] [ka]

[0055] [In formula (a1-r2-1), Ra 031 represents an alkyl group, and Yab 0 represents a carbon atom. 0 Yab 0represents a group which forms an alicyclic hydrocarbon group together with Ya, and some or all of the hydrogen atoms of this alicyclic hydrocarbon group may be substituted. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group which forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms of this cyclic hydrocarbon group may be substituted. Ra 101 ~Ra 103 are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. 101 ~Ra 103 Two or more of may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group which forms an aliphatic cyclic group together with Yaa. Ra 104 In formula (a1-r2-4), Ra' is an aromatic hydrocarbon group which may have a substituent. 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group which may have a substituent. * indicates a bond.]

[0056] In the above formula (a1-r2-1), Ra 031 is preferably a chain alkyl group, and more preferably a linear or branched alkyl group having 1 to 12 carbon atoms which may be partially substituted with a halogen atom or a heteroatom-containing group.

[0057] Ra 031 In the formula, the linear alkyl group has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms. Ra 031 As the branched alkyl group in the formula (I), 4 The same can be mentioned.

[0058] Ra 031 The alkyl group in may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. In addition, some of the carbon atoms (e.g., methylene groups) constituting the alkyl group may be substituted with a heteroatom-containing group. The heteroatom includes an oxygen atom, a sulfur atom, and a nitrogen atom. The heteroatom-containing group includes (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O) 2 -, -S(=O) 2 -O- and the like.

[0059] In formula (a1-r2-1), Xab 0 (Yab 0 The group forming an alicyclic hydrocarbon group together with Ra' in the above formula (a1-r-1) is 3 The groups listed as the aliphatic hydrocarbon group (alicyclic hydrocarbon group) are preferred, which is a monocyclic or polycyclic group. Among them, alicyclic hydrocarbon groups are preferred, monocyclic alicyclic hydrocarbon groups are more preferred, and groups in which two or more hydrogen atoms have been removed from a monocycloalkane are more preferred. The monocycloalkane is preferably one having 3 to 8 carbon atoms, and specific examples thereof include cyclopentane, cyclohexane, cycloheptane, and cyclooctane.

[0060] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes Ra' in the above formula (a1-r-2). 4 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) in the above formula. The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of the substituent include the above-mentioned Ra' 4 Examples of the substituents include those similar to those that the cyclic hydrocarbon group in the above may have. In formula (a1-r2-2), Ra 101 ~Ra103 In the above formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Ra 101 ~Ra 103 In the above formula, examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group. Ra 101 ~Ra 103 Among these, from the viewpoint of ease of synthesis, a hydrogen atom or a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms is preferable, and among these, a hydrogen atom, a methyl group, or an ethyl group is more preferable, and a hydrogen atom is particularly preferable.

[0061] The above Ra 101 ~Ra 103 Examples of the substituents of the chain saturated hydrocarbon group or the cyclic saturated aliphatic hydrocarbon group represented by the formula 05 The same groups as those shown below can be mentioned.

[0062] Ra 101 ~Ra 103 Examples of groups containing a carbon-carbon double bond formed by two or more of the above being bonded to each other to form a cyclic structure include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylidene-ethenyl group, a cyclohexylidene-ethenyl group, etc. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylidene-ethenyl group are preferred.

[0063] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is the same as Ra' in formula (a1-r-2) above. 4 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.

[0064] Ra in formula (a1-r2-3) 104 Examples of the substituent that may be possessed by the group include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), and an alkyloxycarbonyl group.

[0065] In formula (a1-r2-4), Ra' 12 and Ra' 13 Each of Ra' is independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms. 12 and Ra' 13 In the above, the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is 101 ~Ra 103 Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms in the above formula are the same as those in the above formula. Some or all of the hydrogen atoms in the chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, an alkyl group having 1 to 5 carbon atoms is more preferable, a methyl group or an ethyl group is even more preferable, and a methyl group is particularly preferable. The above Ra' 12 and Ra' 13 In the case where the chain saturated hydrocarbon group represented by the formula (I) is substituted, examples of the substituent include the above-mentioned Ra 05 The same groups as those shown below can be mentioned.

[0066] 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.

[0067] Ra' 14 The linear alkyl group in the formula (I) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0068] Ra' 14 The branched alkyl group in the above formula (I) preferably has 3 to 10 carbon atoms, and more preferably has 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and is preferably an isopropyl group.

[0069] 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 thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane.

[0070] Ra' 14 As the aromatic hydrocarbon group in 104 Among them, the aromatic hydrocarbon group Ra' is the same as that in 14 is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene. Ra' 14 Examples of the substituent that may be possessed by Ra include 104 The substituents may be the same as those which may be possessed by the group.

[0071] Ra' in formula (a1-r2-4) 14 When is a naphthyl group, the position at which it is bonded to the tertiary carbon atom in the above formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. Ra' in formula (a1-r2-4) 14 When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the above formula (a1-r2-4) may be any one of the 1-position, 2-position, or 9-position of the anthryl group.

[0072] Specific examples of the group represented by formula (a1-r2-1) are shown below.

[0073] [ka]

[0074]

Chem.

[0075]

Chem.

[0076] Specific examples of the group represented by the formula (a1-r2-2) are given below.

[0077]

Chem.

[0078]

Chem.

[0079]

Chem.

[0080] Specific examples of the group represented by the formula (a1-r2-3) are given below.

[0081]

Chem.

[0082] Specific examples of the group represented by the formula (a1-r2-4) are given below.

[0083]

Chem.

[0084] · Tertiary alkyloxycarbonyl acid dissociable group: Among the polar groups, examples of the acid dissociable group that protects the hydroxyl group include an acid dissociable group represented by the following formula (a1-r-3) (hereinafter, for convenience, may be referred to as a "tertiary alkyloxycarbonyl acid dissociable group").

[0085] [ka]

[0086] [In the formula, Ra' 7 ~Ra' 9 Each represents an alkyl group.

[0087] In formula (a1-r-3), Ra' 7 ~Ra' 9 are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms. The total number of carbon atoms in each alkyl group is preferably 3-7, more preferably 3-5, and most preferably 3-4.

[0088] As the acid-dissociable group, among the groups represented by the above general formulae (a1-r2-1) to (a1-r2-4), the groups represented by the above general formula (a1-r2-1) or (a1-r2-4) are preferred.

[0089] Specific examples of the structural unit (a1) include structural units represented by general formula (a1-1) shown below.

[0090] (Structural unit (a1) represented by general formula (a1-1)) In the resist composition according to the embodiment of the present invention, the base component (A) preferably contains a polymeric compound (A1) having a structural unit (a1) represented by the following general formula (a1-1).

[0091] [ka]

[0092] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 1 is a divalent hydrocarbon group which may have an ether bond. a1 is an integer from 0 to 2. 1 represents an acid dissociable group.]

[0093] In the formula (a1-1), the alkyl group of R having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferred. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is most preferable.

[0094] In the formula (a1-1), Va 1 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure.

[0095] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably has 1 to 6 carbon atoms, further preferably has 1 to 4 carbon atoms, and most preferably has 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, specifically, a methylene group [-CH2 -], ethylene group [-(CH 2 ) 2 -], trimethylene group [-(CH 2 ) 3 -], tetramethylene group [-(CH 2 ) 4 -], pentamethylene group [-(CH 2 ) 5 -] etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 -, etc. alkylmethylene groups; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2 -, etc. alkyl ethylene groups; -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 -, etc.; -CH(CH 3)CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2 The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0096] Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, etc. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, specifically cycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc.

[0097] Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this carbon number does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (aryl group) has been substituted with an alkylene group (for example, a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1. In the formula (a1-1), Ra 1 represents an acid dissociable group. Examples of the acid dissociable group include those described above, and are preferably the acid dissociable groups represented by the above formulae (a1-r2-1) to (a1-r2-4), and more preferably the acid dissociable groups represented by the above formulae (a1-r2-1) or (a1-r2-4).

[0098] In the formula (a1-1), n a1 is an integer from 0 to 2. a1 is preferably 0 or 1, and more preferably 0.

[0099] The formula (a1-1) is preferably the following formula (a1-2).

[0100] [ka]

[0101] In the general formula (a1-2), 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. 3 represents a divalent linking group. 3 represents an integer of 0 to 2. 031 represents an alkyl group, and Yab 0 represents a carbon atom. Xab 0 Yab 0 represents a group which, together with the above, forms an alicyclic hydrocarbon group, and some or all of the hydrogen atoms in the alicyclic hydrocarbon group may be substituted.

[0102] In general formula (a1-2), R, Va 3 R and Va in formula (a1-1) 1 are similar to

[0103] In general formula (a1-2), na 3 represents an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

[0104] In general formula (a1-2), Ra 031 , Xab 0 , Yab 0 is the Ra in formula (a1-r2-1). 031 , Xab 0 , Yab 0 are similar to

[0105] In general formula (a1-2), Ra 031 Among the above, is preferably a chain alkyl group, more preferably a monovalent chain alkyl group having 1 to 3 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, or an isopropyl group is more preferable.

[0106] Specific examples of the structural unit (a1) are given below. In the following formula, R αrepresents a hydrogen atom, a methyl group or a trifluoromethyl group.

[0107]

Chem.

[0108]

Chem.

[0109]

Chem.

[0110]

Chem.

[0111]

Chem.

[0112]

Chem.

[0113]

Chem.

[0114]

Chem.

[0115]

Chem.

[0116]

Chem.

[0117] The structural unit (a1) that the component (A1) may have may be of one type, or two or more types. In the component (A1), the proportion of the structural unit (a1) relative to the total (100 mol %) of all structural units constituting the component (A1) is preferably 20 to 80 mol %, more preferably 30 to 70 mol %, and even more preferably 40 to 60 mol %. By ensuring that the proportion of the structural unit (a1) is at least the lower limit of the above preferred range, lithography properties such as increased sensitivity, resolution, and improved roughness can be achieved. By ensuring that the proportion is at most the upper limit, a balance with other structural units can be achieved, resulting in various favorable lithography properties. Furthermore, in the resist composition according to an embodiment of the present invention, the structural unit (a1) may not contain an acetal-type acid-dissociable group.

[0118] (Structural unit (a2)) The component (A1) further comprises a lactone-containing cyclic group, -SO 2 It may also have a structural unit (a2) that contains a --containing cyclic group or a carbonate-containing cyclic group (provided that this does not include those that fall under the structural unit (a1)). The lactone-containing cyclic group of the structural unit (a2), -SO 2 The --containing cyclic group or carbonate-containing cyclic group 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 inclusion of the structural unit (a2) provides effects such as suitable adjustment of the acid diffusion length, improving the adhesion of the resist film to the substrate, and suitable adjustment of the solubility during development, resulting in good lithography properties.

[0119] The term "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -OC(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and when there is only a lactone ring, it is called a monocyclic group, and when there is further a ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. The lactone-containing cyclic group in the structural unit (a2) is not particularly limited and any suitable group can be used. Specific examples include the groups represented by the following general formulae (a2-r-1) to (a2-r-7).

[0120] [ka]

[0121] [In general formulas (a2-r-1) to (a2-r-7), 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, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2 -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.

[0122] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred. Ra' 21 The alkoxy group in the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. 21 Examples of the alkyl group include those groups in which the alkyl groups mentioned above are linked to an oxygen atom (-O-). Ra' 21Examples of the halogen atom in [compound name] include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferred. Ra’ 21 Examples of the alkyl halide group in [compound name] include those in which some or all of the hydrogen atoms of the alkyl group in the above Ra’ 21 are substituted with the above halogen atoms. As the alkyl halide group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0123] Ra’ 21 In -COOR” and -OC(=O)R” in [compound name], R” is each a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO 2 -containing cyclic group. Examples of the alkyl group in R” may be linear, branched, or cyclic, and preferably have 1 to 15 carbon atoms.

[0124] 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 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. Specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane can be exemplified. More specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, or tetracyclododecane can be mentioned.

[0125] 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. The carbonate-containing cyclic group in R″ is the same as the carbonate-containing cyclic group described later, and specific examples thereof include groups represented by general formulae (ax3-r-1) to (ax3-r-3). -SO in R” 2 Examples of the --containing cyclic group include the -SO 2 Similar to the -containing cyclic group, specific examples include the groups represented by general formulae (a5-r-1) to (a5-r-4).

[0126] Ra' 21 The hydroxyalkyl group in Ra' is preferably one having 1 to 6 carbon atoms. 21 In the above formula, at least one hydrogen atom of the alkyl group is substituted with a hydroxyl group.

[0127] In the general formulae (a2-r-2), (a2-r-3) and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A" is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between the carbon atoms of the alkylene group, and examples thereof include -O-CH 2 -, -CH 2 -O-CH 2 -,-S-CH 2 -, -CH 2 -S-CH 2 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.

[0128] Specific examples of the groups represented by general formulas (a2-r-1) to (a2-r-7) are listed below.

[0129] [ka]

[0130] [ka]

[0131] "-SO 2 "-containing cyclic group" means a group having a -SO 2 A cyclic group containing a ring containing -, specifically, -SO 2 The sulfur atom (S) in - forms part of the ring structure of the cyclic group. 2 The ring containing - is counted as the first ring, and if there is only this ring, it is called a monocyclic group, and if there are other ring structures, it is called a polycyclic group regardless of the structure. 2 The -containing cyclic group may be a monocyclic group or a polycyclic group. -SO 2 The -containing cyclic group in particular has an -O-SO 2 Cyclic groups containing -, i.e. -O-SO 2 It is preferred that -OS- in - is a cyclic group containing a sultone ring forming part of the ring backbone. -SO 2 More specific examples of the --containing cyclic group include groups represented by the following general formulas (a5-r-1) to (a5-r-4).

[0132] [ka]

[0133] [In general formulas (a5-r-1) to (a5-r-4), Ra' 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, a carbonate-containing cyclic group, or -SO 2-containing cyclic group; A″ 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.

[0134] In the general formulae (a5-r-1) and (a5-r-2), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3) and (a2-r-5). Ra' 51 The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in the general formulae (a2-r-1) to (a2-r-7) are each represented by Ra' 21 Examples of the above-mentioned are similar to those mentioned in the explanation of the above. Specific examples of the groups represented by general formulas (a5-r-1) to (a5-r-4) are shown below, in which "Ac" represents an acetyl group.

[0135] [ka]

[0136] [ka]

[0137] [ka]

[0138] The term "carbonate-containing cyclic group" refers to a cyclic group that contains a ring (carbonate ring) containing -OC(=O)-O- in its ring skeleton. The carbonate ring is counted as the first ring, and when there is only a carbonate ring, it is called a monocyclic group, and when there is another ring structure, it is called a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. The carbonate ring-containing cyclic group is not particularly limited and any one can be used. Specific examples include groups represented by the following general formulae (ax3-r-1) to (ax3-r-3).

[0139] [ka]

[0140] [In the formula, Ra' x31 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, a carbonate-containing cyclic group, or -SO 2 -containing cyclic group; A" 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; p' is an integer of 0 to 3, and q' is 0 or 1. * represents a bond.

[0141] In the general formulae (ax3-r-2) to (ax3-r-3), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3) and (a2-r-5). Ra' X31 The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in the general formulae (a2-r-1) to (a2-r-7) are each represented by Ra' 21 Examples of the above-mentioned are similar to those mentioned in the explanation of the above. Specific examples of the groups represented by the general formulae (ax3-r-1) to (ax3-r-3) are listed below.

[0142] [ka]

[0143] Of the various possibilities, the structural unit (a2) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0144] [ka]

[0145] [In the general formula (a2-1), 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. 21 is a single bond or a divalent linking group. 21 is -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, a carbonate-containing cyclic group, or -SO 2 -containing cyclic group.]

[0146] In the formula (a2-1), R is the same as R in the formula (a1-1). R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferable.

[0147] 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.

[0148] Optionally substituted divalent hydrocarbon group: Ya 21When is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0149] Ya 21 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0150] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably contains 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, specifically, a methylene group [-CH 2 -], ethylene group [-(CH 2 ) 2 -], trimethylene group [-(CH 2 ) 3 -], tetramethylene group [-(CH 2 ) 4 -], pentamethylene group [-(CH 2 ) 5 -] etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 - and other alkylmethylene groups such as -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2 - and other alkylethylene groups such as -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 - and other alkyltrimethylene groups such as -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2 - and other alkyltetramethylene groups and the like, such as alkylalkylene groups, can be mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[0151] The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, a carbonyl group, and the like.

[0152] ··· an aliphatic hydrocarbon group containing a ring in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, specifically 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc.

[0153] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and further preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. Examples of the halogenated alkyl group as the substituent include the alkyl groups in which some or all of the hydrogen atoms of the alkyl groups are substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, a part of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. Examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, -S(=O) 2 -, -S(=O) 2 -O- is preferred.

[0154] Ya 21 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1 carbon atom.

[0155] The aromatic hydrocarbon group may have a hydrogen atom substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Examples of the alkoxy group, halogen atom and halogenated alkyl group as the substituent include those exemplified as the substituent substituting a hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0156] Divalent linking groups containing heteroatoms: Ya 21 When is a divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)2 -, -S(=O) 2 -O-, formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O) 2 -OY 22 -, wherein Y 21 and Y 22 each independently represents a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 1 to 3.

[0157] When the divalent linking group containing a hetero atom is -C(=O)-NH-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group, an acyl group, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. Formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O) 2 -OY 22 -Medium, Y 21 and Y 22 Each of the Ya independently represents a divalent hydrocarbon group which may have a substituent. 21Examples of the divalent linking group in the above formula (divalent hydrocarbon group which may have a substituent) include those similar to those mentioned in the above formula (divalent linking group which may have a substituent). Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferable, a straight-chain alkylene group is more preferable, a straight-chain alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or ethylene group is particularly preferable.

[0158] Y 22 is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula − [Y 21 -C(=O)-O] m” -Y 22 In the group represented by -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The group represented by the formula -Y 21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH 2 ) a’ -C(=O)-O-(CH 2 ) b’ In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.

[0159] Among the above, 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.

[0160] In the above formula (a2-1), Ra 21 is a lactone-containing cyclic group, -SO 2 -containing cyclic group or a carbonate-containing cyclic group. Ra 21 The lactone-containing cyclic group, -SO 2 Suitable examples of the --containing cyclic group and the carbonate-containing cyclic group include the groups represented by the above-mentioned general formulae (a2-r-1) to (a2-r-7), (a5-r-1) to (a5-r-4), and (ax3-r-1) to (ax3-r-3), respectively.

[0161] In the above formula (a2-1), Ra 21 Among the above, is a lactone-containing cyclic group or -SO 2 --containing cyclic groups are preferred, with groups represented by the above general formula (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r-1) being more preferred, and groups represented by the above general formula (a2-r-1) or (a2-r-2) being even more preferred. Specifically, groups represented by the above chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), and (r-lc-6-1) are preferred, and groups represented by the above chemical formulas (r-lc-1-1), (r-lc-2-1) and (r-lc-2-12) are more preferred.

[0162] The structural unit (a2) contained in the component (A1) may be of one type, or two or more types. When the component (A1) contains the structural unit (a2), the proportion of the structural unit (a2) is preferably 20 to 80 mol %, 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). When the proportion of the structural unit (a2) is at least as large as the preferred lower limit, the effects achieved by including the structural unit (a2) as described above can be fully obtained. When the proportion of the structural unit (a2) is at most the upper limit, a balance with other structural units can be achieved, and various lithography properties become favorable.

[0163] (Structural unit (a3)) In addition to the structural unit (a1), the component (A1) may further include a structural unit (a3) ​​(excluding those corresponding to the structural unit (a1) or the structural unit (a2)) that contains a polar group-containing aliphatic hydrocarbon group. When the component (A1) includes the structural unit (a3), the hydrophilicity of the component (A) is increased, which contributes to improving the resolution. In addition, the acid diffusion length can be appropriately adjusted.

[0164] Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which some of the hydrogen atoms of an alkyl group are substituted with fluorine atoms, with a hydroxyl group being particularly preferred. Examples of the aliphatic hydrocarbon group include linear or branched hydrocarbon groups (preferably alkylene groups) having 1 to 10 carbon atoms, and cyclic aliphatic hydrocarbon groups (cyclic groups). The cyclic group may be a monocyclic group or a polycyclic group, and can be appropriately selected from the many groups proposed for use in resins for resist compositions for ArF excimer lasers.

[0165] When the cyclic group is a monocyclic group, the number of carbon atoms is more preferably 3 to 10. Among them, a structural unit derived from an acrylic acid ester containing an aliphatic monocyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which a portion of the hydrogen atoms of the alkyl group is substituted with a fluorine atom is more preferred. Examples of the monocyclic group include groups in which two or more hydrogen atoms have been removed from a monocycloalkane. Specific examples include groups in which two or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane, cyclohexane, and cyclooctane. Among these monocyclic groups, groups in which two or more hydrogen atoms have been removed from cyclopentane and groups in which two or more hydrogen atoms have been removed from cyclohexane are industrially preferred.

[0166] When the cyclic group is a polycyclic group, the number of carbon atoms of the polycyclic group is more preferably 7 to 30. Among them, a structural unit derived from an acrylic acid ester containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which a portion of the hydrogen atoms of the alkyl group is substituted with a fluorine atom is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from a bicycloalkane, a tricycloalkane, a tetracycloalkane, etc. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane are industrially preferred.

[0167] There are no particular limitations on the structural unit (a3), and any structural unit can be used as long as it contains a polar group-containing aliphatic hydrocarbon group. The structural unit (a3) ​​is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and which contains a polar group-containing aliphatic hydrocarbon group. As the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a straight-chain or branched-chain hydrocarbon group having 1 to 10 carbon atoms, a structural unit derived from a hydroxyethyl ester of acrylic acid is preferred. Furthermore, when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a polycyclic group, preferred examples of the structural unit (a3) ​​include structural units represented by the following formulae (a3-1), (a3-2), and (a3-3); when the hydrocarbon group is a monocyclic group, preferred examples of the structural unit (a3) ​​include structural units represented by formula (a3-4).

[0168] [ka]

[0169] [In the formula, R is the same as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t' is an integer of 1 to 3, l is an integer of 0 to 5, and s is an integer of 1 to 3.]

[0170] In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3rd position of the adamantyl group. It is preferable that j is 1, and it is particularly preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.

[0171] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5- or 6-position of the norbornyl group.

[0172] In formula (a3-3), t' is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxyl group of the acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5- or 6-position of the norbornyl group.

[0173] In formula (a3-4), t' is preferably 1 or 2. l is preferably 0 or 1. s is preferably 1. The fluorinated alkyl alcohol is preferably bonded to the 3- or 5-position of the cyclohexyl group.

[0174] The structural unit (a3) ​​contained in the component (A1) may be of one type, or two or more types. When the component (A1) contains the structural unit (a3), the proportion of the structural unit (a3) ​​relative to the total (100 mol %) of all structural units constituting the component (A1) is preferably 1 to 30 mol %, more preferably 2 to 25 mol %, and even more preferably 5 to 20 mol %. By ensuring that the proportion of the structural unit (a3) ​​is at least as large as the preferred lower limit, the effects described above can be fully achieved by including the structural unit (a3). By ensuring that the proportion of the structural unit (a3) ​​is at most the preferred upper limit, a balance with other structural units can be achieved, and various lithography properties become favorable.

[0175] (Structural unit (a10)) The component (A1) may further include a structural unit (a10) represented by general formula (a10-1).

[0176] [ka]

[0177] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. x1 is a single bond or a divalent linking group. x1 is (n ax1 +1)valent aromatic hydrocarbon group. ax1 is an integer greater than or equal to 1.]

[0178] In the formula (a10-1), R is the same as R in the formula (a1-1). R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferable.

[0179] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group. In the above chemical formula, Ya x1 As the divalent linking group, Ya in the formula (a2-1) is 21 Examples of the divalent linking group include the same as those exemplified above. Ya x1is 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, more preferably a single bond or an ester bond [-C(=O)-O-, -OC(=O)-], and even more preferably a single bond.

[0180] In the formula (a10-1), Wa x1 is (n ax1 +1)valent aromatic hydrocarbon group. Wa x1 The aromatic hydrocarbon group in the formula (n ax1 4n+1) hydrogen atoms are removed. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Also, Wa x1 The aromatic hydrocarbon group in the formula (n) may be an aromatic compound having two or more aromatic rings (e.g., biphenyl, fluorene, etc.). ax1 +1) hydrogen atoms may also be removed. Among the above, Wa x1 As the aryl group, benzene, naphthalene, anthracene, or biphenyl (n ax1 A group in which (n +1) hydrogen atoms have been removed is preferred, and a group in which (n ax1 A group in which (n +1) hydrogen atoms have been removed from benzene is more preferable. ax1 A group in which +1) hydrogen atoms have been removed is more preferred.

[0181] Wa x1The aromatic hydrocarbon group in may or may not have a substituent, but preferably has no 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 The substituents of the cyclic aliphatic hydrocarbon group in Wa are the same as those mentioned above. x1 However, from the aromatic ring (n ax1 +1) hydrogen atoms from the aromatic ring, ax1 +1) hydrogen atoms are removed from the group. 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.

[0182] 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. ax1 is preferably 1.

[0183] Specific examples of the structural unit (a10) represented by the aforementioned formula (a10-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0184] [ka]

[0185] [ka]

[0186] [ka]

[0187] [ka]

[0188] The structural unit (a10) contained in the component (A1) may be of one type, or 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 5 to 80 mol %, more preferably 5 to 75 mol %, and even more preferably 10 to 70 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a10) is at least as large as the lower limit of the above range, it is possible to further increase the sensitivity, whereas by ensuring that the proportion is at most the upper limit of the above range, it is easier to achieve a balance with other structural units.

[0189] (Structural unit (st)) The component (A1) may further contain, in addition to the structural unit (a1), a structural unit (st) derived from styrene or a styrene derivative. The structural unit (st) is a structural unit derived from styrene or a styrene derivative. A "structural unit derived from styrene" refers to a structural unit formed by cleavage of the ethylenic double bond of styrene. A "structural unit derived from a styrene derivative" refers to a structural unit formed by cleavage of the ethylenic double bond of a styrene derivative.

[0190] The term "styrene derivative" refers to a compound in which at least some of the hydrogen atoms of styrene are substituted with a substituent. Examples of styrene derivatives include those in which the hydrogen atom at the α-position of styrene is substituted with a substituent, those in which one or more hydrogen atoms on the benzene ring of styrene are substituted with a substituent, and those in which the hydrogen atom at the α-position of styrene and one or more hydrogen atoms on the benzene ring are substituted with a substituent.

[0191] Examples of the substituent substituting the hydrogen atom at the α-position of styrene include an alkyl group having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. The substituent substituting the hydrogen atom at the α-position of styrene is preferably an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms or a fluorinated alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group from the viewpoint of industrial availability.

[0192] Examples of the substituent that substitutes the hydrogen atom on the benzene ring of styrene include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and further preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom being preferred. Examples of the halogenated alkyl group as the substituent include the alkyl groups in which some or all of the hydrogen atoms of the alkyl groups are substituted with the halogen atoms. The substituent that substitutes the hydrogen atom on the benzene ring of styrene is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.

[0193] The structural unit (st) is preferably a structural unit derived from styrene, or a structural unit derived from a styrene derivative in which the hydrogen atom at the α-position of styrene is substituted with an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, more preferably a structural unit derived from styrene, or a structural unit derived from a styrene derivative in which the hydrogen atom at the α-position of styrene is substituted with a methyl group, and even more preferably a structural unit derived from styrene.

[0194] The structural unit (st) contained in the component (A1) may be of one type, or two or more types. When the component (A1) contains the structural unit (st), the proportion of the structural unit (st) is preferably 1 to 30 mol %, and more preferably 3 to 30 mol %, based on the total (100 mol %) of all structural units constituting the component (A1).

[0195] Other structural units The component (A1) may contain other structural units in addition to the above-mentioned structural unit (a1), structural unit (a2), structural unit (a3), structural unit (a10), and structural unit (st). Examples of other structural units include structural units (a8) that contain an acid non-dissociable aliphatic cyclic group. As the structural unit (a8), many structural units that are conventionally known to be used in resin components of resist compositions can be used.

[0196] <Acid generator component (component (B))> The resist composition according to an embodiment of the present invention contains, in addition to the above-mentioned component (A), an acid generator component (B) (hereinafter also referred to as “component (B)”) that generates an acid upon exposure. The acid generator component (B) contains an acid generator (B1) (hereinafter sometimes referred to as “component (B1)”) consisting of a compound represented by the following general formula (b1-1): In the present embodiment, the acid generator component (B) contains a compound represented by the following general formula (b1-1) (hereinafter, may be referred to as “component (B1)”).

[0197] [Chemical formula]

[0198] [In general formula (b1-1), X 1 and Y 1 each independently represent a halogen atom other than a fluorine atom, a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group, an electron-withdrawing group, a selenol group, a pentafluorosulfanyl group, a mercapto group, a thiocarboxylic acid group, or a dithiocarboxylic acid group. X 1 and Y 1 may be bonded to each other to form a ring. n1 represents an integer of 1 to 10. m is an integer of 1 or more, and M m+ represents an m-valent organic cation.]

[0199] The component (B) does not contain a compound corresponding to PFAS. The component (B) contains only a compound not corresponding to PFAS. That is, the component (B) does not contain any of a compound having a trifluoromethyl group and a compound having a difluoromethylene group. Further, it is preferable that the component (B) does not contain a fluorine atom.

[0200] [[Anion part (HO-(C=O)-(CX 1 Y 1 )) n1 -SO 3 - )] In the formula (b1-1), X 1 and Y 1 each independently represent a halogen atom other than a fluorine atom, a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group, an electron-withdrawing group, a selenol group, a pentafluorosulfanyl group, a mercapto group, a thiocarboxylic acid group, or a dithiocarboxylic acid group.

[0201] n1 preferably represents 1 or 2, and more preferably represents 1.

[0202] X 1 and Y 1 Examples of the aliphatic hydrocarbon group represented by include a straight-chain alkyl group, a branched-chain alkyl group, a polycyclic aliphatic hydrocarbon group, and a monocyclic aliphatic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably has 1 to 4 carbon atoms, and further preferably has 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred. The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably has 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and is preferably an isopropyl group.

[0203] 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 12 carbon atoms, more preferably 3 to 6 carbon atoms, and specific examples thereof include cyclopropane, cyclobutane, cyclopentane, and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, and tetracyclododecane.

[0204] X 1 and Y 1The aromatic hydrocarbon group represented by the formula (I) preferably has 5 to 30 carbon atoms, more preferably 5 to 25 carbon atoms, further preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. Examples of the aromatic hydrocarbon group include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.

[0205] X 1 and Y 1 Examples of the heterocyclic group represented by the formula (I) include aromatic heterocyclic groups in which a part of the carbon atoms constituting the aromatic hydrocarbon group is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocyclic group include an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the heterocyclic group include furan, benzofuran, thiophene, benzothiophene, pyrrole, pyrazole, imidazole, oxadiazole, indole, carbazole, pyrroloimidazole, pyrrolopyrazole, pyrrolopyrrole, thienopyrrole, thienothiophene, furopyrrole, furofuran, thienofuran, benzoisoxazole, benzoisothiazole, benzimidazole, pyridine, pyrazine, pyridazine, pyrimidine, and triazine, and other aromatic heterocyclic groups in which one hydrogen atom has been removed.

[0206] X 1 and Y 1 Examples of the electron-withdrawing group represented by the formula (I) include a hydroxyl group, a carbonyl group, a nitro group, a cyano group, a carboxy group, an acyl group, a dialkylphosphono group, a diarylphosphono group, an alkylsulfonyl group, a cycloalkylsulfonyl group, an arylsulfonyl group, a sulfonyloxy group, an acylthio group, a sulfamoyl group, a thiocyanate group, and a thiocarbonyl group. Of the above, the electron-withdrawing group is preferably a hydroxyl group, a carbonyl group, a nitro group, a cyano group, a carboxy group, an acyl group, a dialkylphosphono group, a diarylphosphono group, or an alkylsulfonyl group, and more preferably a nitro group or a cyano group.

[0207] X 1 and Y 1When they are bonded to each other to form a ring, the cyclic group is preferably a cyclic hydrocarbon group. Examples of the cyclic hydrocarbon group include a monocyclic aliphatic hydrocarbon group, a polycyclic aliphatic hydrocarbon group, and an aromatic hydrocarbon group, and a monocyclic aliphatic hydrocarbon group is preferred. X 1 and Y 1 When the aliphatic hydrocarbon group is bonded to each other to form a ring, the monocyclic group is preferably a group in which two hydrogen atoms have been removed from a monocycloalkane. Examples of the monocycloalkane include the same as those mentioned above. X 1 and Y 1 As the aliphatic hydrocarbon group that is a polycyclic group in which are bonded to each other to form a ring, a group in which two hydrogen atoms have been removed from a polycycloalkane is preferable, and examples of the polycycloalkane include the same as those mentioned above.

[0208] X 1 and Y 1 may each independently have a substituent, and examples of the substituent include an alkyl group, an alkoxy group, a hydroxyl group, a carbonyl group, a carboxy group, and a sulfo group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group, and even more preferably a methyl group. The alkyl group as the substituent can further include a carboxy group, -SO 3 - (M m+ ) 1 / m (m is an integer of 1 or more, M m+ represents an organic cation with a valence of m. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and further preferably a methoxy group or an ethoxy group.

[0209] In the formula (b1-1), X 1and Y 1 Each of X preferably independently represents a hydrogen atom, an aliphatic hydrocarbon group, or an aromatic hydrocarbon group, and more preferably each of X independently represents a hydrogen atom or an aliphatic hydrocarbon group. 1 and Y 1 preferably each independently represents a hydrogen atom, a group in which one hydrogen atom has been removed from cyclohexane, or a group in which one hydrogen atom has been removed from benzene, and more preferably represents a hydrogen atom or a group in which one hydrogen atom has been removed from cyclohexane. In the formula (b1-1), X 1 and Y 1 It is preferable that at least one of these is a hydrogen atom. In addition, in the formula (b1-1), X 1 is preferably an aliphatic hydrocarbon group from the viewpoint of providing component (B) with excellent solvent solubility and ultraviolet light transmittance. In addition, the compound represented by general formula (b1-1) preferably does not contain a fluorine atom.

[0210] Specific examples of the anion moiety in the component (B1) are listed below. However, the anion moiety in the component (B1) is not limited to these specific examples. In the specific examples below, "1-11" indicates that the repeating number of the repeating unit shown in [ ] is 1 to 11. "Ph" represents a phenyl group.

[0211] [ka]

[0212] [ka]

[0213] [Cation part: (M m+ ) 1 / m ] In the general formula (b1-1), M m+ represents an organic cation with a valence of m. M m+The organic cation in is preferably an onium cation, more preferably a sulfonium cation, an iodonium cation, or an ammonium cation, and further preferably a sulfonium cation or an iodonium cation. m is an integer of 1 or more.

[0214] Preferred cationic moieties ((M m+ ) 1 / m ) includes organic cations represented by any of the following general formulas (ca-1) to (ca-3).

[0215] [ka]

[0216] [In general formulas (ca-1) to (ca-3), R 201 ~R 207 each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent; R 201 ~R 203 , R 206 ~R 207 may be bonded to each other to form a ring together with the sulfur atom in the formula. 208 ~R 209 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO 2 -containing cyclic group, L 201 represents -C(=O)- or -C(=O)-O-.]

[0217] R 201 ~R 207 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 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, an arylthio group, and groups represented by the following formulas (ca-r-1) to (ca-r-7). The aryl group in the arylthio group as a substituent includes an aryl group having 6 to 20 carbon atoms, and is preferably a phenyl group, a naphthyl group, or a biphenyl group. The arylthio group includes a phenylthio group, a naphthylthio group, or a biphenylthio group.

[0218] [ka]

[0219] [In the formula, R' 201 each independently represents 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.

[0220] R' 201 The optionally substituted cyclic group represented by the formula (I) is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Examples of the aromatic hydrocarbon group include an aromatic hydrocarbon ring, or an aryl group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings, with a phenyl group and a naphthyl group being preferred. Examples of the aliphatic hydrocarbon group include groups in which one hydrogen atom has been removed from a monocycloalkane or polycycloalkane, and an adamantyl group or a norbornyl group is preferred.

[0221] R' 201 The optionally substituted chain alkyl group represented by the formula (I) 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. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a henicosyl group, and a docosyl group.

[0222] R' 201 The chain alkenyl group represented by the formula (1) which may have a substituent may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, further preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include a 1-methylpropenyl group and a 2-methylpropenyl group. As the chain alkenyl group, among the above, a propenyl group is particularly preferred.

[0223] R' 201 Examples of the optionally substituted cyclic group or optionally substituted chain alkyl group represented by formula (a1-r2-1) include those similar to the acid dissociable group represented by formula (a1-r2-1) above.

[0224] R' 201 Examples of the substituent in the cyclic group, chain alkyl group, or chain alkenyl group represented by the formula (I) 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.

[0225] R 201 ~R 203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they are not included in the heteroatoms such as sulfur atoms, oxygen atoms, and nitrogen atoms, as well as in the carbonyl groups, -SO-, -SO 2 -, -SO 3 -, -COO-, -CONH- or -N(R N )-(applicable 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 thianthrene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, and a thioxanium ring.

[0226] R 208 ~R 209R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 208 ~R 209 When each of these is independently an alkyl group, they may be bonded to each other to form a ring.

[0227] R 210 represents an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO 2 -containing cyclic group. R 210 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 210 In the formula (I), the optionally substituted -SO 2 In the -containing cyclic group, "-SO 2 "-containing cyclic group" means a group having a -SO 2 A cyclic group containing a ring containing -, specifically, -SO 2 The sulfur atom (S) in - forms part of the ring structure of the cyclic group. 2 The ring containing - is counted as the first ring, and if there is only this ring, it is called a monocyclic group, and if there are other ring structures, it is called a polycyclic group regardless of the structure. 2 The -containing cyclic group may be a monocyclic group or a polycyclic group. -SO 2 The -containing cyclic group in particular has an -O-SO 2 Cyclic groups containing -, i.e. -O-SO 2 It is preferred that -OS- in - is a cyclic group containing a sultone ring forming part of the ring backbone. R210 In the formula (I), the optionally substituted -SO 2 As the -containing cyclic group, a group represented by the above formula (a5-r-1) is preferable.

[0228] The cation represented by formula (ca-1) is preferably a cation represented by the following formula (b-2).

[0229] [ka]

[0230] In formula (b-2), Rb 201 ~Rb 202 each represents an aryl group which may have a substituent; Rb 203 Rb represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. 201 ~Rb 203 may be bonded to each other to form a ring together with the sulfur atom in formula (b-2).

[0231] Rb 201 ~Rb 202 The optionally substituted aryl group represented by R 201 ~R 207 The preferred examples are also the same as those of the aryl group optionally having a substituent as defined above. Rb 203 The optionally substituted aryl group, optionally substituted alkyl group, or optionally substituted alkenyl group represented by the above R 201 ~R 207 The optionally substituted aryl group, the optionally substituted alkyl group, and the optionally substituted alkenyl group as defined above have the same meanings, and preferred examples thereof are also the same.

[0232] Specific examples of suitable cations represented by formula (ca-1) include cations represented by any of the following formulas (ca-1-1) to (ca-1-67).

[0233] [ka]

[0234] [ka]

[0235] [ka]

[0236] [In the formula, g1, g2, and g3 each represent a repeating number, where g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.]

[0237] [ka]

[0238] [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 The substituents are the same as those exemplified as the substituents that may be possessed by the

[0239] Specific examples of suitable cations represented by the formula (ca-3) include cations represented by any of the following formulas (ca-3-1) to (ca-3-6).

[0240] [ka]

[0241] In this embodiment, the compound represented by general formula (b1-1) is preferably a compound represented by the following general formula (b1-2).

[0242] [ka]

[0243] [In general formula (b1-2), X 2 and Y 2 each independently represents a hydrogen atom, an aliphatic hydrocarbon group, or an aromatic hydrocarbon group; n2 represents an integer of 1 or 2; m is an integer of 1 or more, m+ represents an organic cation having a valence of m.

[0244] In general formula (b1-2), X 2 and Y 2 The aliphatic hydrocarbon group and the aromatic hydrocarbon group in 1 and Y 1 The aliphatic hydrocarbon group and the aromatic hydrocarbon group in the above formula (I) are similar to those in the above formula (I). M m+ is an m-valent organic cation, and M in the above formula (b1-1) m+ is the same as:

[0245] In this embodiment, the compounds represented by the above general formulas (b1-1) and (b1-2) are preferably compounds represented by the following general formula (b1-3).

[0246] [ka]

[0247] [In general formula (b1-3), X 2 and Y 2 each independently represents a hydrogen atom, an aliphatic hydrocarbon group, or an aromatic hydrocarbon group; n2 represents an integer of 1 or 2; Rb 01 ~Rb 03 are each independently an aryl group, an alkyl group, or an alkenyl group. The aryl group, the alkyl group, and the alkenyl group may each independently have one or more substituents selected from the group consisting of an alkyl group, an aldehyde group, an acyl group, a hydroxyl group, and a halogen atom. 01 ~Rb 03may be bonded to each other to form a ring together with the sulfur atom in general formula (b1-3).

[0248] In general formula (b1-3), X 2 and Y 2 respectively represent X in general formula (b1-2). 2 and Y 2 is the same as: Rb 01 ~Rb 03 The aryl group, alkyl group, or alkenyl group and the substituents which these groups may have are each Rb 201 ~Rb 203 The substituents are the same as those of the aryl group, alkyl group, or alkenyl group and the substituents that these groups may have in the above formula (I).

[0249] Specific examples of suitable components (B1) are given below.

[0250] [ka]

[0251] In the resist composition of this embodiment, the component (B1) may use either a single type, or a combination of two or more types. In the resist composition of this embodiment, the content of the component (B1) relative to 100 parts by mass of the component (A) is preferably 1 to 40 parts by mass, more preferably 1 to 30 parts by mass, and even more preferably 1 to 25 parts by mass. When the content of the component (B1) is at least as high as the lower limit of the aforementioned preferred range, lithography properties such as sensitivity, CDU, and the like are further improved during resist pattern formation. On the other hand, when the content is no more than the upper limit of the aforementioned 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.

[0252] Regarding component (B2) The resist composition of this embodiment may contain an acid generator component (hereafter referred to as “component (B2)”) other than the component (B1) as long as the effects of the present invention are not impaired. There are no particular restrictions on the component (B2), and any of the compounds proposed as acid generators for chemically amplified resist compositions can be used, although it is preferable for them not to contain fluorine atoms. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes, nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0253] In the resist composition of this embodiment, the component (B2) may use either a single type, or a combination of two or more types. When the resist composition contains the component (B2), the amount of the component (B2) in the resist composition is preferably 50 parts by mass or less, more preferably 1 to 40 parts by mass, and even more preferably 5 to 30 parts by mass, relative to 100 parts by mass of the component (A). By ensuring that the content of the component (B2) falls within the above range, sufficient pattern formation can be achieved. Furthermore, when the components of the resist composition are dissolved in an organic solvent, a homogeneous solution is easily obtained, which is preferable as it results in excellent storage stability of the resist composition.

[0254] ≪(D) ​​Component≫ The resist composition of this embodiment further contains an acid diffusion controller component (hereafter referred to as "component (D)") in addition to components (A) and (B). Component (D) acts as a quencher that traps acid generated in the resist composition upon exposure. The component (D) may be a photodegradable base (D1) (hereinafter referred to as "component (D1)") that decomposes upon exposure to light and loses its acid diffusion controllability, or a nitrogen-containing organic compound (D2) (hereinafter referred to as "component (D2)") that does not fall under the category of component (D1); however, component (D1) is preferred. By using a resist composition that contains the component (D), the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern.

[0255] The component (D) does not contain any compounds that fall under PFAS. The component (D) contains only compounds that do not fall under PFAS. That is, the component (D) does not contain any compounds having a trifluoromethyl group or a difluoromethylene group. Furthermore, it is preferable that the component (D) does not contain a fluorine atom.

[0256] Regarding component (D1) By including the component (D1) in the resist composition, the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. The component (D1) may be used as an acid generator in addition to the component (B) or in place of the component (B). 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)"), except for the components (d1-1) to (d1-3) corresponding to general formula (b1-1). The components (d1-1) to (d1-3) do not act as quenchers in the exposed areas of the resist film because they decompose and lose their acid diffusion control ability (basicity), but they act as quenchers in the unexposed areas of the resist film.

[0257] [ka]

[0258] [In the formula, Rd 1 ~Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 2 In the formula, no fluorine atom is bonded to the carbon atom adjacent to the S atom. 1 is a single bond or a divalent linking group; m is an integer of 1 or more; M m+ are each independently an organic cation having a valence of m.

[0259] {(d1-1) component} Anion section In formula (d1-1), Rd 1 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, each of which is represented by the above R' 201 The same can be mentioned. Among these, Rd 1 As the substituent, 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 is preferable. The substituent which these groups may have includes a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group, 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 connected via an alkylene group, and in this case, the substituent is preferably a linking group represented by each of the following formulas (y-al-1) to (y-al-8).

[0260] [ka]

[0261] [In the formula, V' 101is 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.]

[0262] In the above formula, V' 102 The divalent saturated hydrocarbon group in V' is preferably an alkylene group having 1 to 30 carbon atoms. 102 The alkylene group in the formula (I) is preferably an alkylene group having 1 to 30 carbon atoms, and more preferably an alkylene group having 1 to 10 carbon atoms. An alkylene group having 1 to 5 carbon atoms is more preferred.

[0263] 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, tricyclo[5.2.1.02,6]decane, or tetracyclododecane. The chain alkyl group preferably has 1 to 10 carbon atoms. Specific examples of the chain alkyl group include linear alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; and branched alkyl groups such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0264] When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms of the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and further preferably 1 to 4. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of the atom other than a fluorine atom include an oxygen atom, a sulfur atom, and a nitrogen atom. Rd 1 As the alkyl group, a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group have been substituted with fluorine atoms is preferable, and a fluorinated alkyl group in which all of the hydrogen atoms constituting the linear alkyl group have been substituted with fluorine atoms (linear perfluoroalkyl group) is particularly preferable.

[0265] Preferred specific examples of the anion moiety of the component (d1-1) are shown below.

[0266] [ka]

[0267] ·Cation part In formula (d1-1), M m+ is an m-valent organic cation. M m+ Suitable organic cations include those similar to those represented by the general formulas (ca-1) to (ca-3), more preferably those represented by the general formula (ca-1), and even more preferably those represented by the general formulas (ca-1-1) to (ca-1-67). The component (d1-1) may be used alone or in combination of two or more.

[0268] {Component (d1-2)} Anion section In formula (d1-2), Rd 2 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and the R' 201The same can be mentioned. However, Rd 2 In the above, the carbon atom adjacent to the S atom does not have a fluorine atom bonded thereto (is not substituted with fluorine), and this makes the anion of the (d1-2) component an appropriate weak acid anion, thereby improving the quenching ability of the (D) component. Rd 2 is preferably a chain alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 3 to 10 carbon atoms. The aliphatic cyclic group is more preferably a group (which may have a substituent) in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, or the like; or a group in which one or more hydrogen atoms have been removed from camphor, or the like. Rd 2 The hydrocarbon group may have a substituent, and examples of the substituent include Rd 1 Examples of the substituent include the same as the substituents that may be possessed by the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in the above.

[0269] Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

[0270] [ka]

[0271] ·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.

[0272] {Component (d1-3)} Anion section In formula (d1-3), Rd3 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, 201 The Rd is preferably a fluorine atom-containing cyclic group, a chain alkyl group, or a chain alkenyl group. Among these, a fluorinated alkyl group is preferred, and the Rd 1 More preferred are the same fluorinated alkyl groups as those mentioned above.

[0273] In formula (d1-3), Rd 4 is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and the R' 201 The same can be mentioned. Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group, each of which may have a substituent, is preferable. Rd 4 The alkyl group in Rd is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. 4 A part of the hydrogen atoms of the alkyl group may be substituted with a hydroxyl group, a cyano group, or the like. Rd 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.

[0274] Rd 4 The alkenyl group in R' 201Examples of the alkenyl group include the same as the alkenyl group in the above, and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group are preferred. These groups may further have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

[0275] Rd 4 The cyclic group in R' 201 Examples of the cyclic groups include those similar to those in the above formula, and are preferably alicyclic groups obtained by removing one or more hydrogen atoms from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, or tetracyclododecane, or aromatic groups such as a phenyl group or naphthyl group. 4 When Rd is an alicyclic group, the resist composition dissolves well in an organic solvent, and the lithography properties become good. 4 When is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition exhibits excellent light absorption efficiency and exhibits favorable sensitivity and lithography properties.

[0276] In formula (d1-3), Yd 1 is a single bond or a divalent linking group. Yd 1 The divalent linking group in is not particularly limited, but examples thereof include divalent hydrocarbon groups which may have a substituent (aliphatic hydrocarbon groups, aromatic hydrocarbon groups), and divalent linking groups which contain a hetero atom. These are respectively represented by Ya in the above general formula (a2-1). 21 Examples of the divalent linking group include the same divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom as mentioned in the description of the divalent linking group in the above. Yd 1 is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, and further preferably a methylene group or an ethylene group.

[0277] Preferred specific examples of the anion moiety of the component (d1-3) are shown below.

[0278] [ka]

[0279] [ka]

[0280] ·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.

[0281] The component (D1) may be any one of the above components (d1-1) to (d1-3), or a combination of two or more of them. When the resist composition contains the component (D1), the amount of the component (D1) in the resist composition relative to 100 parts by mass of the component (A) is preferably 0.5 to 25 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 2.5 to 15 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 no more than the upper limit, good sensitivity can be maintained and excellent throughput is also achieved.

[0282] Manufacturing method of component (D1): The method for producing the components (d1-1) and (d1-2) is not particularly limited, and they can be produced by known methods. The method for producing the component (d1-3) is not particularly limited, and it can be produced, for example, in a manner similar to that described in US2012-0149916.

[0283] Regarding component (D2) The acid diffusion controller may contain a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not fall under the category of the above-mentioned component (D1). The component (D2) is not particularly limited as long as it acts as an acid diffusion controller and does not fall under the category of component (D1), and any known amine may be used. Among them, aliphatic amines or aromatic amines are preferred, and aromatic amines are more preferred.

[0284] An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. The aliphatic amine is ammonia NH 3 Examples of the amine include amines in which at least one hydrogen atom is 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 alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0285] 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.

[0286] Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, and the like, with triethanolamine triacetate being preferred.

[0287] Furthermore, an aromatic amine may be used as the component (D2). Examples of aromatic amines include 4-dimethylaminopyridine, 2,6-di-tert-butylpyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, and N-tert-butoxycarbonylpyrrolidine.

[0288] The component (D2) may be used alone or in combination of two or more types. When the resist composition contains the component (D2), the amount of the component (D2) in the resist composition is usually within the range of 0.01 to 5 parts by mass relative to 100 parts by mass of the component (A). By ensuring that the amount is within this range, the resist pattern shape, the storage stability over time, and the like are improved.

[0289] <Optional ingredients> The resist composition of the present embodiment may further contain components (optional components) other than the above-mentioned components (A), (B), and (D). Examples of such optional components include the following components (E), (F), (H), and (S).

[0290] It is preferable that the (E), (F), (H), and (S) components do not contain a compound that corresponds to PFAS. It is preferable that the (E), (F), (H), and (S) components do not contain any compound having a trifluoromethyl group or a compound having a difluoromethylene group. Furthermore, it is more preferable that they do not contain fluorine atoms.

[0291] <<Component (E): at least one compound 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, phosphorus oxoacids and derivatives thereof (hereafter referred to as "component (E)") for the purposes of preventing deterioration of sensitivity and improving the resist pattern shape and stability over time after exposure. Suitable organic carboxylic acids include, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, and isophthalic acid. Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid, with phosphonic acid being particularly preferred. Examples of derivatives of phosphorus oxoacids include esters in which the hydrogen atoms of the above oxoacids are substituted with hydrocarbon groups. Examples of the hydrocarbon groups include alkyl groups having 1 to 5 carbon atoms and aryl groups having 6 to 15 carbon atoms. Examples of the derivatives of phosphoric acid include phosphoric acid esters such as di-n-butyl phosphoric acid ester and diphenyl phosphoric acid ester. Examples of the derivatives of phosphonic acid include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, and dibenzyl phosphonate. Derivatives of phosphinic acid include phosphinic acid esters and phenylphosphinic acid.

[0292] Of the above, the component (E) is preferably an organic carboxylic acid, more preferably an aromatic carboxylic acid, specifically, benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, and isophthalic acid, more preferably salicylic acid.

[0293] In the resist composition of this embodiment, the component (E) may use either a single type, or a combination of two or more types. When the resist composition contains the component (E), the amount of the component (E) per 100 parts by mass of the component (A) is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and even more preferably 0.1 to 3 parts by mass.

[0294] <(F) component: Fluorine additive component> The resist composition in 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 improves lithography properties. As the component (F), for example, fluorine-containing polymeric compounds described in JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226 can be used. More specifically, the component (F) may be a polymer having a structural unit (f11) represented by the following general formula (f1-1).

[0295] The polymer having the structural unit (f11) represented by the following general formula (f1-1) is preferably a polymer (homopolymer) consisting only of the structural unit (f11) represented by the following formula (f1-1); a copolymer of the structural unit (f11) and the structural unit (a3); or a copolymer of the structural unit (f11), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1).

[0296] [ka]

[0297] [In the formula, R is the same as above. 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.

[0298] In the general 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 general formula (f1-1), Rf 102 and Rf 103 Examples of the halogen atom in Rf include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferred. 102 and Rf103 Examples of the alkyl group having 1 to 5 carbon atoms in R include the same alkyl groups having 1 to 5 carbon atoms as those in R, and a methyl group or an ethyl group is preferred. 102 and Rf 103 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. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferred. 102 and Rf 103 is preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group. In general formula (f1-1), n f1 is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

[0299] In general formula (f1-1), Rf 101 is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom. The fluorine atom-containing hydrocarbon group may be linear, branched or cyclic and preferably has 1 to 20 carbon atoms, more preferably has 1 to 15 carbon atoms, and particularly preferably has 1 to 10 carbon atoms. Furthermore, in the hydrocarbon group containing fluorine atoms, preferably 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more, and particularly preferably 60% or more are fluorinated, as this enhances the hydrophobicity of the resist film during immersion exposure. Among them, Rf 101 is preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, more preferably a trifluoromethyl group, -CH 2 -CF 3 , -CH 2 -CF 2 -CF 3 , -CH(CF 3 ) 2 , -CH 2-CH 2 -CF 3 , -CH 2 -CH 2 -CF 2 -CF 2 -CF 2 -CF 3 More preferably, -CH 2 -CF 3 is particularly preferred.

[0300] The weight average molecular weight (Mw) of component (F) (based on polystyrene conversion measured by gel permeation chromatography) is preferably 1000 to 50000, more preferably 5000 to 40000, and most preferably 10000 to 30000. When the weight average molecular weight is equal to or less than the upper limit of this range, the resist composition of this embodiment has sufficient solubility in a resist solvent for use as a resist, and when the weight average molecular weight is equal to or more than the lower limit of this range, the resist composition of this embodiment exhibits good dry etching resistance and the cross-sectional shape of a resist pattern. 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.

[0301] In the resist composition of this embodiment, the component (F) may be used as a single type, or in combination of two or more types. When the resist composition contains the component (F), the component (F) is typically used in an amount of 0.5 to 10 parts by mass per 100 parts by mass of the component (A).

[0302] ≪(H) component≫ The resist composition of this embodiment may contain a surfactant component (hereafter referred to as "component (H)") in order to improve the coatability, defoaming properties, leveling properties, etc. of the resist composition. There are no particular limitations on the component (H), and it may be, for example, a silicon-based or acrylic surfactant. Furthermore, the component (H) may be either an ionic surfactant or a nonionic surfactant. Silicone surfactant may be synthesized by known method, or may be commercially available. Silicone surfactant may contain silane condensate having either or both of urethane or urea bond. Silicone surfactant can be preferably used as unmodified silicone surfactant, polyether modified silicone surfactant, polyester modified silicone surfactant, alkyl modified silicone surfactant, aralkyl modified silicone surfactant, reactive silicone surfactant, and other silicone surfactants. Specific examples of commercially available silicone surfactants include Paintad M (manufactured by Dow Corning Toray Co., Ltd.), Topika K1000, Topika K2000, Topika K5000 (all manufactured by Takachiho Sangyo Co., Ltd.), XL-121 (a polyether-modified silicone surfactant manufactured by Clariant), and BYK-310 (a polyester-modified silicone surfactant manufactured by BYK-Chemie). Furthermore, an example of an acrylic surfactant is BYK-354 (manufactured by BYK Chemical Co., Ltd.). Of these, silicone-based surfactants are preferred.

[0303] In the resist composition of this embodiment, the component (H) may be used either as a single type, or in combination of two or more types. When the resist composition contains the component (H), the content of the component (H) is generally 0.01 to 3 parts by mass, preferably 0.01 to 1 part by mass, and more preferably 0.01 to 0.5 part 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 to form a homogeneous solution, and any solvent can be appropriately selected from those known in the art as a solvent for chemically amplified resist compositions. In the resist composition of this embodiment, the component (S) may be used alone or as a mixed solvent of two or more kinds. Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0305] As the component (S), a mixed solvent of PGMEA and a polar solvent is also preferred. The blending ratio (mass ratio) may be appropriately determined taking into consideration the compatibility between PGMEA and the polar solvent, etc. As the component (S), a mixed solvent of at least one selected from PGMEA and EL with γ-butyrolactone is also preferred. In this case, the mixing ratio of the former to the latter is preferably 70:30 to 95:5 by mass. The amount of the component (S) used is not particularly limited, and is set appropriately depending on the coating film thickness at a concentration that allows application to a substrate, etc. In general, the component (S) is used so that the solids concentration of the resist composition falls within the range of 0.1 to 20 mass %, and preferably 0.2 to 15 mass %.

[0306] The resist composition in this embodiment may further contain, as desired, compatible additives such as an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, or a dye.

[0307] The resist composition of the present embodiment contains the above-mentioned components (A), (B), and (D), and, if necessary, the optional components described above. For example, a resist composition containing the component (A), the component (B), the component (D), and the component (F) is preferred. Further, a resist composition containing the component (A), the component (B), the component (D), the component (F), and the component (S) is preferred.

[0308] The resist composition preferably does not contain a compound corresponding to PFAS. The components contained in the resist composition preferably do not contain any compound having a trifluoromethyl group or a compound having a difluoromethylene group. Furthermore, it is more preferable that the resist composition does not contain a fluorine atom.

[0309] As described above, the resist composition of this embodiment contains the acid generator component (B) containing the compound represented by the general formula (b1-1) described above. The compound represented by the general formula (b1-1) is X 1 and Y 1 is not a fluorine atom, not only can the burden on the environment be reduced, but also the segregation of PAG anions on the resist pattern surface is eliminated, and it is presumed that the resist composition of this embodiment can form a resist pattern with a good shape and excellent lithography properties. Furthermore, since the compound represented by general formula (b1-1) contains a sulfonic acid group and a carboxylic acid group in the same structure, the acid strength is increased (pKa is decreased) by the interaction between the sulfonic acid group and the carboxylic acid group in the same structure, and high sensitivity can be achieved.

[0310] (Method of forming a resist pattern) A method for forming a resist pattern according to another embodiment of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition of the above-mentioned embodiment, exposing the resist film, 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.

[0311] First, the resist composition of the above-described embodiment is applied onto a support using a spinner or the like, and then baked (post-applied bake (PAB)) at a temperature of, for example, 80 to 150° C. for 40 to 120 seconds, preferably 50 to 90 seconds, to form a resist film. Next, the resist film is selectively exposed by exposure through a mask (mask pattern) having a predetermined pattern formed thereon, or by exposure such as direct irradiation with electron beams without a mask pattern, using an exposure device such as an electron beam lithography device or an EUV exposure device, etc. Thereafter, a bake (post-exposure bake (PEB)) process is performed at a temperature condition of, for example, 80 to 150° C. for 40 to 120 seconds, preferably 50 to 90 seconds. Next, the resist film is developed using an alkaline developer in the case of an alkaline development process, or a developer containing an organic solvent (organic developer) in the case of a solvent development process. After the development process, a rinse process is preferably carried out. In the case of an alkaline development process, the rinse process is preferably a water rinse using pure water, and in the case of a solvent development process, a rinse liquid containing an organic solvent is preferably used. In the case of a solvent development process, after the development treatment or rinsing treatment, a treatment may be carried out in which the developer or rinsing liquid adhering to the pattern is removed by using a supercritical fluid. After the development treatment or rinsing treatment, drying is performed. In some cases, a baking treatment (post-baking) may be performed after the development treatment. In this manner, a resist pattern can be formed.

[0312] The support is not particularly limited, and may be a conventionally known support, such as a substrate for electronic components or a substrate on which a predetermined wiring pattern is formed. More specifically, it may be a silicon wafer, a substrate made of metal such as copper, chromium, iron, or aluminum, or a glass substrate. As the material for the wiring pattern, for example, copper, aluminum, nickel, or gold may be used.

[0313] The wavelength used for exposure is not particularly limited, and radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. The resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB or EUV.

[0314] The exposure method for the resist film may be a normal exposure method (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography, with liquid immersion lithography being preferred. Immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure tool is filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. The immersion medium is preferably a solvent having a refractive index larger than that of air and smaller than that of the resist film to be exposed. The refractive index of the solvent is not particularly limited as long as it is within the above range. Examples of the solvent having a refractive index larger than that of air and smaller than that of the resist film include water, fluorine-based inert liquids, silicone-based solvents, and hydrocarbon-based solvents. As the liquid immersion medium, water is preferably used.

[0315] An example of an alkaline developer used in the development treatment in the alkaline development process is a 0.1 to 10 mass % aqueous solution of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used in the development treatment in the solvent development process may be any organic solvent capable of dissolving the component (A) (the component (A) before exposure), and may be appropriately selected from known organic solvents. Specific examples of the organic solvent include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, and hydrocarbon solvents.

[0316] 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.

[0317] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, butyronitrile, and the like.

[0318] The organic developer may contain known additives as necessary. Examples of such additives include surfactants. The surfactants are not particularly limited, but may include, for example, ionic or nonionic fluorine-based and / or silicone-based surfactants.

[0319] 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 still for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), and a method of continuously discharging the developer while scanning a developer discharge nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0320] The development process can be carried out by a known development method, such as a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it there for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), and a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0321] The rinse treatment (cleaning treatment) using a rinse liquid can be carried out by a known rinse method, such as a method of continuously discharging the rinse liquid onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dip method), or a method of spraying the rinse liquid onto the surface of the support (spray method).

[0322] The resist composition of the above-mentioned embodiment and various materials used in the pattern forming method of the above-mentioned embodiment (for example, resist solvent, developer, rinse solution, anti-reflective film forming composition, top coat forming composition, etc.) preferably do not contain impurities such as metals, metal salts containing halogens, acids, alkalis, and components containing sulfur atoms or phosphorus atoms. Here, examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The content of impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device).

[0323] In the method of forming a resist pattern according to the present embodiment as explained above, the resist composition according to the embodiment of the present invention is used, so when forming a resist pattern, high sensitivity can be achieved, and a resist pattern with excellent lithography properties and a good shape can be formed.

[0324] [Compound] The compound according to the third embodiment of the present invention is a compound represented by the following general formula (b1-1).

[0325] [ka]

[0326] [In general formula (b1-1), X 1 and Y 1 each independently represents a halogen atom other than a fluorine atom, a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group, an electron-withdrawing group, a selenol group, a pentafluorosulfanyl group, a mercapto group, a thiocarboxylic acid group, or a dithiocarboxylic acid group. 1 and Y 1 may be bonded to each other to form a ring. n1 represents an integer of 1 to 10. m represents an integer of 1 or more, and M m+ represents an organic cation having a valence of m.

[0327] The compound represented by the above general formula (b1-1) is the same as the component (b1-1) in the resist composition according to the above-mentioned embodiment of the present invention, and the preferred embodiments are also the same.

[0328] [Method for producing a compound represented by formula (b1-1)] The compound represented by general formula (b1-1) can be produced by a known method. For example, a compound represented by general formula (b1-1) can be obtained by performing a salt exchange reaction between a precursor Bpre represented by the following general formula (Bpre) and a compound S-0 represented by the following general formula (S-0).

[0329] [ka]

[0330] [In the formula, X 1 and Y 1Each independently represents a halogen atom other than a fluorine atom, a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group, an electron-withdrawing group, a selenol group, a pentafluorosulfanyl group, a mercapto group, a thiocarboxylic acid group, or a dithiocarboxylic acid group. X 1 and Y 1 may be bonded to each other to form a ring. n1 represents an integer of 1 to 10. m is an integer of 1 or more, and M m+ represents an m-valent organic cation. Z - is a non-nucleophilic ion. ]]

[0331] More specifically, the salt exchange reaction is a step of reacting a precursor Bpre and a compound S-0 for salt exchange in a solvent such as water, dichloromethane, acetonitrile, or chloroform to exchange the cation (Na) of the precursor Bpre with the cation of the compound S-0, thereby obtaining a compound represented by the general formula (b1-1).

[0332] In the above formula, Z - includes ions that can be an acid with a lower acidity than the precursor Bpre. Specifically, halogen ions such as bromide ions and chloride ions, BF 4 - , AsF 6 - , SbF 6 - , PF 6 - , ClO 4 - etc. are included.

[0333] The reaction temperature of the salt exchange reaction is, for example, 0 to 100 °C, and the reaction time is, for example, 10 minutes or more and 24 hours or less.

[0334] After the salt exchange reaction is completed, the compound in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be appropriately combined and used. The structure of the compound obtained as described above is 1H-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.

[0335] The raw materials used in each step may be commercially available products or may be synthesized by a known method.

[0336] [Acid Generator] An acid generator according to a fourth embodiment of the present invention contains the compound according to the third embodiment 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, it is possible to reduce the environmental burden in resist pattern formation, achieve high sensitivity, and form a resist pattern that has excellent lithography properties. EXAMPLES

[0337] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0338] <Synthesis Example of Compound B-2>

[0339] [ka]

[0340] In a nitrogen atmosphere, precursor compound Bpre1 (11.5 g, 48.2 mmol, 1 equiv.), ion-exchanged water (58 mL), and triphenylmethylsulfonium chloride (15.1 g, 50.6 mmol, 1.05 equiv.) were added in sequence to a 100 mL eggplant flask and stirred for 2 hours. The reaction solution was extracted with methylene chloride, and the resulting organic layer was washed with ion-exchanged water. Magnesium sulfate was added to the organic layer, and the filtrate obtained by filtration was concentrated. The concentrated solid was dried under reduced pressure at 50°C for 16 hours to obtain 18.8 g of compound B-2 as a white solid.

[0341] <Synthesis of Compounds B-1, B-3 to B-8, and B-10> Compounds B-1, B-3 to B-8, and B-10 were obtained in the same manner as in the above "Synthesis Example of Compound B-2" by changing the above precursor compound and the salt exchange compound. NMR measurements were carried out on each of the obtained compounds, and their structures were identified from the following analytical results.

[0342] [Table 1]

[0343] <Preparation of resist composition> (Examples 1 to 12, Comparative Examples 1 to 5) The components shown in Table 2 were mixed and dissolved to prepare resist compositions of each example.

[0344] [Table 2]

[0345] In Table 2, the abbreviations have the following meanings. The numbers in brackets [ ] indicate the blend amount (parts by mass).

[0346] 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, determined by GPC measurement, is 7000, and the molecular weight dispersity (Mw / Mn) is 1.60. 13The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m / n = 40 / 40 / 20.

[0347] 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, determined by GPC measurement, is 10,000, and the molecular weight dispersity (Mw / Mn) is 2.07. 13 The copolymer composition ratio (proportion (molar ratio) of each structural unit in the structural formula) determined by C-NMR was l / m / n = 60 / 15 / 25.

[0348] A-3: A polymer compound represented by the following chemical formula A-3. The weight average molecular weight (Mw) of this polymer compound A-3, calculated in terms of standard polystyrene, determined by GPC measurement, is 7000, and the molecular weight dispersity (Mw / Mn) is 1.56. 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.

[0349] [ka]

[0350] B-1 to B-10: Acid generators each consisting of the above-mentioned compounds B-1 to B-10

[0351] D-1: An acid diffusion controller consisting of a compound represented by the following chemical formula D-1.

[0352] [ka]

[0353] H-1: A silicone-based surfactant (polypropylene glycol-polybutylene glycol-monomethacrylate (average repeat number of propylene glycol: 1, average repeat number of butylene glycol: 6) and a monomethacrylate compound having a polysiloxane bond represented by the following formula (number average of x2 is 10) obtained by polymerization reaction (synthesized by the method described in Synthesis Example 1 of WO 2023 / 140036).

[0354] [ka]

[0355] S-1: A mixed solvent of 45% by mass of propylene glycol monomethyl ether acetate, 30% by mass of propylene glycol monomethyl ether, and 25% by mass of cyclohexanone

[0356] [Lithography Evaluation 1 (ArF Evaluation)] For Examples 1 to 8 and Comparative Examples 1 to 3, KrF evaluations (resist pattern formation 1, optimum exposure dose (Eop) evaluation 1, EL (Exposure Latitude) evaluation 1, and LS pattern shape evaluation 1) were carried out.

[0357] <Formation of resist pattern 1> An organic anti-reflective coating composition "ARC95" (manufactured by Brewer Science) was applied onto a 12-inch silicon wafer using a spinner, and then baked on a hot plate at 205°C for 60 seconds to dry, forming an organic anti-reflective coating with a thickness of 90 nm. A resist composition was applied onto the formed anti-reflective coating using a spinner, and the composition was pre-baked (PAB) on a hot plate at 110° C. for 60 seconds, and then dried to form a resist film with a thickness of 100 nm.

[0358] Next, the resist film was selectively irradiated with an ArF excimer laser (193 nm) through a binary mask using an ArF exposure device NSR-S308F [Nikon Corporation; NA (numerical aperture) = 0.92, Sigma = 0.95], and then subjected to PEB treatment at 110°C for 60 seconds. Next, alkaline development was performed for 30 seconds with a 2.38% by mass TMAH aqueous solution (product name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23° C. Thereafter, water rinsing was performed for 30 seconds with pure water, and the film was shaken off and dried. As a result, in each example, a 1:1 line and space (LS) pattern with a line width of 100 nm and a pitch of 200 nm was formed.

[0359] [Evaluation of optimal exposure (Eop) 1] The line size in the above <Formation of resist pattern 1> was observed, and the exposure dose in which an LS pattern with a line width of 100 nm and a pitch of 200 nm was formed was determined as the optimal exposure dose (mJ / cm 2 ) are shown in Table 2.

[0360] [EL (Exposure Latitude) Rating 1] The exposure dose when lines of an LS pattern with a line width of 100 nm and a pitch of 200 nm were formed within a range of ±5% (95 nm to 105 nm) of the target dimension (line width 100 nm) using the above <Formation of resist pattern 1> was determined, and EL (unit: %) was calculated using the following formula. 5%EL(%)=(|E1-E2| / Eop)×100 [E1 is the exposure dose (mJ / cm) when a LS pattern with a line width of 95 nm is formed. 2 ), and E2 is the exposure dose (mJ / cm2) when a LS pattern with a line width of 105 nm is formed. 2 ).

[0361] [LS pattern shape evaluation 1] The shape of the LS pattern formed by the above <Formation of Resist Pattern 1> was observed by a length measuring SEM (scanning electron microscope, acceleration voltage 800V, product name: SU-8000, manufactured by Hitachi High-Technologies Corporation), and the Top CD and Bottom CD were measured (average value of N=3). The ratio of Top CD to Bottom CD was calculated, and the result is shown in Table 2 as "shape". The closer the Top / Bottom is to "1", the better the shape is.

[0362] [Lithography evaluation 2 (KrF evaluation)] For Example 9, Example 10, Comparative Example 4, and Comparative Example 5, KrF evaluations (resist pattern formation 2, evaluation of optimum exposure dose (Eop) 2, and evaluation of LS pattern shape 2) were carried out.

[0363] <Formation of resist pattern 2> An organic anti-reflective coating composition "DUV-42P" (manufactured by Brewer Science) was applied onto a 6-inch silicon wafer using a spinner, and then baked on a hot plate at 205°C for 60 seconds to dry, forming an organic anti-reflective coating with a thickness of 60 nm. The resist was applied onto the anti-reflective coating using a spinner, pre-baked (PAB) on a hot plate at 110° C. for 60 seconds, and then dried to form a resist film with a thickness of 420 nm. Using a KrF exposure device NSR-S203B [Nikon Corporation; NA (numerical aperture) = 0.68, Sigma = 0.75], the film was selectively irradiated with a KrF excimer laser (248 nm) through a photomask (binary mask), followed by PEB treatment at 110°C for 60 seconds. Next, alkaline development was carried out for 60 seconds with a 2.38% by mass aqueous solution of TMAH (product name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23° C., and then a water rinse was carried out for 30 seconds with pure water, followed by shaking off and drying. As a result, in each example, a 1:1 line and space (LS) pattern with a line width of 170 nm and a pitch of 340 nm was formed.

[0364] [Evaluation of optimal exposure (Eop) 2] The line size in the above <Formation of resist pattern 2> was observed, and the exposure dose at which an LS pattern with a line width of 170 nm and a pitch of 340 nm was formed was determined as the optimal exposure dose (mJ / cm 2 ) are shown in Table 2.

[0365] [LS pattern shape evaluation 2] The shape of the LS pattern formed by the above <Formation of Resist Pattern 2> was observed by a length measuring SEM (scanning electron microscope, acceleration voltage 800V, product name: SU-8000, manufactured by Hitachi High-Technologies Corporation), and the Top CD and Bottom CD were measured (average value of N=3). The ratio of Top CD to Bottom CD was calculated, and the result is shown in Table 2 as "shape". The closer the Top / Bottom is to "1", the better the shape is.

[0366] From the results shown in Table 2, it can be seen that the resist compositions of the examples to which the present invention is applied can achieve high sensitivity in the formation of a resist pattern, and can also form resist patterns with excellent lithography properties and a good shape.

[0367] [Lithography evaluation 3 (KrF evaluation)] For Example 11 and Example 12, KrF evaluations (resist pattern formation 3, evaluation of optimum exposure (Eop) 3, and evaluation of LS pattern shape 3) were carried out.

[0368] <Formation of resist pattern 3> The resist compositions of Examples 11 and 12 were applied onto a 6-inch silicon wafer that had been subjected to HMDS treatment using a spinner, and the wafer was pre-baked (PAB) at 110°C for 60 seconds on a hot plate, and then dried to form a resist film with a thickness of 1.7 µm. Using a KrF exposure device NSR-S205C [Nikon Corporation; NA (numerical aperture) = 0.6, Sigma = 0.5], the film was selectively irradiated with a KrF excimer laser (248 nm) through a photomask (binary mask), followed by PEB treatment at 110°C for 60 seconds. Subsequently, alkali development was carried out for 60 seconds with a 2.38 mass% aqueous TMAH solution (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23°C. Then, water rinsing was carried out for 30 seconds using pure water, followed by spin drying. As a result, a 1:1 line and space (LS) pattern with a line width of 400 nm and a pitch of 800 nm was formed in each example.

[0369] [Evaluation 3 of Optimum Exposure Dose (Eop)] The line size in the above <Formation 3 of Resist Pattern> was observed, and the exposure dose at which an LS pattern with a line width of 400 nm and a pitch of 800 nm was formed was defined as the optimum exposure dose (mJ / cm 2 2) and shown in Table 2.

[0370] [Evaluation 3 of LS Pattern Shape] The shape of the LS pattern formed by the above <Formation 2 of Resist Pattern> was observed with a length-measuring SEM (scanning electron microscope, acceleration voltage 800 V, trade name: SU-8000, manufactured by Hitachi High-Technologies Corporation), and Top CD and Bottom CD were measured (N = 3 average value). The ratio of Top CD to Bottom CD was calculated and the result was shown in Table 2 as "Shape". A shape was considered better when Top / Bottom was closer to "1". From the results shown in Table 2, it was confirmed that according to the resist composition of the example to which the present invention was applied, a resist pattern excellent in lithography characteristics could be formed even when a resist film with a thickness of 1 μm or more was formed.

Claims

1. A resist composition which generates an acid upon exposure and changes its solubility in a developer by the action of the acid, The composition contains a base component (A) whose solubility in a developer changes under the action of an acid, an acid generator component (B) that generates an acid upon exposure to light, and an acid diffusion controller component (D), The resist composition, wherein the acid generator component (B) contains a compound represented by the following general formula (b1-1): 【Chemistry 1】 [In general formula (b1-1), X １ and Y １ each independently represents a halogen atom other than a fluorine atom, a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group, an electron-withdrawing group, a selenol group, a pentafluorosulfanyl group, a mercapto group, a thiocarboxylic acid group, or a dithiocarboxylic acid group. １ and Y １ may be bonded to each other to form a ring. n1 represents an integer of 1 to 10. m represents an integer of 1 or more, and M ｍ＋ represents an m-valent organic cation.

2. 2. The resist composition according to claim 1, wherein the compound represented by general formula (b1-1) is a compound represented by the following general formula (b1-2): 【Chemistry 2】 [In general formula (b1-2), X ２ and Y ２ each independently represents a hydrogen atom, an aliphatic hydrocarbon group, or an aromatic hydrocarbon group; n2 represents an integer of 1 or 2; m is an integer of 1 or more, ｍ＋ represents an m-valent organic cation.

3. 2. The resist composition according to claim 1, wherein the compound represented by general formula (b1-1) is a compound represented by the following general formula (b1-3): 【Chemistry 3】 [In general formula (b1-3), X ２ and Y ２ each independently represents a hydrogen atom, an aliphatic hydrocarbon group, or an aromatic hydrocarbon group; n2 represents an integer of 1 or 2. ０１ ~Rb ０３ are each independently an aryl group, an alkyl group, or an alkenyl group. The aryl group, the alkyl group, and the alkenyl group may each independently have one or more substituents selected from the group consisting of an alkyl group, an aldehyde group, an acyl group, a hydroxyl group, and a halogen atom. ０１ ~Rb ０３ may be bonded to each other to form a ring together with the sulfur atom in general formula (b1-3).

4. 3. The resist composition according to claim 1, wherein the base component (A) comprises a polymeric compound (A1) having a structural unit (a1) represented by the following general formula (a1-1): 【Chemistry 4】 [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. １ represents a divalent hydrocarbon group which may have an ether bond. ａ１ is an integer from 0 to 2. １ represents an acid dissociable group.

5. 3. The resist composition according to claim 1, wherein the acid diffusion controller component (D) comprises a compound represented by any one of the following general formulas (d1-1) to (d1-3): 【Chemistry 5】 [In general formulas (d1-1) to (d1-3), Rd １ ~Rd ４ 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. ２ In the above, no fluorine atom is bonded to the carbon atom adjacent to the S atom. １ represents a single bond or a divalent linking group; m represents an integer of 1 or more; M ｍ＋ each independently represents an m-valent organic cation.

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

7. A compound represented by the following general formula (b1-1): 【Chemistry 6】 [In general formula (b1-1), X １ and Y １ each independently represents a halogen atom other than a fluorine atom, a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group, an electron-withdrawing group, a selenol group, a pentafluorosulfanyl group, a mercapto group, a thiocarboxylic acid group, or a dithiocarboxylic acid group. １ and Y １ may be bonded to each other to form a ring. n1 represents an integer of 1 to 10. m represents an integer of 1 or more, and M ｍ＋ represents an m-valent organic cation.

8. An acid generator containing a compound represented by the following general formula (b1-1): 【Chemistry 7】 [In general formula (b1-1), X １ and Y １ each independently represents a halogen atom other than a fluorine atom, a hydrogen atom, an aliphatic hydrocarbon group, an aromatic hydrocarbon group, a heterocyclic group, an electron-withdrawing group, a selenol group, a pentafluorosulfanyl group, a mercapto group, a thiocarboxylic acid group, or a dithiocarboxylic acid group. １ and Y １ may be bonded to each other to form a ring. n1 represents an integer of 1 to 10. m represents an integer of 1 or more, and M ｍ＋ represents an m-valent organic cation.

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