Resist composition, and method for forming resist pattern

Abstract

To provide: a resist composition that can form a resist pattern in which roughness reducing properties are satisfactory; and a method for forming the resist pattern with use of the resist composition.SOLUTION: A resist composition generates an acid by being exposed to light, and changes solubility in a developing solution due to an action of the acid; and includes a base material component (A) which changes solubility in the developing solution due to the action of the acid, and an acid diffusion control component (D). The base material component (A) includes: a polymer compound (A1) having weight-average molecular weight of 30,000 or more; and the polymer compound (A1) has a constitutional unit (a1) that is represented by a general formula (a-1) and a constitutional unit (a2) that is represented by a general formula (a-2) described in the specification. The acid diffusion control component (D) includes one or more kinds of chemical compounds (D1) selected from a group consisting of a chemical compound represented by a general formula (d1-1) described in the specification and a chemical compound represented by a general formula (d1-2) described in the specification.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resist composition and a method of forming a resist pattern. [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.

[0003] 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.

[0004] Resist materials are required to have lithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist composition that contains 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.

[0005] The base resin used as the substrate component in a chemically amplified resist composition generally has a plurality of structural units in order to improve lithography properties and the like. For example, Patent Document 1 discusses a resist composition and a method for forming a resist pattern that can achieve high sensitivity, have excellent lithography properties, and form a resist pattern with a good shape. Patent Document 1 also describes a resist composition that employs a polymer compound having multiple structural units of a specific structure and improves dissociation performance against acid. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2020-098250 A Summary of the Invention [Problem to be solved by the invention]

[0007] As lithography technology continues to advance and resist patterns become increasingly finer, there is a demand for resist compositions that can form fine patterns in good shapes. However, in the conventional techniques, the reduction in roughness during resist pattern formation is not necessarily sufficient, and a higher level of reduction in roughness is required.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a resist composition capable of forming a resist pattern with excellent roughness reduction, a method of forming a resist pattern using the resist composition, and a salt that is useful for the resist composition. [Means for solving the problem]

[0009] Means for Solving the Problems The present inventors conducted intensive research in order to solve the above-mentioned problems, and as a result, discovered that the following configuration makes it possible to obtain a resist composition that is capable of forming a resist pattern that achieves reduced roughness, and a method of forming a resist pattern using the resist composition, and have thus completed the present invention.

[0010] That is, the present invention is as follows.

[0011] The resist composition according to an embodiment of the present invention comprises 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, and an acid diffusion control component (D), The base component (A) contains a polymer compound (A1) having a weight average molecular weight of 30,000 or more, and the polymer compound (A1) has a structural unit (a1) represented by the following general formula (a-1) and a structural unit (a2) represented by the following general formula (a-2), The acid diffusion control component (D) contains one or more compounds (D1) selected from the group consisting of compounds represented by the following general formula (d1-1) and compounds represented by the following general formula (d1-2):

[0012] [ka] (a-1)

[0013] [In general formula (a-1), R 01 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 01 is a divalent hydrocarbon group which may have an ether bond. a01 is an integer from 0 to 2. 01 is an acid dissociable group.

[0014] [ka] (a-2)

[0015] [In general formula (a-2), R 02 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 02 is a divalent hydrocarbon group which may have an ether bond. a02is an integer from 0 to 2. 02 is a lactone-containing cyclic group, an -SO2- containing cyclic group, or a carbonate-containing cyclic group.

[0016] [ka]

[0017] [In general formula (d1-1) and general formula (d1-2), Rd 1 and Rd 2 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 2 In the formula, no fluorine atom is bonded to the carbon atom adjacent to the S atom. m is an integer of 1 or more, and M m+ are each independently an organic cation having a valence of m.

[0018] A method for forming a resist pattern according to another 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. Effect of the Invention

[0019] The present invention is capable of providing a resist composition capable of forming a resist pattern with excellent roughness reduction properties, and a method of forming a resist pattern using the resist composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] 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.

[0021] In this specification and claims, the term "aliphatic" is a relative concept to aromaticity and is defined as meaning a group, compound, etc. that does not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in an alkoxy group. 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 phrase "optionally has a substituent" includes both the case where a hydrogen atom (-H) is replaced with a monovalent group and the case where a methylene group (-CH2-) is replaced with a divalent group. The term "exposure" is intended to include any concept including irradiation with radiation.

[0022] The term "acid-decomposable group" refers to a group having acid decomposability in which at least a part of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases under the action of an acid include groups that are decomposed by the action of an acid to generate a polar group. Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (-SO3H). More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

[0023] The term "acid dissociable group" refers to both (i) a group having acid dissociability in which the bond between the acid dissociable group and an atom adjacent to the acid dissociable group can be cleaved by the action of an acid, and (ii) a group in which a portion of the bond is cleaved by the action of an acid and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid dissociable group and an atom adjacent to the acid dissociable group. The acid dissociable group constituting the acid decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid dissociable group, and thus, when the acid dissociable group is dissociated by the action of an acid, a polar group with higher polarity than the acid dissociable group is generated, increasing the polarity. As a result, the polarity of the entire component (A1) described below 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.

[0024] The "base component" refers to an organic compound having a film-forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved, and in addition, it becomes easier to form a nano-level resist pattern. The organic compounds used as the base component are roughly classified into non-polymers and polymers. As the non-polymers, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, the term "low molecular weight compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4000. As the polymers, those having a molecular weight of 1000 or more are usually used. Hereinafter, the term "resin", "polymer compound" or "polymer" refers to a polymer having a molecular weight of 1000 or more. As the molecular weight of the polymer, the weight average molecular weight in terms of polystyrene by GPC (gel permeation chromatography) is used.

[0025] 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. An "acrylic ester" is a compound in which the hydrogen atom at the carboxyl terminal of acrylic acid (CH2=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. 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 acrylic acid 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."

[0026] 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.

[0027] 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 specification and claims, some structures represented by chemical formulas may have asymmetric carbons, and may have enantiomers or diastereomers. In such cases, a single chemical formula represents all of the isomers. These isomers may be used alone or as a mixture. In the present disclosure, "mass %" and "weight %" are synonymous, and "parts by mass" and "parts by weight" are synonymous.

[0028] [Resist Composition] A resist composition according to an embodiment of the present invention is a resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid. The resist composition comprises a base component (A) (hereinafter also referred to as “component (A)”) whose solubility in a developer changes due to the action of an acid, and an acid diffusion control component (D) (hereinafter also referred to as “component (D)”). The base component (A) comprises a polymer compound (A1) having a weight-average molecular weight of 30,000 or more. The polymer compound (A1) (hereinafter also referred to as “component (A1)”) has a structural unit (a1) represented by the following general formula (a-1) and a structural unit (a2) represented by the following general formula (a-2). The acid diffusion control component (D) comprises one or more compounds (D1) selected from the group consisting of compounds represented by the following general formula (d1-1) and compounds represented by the following general formula (d1-2).

[0029] [ka] (a-1)

[0030] [In general formula (a-1), R 01 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 01 is a divalent hydrocarbon group which may have an ether bond. a01 is an integer from 0 to 2. 01 is an acid dissociable group.

[0031] [ka] (a-2)

[0032] [In general formula (a-2), R 02 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 02 is a divalent hydrocarbon group which may have an ether bond. a02 is an integer from 0 to 2. 02 is a lactone-containing cyclic group, an -SO2- containing cyclic group, or a carbonate-containing cyclic group.

[0033] [ka]

[0034] [In general formula (d1-1) and general formula (d1-2), Rd 1 and Rd 2 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 2 In the formula, no fluorine atom is bonded to the carbon atom adjacent to the S atom. m is an integer of 1 or more, and M m+ are each independently an organic cation having a valence of m.

[0035] When a resist film is formed using the resist composition according to the embodiment of the present invention 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.

[0036] In this specification, a resist composition that forms a positive resist pattern by dissolving and removing exposed areas 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 areas of the resist film is referred to as a negative resist composition. The resist composition according to an embodiment of the present invention may be a positive resist composition, or a negative resist composition. Furthermore, the resist composition according to an embodiment of the present invention may be for an alkaline development process in which an alkaline developer is used in the development treatment during resist pattern formation, or may be for a solvent development process in which a developer containing an organic solvent (organic developer) is used in the development treatment.

[0037] The resist composition according to the embodiment of the present invention has an acid generating ability to generate an acid upon exposure. The component (A) may generate an acid upon exposure, or an additive component that is formulated separately from the component (A) may generate an acid upon exposure. Specifically, the resist composition according to the embodiment of the present invention may further contain (1) an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “component (B)”); (2) the component (A) may be a component that generates an acid upon exposure; or (3) the component (A) may be a component that generates an acid upon exposure, and may further contain component (B). That is, in the above cases (2) and (3), the component (A) is a "base component that generates an acid upon exposure and changes its solubility in a developer by the action of the acid". When the component (A) is a base component that generates an acid upon exposure and changes its solubility in a developer by the action of the acid, it is preferable that the component (A1) described below is a polymeric compound that generates an acid upon exposure and changes its solubility in a developer by the action of the acid. As such a polymeric compound, a resin having a structural unit that generates an acid upon exposure can be used. As the structural unit that generates an acid upon exposure, a known one can be used. Among them, the resist composition according to the embodiment of the present invention is preferably the above case (1).

[0038] The resist composition according to the embodiment of the present invention is effective in improving the reduction of roughness of a resist film when used for forming a resist film, since the polymer compound (A1) contained in the base component (A) has a weight average molecular weight of 30,000 or more, has a structural unit (a1) represented by general formula (a-1) and a structural unit (a2) represented by general formula (a-2), and contains an acid diffusion control component (D) of a specific structure. In addition, in an alkaline development process, the solubility of the resist film in an alkaline developer is increased during development. The synergistic effect of the base material component (A) having a weight average molecular weight of 30,000 or more and a specific structure and the acid diffusion control component (D) having a specific structure makes it possible to suppress the variation in the deprotection reaction and improve the acid diffusion control ability, and the reaction contrast at the interface between the exposed and unexposed areas can be further increased. Therefore, it is presumed that the resist composition according to the embodiment of the present invention can reduce roughness and form a resist pattern with a good shape.

[0039] Component (A) In the resist composition according to the embodiment of the present invention, the component (A) is a base component whose solubility in a developer changes under the action of an acid, and contains the above-mentioned component (A1). 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 (A), the polarity of the base component 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.

[0040] When an alkali development process is applied, the base material component containing the component (A1) is poorly soluble in an alkali developer before exposure, and when an acid is generated by exposure, for example, the polarity increases due to the action of the acid, and the solubility in an alkali 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 alkali developer to soluble, while the unexposed part of the resist film remains poorly soluble in alkali, and a positive resist pattern is formed by alkali development.

[0041] On the other hand, when a solvent development process is applied, the base material component containing the component (A1) is highly soluble in an organic developer before exposure, and when an acid is generated by exposure, the polarity 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 thus a contrast can be created between the exposed part and the unexposed part by developing with an organic developer, and a negative resist pattern is formed.

[0042] 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. 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).

[0043] <Constituent unit (a1)> The structural unit (a1) is represented by the following general formula (a-1).

[0044] [ka] (a-1)

[0045] [In general formula (a-1), R 01 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 01 is a divalent hydrocarbon group which may have an ether bond. a01 is an integer from 0 to 2. 01 is an acid dissociable group.

[0046] In general formula (a-1), R 01 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. R 01 The alkyl group having 1 to 5 carbon atoms represented by is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is most preferable.

[0047] In the formula (a-1), Va 01is a divalent hydrocarbon group which may have an ether bond. 01 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0048] Va 01 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.

[0049] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0050] 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 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc.

[0051] Va 01 The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this number of carbon atoms does not include the number of carbon atoms in the substituents. Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (aryl group) has been substituted with an alkylene group (for example, a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0052] n a1 is an integer of 0 to 2, with 0 being preferred.

[0053] Ra 01 is an acid-dissociable group. In the structural unit (a1), Ra 01 Examples of the acid-dissociable group represented by the formula (I) 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.”

[0054] 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").

[0055] [ka] (a1-r-1)

[0056] [In formula (a1-r-1), 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.

[0057] 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.

[0058] In formula (a1-r-1), Ra' 3 The hydrocarbon group is preferably an aliphatic hydrocarbon group and may be either a polycyclic group or a monocyclic group, with a monocyclic group being preferred.

[0059] 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.

[0060] Ra' 3 The alicyclic 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. Also, R P2 is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P1 and R 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.

[0061] Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

[0062] Ra' 3 But Ra' 1 , Ra' 2 When it is bonded to any one of the above to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group, a tetrahydrofuranyl group, etc.

[0063] Tertiary alkyl ester type acid-labile group: Among the above polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2). Among the acid-dissociable groups represented by the following formula (a1-r-2), Ra' 4 ~Ra' 6 where each is an alkyl group is sometimes referred to as a "tertiary alkyl ester type acid-dissociable group" for convenience.

[0064] [ka] (a1-r-2)

[0065] [In formula (a1-r-2), Ra' 4 ~Ra' 6 are each a hydrocarbon group, and Ra' 4 ~Ra' 6 At least one of Ra' is an alicyclic hydrocarbon group, or 5 , Ra' 6 are bonded to each other to form an alicyclic hydrocarbon group.

[0066] Ra' 4 Examples of the hydrocarbon group of Ra' include a linear or branched alkyl group, a linear or cyclic alkenyl group, and a cyclic hydrocarbon group. 4 ~Ra' 6 At least one of Ra' is an alicyclic hydrocarbon group, or 5 , Ra' 6 are bonded to each other to form an alicyclic hydrocarbon group.

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

[0068] 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.

[0069] Ra' 4 ~Ra' 6 When any of the above is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.

[0070] Ra' 4 ~Ra' 6 When any of the above 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.

[0071] Specific examples of the aromatic hydrocarbon group 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 (such as 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 (such as 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.

[0072] The cyclic hydrocarbon group may have a substituent. Examples of the substituent include Ra' in the above formula (a1-r-1). 3 The substituents may be the same as those that the alicyclic hydrocarbon group in the above may have.

[0073] Ra' 5 and Ra' 6 and (a1-r2-3) are each bonded to each other to form a ring. Suitable examples of the acid-dissociable group include a group represented by the following formula (a1-r2-1), a group represented by the following formula (a1-r2-2), and a group represented by the following formula (a1-r2-3). On the other hand, Ra' 4 ~Ra' 6 When are not bonded to each other and are independent hydrocarbon groups, suitable examples of the acid-dissociable group include groups represented by the following formula (a1-r2-4).

[0074] [ka]

[0075] [In formula (a1-r2-1), Ra 031 represents an alkyl group having 1 to 10 carbon atoms. 0 represents a carbon atom. 0 Yab 0 represents a group which forms an alicyclic hydrocarbon group together with In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms an alicyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra 101 ~Ra 103 are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent cyclic aliphatic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms in the linear saturated hydrocarbon group and the cyclic aliphatic saturated hydrocarbon group may be substituted. 101 ~Ra 103 Two or more of these may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group that forms an aliphatic cyclic group together with Yaa. Ra 104 is an aromatic hydrocarbon group which may have a substituent. In formula (a1-r2-4), Ra' 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. 14 is an alicyclic hydrocarbon group. * indicates a bond.]

[0076] In the above formula (a1-r2-1), Ra 031 The alkyl group having 1 to 10 carbon atoms in the formula (I) may be a straight-chain or branched-chain alkyl group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and the like, and among these, a methyl group or an ethyl group is 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.

[0077] Ra in the above formula (a1-r2-1) 031 Among the above, a linear alkyl group having 1 to 5 carbon atoms is preferable, and specifically, a methyl group and an ethyl group are preferable.

[0078] In formula (a1-r2-1), Xab 0 (Yab 0 The aliphatic cyclic group forming an alicyclic hydrocarbon together with is preferably a monocyclic alicyclic hydrocarbon group, and examples thereof include groups in which two or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 10 carbon atoms, more preferably has 3 to 8 carbon atoms, and even more preferably has 3 to 6 carbon atoms. Specific examples of suitable monocycloalkanes include cyclopentane and cyclohexane.

[0079] In the formula (a1-r2-2), the alicyclic hydrocarbon group formed by Xa together with Ya is preferably a monocyclic alicyclic hydrocarbon group. 0 This is similar to the content explained in . In formula (a1-r2-2), Ra 101 ~Ra 103 In the above formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Ra101 ~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. Ra 101 ~Ra 103 Of the above, from the viewpoint of ease of synthesis of the monomer compound, a hydrogen atom or a monovalent chain 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.

[0080] 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.

[0081] Ra 101 ~Ra 103 Examples of groups containing a carbon-carbon double bond resulting from 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 of the monomer compound, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylidene-ethenyl group are preferred.

[0082] In formula (a1-r2-3), the alicyclic hydrocarbon group formed by Xaa together with Yaa is preferably a monocyclic alicyclic hydrocarbon group. 4 This is similar to the content explained in . 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. 104is 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.

[0083] Ra in formula (a1-r2-3) 104 Examples of the substituent that may be possessed by the alkyl group include a methyl group, an ethyl group, a propyl group, a hydroxy group, a carboxyl group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, etc.), an alkoxy group (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, etc.), and an alkyloxycarbonyl group.

[0084] 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 (1) include those in which some or all of the hydrogen atoms in the chain saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among these, an alkyl group having 1 to 5 carbon atoms is preferable, a methyl group or an ethyl group is more preferable, and a methyl group is even more 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.

[0085] In formula (a1-r2-4), Ra' 14is an alicyclic hydrocarbon group, and is preferably a monocyclic alicyclic hydrocarbon group which may have a substituent. 14 In the above formula, the alicyclic hydrocarbon group may be, for example, a group in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 10 carbon atoms, more preferably has 3 to 8 carbon atoms, and even more preferably has 3 to 6 carbon atoms. Specific examples of suitable monocycloalkanes include cyclopentane and cyclohexane.

[0086] Rax' 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.

[0087] Specific examples of the group represented by formula (a1-r2-1) are shown below. In the following formula, * represents a bond.

[0088] [ka]

[0089] [ka]

[0090] Specific examples of the group represented by formula (a1-r2-2) are shown below. In the following formula, * represents a bond.

[0091] [ka]

[0092] [ka]

[0093] [ka]

[0094] Specific examples of the group represented by the formula (a1-r2-3) are shown below. In the following formula, * represents a bond.

[0095] [ka]

[0096] Specific examples of the group represented by formula (a1-r2-4) are shown below.

[0097] [ka]

[0098] Tertiary alkyloxycarbonyl acid dissociating 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 (ar-3) (hereinafter, for convenience, may be referred to as a "tertiary alkyloxycarbonyl acid dissociable group").

[0099] [ka] (ar-3)

[0100] [In the formula, Ra' 7 ~Ra' 9 Each represents an alkyl group.

[0101] In formula (ar-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.

[0102] As the acid-dissociable group, among the groups represented by the above general formulae (a1-r2-1) to (a1-r2-4), the group represented by the above general formula (a1-r2-1) is preferred. That is, the base component (A) according to the embodiment of the present invention preferably contains a polymeric compound (A1) having a structural unit containing an acid-dissociable group represented by the above formula (a1-r2-1).

[0103] In the structural unit (a1), general formula (a-1) is preferably represented by the following general formula (a1-2).

[0104] [ka]

[0105] (In general formula (a1-2), R 01 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 01 represents a divalent hydrocarbon group which may have an ether bond. na3 represents an integer of 0 to 2. Ra 031 represents an alkyl group, and Yab 0 represents a carbon atom. 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.

[0106] In general formula (a1-2), R 01 and Va 01 are R in the general formula (a-1), 01 and Va 01 is the same as:

[0107] In general formula (a1-2), na3 represents an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

[0108] In general formula (a1-2), Ra 031 is as mentioned above.

[0109] 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.

[0110] In general formula (a1-2), Yab 0 and Xab 0 are each independently represented by Yab 0 and Xab 0 is the same as:

[0111] Specific examples of the structural unit (a1) are shown below. In the following formula, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0112] [ka]

[0113] [ka]

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] [ka]

[0118] [ka]

[0119] [ka]

[0120] [ka]

[0121] [ka]

[0122] 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.

[0123] <Constituent unit (a2)> The structural unit (a2) is a structural unit represented by the following general formula (a-2).

[0124] [ka] (a-2)

[0125] [In general formula (a-2), R02 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 02 is a divalent hydrocarbon group which may have an ether bond. a02 is an integer from 0 to 2. 02 is a lactone-containing cyclic group, an -SO2- containing cyclic group, or a carbonate-containing cyclic group.

[0126] In the formula (a-2), R 02 is R in the formula (a-1) 01 is the same as R 02 As the alkyl group, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferable.

[0127] In the formula (a-2), Va 02 The divalent hydrocarbon group which may have an ether bond in the formula (I) may have a substituent.

[0128] Optionally substituted divalent hydrocarbon group: Va 02 When is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0129] ··Va 02 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.

[0130] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably contains 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the straight-chain aliphatic hydrocarbon group, a straight-chain alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0131] The linear or branched aliphatic hydrocarbon group may or may not have a substituent, which may include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms and substituted with a fluorine atom, and a carbonyl group.

[0132] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, specifically 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc.

[0133] 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, some of the carbon atoms constituting the ring structure may be substituted with a heteroatom-containing substituent, preferably -O-, -C(=O)-O-, -S-, -S(=O)2-, or -S(=O)2-O-.

[0134] ··Va 02 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.

[0135] 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.

[0136] Va 02 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.

[0137] In the formula (a-2), Ra 02is a lactone-containing cyclic group, an -SO2- containing cyclic group, or a carbonate-containing cyclic group.

[0138] The lactone-containing cyclic group, -SO2-containing cyclic group, or carbonate-containing cyclic group in the structural unit (a2) is effective in improving the adhesion of the resist film to the substrate when the component (A1) is used to form a resist film. In addition, the structural unit (a2) has the effects of, for example, appropriately adjusting the acid diffusion length, improving the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development, thereby improving the lithography properties, etc.

[0139] 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 groups represented by any of the following general formulae (a2-r-1) to (a2-r-7).

[0140] [ka]

[0141] [In 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 a -SO2- 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.]

[0142] In the above 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' 21 Examples of the halogen atom in include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable. Ra' 21 As the halogenated alkyl group in the above, Ra' 21 and groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the above halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferred, and a perfluoroalkyl group is particularly preferred.

[0143] Ra' 21 In the -COOR" and -OC(=O)R" in the above, R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2- containing cyclic group. The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms.

[0144] When R″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably has 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane. More specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, or tetracyclododecane.

[0145] Examples of the lactone-containing cyclic group in R″ include the same groups as those represented by any one of 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 any of the general formulae (ax3-r-1) to (ax3-r-3). The -SO2-containing cyclic group in R'' is the same as the -SO2-containing cyclic group described later, and specific examples thereof include groups represented by any of the general formulae (a5-r-1) to (a5-r-4).

[0146] 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.

[0147] In the general formulae (a2-r-2), (a2-r-3) and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A" is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between the carbon atoms of the alkylene group, and examples thereof include -O-CH2-, -CH2-O-CH2-, -S-CH2- and -CH2-S-CH2-. A" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0148] Specific examples of the group represented by any one of general formulas (a2-r-1) to (a2-r-7) are shown below.

[0149] [ka]

[0150] [ka]

[0151] The term "-SO2-containing cyclic group" refers to a cyclic group containing a ring containing -SO2- in its ring structure, specifically, a cyclic group in which the sulfur atom (S) in -SO2- forms a part of the ring structure of the cyclic group. The ring containing -SO2- in the ring structure is counted as the first ring, and if there is only this ring, it is called a monocyclic group, and if there is another ring structure, it is called a polycyclic group regardless of the structure. The -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2- containing cyclic group is preferably a cyclic group containing -O-SO2- in its ring skeleton, that is, a cyclic group containing a sultone ring in which -OS- in -O-SO2- forms a part of the ring skeleton. More specific examples of the -SO2- containing cyclic group include groups represented by any of the following general formulas (a5-r-1) to (a5-r-4).

[0152] [ka]

[0153] [In 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 a -SO2- 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. * indicates a bond.]

[0154] In the formulae (a5-r-1) and (a5-r-2), A" is the same as A" in the 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 formulae (a5-r-1) to (a5-r-4) are shown below, in which "Ac" represents an acetyl group.

[0155] [ka]

[0156] [ka]

[0157] [ka]

[0158] 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-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).

[0159] [ka]

[0160] [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 a -SO2- 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.]

[0161] 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' X31The 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.

[0162] [ka]

[0163] Ra 02 Suitable examples of the lactone-containing cyclic group, the -SO2- containing cyclic group and the carbonate-containing cyclic group in the above formula (a2-r-1) to (a2-r-7), the groups represented by the general formulas (a5-r-1) to (a5-r-4) and the groups represented by the general formulas (ax3-r-1) to (ax3-r-3) are respectively.

[0164] In the formula (a-2), Ra 02 is preferably a lactone-containing cyclic group or an -SO2- containing cyclic group, and is preferably a substituent represented by any one of the general formulae (a2-r-1) to (a2-r-7) or the general formulae (a5-r-1) to (a5-r-4), more preferably a group represented by any one of the general formulae (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r-1), and further preferably a group represented by any one of the general formulae (a2-r-1) or (a2-r-2). Specifically, a group represented by any one of the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-lc-6-1), and (r-s1-1-1) is preferred, and a group represented by any one of the chemical formulas (r-lc-1-1), (r-lc-1-2), (r-lc-2-1), (r-lc-2-12), and (r-s1-1-1) is more preferred.

[0165] 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.

[0166] Other structural units The component (A1) may further contain other structural units in addition to the above-mentioned structural units (a1) and (a2). Examples of other structural units include structural units (a3) ​​that contain a polar group-containing aliphatic hydrocarbon group. As the structural unit (a3), with the exception of those that correspond to the structural unit (a1) or the structural unit (a2), many of the structural units that are conventionally known to be used as resin components in resist compositions can be used.

[0167] Regarding the 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.

[0168] 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 having 1 to 10 carbon atoms (preferably alkylene groups) 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.

[0169] 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.

[0170] 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, tricyclo[5.2.1.02,6]decane, 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 preferable.

[0171] 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).

[0172] [ka]

[0173] [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, 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.]

[0174] In the formulas (a3-1) to (a3-4), R represents R in the general formula (a-1). 01 R is preferably a hydrogen atom or a methyl group. 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.

[0175] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5- or 6-position of the norbornyl group.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] The (A1) component can be produced by dissolving monomers that derive each structural unit in a polymerization solvent, and then adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate (e.g., V-601) to the solution and polymerizing the resulting mixture. Alternatively, the component (A1) can be produced by dissolving a monomer that derives the structural unit (a1) and a monomer that derives the structural unit (a2) in a polymerization solvent, and adding the above-mentioned radical polymerization initiator to the solution to carry out polymerization.

[0180] In addition, during polymerization, a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH may be used in combination to introduce a -C(CF3)2-OH group to the end. In this way, a copolymer having a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms is introduced, which is effective in reducing development defects and LER (line edge roughness: unevenness of the line sidewall).

[0181] In the resist composition according to the embodiment of the present invention, the weight average molecular weight (Mw) of the component (A1) (based on polystyrene equivalent by gel permeation chromatography (GPC)) must be at least 30,000, and is preferably at least 32,000, more preferably at least 33,000, and even more preferably at least 35,000. The Mw of the component (A1) is preferably 120,000 or less, more preferably 100,000 or less, and even more preferably 80,000 or less. The Mw of the component (A1) in the resist composition according to an embodiment of the present invention is preferably from 32,000 to 120,000, more preferably from 33,000 to 100,000, and even more preferably from 35,000 to 80,000. When the Mw of the component (A1) is less than or equal to the preferred upper limit of this range, the compound has sufficient solubility in a resist solvent for use as a resist, and when it is equal to or greater than the preferred lower limit of this range, the dry etching resistance, LWR (line width roughness), and LER are excellent.

[0182] The dispersity (Mw / Mn) of the (A1) component is not particularly limited, and is preferably 1.0 or more, and is preferably 4.0 or less, more preferably 3.0 or less, and particularly preferably 2.0 or less. The dispersity (Mw / Mn) of the (A1) component is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Here, Mn indicates the number average molecular weight.

[0183] Base components other than component (A1) The resist composition according to an embodiment of the present invention may use, in combination with the component (A), a base component (A2) that does not fall under the category of the component (A1) and whose solubility in a developer changes under the action of an acid. There are no particular restrictions on the component (A2), and it may be selected from the many conventional base components for chemically amplified resist compositions. The component (A2) may be a polymeric compound or a low molecular weight compound, and may be used alone or in combination of two or more kinds.

[0184] The proportion of the (A1) component in the (A) component is preferably 25% by mass or more, more preferably 50% by mass or more, even more preferably 75% by mass or more, and may be 100% by mass, based on the total mass of the (A) component. If the proportion is 25% by mass or more, a resist pattern having excellent lithography properties such as high sensitivity, resolution, and improved roughness is easily formed. The proportion of the (A1) component in the (A) component is not particularly limited, but can be, for example, 100% by mass or less.

[0185] In the resist composition according to the embodiment of the present invention, the content of the component (A) may be adjusted according to the resist film thickness to be formed, and is not particularly limited, but is preferably 2 mass% or more, and more preferably 3 mass% or more, based on the total mass (100 mass%) of the resist composition. The upper limit of the content of the component (A) is not particularly limited as long as it is a concentration that allows the formation of a resist film, but is, for example, preferably 10 mass% or less, and more preferably 5 mass% or less.

[0186] <Acid generator component (B)> The resist composition according to the embodiment of the present invention may further contain, in addition to the above-mentioned component (A) and the below-described component (D), an acid generator component (B) that generates acid upon exposure (hereafter referred to as “component (B)”). There are no particular limitations on the component (B), and any of the compounds that have been proposed as acid generators for chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes, nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators. The component (B) preferably contains a compound (B1) made of an onium salt (hereinafter sometimes referred to as "component (B1)") or a compound (B2) made of an onium salt (hereinafter sometimes referred to as "component (B2)").

[0187] <(B1) component> The resist composition according to an embodiment of the present invention contains an acid generator component (B) that generates an acid upon exposure. The acid generator component (B) may contain a compound (B1) represented by the following general formula (b-01) (hereinafter also referred to as acid generator (B1)).

[0188] [ka] (b-01)

[0189] [In general formula (b-01), R a ~R c each independently represents an at least partially fluorinated alkyl or cycloalkyl group, or R a ~R c At least two of these may be bonded to form a fluorinated alkylene group. m represents an integer of 1 or more, M m+ represents an organic cation with a valence of m.

[0190] In general formula (b-01), R a ~R c are each independently an at least partially fluorinated alkyl group (preferably having 1 to 8 carbon atoms) or cycloalkyl group (preferably having 3 to 8 carbon atoms), or R a ~R c At least two of these are bonded to represent a fluorinated alkylene group. As the compound that generates the acid represented by (b-01), those represented by the following formulae (P1) to (P2) are particularly preferred.

[0191] [ka] (P1)

[0192] [ka] (P2)

[0193] In formulas (P1) to (P2), R 1 represents a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group (preferably having 1 to 10 carbon atoms), a linear or branched alkoxyl group (preferably having 1 to 10 carbon atoms), or a linear or branched alkoxycarbonyl group (preferably having 2 to 11 carbon atoms). R 2 represents a linear or branched alkyl group (preferably having 1 to 10 carbon atoms), a linear or branched alkoxyl group (preferably having 1 to 10 carbon atoms), or a linear, branched, or cyclic alkanesulfonyl group (preferably having 1 to 10 carbon atoms). n is an integer of 0 to 2, and m is an integer of 0 to 10. In formula (P1), X represents a divalent group (preferably having 2 to 10 carbon atoms), R 5each independently represents a fluorinated alkyl group (preferably having 1 to 8 carbon atoms) or a fluorinated cycloalkyl group (preferably having 3 to 8 carbon atoms).

[0194] In (P2), R 3 each independently represents a linear or branched alkyl group (preferably having 1 to 10 carbon atoms), an optionally substituted phenyl group, or a substituted naphthyl group; R 5 Each ' independently represents a linear or branched fluorinated alkyl group (preferably having 1 to 8 carbon atoms).

[0195] R 1 , R 2 , or R 3 In the formula (I), preferred linear or branched alkyl groups having 1 to 10 carbon atoms include, for example, methyl, ethyl, n-propyl, i-propyl, n-butyl, 2-methylpropyl, 1-methylpropyl, t-butyl, n-pentyl, neopentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl groups. Among these alkyl groups, methyl, ethyl, n-butyl, and t-butyl groups are more preferred.

[0196] R 1 or R 2 Preferred examples of the linear or branched alkoxyl group having 1 to 10 carbon atoms in the formula (1) include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a 2-methylpropoxy group, a 1-methylpropoxy group, a t-butoxy group, an n-pentyloxy group, a neopentyloxy group, an n-hexyloxy group, an n-heptyloxy group, an n-octyloxy group, a 2-ethylhexyloxy group, an n-nonyloxy group, an n-decyloxy group, etc. Among these alkoxyl groups, a methoxy group, an ethoxy group, an n-propoxy group, and an n-butoxy group are more preferred.

[0197] R 1Preferred examples of the linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms in the formula (1) include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, an n-butoxycarbonyl group, a 2-methylpropoxycarbonyl group, a 1-methylpropoxycarbonyl group, a t-butoxycarbonyl group, an n-pentyloxycarbonyl group, a neopentyloxycarbonyl group, an n-hexyloxycarbonyl group, an n-heptyloxycarbonyl group, an n-octyloxycarbonyl group, a 2-ethylhexyloxycarbonyl group, an n-nonyloxycarbonyl group, and an n-decyloxycarbonyl group. Among these alkoxycarbonyl groups, a methoxycarbonyl group, an ethoxycarbonyl group, and an n-butoxycarbonyl group are more preferred.

[0198] R 2 Examples of preferred linear, branched, or cyclic alkanesulfonyl groups having 1 to 10 carbon atoms include methanesulfonyl, ethanesulfonyl, n-propanesulfonyl, n-butanesulfonyl, tert-butanesulfonyl, n-pentanesulfonyl, neopentanesulfonyl, n-hexanesulfonyl, n-heptanesulfonyl, n-octanesulfonyl, 2-ethylhexanesulfonyl, n-nonanesulfonyl, n-decanesulfonyl, cyclopentanesulfonyl, and cyclohexanesulfonyl groups. Among these alkanesulfonyl groups, methanesulfonyl, ethanesulfonyl, n-propanesulfonyl, n-butanesulfonyl, cyclopentanesulfonyl, and cyclohexanesulfonyl groups are preferred. Moreover, m is preferably 0 to 2.

[0199] R 3Examples of the optionally substituted phenyl group in the formula (I) include phenyl groups such as phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2,3-dimethylphenyl group, 2,4-dimethylphenyl group, 2,5-dimethylphenyl group, 2,6-dimethylphenyl group, 3,4-dimethylphenyl group, 3,5-dimethylphenyl group, 2,4,6-trimethylphenyl group, 4-ethylphenyl group, 4-t-butylphenyl group, 4-cyclohexylphenyl group, and 4-fluorophenyl group, or phenyl groups substituted with a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms; and groups in which such phenyl groups or alkyl-substituted phenyl groups are substituted with at least one group such as a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group.

[0200] Among the substituents for the phenyl group and the alkyl-substituted phenyl group, examples of the alkoxyl group include linear, branched or cyclic alkoxyl groups having 1 to 20 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a 2-methylpropoxy group, a 1-methylpropoxy group, a t-butoxy group, a cyclopentyloxy group, and a cyclohexyloxy group. Examples of the alkoxyalkyl group include linear, branched, or cyclic alkoxyalkyl groups having 2 to 21 carbon atoms, such as a methoxymethyl group, an ethoxymethyl group, a 1-methoxyethyl group, a 2-methoxyethyl group, a 1-ethoxyethyl group, or a 2-ethoxyethyl group. Examples of the alkoxycarbonyl group include linear, branched, or cyclic alkoxycarbonyl groups having 2 to 21 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, an n-butoxycarbonyl group, a 2-methylpropoxycarbonyl group, a 1-methylpropoxycarbonyl group, a t-butoxycarbonyl group, a cyclopentyloxycarbonyl group, or a cyclohexyloxycarbonyl group. Examples of the alkoxycarbonyloxy group include linear, branched or cyclic alkoxycarbonyloxy groups having 2 to 21 carbon atoms, such as a methoxycarbonyloxy group, an ethoxycarbonyloxy group, an n-propoxycarbonyloxy group, an i-propoxycarbonyloxy group, an n-butoxycarbonyloxy group, a t-butoxycarbonyloxy group, a cyclopentyloxycarbonyl group or a cyclohexyloxycarbonyl group. R 3 Among the optionally substituted phenyl groups in the formula (I), preferred are a phenyl group, a 4-cyclohexylphenyl group, a 4-t-butylphenyl group, a 4-methoxyphenyl group, and a 4-t-butoxyphenyl group.

[0201] R 3 Examples of the optionally substituted naphthyl group in the above formula include a 1-naphthyl group, a 2-methyl-1-naphthyl group, a 3-methyl-1-naphthyl group, a 4-methyl-1-naphthyl group, a 4-methyl-1-naphthyl group, a 5-methyl-1-naphthyl group, a 6-methyl-1-naphthyl group, a 7-methyl-1-naphthyl group, an 8-methyl-1-naphthyl group, a 2,3-dimethyl-1-naphthyl group, a 2,4-dimethyl-1-naphthyl group, a 2,5-dimethyl-1-naphthyl group, a 2,6-dimethyl-1-naphthyl group, a 2,7-dimethyl-1-naphthyl group, a 2,8-dimethyl-1-naphthyl group, a 3,4-dimethyl-1-naphthyl group, a 3,5-dimethyl-1-naphthyl group, a 3,6-dimethyl-1-naphthyl group, a 3,7 naphthyl groups such as 1-dimethyl-1-naphthyl group, 3,8-dimethyl-1-naphthyl group, 4,5-dimethyl-1-naphthyl group, 5,8-dimethyl-1-naphthyl group, 4-ethyl-1-naphthyl group, 2-naphthyl group, 1-methyl-2-naphthyl group, 3-methyl-2-naphthyl group, and 4-methyl-2-naphthyl group, or naphthyl groups substituted with a straight-chain, branched, or cyclic alkyl group having 1 to 10 carbon atoms; and groups in which such naphthyl groups or alkyl-substituted naphthyl groups are substituted with at least one type of group such as a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, or an alkoxycarbonyloxy group. Examples of the alkoxyl group, alkoxyalkyl group, alkoxycarbonyl group and alkoxycarbonyloxy group which are the above-mentioned substituents include the groups exemplified for the above-mentioned phenyl group and alkyl-substituted phenyl group. R 3 The optionally substituted naphthyl group in is preferably a 1-naphthyl group, a 1-(4-methoxynaphthyl) group, a 1-(4-ethoxynaphthyl) group, a 1-(4-n-propoxynaphthyl) group, a 1-(4-n-butoxynaphthyl) group, a 2-(7-methoxynaphthyl) group, a 2-(7-ethoxynaphthyl) group, a 2-(7-n-propoxynaphthyl) group, or a 2-(7-n-butoxynaphthyl) group. R 3 As the alkyl group, a methyl group, an ethyl group, a phenyl group, a 4-methoxyphenyl group, and a 1-naphthyl group are preferable.

[0202] X represents a divalent group having 2 to 10 carbon atoms, and the divalent group having 2 to 10 carbon atoms is preferably a group which forms a 5- or 6-membered ring, particularly preferably a 5-membered ring (i.e., a tetrahydrothiophene ring) together with the sulfur atom in formula (P1) or formula (P2). In addition, examples of the substituent for the divalent group include a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxyl group, an alkoxyalkyl group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group, which are exemplified as the substituent for the phenyl group and the alkyl-substituted phenyl group. X is preferably a divalent group which forms a tetrahydrothiophene ring structure together with a sulfur atom.

[0203] R 5 , and R 5Examples of the fluorinated alkyl group having 1 to 8 carbon atoms represented by ' include perfluoro or partially fluorinated alkyl groups, such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoro-n-butyl group, a heptafluoro-i-propyl group, a nonafluoro-n-butyl group, a nonafluoro-2-methylpropyl group, a nonafluoro-1-methylpropyl group, a nonafluoro-t-butyl group, a perfluoro-n-pentyl group, a perfluoroneopentyl group, a perfluoro-n-hexyl group, a perfluoro-n-heptyl group, and a perfluoro-n-octyl group.

[0204] Preferable examples of the cationic moiety of the acid generator (B1) represented by formula (P1) or (P2) include the following compounds.

[0205] [ka]

[0206] [ka]

[0207] Preferable examples of the anion moiety of the acid generator (B1) represented by formula (P1) to (P2) include the following compounds.

[0208] [ka]

[0209] All combinations of the above cationic and anionic moieties can be preferably used. In addition, sulfonium salts represented by the following formula are preferred.

[0210] [ka]

[0211] [ka]

[0212] [ka]

[0213] [ka]

[0214] [ka]

[0215] [ka]

[0216] Among the above, particularly preferred sulfonium salts are B1-1 to B1-3 and B1-19 to B1-21, and particularly preferred sulfonium salts are B1-1 and B1-19.

[0217] The component (B1) may be used alone or in combination of two or more. The component (B1) is contained in an amount of preferably 1 to 60 mass %, more preferably 2.5 to 50 mass %, and particularly preferably 5 to 30 mass %, based on the total solid content in the composition.

[0218] <(B2) component> Furthermore, the resist composition according to the embodiment of the present invention contains an acid generator component (B) that generates an acid upon exposure, and the acid generator component (B) may contain a compound (B2) represented by the following general formula (b-02):

[0219] [ka] (b-02)

[0220] [In general formula (b-02), Rf 01 and Rf 02 each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group; Rf 01 , Rf 02 At least one of them contains a fluorine atom. X represents a divalent linking group, and Y represents a cyclic group which may have a substituent. m represents an integer of 1 or more, M m+ represents an organic cation with a valence of m.

[0221] [Anion part (YXC(Rf 01 )(Rf 02 )-SO3 - )] In general formula (b-02), YXC(Rf 01 )(Rf 02 )-SO3 - is a counter anion. There are no particular limitations on the counter anion, and any of the anions proposed as the anion moiety of an acid generator for a chemically amplified resist composition can be used.

[0222] In general formula (b-02), Rf 01 and Rf 02 each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group.

[0223] Rf 01 and Rf 02 Each of the fluorinated alkyl groups represented by the formula (I) may be independently chain-like or cyclic, and is preferably linear or branched. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and further preferably 1 to 4.

[0224] Specific examples include linear alkyl groups, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl groups, in which some or all of the hydrogen atoms have been substituted with fluorine atoms, and branched alkyl groups, such as 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl and 3-methylbutyl groups, in which some or all of the hydrogen atoms have been substituted with fluorine atoms. Also, Rf 01 and Rf 02 Each of the fluorinated alkyl groups represented by the formula (I) may independently contain an atom other than a fluorine atom, a carbon atom or a hydrogen atom, such as an oxygen atom, a sulfur atom or a nitrogen atom. Among them, Rf 01 and Rf 02 The fluorinated alkyl group represented by is preferably a group in which some or all of the hydrogen atoms constituting a linear alkyl group have been substituted with fluorine atoms, and is preferably a group in which all of the hydrogen atoms constituting a linear alkyl group have been substituted with fluorine atoms (perfluoroalkyl group).

[0225] In general formula (b-02), Rf 01 and Rf 02 preferably each represents a fluorine atom.

[0226] In general formula (b-02), X represents a divalent linking group, and is preferably a divalent linking group containing an oxygen atom. When X is a divalent linking group containing an oxygen atom, X may contain an atom other than an oxygen atom. Examples of the atom other than an oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom.

[0227] Examples of the divalent linking group containing an oxygen atom include non-hydrocarbon oxygen-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), and a carbonate bond (-OC(=O)-O-); and combinations of the non-hydrocarbon oxygen-containing linking groups and alkylene groups. A sulfonyl group (-SO2-) may be further linked to this combination. Examples of the divalent linking group containing an oxygen atom include linking groups represented by the following general formulae (y-al-1) to (y-al-7). In the following general formulae (y-al-1) to (y-al-7), the bond to Y in the above general formula (b-02) is V' in the following general formulae (y-al-1) to (y-al-7). 101 It is.

[0228] [ka]

[0229] [In the formula, V' 101 is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' 102 is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.

[0230] V' 102 The divalent saturated hydrocarbon group in is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 5 carbon atoms.

[0231] V ’101 and V' 102 The alkylene group in may be a straight-chain alkylene group or a branched-chain alkylene group, and is preferably a straight-chain alkylene group. V ’101Specific examples of the alkylene group in V'102 include a methylene group [-CH2-]; alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, and -C(CH2CH3)2-; an ethylene group [-CH2CH2-]; -CH(CH3)CH2-, -CH(CH3)CH(CCH3)-, -C(CH3)2CH2-, and -CH(CH2CH3 )CH2-, etc.; a trimethylene group (n-propylene group) [-CH2CH2CH2-]; alkyl trimethylene groups, such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; a tetramethylene group [-CH2CH2CH2CH2-]; alkyl tetramethylene groups, such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-; and a pentamethylene group [-CH2CH2CH2CH2CH2-]. Also, V ’101 or V' 102 In the above formula (a1-r-1), some of the methylene groups in the alkylene group may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is represented by Ra' in the above formula (a1-r-1). 3 A divalent group in which one hydrogen atom has been further removed from a cyclic aliphatic hydrocarbon group (a monocyclic aliphatic hydrocarbon group, a polycyclic aliphatic hydrocarbon group) such as those mentioned above is preferred, and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferred.

[0232] X is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, and more preferably a linking group represented by any of the above formulas (y-al-1) to (y-al-5).

[0233] In formula (b-02), Y represents a cyclic group which may have a substituent. The cyclic group which may have a substituent is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group which does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0234] The aromatic hydrocarbon group for Y is a hydrocarbon group having an aromatic ring. The number of carbon atoms in the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring of the aromatic hydrocarbon group in Y include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, and aromatic heterocycles in which some of the carbon atoms constituting these aromatic rings are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group in Y include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0235] The cyclic aliphatic hydrocarbon group for Y includes an aliphatic hydrocarbon group containing a ring in the structure. The cyclic aliphatic hydrocarbon group for Y preferably has 3 to 50 carbon atoms, more preferably has 4 to 45 carbon atoms, and more preferably has 5 to 40 carbon atoms. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is present in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically, cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc.; or a polycycloalkane having a polycyclic skeleton of a condensed ring system such as a cyclic group having a steroid skeleton.

[0236] Among these, the cyclic aliphatic hydrocarbon group for Y is preferably a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane, more preferably a group in which one hydrogen atom has been removed from a polycycloalkane, further preferably an adamantyl group or a norbornyl group, and particularly preferably an adamantyl group.

[0237] Among the cyclic aliphatic hydrocarbon groups represented by Y, specific preferred examples are as follows: * represents a bond.

[0238] [ka]

[0239] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, further preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specific examples thereof include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, further preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specific examples thereof include alkyl alkylene groups such as alkyl methylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-, etc.; alkyl ethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-, etc.; alkyl trimethylene groups such as -CH(CH3)CH2CH2- and -CH2CH(CH3)CH2-; and alkyl tetramethylene groups such as -CH(CH3)CH2CH2CH2- and -CH2CH(CH3)CH2CH2-. The alkyl group in the alkylalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0240] The cyclic hydrocarbon group in Y may contain a heteroatom, such as a heterocycle. Specific examples include the lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above, the -SO2-containing cyclic groups represented by the general formulae (a5-r-1) to (a5-r-4) above, and the heterocyclic groups represented by the following chemical formulae (r-hr-1) to (r-hr-16). In the formulae, * represents a bond bonded to X in general formula (b-02).

[0241] [ka]

[0242] Examples of the substituent in the cyclic group of Y include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy 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 the halogenated alkyl group as a substituent include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, in which some or all of the hydrogen atoms have been substituted with the above-mentioned halogen atoms. The carbonyl group as a substituent is a group that substitutes a methylene group (-CH2-) that constitutes a cyclic hydrocarbon group.

[0243] The cyclic hydrocarbon group in Y may be a fused ring group containing a fused ring in which an aliphatic hydrocarbon ring and an aromatic ring are fused. Examples of the fused ring include a polycycloalkane having a polycyclic skeleton of a bridged ring system to which one or more aromatic rings are fused. Specific examples of the bridged ring polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. The fused ring group is preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicycloalkane, and more preferably a group containing a fused ring in which two or three aromatic rings are fused to a bicyclo[2.2.2]octane. Specific examples of the fused ring group in Y include those represented by the following formulas (r-br-1) to (r-br-2). In the formulas, * represents a bond bonded to X in general formula (b-02).

[0244] [ka]

[0245] Examples of the substituent that the fused cyclic group for Y may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group. Examples of the alkyl group, alkoxy group, halogen atom and halogenated alkyl group as the substituent of the fused cyclic group include the same as those exemplified as the substituent of the cyclic group for Y above. Examples of the aromatic hydrocarbon group as the substituent of the fused ring group include a group in which one hydrogen atom has been removed from an aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.), and the heterocyclic groups represented by the above formulas (r-hr-1) to (r-hr-6). Examples of the alicyclic hydrocarbon group as a substituent of the fused cyclic group include groups obtained by removing one hydrogen atom from a monocycloalkane such as cyclopentane or cyclohexane; groups obtained by removing one hydrogen atom from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane or tetracyclododecane; lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) above; -SO2- containing cyclic groups represented by the general formulae (a5-r-1) to (a5-r-4) above; and heterocyclic groups represented by the formulae (r-hr-7) to (r-hr-16) above.

[0246] The cyclic hydrocarbon group in Y may be a group in which two or more aliphatic rings and / or aromatic rings are linked by a linear or branched aliphatic hydrocarbon group which may have a substituent. In the linear or branched aliphatic hydrocarbon group linking the alicyclic hydrocarbon group, the methylene group (-CH2-) constituting the aliphatic hydrocarbon chain may be substituted with a divalent group containing a hetero atom. Examples of the divalent group containing a hetero atom include (-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.

[0247] Among the above, Y is preferably a chain-like alkyl group which may have a substituent, or an alicyclic hydrocarbon group which may have a substituent, more preferably a chain-like alkyl group which may have a halogen atom, a group in which one or more hydrogen atoms have been removed from a polycycloalkane which may have a substituent, or an -SO2- containing cyclic group represented by any of the general formulae (a5-r-1) to (a5-r-4) above, still more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane which may have a substituent, or an -SO2- containing cyclic group represented by any of the general formulae (a5-r-1) to (a5-r-4) above, and particularly preferably an adamantyl group which may have a hydroxy group, or an -SO2- containing cyclic group represented by the general formula (a5-r-1) above.

[0248] X is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, more preferably a linking group represented by any one of the above formulas (y-al-1) to (y-al-5), and further preferably a linking group represented by the above formula (y-al-1) or (y-al-3).

[0249] Specific examples of the anion moiety represented by general formula (b-02), when X is a single bond, include fluorinated alkylsulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; and when X is a divalent linking group containing an oxygen atom, include anions represented by the following formulas (an-1) to (an-3), respectively.

[0250] [ka]

[0251] [In the formula, R” 101 R" is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by any one of the above chemical formulas (r-hr-1) to (r-hr-6), a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), or a chain alkyl group which may have a substituent. 102 R" is an aliphatic cyclic group which may have a substituent, a fused cyclic group represented by the above formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by any one of the above general formulas (a2-r-1), (a2-r-3) to (a2-r-7), or an SO2-containing cyclic group represented by any one of the above general formulas (a5-r-1) to (a5-r-4). 103 V" is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. 101 R is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. 102is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Each v" is independently an integer of 0 to 3, each q" is independently an integer of 0 to 20, and n" is 0 or 1.

[0252] R” 101 , R.” 102 and R.” 103 The aliphatic cyclic group which may have a substituent is preferably a group exemplified as the cyclic aliphatic hydrocarbon group for Y in the general formula (b-02). Examples of the substituent include the same as the substituent which may substitute the cyclic aliphatic hydrocarbon group for Y in the general formula (b-02).

[0253] R” 103 The aromatic cyclic group which may have a substituent in is preferably a group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in Y in the general formula (b-02). Examples of the substituent include the same as the substituent which may substitute the aromatic hydrocarbon group in Y in the general formula (b-02).

[0254] R” 101 The chain alkyl group which may have a substituent in the above formula (b-02) is preferably a group exemplified as the chain alkyl group in the above formula (b-02). R” 103 The chain alkenyl group which may have a substituent in the above formula (b-02) is preferably a group exemplified as the chain alkenyl group in the above formula (b-02).

[0255] Among the anions in the above general formula (b-02), anions represented by any of the above general formulas (an-1) to (an-3) are more preferred, anions represented by any of the general formulas (an-1) or (an-2) are even more preferred, and anions represented by the general formula (an-1) are particularly preferred.

[0256] Specific examples of the anion represented by general formula (b-02) are shown below, but are not limited to these.

[0257] [ka]

[0258] [ka]

[0259] [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.

[0260] Preferred cationic moieties ((M m+ ) 1 / m ) may be an organic cation represented by any one of the following general formulas (ca-1) to (ca-3).

[0261] [ka]

[0262] [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 210is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group; L 201 represents -C(=O)- or -C(=O)-O-.]

[0263] R 201 ~R 207 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 201 ~R 207 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 201 ~R 207 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 201 ~R 207 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 a group represented by any one of the following formulae (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.

[0264] [ka]

[0265] [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.

[0266] R' 201The 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.

[0267] 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.

[0268] 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 Examples of the branched alkenyl group include a vinyl group, a propenyl group (allyl group), a butenyl group, etc. Examples of the branched alkenyl group include a 1-methylpropenyl group, a 2-methylpropenyl group, etc. As the chain alkenyl group, among the above, a propenyl group is particularly preferred.

[0269] R' 201Examples of the optionally substituted cyclic group or optionally substituted chain alkyl group represented by the formula (I) include the same as those of the above-mentioned acid-dissociable group.

[0270] 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.

[0271] R 201 ~R 203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they do not include a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH-, or -N(R N )-(applicable R Nis an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, 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.

[0272] R 208 ~R 209 R 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.

[0273] R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 210In the -SO2-containing cyclic group which may have a substituent, "-SO2-containing cyclic group" refers to a cyclic group containing a ring containing -SO2- in its ring skeleton, specifically, a cyclic group in which the sulfur atom (S) in -SO2- forms a part of the ring skeleton of the cyclic group. The ring containing -SO2- in the ring skeleton is counted as the first ring, and if there is only this ring, it is called a monocyclic group, and if there is another ring structure, it is called a polycyclic group regardless of the structure. The -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2- containing cyclic group is preferably a cyclic group containing -O-SO2- in its ring skeleton, that is, a cyclic group containing a sultone ring in which -OS- in -O-SO2- forms a part of the ring skeleton. R 210 As the -SO2- containing cyclic group which may have a substituent in the above formula (a5-r-1), a group represented by the above formula (a5-r-1) is preferable.

[0274] The cation represented by formula (ca-1) is preferably a cation represented by the following formula (b-2).

[0275] [ka]

[0276] [In formula (b-2), Rb 201 ~Rb 202 R represents an aryl group which may have a substituent; 203 Rb represents an optionally substituted aryl group, an optionally substituted alkyl group, or an optionally substituted alkenyl group. 201 ~Rb 203 may be bonded to each other to form a ring together with the sulfur atom in formula (b-2).

[0277] Rb 201 ~Rb 202 The optionally substituted aryl group represented by R 201 ~R 207The 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, or the optionally substituted alkenyl group as defined above, and preferred examples thereof are also the same.

[0278] 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).

[0279] [ka]

[0280] [ka]

[0281] [ka]

[0282] [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.]

[0283] [ka]

[0284] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituent is the same as R 201 ~R 207 , and R210 The substituents are the same as those exemplified as the substituents that may be possessed by the

[0285] 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).

[0286] [ka]

[0287] In the resist composition according to one embodiment of the present invention, the component (B2) may be used as a single type, or a combination of two or more types.

[0288] In the resist composition according to an embodiment of the present invention, the content of the component (B2) relative to 100 parts by mass of the component (A) is preferably 1 to 60 parts by mass, more preferably 2.5 to 50 parts by mass, and even more preferably 5 to 30 parts by mass. When the proportion of the component (B2) is at least the preferred lower limit, lithography properties such as reduced roughness and high sensitivity are improved, while when it is no more than the upper limit, a resist pattern with excellent exposure latitude is easily formed.

[0289] Regarding ingredient (B3) The resist composition according to an embodiment of the present invention may contain an acid generator component (hereafter referred to as “component (B3)”) other than the component (B1) or (B2), as long as the effects of the present invention are not impaired. There are no particular restrictions on the component (B3), and any of the compounds that have been proposed as acid generators for use in chemically amplified resist compositions can be used. Examples of such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes, nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0290] In the resist composition according to this embodiment of the present invention, the component (B3) may use either a single type, or a combination of two or more types. When the resist composition contains the component (B3), the amount of the component (B3) in the resist composition is preferably no more than 30 parts by mass, and more preferably 1 to 25 parts by mass, per 100 parts by mass of the component (A). By setting the content of the component (B3) in the resist composition within the above range, sufficient pattern formation can be achieved. Furthermore, when each component of the resist composition is dissolved in an organic solvent, a homogeneous solution is easily obtained, and the storage stability of the resist composition is favorable, which is preferable.

[0291] In the resist composition according to an embodiment of the present invention, the content of the acid generator component (B) is preferably 1 to 40 parts by mass, more preferably 2.5 to 30 parts by mass, and even more preferably 5 to 25 parts by mass, relative to 100 parts by mass of the base component (A). By ensuring that the content of acid generator component (B) in the resist composition falls within the above range, it becomes easier to obtain a resist composition that has excellent stability over time, and it also becomes easier to form a resist pattern that satisfies both high exposure latitude and high sensitivity to the exposure light source.

[0292] <Acid diffusion control component (D)> The resist composition according to an embodiment of the present invention further contains, in addition to the component (A), an acid diffusion control component (D). The acid diffusion control component (D) (component (D)) acts as a quencher (acid diffusion controller) that traps acid generated in the resist composition upon exposure. The component (D) may be, for example, a photodecomposable 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.

[0293] Regarding component (D1) By using a resist composition that contains the component (D1), the contrast between exposed and unexposed areas of the resist film can be further improved when forming a resist pattern. The component (D1) 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)") and a compound represented by the following general formula (d1-2) (hereinafter referred to as "component (d1-2)"): The components (d1-1) and (d1-2) 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 act as quenchers in the unexposed areas of the resist film.

[0294] [ka]

[0295] [In general formula (d1-1) and general formula (d1-2), Rd 1 and Rd 2 are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 2In the formula, no fluorine atom is bonded to the carbon atom adjacent to the S atom. m is an integer of 1 or more, and M m+ are each independently an organic cation having a valence of m.

[0296] {(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 any one of the above formulas (y-al-1) to (y-al-5).

[0297] 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.

[0298] 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.

[0299] Preferred specific examples of the anion moiety of the component (d1-1) are shown below.

[0300] [ka]

[0301] ·Cation part In formula (d1-1), M m+ is an m-valent organic cation. M m+Suitable organic cations include those similar to the cations represented by any one of the general formulas (ca-1) to (ca-3) above, more preferably the cation represented by the general formula (ca-1), and even more preferably the cation represented by any one of the general formulas (ca-1-1) to (ca-1-67) above. The component (d1-1) may be used alone or in combination of two or more.

[0302] {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' 201 The same can be mentioned. However, Rd 2 In the above, the carbon atom adjacent to the S atom does not have a fluorine atom bonded thereto (is not substituted with fluorine), and this makes the anion of the (d1-2) component an appropriate weak acid anion, thereby improving the quenching ability of the (D) component. Rd 2 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.

[0303] Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

[0304] [ka]

[0305] ·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.

[0306] The component (D1) may be any one of the above components (d1-1) and (d1-2), 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.

[0307] Manufacturing method of component (D1): The method for producing the above-mentioned components (d1-1) and (d1-2) is not particularly limited, and they can be produced by known methods. For example, they can be produced in the same manner as the method described in U.S. Patent Publication No. 2012-0149916.

[0308] Regarding component (D2) The component (D) may contain, as an acid diffusion controller, a nitrogen-containing organic compound component (hereinafter referred to as "component (D2)") that does not fall under the category of the above component (D1). The component (D2) is not particularly limited as long as it acts as an acid diffusion 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.

[0309] An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. Examples of aliphatic amines include amines in which at least one hydrogen atom of ammonia NH3 is substituted with an alkyl group having 12 or less carbon atoms or a hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines), or cyclic amines. Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferred, and tri-n-pentylamine or tri-n-octylamine is particularly preferred.

[0310] 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.

[0311] 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.

[0312] 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.

[0313] 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.

[0314] <Optional ingredients> The resist composition according to an embodiment of the present invention may further contain components (optional components) other than the above-mentioned components (A) and (D). Examples of such optional components include the above-mentioned component (B), and the following components (E), (F), and (S).

[0315] <<Component (E): at least one compound selected from the group consisting of organic carboxylic acids, phosphorus oxoacids and derivatives thereof>> The resist composition according to the embodiment of the present invention 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 in sensitivity and improving the resist pattern shape and stability over time after exposure to light. 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.

[0316] 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.

[0317] In the resist composition according to an embodiment of the present invention, 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.

[0318] <(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).

[0319] The polymer having the structural unit (f11) represented by the following general formula (f1-1) is preferably a polymer (homopolymer) consisting of only the structural unit (f11) represented by the following formula (f1-1), a copolymer of the structural unit (f11) and the structural unit (a1), or a copolymer of the structural unit (f11), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a3). Here, the structural unit (a1) copolymerized with the structural unit (f11) is preferably a structural unit containing an acid-dissociable group represented by the formula (a1-r2-1).

[0320] [ka]

[0321] [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. 102 and Rf 103 each independently represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Rf 102 and Rf 103 may be the same or different. 1 is an integer from 0 to 5, and Rf 101 is an organic group containing a fluorine atom.

[0322] In general formula (f1-1), R bonded to the carbon atom at the α-position is R in general formula (a-1). 01 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 Rf 103 Examples of the alkyl group having 1 to 5 carbon atoms in R include the same alkyl groups having 1 to 5 carbon atoms as those in R, and a methyl group or an ethyl group is preferred. 102 and Rf 103Specific 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.

[0323] 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 more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, further preferably a trifluoromethyl group, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, -CH2-CH2-CF2-CF2-CF2-CF3-CF3, and particularly preferably -CH2-CF3.

[0324] 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.

[0325] 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).

[0326] <Organic solvent component (S)> The resist composition according to the embodiment of the present invention can be produced by dissolving a resist material 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 according to the embodiment of the present invention, the component (S) may be used alone or as a mixed solvent of two or more kinds. Among them, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferred.

[0327] As the component (S), a mixed solvent of PGMEA and a polar solvent is also preferred. The blending ratio (mass ratio) may be appropriately determined taking into consideration the compatibility between PGMEA and the polar solvent, etc. As the component (S), a mixed solvent of at least one selected from PGMEA and EL 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 %.

[0328] 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.

[0329] A resist composition according to an embodiment of the present invention contains the above-mentioned components (A) and (D), and, if necessary, the above-mentioned optional components. For example, a resist composition containing the component (A), the component (B), and the component (D) is preferred. Further, a resist composition containing the component (A), the component (B), the component (D), and the component (F) is preferred.

[0330] As explained above, the resist composition according to an embodiment of the present invention contains the base component (A) including the above-mentioned polymer compound (A1) having a weight average molecular weight of 30,000 or more, and the acid diffusion control component (D). It is presumed that the acid diffusion control component (D) in the resist composition contains a compound having a specific structure, and thereby can efficiently undergo salt exchange with the strong acid derived from the acid generator, making it possible to form a resist pattern with excellent LWR.

[0331] [Method of forming a resist pattern] A method for forming a resist pattern according to a second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition of the above-mentioned embodiment, exposing the resist film to light, and developing the 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.

[0332] 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 using an exposure device such as an electron beam lithography device or an EUV exposure device, either through a mask (mask pattern) on which a predetermined pattern has been formed, or by lithography using direct irradiation with an electron beam without using a mask pattern, and then baked (post-exposure bake (PEB)) for 40 to 120 seconds, preferably 50 to 90 seconds, at a temperature of 80 to 150°C. Next, the resist film is developed using an alkaline developer in the case of an alkaline development process, or a developer containing an organic solvent (organic developer) in the case of a solvent development process. After the development process, a rinse process is preferably carried out. In the case of an alkaline development process, the rinse process is preferably a water rinse using pure water, and in the case of a solvent development process, a rinse liquid containing an organic solvent is preferably used. In the case of a solvent development process, after the development treatment or rinsing treatment, a treatment may be carried out in which the developer or rinsing liquid adhering to the pattern is removed by using a supercritical fluid. After the development treatment or rinsing treatment, drying is performed. In some cases, a baking treatment (post-baking) may be performed after the development treatment.

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

[0334] The wavelength used for exposure is not particularly limited, and radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays can be used.

[0335] The exposure method for the resist film may be a normal exposure method (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography, 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, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent. As the liquid immersion medium, water is preferably used.

[0336] An example of an alkaline developer used in the development treatment in the alkaline development process is a 0.1 to 10 mass % aqueous solution of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used in the development treatment in the solvent development process may be any organic solvent capable of dissolving the component (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. Ketone-based solvents are organic solvents that contain CC(=O)-C or CC(=O)-H in their structure. Ester-based solvents are organic solvents that contain CC(=O)-OC or HC(=O)-OC in their structure. Alcohol-based solvents are organic solvents that contain an alcoholic hydroxyl group in their structure. "Alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Nitrile-based solvents are organic solvents that contain a nitrile group in their structure. Amide-based solvents are organic solvents that contain an amide group in their structure. Ether-based solvents are organic solvents that contain COC in their structure. Some organic solvents contain multiple types of functional groups that characterize the above-mentioned solvents in their structures, and in such cases, the organic solvent is considered to fall under any of the solvent types that contain the functional groups possessed by the organic solvent. For example, diethylene glycol monomethyl ether is considered to fall under both the alcohol-based solvents and the ether-based solvents in the above classification. The hydrocarbon solvent is a hydrocarbon solvent that is composed of a hydrocarbon that may be halogenated and has no substituents other than 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 preferred. Of the above, the organic solvent contained in the organic developer is preferably a polar solvent, and more preferably a ketone solvent, an ester solvent, a nitrile solvent, or the like.

[0337] Examples of the ester solvent include methyl acetate, butyl acetate, and ethyl acetate.

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

[0339] The organic developer can be mixed with known additives as necessary. The additives include, for example, surfactants. The surfactants are not particularly limited, but can be, for example, ionic or nonionic fluorine-based and / or silicon-based surfactants.

[0340] The development process can be carried out by a known development method, such as a method of immersing the support in a developer for a certain period of time (dip method), a method of piling up the developer on the surface of the support by surface tension and leaving it there for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), and a method of continuously applying the developer while scanning a developer application nozzle at a constant speed onto a support rotating at a constant speed (dynamic dispense method).

[0341] The organic solvent contained in the rinse solution used in the rinsing treatment after the development treatment in the solvent development process can be appropriately selected from the organic solvents listed above as the organic solvents used in the organic developer, which do not easily dissolve the resist pattern. Usually, at least one solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents is used. These organic solvents may be used alone or in combination of two or more thereof, and may be used in combination with other organic solvents or water.

[0342] The rinse treatment (cleaning treatment) using a rinse liquid can be carried out by a known rinse method, such as a method of continuously applying the rinse liquid onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinse liquid for a certain period of time (dip method), or a method of spraying the rinse liquid onto the surface of the support (spray method).

[0343] 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, and salts thereof. The content of impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, even more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free (below the detection limit of the measuring device).

[0344] In the method of forming a resist pattern according to the embodiment of the present invention described above, the resist composition according to the embodiment of the present invention described above is used, and therefore it is possible to form a resist pattern that achieves both high exposure latitude and high sensitivity to the exposure light source. EXAMPLES

[0345] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0346] Each polymer compound was synthesized using monomers in a predetermined molar ratio that derive the structural units constituting the polymer compounds (A)-1 to (A)-19 and (A)-X1 to (A)-X5 shown below. Regarding the obtained polymer compound, 13 The copolymer composition ratio of the polymer compound (the ratio (molar ratio) of each structural unit in the polymer compound) determined by C-NMR, and the weight average molecular weight (Mw) and polystyrene-equivalent polydispersity (PDI) (Mw / Mn) determined by GPC measurement are also shown.

[0347] [ka]

[0348] [ka]

[0349] [ka]

[0350] [ka]

[0351] [ka]

[0352] [ka]

[0353] <Preparation of resist composition> (Examples 1 to 36, Comparative Examples 1 to 6) The components shown in Tables 1 and 2 were mixed together.

[0354] [Table 1]

[0355] [Table 2]

[0356] In Tables 1 and 2, the abbreviations have the following meanings: A-1 to A-19: The above polymer compounds (A)-1 to (A)-19. A-X1 to A-X5: the above polymer compounds (A)-X1 to (A)-X5. B-1 to B-7: Acid generators consisting of compounds represented by the following chemical formulas (B)-1 to (B)-7. D-1 to D-8: Acid diffusion controllers consisting of compounds represented by the following chemical formulas (D)-1 to (D)-8. D-X1: An acid diffusion controller consisting of a compound represented by the following chemical formula (D)-X1. F-1: Hydrophobic resin F-1 containing the following structural units (composition ratio (molar ratio): l / m=80 / 20, Mw: 25,000, Mw / Mn: 1.5). S-1: A mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / cyclohexanone = 55 / 20 / 25 (mass ratio).

[0357] [ka]

[0358] [ka]

[0359] [ka]

[0360] [ka]

[0361] <Formation of Resist Pattern> 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. Furthermore, a resist composition was applied onto the above-mentioned anti-reflective coating using a spinner, and a pre-baked (PAB) treatment was performed on a hot plate at 80° C. for 60 seconds, followed by drying to form a resist film with a thickness of 110 nm.

[0362] Using an ArF immersion exposure tool XT1900Gi [ASML; NA (numerical aperture) = 1.35, Dipole 90X, Sigma (Ont 0.97, In 0.78) TE-pol, immersion medium: ultrapure water], the substrate was selectively irradiated with an ArF excimer laser (193 nm) through a photomask (6% halftone). Then, a PEB process was performed at 90°C for 60 seconds.

[0363] Next, alkaline development was performed for 10 seconds with a 2.38% by mass TMAH aqueous solution (product name: NMD-W, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23° C., followed by rinsing with pure water for 15 seconds and then shaking and drying. As a result, in each example, a 1:1 line and space (LS) pattern with a line width of 60 nm and a pitch of 120 nm was formed.

[0364] [Evaluation of LWR (Line Width Roughness)] For the LS pattern formed in the above <Formation of Resist Pattern>, 3σ, which is a scale indicating LWR, was obtained. "3σ" indicates three times the standard deviation (σ) (unit: nm) obtained from the measurement results of measuring 400 line positions in the longitudinal direction of the line using a length-measuring SEM (scanning electron microscope, accelerating voltage 500V, product name: CG6300, manufactured by Hitachi High-Technologies Corporation). The smaller the 3σ value, the less rough the line sidewall is, meaning that a LS pattern with a more uniform width is obtained.

[0365] From the results shown in Table 1, it was confirmed that the resist compositions of the examples were all more favorable in terms of roughness reduction properties than the resist compositions of the comparative examples.

[0366] In the resist compositions of Comparative Examples 1 to 3, the polymer compounds (A)-X1 to (A)-X3 contained in the base component (A) had a weight-average molecular weight of less than 30,000. Therefore, the resist compositions were inferior in roughness reduction ability to the resist compositions of Examples 1 to 4, which contained polymer compounds (A)-1 to (A)-4, respectively, having a weight-average molecular weight of 30,000 or more composed of the same structural units.

[0367] The resist composition of Comparative Example 4 used the compound (D)-X1 which does not have a specific structure instead of the component (D1) having a specific structure as an acid diffusion controller, and therefore was inferior in terms of roughness reduction properties compared to the resist compositions of the Examples.

[0368] The resist compositions of Comparative Examples 5 and 6 used polymer compounds (A)-X4 and (A)-X5, respectively, which do not have a specific structure instead of the component (A1) having a specific structure as the polymer compound contained in the base component (A). Therefore, the roughness reduction properties were inferior to the resist compositions of the Examples. [Industrial Applicability]

[0369] According to the present invention, it is possible to provide a resist composition capable of forming a resist pattern that has excellent roughness reduction properties, and a method of forming a resist pattern using the resist composition.

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, and an acid diffusion control component (D), The base component (A) contains a polymer compound (A1) having a weight average molecular weight of 30,000 or more, and the polymer compound (A1) has a structural unit (a1) represented by the following general formula (a-1) and a structural unit (a2) represented by the following general formula (a-2), The acid diffusion control component (D) comprises one or more compounds (D1) selected from the group consisting of compounds represented by the following general formula (d1-1) and compounds represented by the following general formula (d1-2): 【Chemistry 1】 (a-1) [In general formula (a-1), R ０１ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０１ is a divalent hydrocarbon group which may have an ether bond. ａ０１ is an integer from 0 to 2. ０１ is an acid dissociable group. 【Chemistry 2】 (a-2) [In general formula (a-2), R ０２ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ０２ is a divalent hydrocarbon group which may have an ether bond. ａ０２ is an integer from 0 to 2. ０２ is a lactone-containing cyclic group, -SO ２ -containing cyclic group, or carbonate-containing cyclic group. 【Chemistry 3】 [In general formula (d1-1) and general formula (d1-2), Rd １ and Rd ２ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ２ In the formula (I), no fluorine atom is bonded to the carbon atom adjacent to the S atom. m is an integer of 1 or more, and M ｍ＋ are each independently an m-valent organic cation.

2. 2. The resist composition according to claim 1, further comprising an acid generator component (B) (excluding the compound (D1)) that generates an acid upon exposure.

3. 3. The resist composition according to claim 2, wherein the acid generator component (B) comprises a compound (B1) represented by the following general formula (b-01): 【Chemistry 4】 (b-01) [In general formula (b-01), R ａ ~R ｃ each independently represents an at least partially fluorinated alkyl or cycloalkyl group, or R ａ ~R ｃ At least two of these may be bonded to form a fluorinated alkylene group. m represents an integer of 1 or more; M ｍ＋ represents an m-valent organic cation.

4. 3. The resist composition according to claim 2, wherein the acid generator component (B) comprises a compound (B2) represented by the following general formula (b-02): 【Chemistry 5】 (b-02) [In general formula (b-02), Rf ０１ and Rf ０２ each independently represents a hydrogen atom, a fluorine atom or a fluorinated alkyl group; Rf ０１ , Rf ０２ At least one of them contains a fluorine atom. X represents a divalent linking group, and Y represents a cyclic group which may have a substituent. m represents an integer of 1 or more; M ｍ＋ represents an m-valent organic cation.

5. The Ra in the general formula (a-2) ０２ is a substituent represented by any one of the following formulas (a2-r-1) to (a2-r-7) or (a5-r-1) to (a5-r-4): 【Chemistry 6】 【change】 [In 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. 【Chemistry 7】 [In 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; n' is an integer of 0 to 2. * represents a bond.

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.

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