Resist composition and method for forming resist pattern

Abstract

To provide a resist composition which has preferable through-put in etching and preferable CDU, and a resist pattern formation method using the same resist composition.SOLUTION: A resist composition contains: a resin component (A1) having a constitutional unit (a10) including a phenolic hydroxyl group; and a compound (B0) expressed by general formula (b0-1), in which the ratio of the constitutional unit (a10) in the resin component (A1) is greater than 5 mol% and less than 45 mol% with respect to a total sum (100 mol%) of all constitutional units forming the resin component (A1). (In the formula, Rb1 is a hydrocarbon group having C1-C30, Q1 and Q2 are a fluorine atom, or a perfluoroalkyl group having C1-C6, and L is an ester linkage.)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, and a development 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 dissolves in a developer is called a positive type, and a resist material in which the exposed portion of the resist film changes to a property that does not dissolve in a developer is called a negative type. In recent years, advances in lithography technology have led to rapid progress in miniaturization of patterns in the manufacture of semiconductor elements and liquid crystal display elements. A common method of miniaturization is to shorten the wavelength (higher energy) of the exposure light source. Specifically, ultraviolet rays such as g-line and i-line have traditionally been used, but currently mass production of semiconductor elements is being carried out using KrF excimer laser light and ArF excimer laser light. In addition, EUV (extreme ultraviolet), EB (electron beam), X-rays, and other light sources with shorter wavelengths (higher energy) than these excimer laser lights are also being investigated.

[0003] Resist materials are required to have lithography properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist composition that contains a base component whose solubility in a developer changes due to the action of acid, and an acid generator component that generates acid upon exposure, has been used so far. For example, when the developer is an alkaline developer (alkaline development process), a positive chemically amplified resist composition generally contains a resin component (base resin) whose solubility in an alkaline developer increases under the action of an acid, and an acid generator component. When a resist film formed using such a resist composition is selectively exposed during resist pattern formation, an acid is generated from the acid generator component in the exposed area, and the polarity of the base resin increases under the action of the acid, making the exposed area of ​​the resist film soluble in an alkaline developer. Therefore, by performing alkaline development, a positive pattern is formed in which the unexposed area of ​​the resist film remains as a pattern. On the other hand, when such a chemically amplified resist composition is applied to a solvent development process using a developer containing an organic solvent (organic developer), the solubility in the organic developer decreases relatively as the polarity of the base resin increases, so that the unexposed parts of the resist film are dissolved and removed by the organic developer, and a negative resist pattern is formed in which the exposed parts of the resist film remain as a pattern. The solvent development process that forms a negative resist pattern in this way is sometimes called a negative development process.

[0004] In recent years, photofabrication has become the mainstream of precision microfabrication technology. Photofabrication refers to a processing technology in which the above-mentioned chemically amplified resist composition is applied to the surface of a workpiece to form a resist film, a resist pattern of a predetermined shape is formed on the resist film, and the resist film is used as a mask to perform chemical etching, electrolytic etching, electroforming mainly based on electroplating, or the like, to manufacture various precision parts.

[0005] In such photofabrication, depending on the application, a thick resist film, for example, with a thickness on the order of microns, may be formed on the surface of the workpiece, and a resist pattern may be formed and then etched, etc. For example, in the development of three-dimensional structure devices (3D NAND), the memory capacity is increased by vertically stacking several tens of layers of cells fabricated using thick resist patterns.

[0006] Patent Document 1 describes a resist composition for forming a thick-film resist pattern, which contains a base component having a structural unit derived from hydroxystyrene, an acid generator, and a dissolution inhibitor. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2020-86439 A Summary of the Invention [Problem to be solved by the invention]

[0008] Thick-film resist patterns are required to have both appropriate etching resistance to improve throughput and constant dimension uniformity (CDU). It is known that in thick-film resists, the throughput during etching can be improved by reducing the ratio of structural units derived from hydroxystyrene in the base material component. However, there is a problem in that reducing the ratio of structural units derived from hydroxystyrene in the base material component reduces the Tg of the base material component, thereby reducing the CDU.

[0009] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a resist composition that has a good throughput during etching and a good CDU, and a method of forming a resist pattern using the resist composition. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention employs the following configuration. That is, a first aspect of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, the resist composition comprising a resin component (A1) whose solubility in a developer changes due to the action of the acid, and an acid generator component (B) that generates an acid upon exposure, wherein the resin component (A1) has a structural unit (a10) represented by the following general formula (a10-1), and the acid generator component (B) contains a compound (B0) represented by the following general formula (b0-1), and the proportion of the structural unit (a10) in the resin component (A1) is more than 5 mol % and less than 45 mol % with respect to the total (100 mol %) of all structural units constituting the resin component (A1).

[0011] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. x1 is a single bond or a divalent linking group. x1 is an aromatic hydrocarbon group which may have a substituent. ax1 is an integer greater than or equal to 1.

[0012] [ka] [In the formula, R b1 is a hydrocarbon group having 1 to 30 carbon atoms, b1 When the hydrocarbon group as the formula (I) contains one or more methylene groups, at least a part of the methylene groups is -O-, -S-, -CO-, -CO-O-, -SO-, -SO 2 -, -CR b4 R b5 - and -NR b6 -, wherein R b1 When the hydrocarbon group as R contains a hydrocarbon ring, at least one of the carbon atoms constituting the hydrocarbon ring may be substituted with a heteroatom selected from the group consisting of N, O, P, S, and Se, or an atomic group containing such a heteroatom; b4 and the above R b5are each independently a hydrogen atom or a halogen atom, b4 and the above R b5 At least one of R is a halogen atom. b6 is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms; (R a1 )n, (R a2 ) m, n and m are integers from 0 to 3; R a1 and R a2 are each independently a hydrogen atom or an organic group; Q 1 , and Q 2 are each independently a fluorine atom or a perfluoroalkyl group having from 1 to 6 carbon atoms; and L is an ester bond.

[0013] A second aspect of the present invention is a method for forming a resist pattern, comprising the steps of forming a resist film on a support using the resist composition related to the first aspect, exposing the resist film, and developing the exposed resist film to form a resist pattern. Effect of the Invention

[0014] EFFECT OF THE PRESENT DISCLOSURE According to the present invention, it is possible to provide a resist composition that provides good throughput during etching and good CDU, and a method of forming a resist pattern using the resist composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] In this specification and claims, the term "aliphatic" is a relative concept to aromaticity and is defined as meaning a group, compound, etc. that does not have aromaticity. Unless otherwise specified, the term "alkyl group" includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in an alkoxy group. Unless otherwise specified, the term "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups. The "halogen atom" includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The term "structural unit" refers to a monomer unit that constitutes a polymeric compound (resin, polymer, copolymer). When describing "optionally having a substituent," it means replacing a hydrogen atom (-H) with a monovalent group or a methylene group (-CH 2 -) is replaced with a divalent group. The term "exposure" is intended to include any concept including irradiation with radiation.

[0016] The term "acid-decomposable group" refers to a group having acid decomposability in which at least a part of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases under the action of an acid include groups that are decomposed by the action of an acid to generate a polar group. Examples of polar groups include carboxyl groups, hydroxyl groups, amino groups, and sulfo groups (-SO 3 H) etc. More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

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

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

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

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

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

[0022] (Resist composition) The resist composition according to the first aspect of the present invention contains a resin component (A1) (hereinafter also referred to as "component (A1)") having a structural unit (a10) represented by general formula (a10-1), and an acid generator (B) (hereinafter also referred to as "component (B)"). In the resist composition of this embodiment, the component (B) contains a compound (B0) represented by general formula (b0-1). Furthermore, in the resist composition of this embodiment, the proportion of the structural unit (a10) in the component (A1) is more than 5 mol % and less than 45 mol % with respect to the total (100 mol %) of all structural units constituting the component (A1).

[0023] The resist composition of this embodiment is suitable for forming a resist pattern by exposure using an exposure light source such as ultraviolet light such as g-line or i-line, or a KrF excimer laser. The resist composition of the present embodiment is suitable for forming a resist film of, for example, 1 to 20 μm on a support, and is particularly suitable for forming a resist pattern by forming a thick resist film. Here, the term "thick film" refers to a film having a thickness of 1 μm or more. The resist composition of the present embodiment is suitable for forming a resist film having a thickness of preferably 3 μm or more, more preferably 3.5 μm or more, and even more preferably 5 μm or more.

[0024] When a resist film is formed using such a resist composition and selectively exposed to light, 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, whereas the solubility of the component (A) in the developer does not change in the unexposed portion of the resist film, resulting in a difference in solubility in the developer between the exposed portion and the unexposed portion of the resist film. Therefore, when the resist film is developed, if the resist composition is a positive type, the exposed portion of the resist film is dissolved and removed to form a positive type resist pattern, and if the resist composition is a negative type, the unexposed portion of the resist film is dissolved and removed to form a negative type resist pattern.

[0025] In this specification, a resist composition that dissolves and removes an exposed portion of a resist film to form a positive resist pattern is referred to as a positive resist composition, and a resist composition that dissolves and removes an unexposed portion of a resist film to form a negative resist pattern is referred to as a negative resist composition. The resist composition of this embodiment may be a positive resist composition or a negative resist composition. In addition, the resist composition of this embodiment may be for an alkaline development process in which an alkaline developer is used for the development treatment when forming a resist pattern, or may be for a solvent development process in which a developer containing an organic solvent (organic developer) is used for the development treatment.

[0026] <Component (A)> The component (A) is a base component whose solubility in a developer changes under the action of an acid. In the present invention, the "base component" refers to an organic compound having a film-forming ability, and preferably has a molecular weight of at least 500. When the molecular weight of the organic compound is at least 500, 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 broadly divided into non-polymers and polymers. The non-polymer used is usually one having a molecular weight of 500 or more and less than 4000. Hereinafter, the term "low molecular weight compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4000. The polymer used is usually one having a molecular weight of 1000 or more. Hereinafter, when the term "resin," "polymeric compound," or "polymer" is used, it refers to a polymer having a molecular weight of 1000 or more. The molecular weight of the polymer is determined by GPC (gel permeation chromatography) and converted into polystyrene equivalent weight average molecular weight.

[0027] In the resist composition of this embodiment, the component (A) contains at least a polymeric compound (A1) having a structural unit (a10) represented by general formula (a0-1), and may also contain a polymeric compound and / or a low molecular weight compound other than the component (A1).

[0028] When the resist composition of this embodiment is a "positive resist composition for an alkaline development process" that forms a positive resist pattern in an alkaline development process, or a "negative resist composition for a solvent development process" that forms a negative resist pattern in a solvent development process, the component (A) is preferably a base component (A-1) (hereinafter referred to as "component (A-1)") whose polarity increases under the action of an acid. By using component (A-1), 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. When an alkali development process is applied, the component (A-1) is poorly soluble in an alkali developer before exposure, and when, for example, an acid is generated from the component (B) upon exposure, 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 onto a support is selectively exposed, the exposed portion of the resist film changes from poorly soluble in an alkali developer to soluble, while the unexposed portion of the resist film remains poorly soluble in alkali, and thus a positive resist pattern is formed by alkali development. On the other hand, when a solvent development process is applied, the component (A-1) is highly soluble in an organic developer before exposure, and when an acid is generated from the component (B) 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 therefore, by developing with an organic developer, a contrast can be created between the exposed part and the unexposed part, and a negative resist pattern is formed.

[0029] When the resist composition of the present embodiment is a "negative resist composition for an alkaline developing process" that forms a negative resist pattern in an alkaline developing process, or a "positive resist composition for a solvent developing process" that forms a positive resist pattern in a solvent developing process, the component (A) is preferably a base component (A-2) (hereinafter referred to as "component (A-2)") that is soluble in an alkaline developer, and a crosslinker component is further blended in. When, for example, an acid is generated from component (B) upon exposure to light, the acid acts to cause crosslinking between component (A-2) and the crosslinker component, resulting in a decrease in solubility in an alkaline developer (an increase in solubility in an organic developer). Therefore, in forming a resist pattern, when the resist film obtained by applying the resist composition onto a support is selectively exposed, the exposed portion of the resist film becomes poorly soluble in an alkaline developer (soluble in an organic developer), while the unexposed portion of the resist film remains soluble in an alkaline developer (poorly soluble in an organic developer), and thus a negative resist pattern is formed by developing with an alkaline developer. At this time, a positive resist pattern is formed by developing with an organic developer. As the component (A-2), a resin that is soluble in an alkali developer (hereinafter referred to as an "alkali-soluble resin") is preferably used. Examples of alkali-soluble resins include resins having a structural unit derived from at least one selected from α-(hydroxyalkyl)acrylic acid or alkyl esters of α-(hydroxyalkyl)acrylic acid (preferably alkyl esters having 1 to 5 carbon atoms), as disclosed in JP-A-2000-206694; acrylic resins or polycycloolefin resins having a sulfonamide group and in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, as disclosed in U.S. Pat. No. 6,949,325; acrylic resins containing a fluorinated alcohol and in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, as disclosed in U.S. Pat. No. 6,949,325, JP-A-2005-336452, and JP-A-2006-317803; and polycycloolefin resins having a fluorinated alcohol, as disclosed in JP-A-2006-259582, which are capable of forming good resist patterns with little swelling. The α-(hydroxyalkyl)acrylic acid refers to one or both of acrylic acids in which a hydrogen atom bonded to the carbon atom at the α-position to which a carboxy group is bonded, and α-hydroxyalkylacrylic acids in which a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) is bonded to the carbon atom at the α-position, among acrylic acids in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. As the crosslinking agent component, for example, an amino-based crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, or a melamine-based crosslinking agent, etc., is preferably used, since it is easy to form a good resist pattern with little swelling. The blending amount of the crosslinking agent component is preferably 1 to 50 parts by mass relative to 100 parts by mass of the alkali-soluble resin.

[0030] In the resist composition of this embodiment, the component (A) may use either a single type, or a combination of two or more types.

[0031] In the resist composition of this embodiment, the component (A) is preferably the aforementioned component (A-1). In other words, the resist composition of this embodiment is preferably a "positive resist composition for an alkaline developing process" that forms a positive resist pattern in an alkaline developing process, or a "negative resist composition for a solvent developing process" that forms a negative resist pattern in a solvent developing process. At least one of a polymeric compound and a low molecular weight compound can be used as the component (A).

[0032] Regarding component (A1) The component (A1) is a polymeric compound that has a structural unit (a10) represented by general formula (a10-1). The component (A1) is preferably a copolymer that contains, in addition to the structural unit (a10), a structural unit (a11) that contains an aromatic ring (excluding an aromatic ring having a hydroxy group bonded thereto) in its side chain. Furthermore, the component (A1) may contain other structural units in addition to the structural units (a10) and (a11).

[0033] Regarding the structural unit (a10): The structural unit (a10) is a structural unit represented by general formula (a10-1) shown below.

[0034] [ka] [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. x1 is a single bond or a divalent linking group. x1 is an aromatic hydrocarbon group which may have a substituent. ax1 is an integer greater than or equal to 1. [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. x1 is a single bond or a divalent linking group. x1 is an aromatic hydrocarbon group which may have a substituent. ax1 is an integer greater than or equal to 1.

[0035] In the above formula (a10-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms for R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms for R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. 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, a methyl group, or a trifluoromethyl group is more preferable, a hydrogen atom or a methyl group is further preferable, and a hydrogen atom is particularly preferable.

[0036] In the formula (a10-1), Ya x1 is a single bond or a divalent linking group. In the above chemical formula, Ya x1 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0037] Optionally substituted divalent hydrocarbon group: Ya x1 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.

[0038] Ya x1 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.

[0039] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably has 1 to 6 carbon atoms, further preferably has 1 to 4 carbon atoms, and most preferably has 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, specifically, a methylene group [-CH 2 -], ethylene group [-(CH 2 ) 2 -], trimethylene group [-(CH 2 ) 3 -], tetramethylene group [-(CH 2 ) 4 -], pentamethylene group [-(CH 2 ) 5 -] etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 -, etc. alkylmethylene groups; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2 -, etc. alkyl ethylene groups; -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 -, etc.; -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2 The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0040] 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.

[0041] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0042] The cyclic aliphatic hydrocarbon group may or may not have a substituent, such as an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, or a carbonyl group. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and further preferably a methoxy group or an ethoxy group. The halogen atom as the substituent is preferably a fluorine atom. Examples of the halogenated alkyl group as the substituent include the alkyl groups in which some or all of the hydrogen atoms of the alkyl groups are substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. Examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, -S(=O) 2 -, -S(=O) 2 -O- is preferred.

[0043] Ya x1 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0044] 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.

[0045] Divalent linking groups containing heteroatoms: Ya x1 When is a divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O) 2 -, -S(=O) 2 -O-, general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O) 2 -OY 22 -, wherein Y 21 and Y 22 each independently represents a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 0 to 3. When the divalent linking group containing a hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group, acyl, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. General formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O) 2 -OY 22 -Medium, Y 21 and Y 22 Each of Ya is independently a divalent hydrocarbon group which may have a substituent. x1 Examples of the divalent linking group in the above formula (divalent hydrocarbon group which may have a substituent) include those mentioned above. Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferable, a straight-chain alkylene group is more preferable, a straight-chain alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or ethylene group is particularly preferable. Y 22 is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula − [Y 21 -C(=O)-O] m” -Y 22 In the group represented by -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The group represented by the formula -Y 21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH 2 ) a’-C(=O)-O-(CH 2 ) b’ In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.

[0046] Among the above, Ya x1 is preferably a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof, and more preferably a single bond or an ester bond [-C(=O)-O-, -OC(=O)-].

[0047] In the formula (a10-1), Wa x1 is an aromatic hydrocarbon group which may have a substituent. Wa x1 The aromatic hydrocarbon group in the formula (n) is an aromatic ring which may have a substituent. ax1 4n+1) hydrogen atoms are removed. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Also, Wa x1 The aromatic hydrocarbon group in the formula (n) may be an aromatic compound having an aromatic ring which may have two or more substituents (e.g., biphenyl, fluorene, etc.). ax1 +1) hydrogen atoms may also be removed. Among the above, Wa x1 As the aryl group, benzene, naphthalene, anthracene, or biphenyl (n ax1 A group in which (n +1) hydrogen atoms have been removed is preferred, and a group in which (n ax1 A group in which (n +1) hydrogen atoms have been removed from benzene is more preferable. ax1 A group in which +1) hydrogen atoms have been removed is more preferred.

[0048] Wa x1 The aromatic hydrocarbon group in may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. Examples of the alkyl group, the alkoxy group, the halogen atom, and the halogenated alkyl group as the substituent include Ya x1 The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, further preferably an ethyl group or a methyl group, and particularly preferably a methyl group. x1 The aromatic hydrocarbon group in the formula (I) preferably does not have a substituent.

[0049] In the formula (a10-1), n ax1 is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, further preferably 1, 2 or 3, and particularly preferably 1 or 2.

[0050] Specific examples of the structural unit (a10) represented by the aforementioned formula (a10-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] The structural unit (a10) contained in the component (A1) may be of one type, or two or more types. The proportion of the structural unit (a10) in the component (A1) is greater than 5 mol % and less than 45 mol %, preferably from 6 to 44 mol %, more preferably from 7 to 43 mol %, even more preferably from 8 to 42 mol %, and particularly preferably from 9 to 41 mol %, based on the total (100 mol %) of all structural units constituting the component (A1). By making the proportion of the structural unit (a10) greater than 5 mol %, development properties and lithography properties such as CDU are improved. On the other hand, by making the proportion of the structural unit (a10) less than 45 mol %, throughput during etching is improved and it is easier to achieve a balance with other structural units. By ensuring that the proportion of the structural unit (a10) is at least as high as the lower limit of the above preferred range, development properties and lithography properties such as CDU are further improved. On the other hand, by ensuring that the proportion of the structural unit (a10) is at most the upper limit of the above preferred range, throughput during etching is likely to be improved and a balance with other structural units is likely to be achieved.

[0056] <Structural unit (a1)> In this embodiment, the component (A1) preferably contains a structural unit (a1) that contains an acid-decomposable group whose polarity increases due to the action of acid. The term "acid-decomposable group" refers to a group having acid decomposability in which at least a part of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of acid-decomposable groups whose polarity increases under the action of an acid include groups that are decomposed by the action of an acid to generate a polar group. Examples of polar groups include carboxyl groups, hydroxyl groups, amino groups, and sulfo groups (-SO 3 Among these, polar groups containing -OH in the structure (hereinafter sometimes referred to as "OH-containing polar groups") are preferred, with a carboxy group or a hydroxyl group being more preferred, and a carboxy group being particularly preferred. More specific examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).

[0057] The term "acid dissociable group" as used herein refers to both (i) a group having acid dissociability in which the bond between the acid dissociable group and an atom adjacent to the acid dissociable group can be cleaved by the action of an acid, and (ii) a group in which a portion of the bond is cleaved by the action of an acid and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid dissociable group and an atom adjacent to the acid dissociable group. The acid dissociable group constituting the acid decomposable group must be a group with lower polarity than the polar group generated by dissociation of the acid dissociable group, and thus, when the acid dissociable group is dissociated by the action of an acid, a polar group with higher polarity than the acid dissociable group is generated, increasing the polarity. As a result, the polarity of the entire (A1) component increases. The increase in polarity relatively changes the solubility in the developer, increasing the solubility when the developer is an alkaline developer, and decreasing the solubility when the developer is an organic developer.

[0058] Examples of the acid-dissociable group include those that have been proposed as acid-dissociable groups in base resins for chemically amplified resist compositions. Specific examples of the acid dissociable group that have been proposed for the base resin of the chemically amplified resist composition include the “acetal type acid dissociable group,” “tertiary alkyl ester type acid dissociable group,” and “tertiary alkyloxycarbonyl acid dissociable group,” which are described below.

[0059] Acetal type acid dissociable group: Among the polar groups, examples of the acid-dissociable group that protects a carboxy group or a hydroxyl group include an acid-dissociable group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an "acetal-type acid-dissociable group").

[0060] [ka] [In the formula, Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. 3 is a hydrocarbon group, and Ra' 3 Is, Ra' 1 , Ra' 2 may be bonded to any one of the following to form a ring.

[0061] In formula (a1-r-1), Ra' 1 and Ra' 2 At least one of these is preferably a hydrogen atom, and both are more preferably hydrogen atoms. Ra' 1 Or Ra' 2 When is an alkyl group, the alkyl group may be the same as the alkyl group exemplified as the substituent that may be bonded to the carbon atom at the α-position in the explanation of the α-substituted acrylic acid ester above, and an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a linear or branched alkyl group is preferable. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like are preferable, and a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.

[0062] In formula (a1-r-1), Ra' 3 Examples of the hydrocarbon group include a linear or branched alkyl group, and a cyclic hydrocarbon group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably has 1 to 4 carbon atoms, and further preferably has 1 or 2 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

[0063] 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.

[0064] Ra' 3 When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0065] Ra' 3 When the cyclic hydrocarbon group is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, further preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Ra' 3 Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound containing two or more aromatic rings (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.

[0066] Ra' 3 The cyclic hydrocarbon group in may have a substituent. Examples of the substituent include -R P1 , -R P2 -OR P1 , -R P2 -CO-R P1 , -R P2 -CO-OR P1 , -R P2 -O-CO-R P1 , -R P2 -OH, -R P2 -CN or -R P2 -COOH (hereinafter, these substituents are collectively referred to as "Ra 05 " Also known as ".) Here, R P1 is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms.P2 is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. P1 and R P2 Some or all of the hydrogen atoms in the chain saturated hydrocarbon group, the alicyclic saturated hydrocarbon group and the aromatic hydrocarbon group may be substituted with fluorine atoms. The alicyclic hydrocarbon group may have one or more of the above-mentioned substituents or may have one or more of each of the above-mentioned substituents. Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups in which one hydrogen atom has been removed from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.

[0067] 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.

[0068] Tertiary alkyl ester type acid-labile group: Among the above polar groups, examples of the acid-dissociable group that protects the carboxy group include acid-dissociable groups represented by the following general formula (a1-r-2). Among the acid-dissociable groups represented by the following formula (a1-r-2), those constituted by an alkyl group may be referred to as "tertiary alkyl ester-type acid-dissociable groups" hereinafter for the sake of convenience.

[0069] [ka] [In the formula, Ra' 4 ~Ra' 6 are each a hydrocarbon group, and Ra' 5 , Ra' 6 may be bonded to each other to form a ring.

[0070] Ra' 4 Examples of the hydrocarbon group include a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic hydrocarbon group. Ra' 4 The linear or branched alkyl group and the cyclic hydrocarbon group (the monocyclic aliphatic hydrocarbon group, the polycyclic aliphatic hydrocarbon group, and the aromatic hydrocarbon group) in 3 The same can be mentioned. Ra' 4 The chain or cyclic alkenyl group in is preferably an alkenyl group having 2 to 10 carbon atoms. Ra' 5 , Ra' 6 As the hydrocarbon group of Ra' 3 The same can be mentioned.

[0071] Ra' 5 and Ra' 6 and (a1-r2-3) are preferably used. On the other hand, Ra' 4 ~Ra' 6When are not bonded to each other and are independent hydrocarbon groups, preferred examples include groups represented by the following general formula (a1-r2-4).

[0072] [ka] [In formula (a1-r2-1), Ra' 10 Ra' represents an alkyl group having 1 to 10 carbon atoms or a group represented by the following general formula (a1-r2-r1). 11 Is Ra' 10 In formula (a1-r2-2), Ya is a carbon atom. Xa is a group that forms a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra 01 ~Ra 03 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. 01 ~Ra 03 Two or more of may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group which forms an aliphatic cyclic group together with Yaa. Ra 04 In formula (a1-r2-4), Ra' is an aromatic hydrocarbon group which may have a substituent. 12 and Ra' 13 are each independently a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Some or all of the hydrogen atoms in this chain saturated hydrocarbon group may be substituted. 14 is a hydrocarbon group which may have a substituent. * indicates a bond (hereinafter the same).

[0073] [ka] [Wherein, Ya 0 is a quaternary carbon atom. 031, Ra 032 and Ra 033 are each independently a hydrocarbon group which may have a substituent. 031 , Ra 032 and Ra 033 At least one of the groups is a hydrocarbon group having at least one polar group.

[0074] In the above formula (a1-r2-1), Ra' 10 The alkyl group having 1 to 10 carbon atoms is represented by Ra' in the formula (a1-r-1). 3 The groups listed as the linear or branched alkyl group of Ra' are preferred. 10 is preferably an alkyl group having 1 to 5 carbon atoms.

[0075] In the above formula (a1-r2-r1), Ya 0 is a quaternary carbon atom. That is, Ya 0 (carbon atom) has four adjacent carbon atoms bonded to it.

[0076] In the above formula (a1-r2-r1), Ra 031 , Ra 032 and Ra 033 Each of Ra is independently a hydrocarbon group which may have a substituent. 031 , Ra 032 and Ra 033 The hydrocarbon groups in each of the above may independently be a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic hydrocarbon group.

[0077] Ra 031 , Ra 032 and Ra 033 In the linear alkyl group, the carbon number is preferably 1 to 5, more preferably 1 to 4, and further preferably 1 or 2. 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. Ra 031 , Ra 032and Ra 033 In the above, the branched alkyl group preferably has a carbon number of 3 to 10, and more preferably 3 to 5. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and is preferably an isopropyl group. Ra 031 , Ra 032 and Ra 033 The chain or cyclic alkenyl group in is preferably an alkenyl group having 2 to 10 carbon atoms.

[0078] Ra 031 , Ra 032 and Ra 033 The cyclic hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0079] Ra 031 , Ra 032 and Ra 033The aromatic hydrocarbon group in the above formula (1) is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group 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.

[0080] The above Ra 031 , Ra 032 and Ra 033 When the hydrocarbon group represented by the formula (I) is substituted, examples of the substituent include a hydroxy group, a carboxy 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.), an alkyloxycarbonyl group, etc.

[0081] Among the above, Ra 031 , Ra 032 and Ra 033The optionally substituted hydrocarbon group in is preferably a linear or branched alkyl group which may have a substituent, more preferably a linear alkyl group which may have a substituent.

[0082] However, Ra 031 , Ra 032 and Ra 033 At least one of the groups is a hydrocarbon group having at least a polar group. A "hydrocarbon group having a polar group" is a methylene group (-CH 2 -) is substituted with a polar group, or at least one hydrogen atom constituting a hydrocarbon group is substituted with a polar group. Such a "hydrocarbon group having a polar group" is preferably a functional group represented by the following general formula (a1-p1).

[0083] [ka] [In the formula, Ra 07 represents a divalent hydrocarbon group having 2 to 12 carbon atoms. 08 represents a divalent linking group containing a hetero atom. 06 represents a monovalent hydrocarbon group having 1 to 12 carbon atoms. p0 is an integer from 1 to 6.

[0084] In the above formula (a1-p1), Ra 07 represents a divalent hydrocarbon group having 2 to 12 carbon atoms. Ra 07 has 2 to 12 carbon atoms, preferably 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms, further preferably 2 to 4 carbon atoms, and particularly preferably 2 carbon atoms. Ra 07 The hydrocarbon group in is preferably a chain or cyclic aliphatic hydrocarbon group, and more preferably a chain hydrocarbon group. Ra 07Examples of the alkyl group include linear alkanediyl groups such as an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, and a dodecane-1,12-diyl group; a propane-1,2-diyl group, a 1-methylbutane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and the like. branched alkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, and the like; and polycyclic divalent alicyclic hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and the like. Among the above, an alkanediyl group is preferred, and a linear alkanediyl group is more preferred.

[0085] In the above formula (a1-p1), Ra 08 represents a divalent linking group containing a hetero atom. Ra 08 Examples of the alkyl group include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O) 2 -, -S(=O) 2 -O- and the like. Among these, from the viewpoint of solubility in a developer, -O-, -C(=O)-O-, -C(=O)- and -OC(=O)-O- are preferred, with -O- and -C(=O)- being particularly preferred.

[0086] In the above formula (a1-p1), Ra 06 represents a monovalent hydrocarbon group having 1 to 12 carbon atoms. Ra 06has 1 to 12 carbon atoms, and from the viewpoint of solubility in a developer, preferably has 1 to 8 carbon atoms, more preferably has 1 to 5 carbon atoms, even more preferably has 1 to 3 carbon atoms, particularly preferably has 1 or 2 carbon atoms, and most preferably has 1 carbon atom.

[0087] Ra 06 The hydrocarbon group in the formula (I) may be a chain hydrocarbon group, a cyclic hydrocarbon group, or a combination of a chain and a cyclic hydrocarbon group. Examples of chain hydrocarbon groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, 2-ethylhexyl, n-octyl, n-nonyl, n-decyl, n-undecyl, and n-dodecyl groups.

[0088] The cyclic hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, cycloheptyl, cyclooctyl, cycloheptyl, and cyclodecyl. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl, adamantyl, 2-alkyladamantan-2-yl, 1-(adamantan-1-yl)alkane-1-yl, norbornyl, methylnorbornyl, and isobornyl. Examples of aromatic hydrocarbon groups include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.

[0089] Ra 06From the viewpoint of solubility in a developer, the alkyl group is preferably a chain hydrocarbon group, more preferably an alkyl group, and even more preferably a linear alkyl group.

[0090] In the above formula (a1-p1), n p0 represents an integer of 1 to 6, preferably an integer of 1 to 3, more preferably 1 or 2, and even more preferably 1.

[0091] Specific examples of the hydrocarbon group having at least a polar group are shown below. In the following formulae, * denotes a quaternary carbon atom (Ya 0 ) is the bond that bonds to the

[0092] [ka]

[0093] In the above formula (a1-r2-r1), Ra 031 , Ra 032 and Ra 033 The number of hydrocarbon groups having at least a polar group is one or more, but may be appropriately determined in consideration of the solubility in a developer when forming a resist pattern. For example, Ra 031 , Ra 032 and Ra 033 It is preferable that the number of the two is one or two, and it is particularly preferable that the number of the two is one.

[0094] The hydrocarbon group having at least a polar group may have a substituent other than the polar group, such as a halogen atom (such as a fluorine atom, a chlorine atom, or a bromine atom) or a halogenated alkyl group having 1 to 5 carbon atoms.

[0095] In formula (a1-r2-1), Ra' 11 (Ra' 10 The aliphatic cyclic group formed together with the carbon atom to which is bonded) is Ra' in formula (a1-r-1). 3 The groups mentioned above as the aliphatic hydrocarbon group are preferably monocyclic or polycyclic groups.

[0096] In the formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya includes Ra' in the formula (a1-r-1). 3 Examples of such groups include groups in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) in the above formula. The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of the substituent include the above-mentioned Ra' 3 Examples of the substituents include those similar to those that the cyclic hydrocarbon group in the above may have. In formula (a1-r2-2), Ra 01 ~Ra 03 In the above formula, examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group. Ra 01 ~Ra 03 In the above formula, examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group. Ra 01 ~Ra 03 Of these, from the viewpoint of ease of synthesis of the monomer compound from which the structural unit (a1) is derived, a hydrogen atom or a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms is preferred, and of these, a hydrogen atom, a methyl group, or an ethyl group is more preferred, with a hydrogen atom being particularly preferred.

[0097] The above Ra 01 ~Ra 03 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.

[0098] Ra 01 ~Ra 03 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 from which the structural unit (a1) is derived, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylidene-ethenyl group are preferred.

[0099] In formula (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is represented by Ra' in formula (a1-r-1). 3 The groups mentioned above as the aliphatic hydrocarbon group are preferably monocyclic or polycyclic groups. In formula (a1-r2-3), Ra 04 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. 04 is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.

[0100] Ra in formula (a1-r2-3) 04 Examples of the substituent that may be possessed by the alkyl group include a methyl group, an ethyl group, a propyl group, a hydroxyl 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.), an alkyloxycarbonyl group, and the like.

[0101] In formula (a1-r2-4), Ra' 12 and Ra' 13is, independently of each other, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom. Ra’ 12 and Ra’ 13 In the case of, as the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, the above Ra 01 ~Ra 03 In the case of, the same as the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in the above can be mentioned. Some or all of the hydrogen atoms of this linear saturated hydrocarbon group may be substituted. Ra’ 12 and Ra’ 13 Among them, a hydrogen atom and an alkyl group having 1 to 5 carbon atoms are preferable, an alkyl group having 1 to 5 carbon atoms is more preferable, a methyl group and an ethyl group are further preferable, and a methyl group is particularly preferable. The above Ra’ 12 and Ra’ 13 When the linear saturated hydrocarbon group represented by is substituted, examples of the substituent include the same groups as the above Ra 05 and the like.

[0102] In formula (a1-r2-4), Ra’ 14 is a hydrocarbon group which may have a substituent. As the hydrocarbon group in Ra’ 14 a linear or branched alkyl group or a cyclic hydrocarbon group can be mentioned.

[0103] Ra’ 14 The linear alkyl group in is preferably having 1 to 5 carbon atoms, more preferably 1 to 4, and further preferably 1 or 2. Specifically, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group and the like can be mentioned. Among these, a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

[0104] Ra’ 14The branched alkyl group in the above formula (I) preferably has a carbon number of 3 to 10, and more preferably 3 to 5. Specific examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group, and is preferably an isopropyl group.

[0105] Ra' 14 When is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group. The monocyclic aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The aliphatic hydrocarbon group that is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specific examples of which include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0106] Ra' 14 As the aromatic hydrocarbon group in 04 Among them, the aromatic hydrocarbon group Ra' is the same as that in 14 is preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene. Ra' 14 Examples of the substituent that may be possessed by Ra include 04 The substituents may be the same as those which may be possessed by the group.

[0107] Ra' in formula (a1-r2-4)14 When is a naphthyl group, the position at which it is bonded to the tertiary carbon atom in the above formula (a1-r2-4) may be either the 1st or 2nd position of the naphthyl group. Ra' in formula (a1-r2-4) 14 When is an anthryl group, the position at which it is bonded to the tertiary carbon atom in the above formula (a1-r2-4) may be any one of the 1-position, 2-position, or 9-position of the anthryl group.

[0108] Specific examples of the group represented by formula (a1-r2-1) are shown below.

[0109] [ka]

[0110] [ka]

[0111] [ka]

[0112] Specific examples of the group represented by formula (a1-r2-2) are shown below.

[0113] [ka]

[0114] [ka]

[0115] [ka]

[0116] Specific examples of the group represented by formula (a1-r2-3) are shown below.

[0117] [ka]

[0118] Specific examples of the group represented by formula (a1-r2-4) are shown below.

[0119] [ka]

[0120] Tertiary alkyloxycarbonyl acid dissociating group: Among the polar groups, examples of the acid dissociable group that protects the hydroxyl group include acid dissociable groups represented by the following general formula (a1-r-3) (hereinafter, for convenience, may be referred to as "tertiary alkyloxycarbonyl acid dissociable group").

[0121] [ka] [In the formula, Ra' 7 ~Ra' 9 are each an alkyl group.

[0122] In formula (a1-r-3), Ra' 7 ~Ra' 9 is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. The total number of carbon atoms in each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

[0123] Examples of the constitutional unit (a1) include a constitutional unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, a constitutional unit derived from acrylamide, a constitutional unit in which at least a part of the hydrogen atoms in the hydroxyl group of a constitutional unit derived from hydroxystyrene or a hydroxystyrene derivative is protected with a substituent containing the acid-decomposable group, a constitutional unit in which at least a part of the hydrogen atoms in -C(=O)-OH of a constitutional unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative is protected with a substituent containing the acid-decomposable group, and the like.

[0124] Among these, as the constitutional unit (a1), a constitutional unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent is preferable. Preferable specific examples of such a constitutional unit (a1) include constitutional units represented by the following general formula (a1-1) or (a1-2).

[0125] [Chemical formula] [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. Va 1 is a divalent hydrocarbon group which may have an ether bond. n a1 is an integer of 0 to 2. Ra 1 is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-2). Wa 1 is n a2 + a monovalent hydrocarbon group, n a2 is an integer of 1 to 3, and Ra 2 is an acid dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).]

[0126] In the formula (a1-1), the alkyl group of R having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferred. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom or a methyl group in terms of industrial availability, and even more preferably a hydrogen atom.

[0127] In the formula (a1-1), Va 1 The divalent hydrocarbon group in may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0128] Va 1 The aliphatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) may be saturated or unsaturated, and is usually preferably saturated. More specifically, the aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in the structure.

[0129] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably has 1 to 6 carbon atoms, further preferably has 1 to 4 carbon atoms, and most preferably has 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, specifically, a methylene group [-CH 2 -], ethylene group [-(CH 2 ) 2 -], trimethylene group [-(CH 2 ) 3 -], tetramethylene group [-(CH 2 ) 4 -], 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, specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 -, etc. alkylmethylene groups; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2 -, etc. alkyl ethylene groups; -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 -, etc.; -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0130] Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, etc. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, specifically cycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0131] Va 1 The aromatic hydrocarbon group as the divalent hydrocarbon group in the formula (I) is a hydrocarbon group having an aromatic ring. Such an aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, even more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. However, this carbon number does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a heteroatom, etc. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (arylene group); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (aryl group) has been substituted with an alkylene group (for example, a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0132] In the formula (a1-1), Ra 1 is an acid-dissociable group represented by the above formula (a1-r-1) or (a1-r-2).

[0133] In the formula (a1-2), Wa 1 n in a2 The +1-valent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. The aliphatic hydrocarbon group may be a straight-chain or branched-chain aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in its structure, or a group that combines a straight-chain or branched-chain aliphatic hydrocarbon group with an aliphatic hydrocarbon group containing a ring in its structure. The above n a2 The +1 valency is preferably 2 to 4, more preferably 2 or 3.

[0134] In the formula (a1-2), Ra 2is an acid-dissociable group represented by the above general formula (a1-r-1) or (a1-r-3).

[0135] Specific examples of the structural unit represented by the formula (a1-1) are shown below. In each of the following formulas, R α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0136] [ka]

[0137] [ka]

[0138] [ka]

[0139] [ka]

[0140] [ka]

[0141] [ka]

[0142] [ka]

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] [ka]

[0147] Specific examples of the structural unit represented by formula (a1-2) are shown below.

[0148] [ka]

[0149] The structural unit (a1) contained in the component (A1) may be of one type, or two or more types. As the structural unit (a1), a structural unit represented by the above formula (a1-1) is more preferable because it is more likely to improve characteristics (sensitivity, CDU, shape, etc.) in lithography using ultraviolet light such as g-line or i-line, or a KrF excimer laser. Among these, as the structural unit (a1), those containing a structural unit represented by general formula (a1-1-1) shown below are particularly preferable.

[0150] [ka] [In the formula, Ra 1 " is an acid-dissociable group represented by general formula (a1-r2-1), (a1-r2-3) or (a1-r2-4).

[0151] In the formula (a1-1-1), R and Va 1 and n a1 R and Va in the formula (a1-1) 1 and n a1 is the same as: The acid-dissociable group represented by formula (a1-r2-1), (a1-r2-3) or (a1-r2-4) is as described above. Among them, Ra 1 " is preferably an acid dissociable group represented by general formula (a1-r2-1) or (a1-r2-4), and Ra in general formula (a1-r2-1) is preferably an acid dissociable group represented by general formula (a1-r2-4). ’ 11 is an acid-dissociable group which is a monocyclic aliphatic hydrocarbon group, or Ra' in general formula (a1-r2-4) 12 , Ra' 13 and Ra' 14 are more preferably acid-dissociable groups each independently an alkyl group having 1 to 5 carbon atoms.

[0152] The proportion of the structural unit (a1) in the component (A1) relative to the total (100 mol %) of all structural units constituting the component (A1), is preferably 1 to 80 mol %, more preferably 5 to 70 mol %, and even more preferably 10 to 65 mol %. By ensuring that the proportion of the structural unit (a1) is at least as large as the lower limit, lithography properties such as sensitivity, resolution, and roughness can be improved. By ensuring that the proportion is at most the upper limit, a balance with other structural units can be achieved, and various lithography properties become favorable.

[0153] Other structural units The component (A1) may contain other structural units, in addition to the structural unit (a1) described above, as necessary. Other structural units include, for example, lactone-containing cyclic groups, -SO 2 Examples of such structural units include (a2) a structural unit containing a --containing cyclic group or a carbonate-containing cyclic group; (a3) ​​a structural unit containing a polar group-containing aliphatic hydrocarbon group; (a4) a structural unit containing an acid non-dissociable aliphatic cyclic group; and (a11) a structural unit derived from a compound that contains an aromatic ring (excluding an aromatic ring having a hydroxyl group bonded thereto) in the side chain.

[0154] Regarding the structural unit (a2): The component (A1) contains, in addition to the structural unit (a1), a lactone-containing cyclic group, -SO 2 It may also have a structural unit (a2) that contains a --containing cyclic group or a carbonate-containing cyclic group (provided that this does not include those that fall under the structural unit (a1)). The lactone-containing cyclic group of the structural unit (a2), -SO2 The --containing cyclic group or carbonate-containing cyclic group is effective in improving the adhesion of the resist film to the substrate when the component (A1) is used to form a resist film. Furthermore, the inclusion of the structural unit (a2) provides effects such as appropriate adjustment of the acid diffusion length, improved adhesion of the resist film to the substrate, and appropriate adjustment of the solubility during development, resulting in improved lithography properties.

[0155] A "lactone-containing cyclic group" refers to a cyclic group that contains a ring (lactone ring) containing -OC(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and when there is only a lactone ring, it is called a monocyclic group, and when there is further a ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. The lactone-containing cyclic group in the structural unit (a2) is not particularly limited and any suitable group can be used. Specific examples include the groups represented by the following general formulae (a2-r-1) to (a2-r-7).

[0156] [ka] [In the formula, Ra' 21 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, 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.

[0157] In the general formulas (a2-r-1) to (a2-r-7), Ra' 21The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferred, and a methyl group is particularly preferred. Ra' 21 The alkoxy group in the formula (1) is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the formula (1) is preferably a linear or branched alkoxy group. 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.

[0158] Ra' 21 In -COOR" and -OC(=O)R", R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2 -containing cyclic group. The alkyl group in R'' may be linear, branched, or cyclic, and preferably has 1 to 15 carbon atoms. When R″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably has 1 to 5 carbon atoms, and is particularly preferably a methyl group or an ethyl group. When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, tricycloalkane, or tetracycloalkane. More specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples of the lactone-containing cyclic group in R″ include the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7) above. The carbonate-containing cyclic group in R″ is the same as the carbonate-containing cyclic group described later, and specific examples thereof include groups represented by general formulae (ax3-r-1) to (ax3-r-3). -SO in R” 2 Examples of the --containing cyclic group include the -SO 2 Similar to the -containing cyclic group, specific examples include the groups represented by general formulae (a5-r-1) to (a5-r-4). 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.

[0159] 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 of such an alkylene group include a methylene group, an ethylene group, an n-propylene group and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include groups in which -O- or -S- is present at the terminal or between the carbon atoms of the alkylene group, and examples thereof include O-CH 2 -, -CH 2 -O-CH 2 -,-S-CH 2 -, -CH 2 -S-CH 2 A" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0160] Specific examples of the groups represented by general formulas (a2-r-1) to (a2-r-7) are listed below.

[0161] [ka]

[0162] [ka]

[0163] "-SO 2 "-containing cyclic group" means a group having a -SO 2 A cyclic group containing a ring containing -, specifically, -SO 2 The sulfur atom (S) in - forms part of the ring structure of the cyclic group. 2 The ring containing - is counted as the first ring, and if there is only this ring, it is called a monocyclic group, and if there are other ring structures, it is called a polycyclic group regardless of the structure. 2 The -containing cyclic group may be a monocyclic group or a polycyclic group. -SO 2 The -containing cyclic group in particular has an -O-SO2 Cyclic groups containing -, i.e. -O-SO 2 It is preferred that -OS- in - is a cyclic group containing a sultone ring forming part of the ring backbone. -SO 2 More specific examples of the --containing cyclic group include groups represented by the following general formulas (a5-r-1) to (a5-r-4).

[0164] [ka] [In the formula, Ra' 51 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2 -containing cyclic group; A″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, and n′ is an integer of 0 to 2.

[0165] In the general formulae (a5-r-1) and (a5-r-2), A" is the same as A" in the general formulae (a2-r-2), (a2-r-3) and (a2-r-5). Ra' 51 The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group in the general formulae (a2-r-1) to (a2-r-7) are each represented by Ra' 21 Examples of the above-mentioned are similar to those mentioned in the explanation of the above. Specific examples of the groups represented by general formulas (a5-r-1) to (a5-r-4) are shown below, in which "Ac" represents an acetyl group.

[0166] [ka]

[0167] [ka]

[0168] [ka]

[0169] The term "carbonate-containing cyclic group" refers to a cyclic group that contains a ring (carbonate ring) containing -OC(=O)-O- in its ring skeleton. The carbonate ring is counted as the first ring, and when there is only a carbonate ring, it is called a monocyclic group, and when there is another ring structure, it is called a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. The carbonate ring-containing cyclic group is not particularly limited and any one can be used. Specific examples include groups represented by the following general formulae (ax3-r-1) to (ax3-r-3).

[0170] [ka] [In the formula, Ra' x31 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2 -containing cyclic group; A″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom; p′ is an integer of 0 to 3, and q′ is 0 or 1.

[0171] 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' 31The 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.

[0172] [ka]

[0173] Of the various possibilities, the structural unit (a2) is preferably a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[0174] [ka] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. 21 is a single bond or a divalent linking group. 21 is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, where R' represents a hydrogen atom or a methyl group. 21 If -O-, Ya 21 does not become -CO-. Ra 21 is a lactone-containing cyclic group, a carbonate-containing cyclic group, or -SO 2 -containing cyclic group.]

[0175] In the formula (a2-1), R is the same as defined above. R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferable.

[0176] In the formula (a2-1), Ya 21 The divalent linking group in is not particularly limited, but suitable examples include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0177] Optionally substituted divalent hydrocarbon group: Ya 21 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.

[0178] Ya 21 Aliphatic hydrocarbon groups in The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.

[0179] Linear or branched aliphatic hydrocarbon groups The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably has 1 to 6 carbon atoms, further preferably has 1 to 4 carbon atoms, and most preferably has 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, specifically, a methylene group [-CH 2 -], ethylene group [-(CH 2 ) 2 -], trimethylene group [-(CH 2 ) 3 -], tetramethylene group [-(CH 2 ) 4 -], pentamethylene group [-(CH 2 ) 5 -] etc. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably has 3 to 6 carbon atoms, even more preferably has 3 or 4 carbon atoms, and most preferably has 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 -, etc. alkylmethylene groups; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2 -, etc. alkyl ethylene groups; -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 -, etc.; -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2 The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0180] 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.

[0181] Aliphatic hydrocarbon groups containing rings in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a heteroatom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably one having 3 to 6 carbon atoms, specifically cyclopentane, cyclohexane, etc. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc.

[0182] 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 substituent containing a hetero atom. Examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, -S(=O) 2 -, -S(=O) 2 -O- is preferred.

[0183] Ya 21 Aromatic hydrocarbon groups in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, further preferably 6 to 15, and particularly preferably 6 to 12. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is replaced with a heteroatom. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring. Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound containing two or more aromatic rings (e.g., biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) has been substituted with an alkylene group (e.g., a group in which one hydrogen atom has been further removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0184] 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.

[0185] Divalent linking groups containing heteroatoms: Ya 21 When is a divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O)2 -, -S(=O) 2 -O-, general formula -Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O) 2 -OY 22 -, wherein Y 21 and Y 22 each independently represents a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m″ is an integer of 0 to 3. When the divalent linking group containing a hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, or -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group, an acyl group, etc. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8, and particularly preferably 1 to 5 carbon atoms. General formula-Y 21 -OY 22 -, -Y 21 -O-, -Y 21 -C(=O)-O-, -C(=O)-OY 21 -, -[Y 21 -C(=O)-O] m” -Y 22 -, -Y 21 -OC(=O)-Y 22 -or-Y 21 -S(=O) 2 -OY 22 -Medium, Y 21 and Y 22 Each of the Ya independently represents a divalent hydrocarbon group which may have a substituent. 21 Examples of the divalent linking group in the above formula (divalent hydrocarbon group which may have a substituent) include those similar to those mentioned in the above formula (divalent linking group which may have a substituent). Y 21 As the alkyl group, a straight-chain aliphatic hydrocarbon group is preferable, a straight-chain alkylene group is more preferable, a straight-chain alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or ethylene group is particularly preferable. Y 22 is preferably a linear or branched aliphatic hydrocarbon group, more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group. Formula − [Y 21 -C(=O)-O] m” -Y 22 In the group represented by -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. That is, the group represented by the formula -[Y 21 -C(=O)-O] m” -Y 22 The group represented by the formula -Y 21 -C(=O)-OY 22 Particularly preferred is a group represented by the formula -(CH 2 ) a’ -C(=O)-O-(CH 2 ) b’ In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.

[0186] Among the above, Ya 21 is preferably a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

[0187] In the above formula (a2-1), Ra 21 is a lactone-containing cyclic group, -SO 2-containing cyclic group or a carbonate-containing cyclic group. Ra 21 The lactone-containing cyclic group, -SO 2 Suitable examples of the --containing cyclic group and the carbonate-containing cyclic group include the groups represented by the above-mentioned general formulae (a2-r-1) to (a2-r-7), (a5-r-1) to (a5-r-4), and (ax3-r-1) to (ax3-r-3), respectively. Among these, lactone-containing cyclic groups or -SO 2 -containing cyclic groups are preferred, and the groups represented by the general formulae (a2-r-1), (a2-r-2), (a2-r-6) and (a5-r-1) are more preferred. Specifically, any of the groups represented by the chemical formulae (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-lc-6-1), (r-sl-1-1) and (r-sl-1-18) are more preferred.

[0188] 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) relative to the total (100 mol%) of all structural units constituting the component (A1) is preferably 5 to 60 mol%, more preferably 10 to 60 mol%, even more preferably 20 to 55 mol%, and particularly preferably 30 to 50 mol%. When the proportion of the structural unit (a2) is at least as large as the preferred lower limit, the effects achieved by including the structural unit (a2) as described above can be fully obtained. When the proportion of the structural unit (a2) is at most the upper limit, a balance with other structural units can be achieved, and various lithography properties become favorable.

[0189] 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.

[0190] Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which some of the hydrogen atoms of an alkyl group are substituted with fluorine atoms, with a hydroxyl group being particularly preferred. Examples of the aliphatic hydrocarbon group include linear or branched hydrocarbon groups (preferably alkylene groups) having 1 to 10 carbon atoms, and cyclic aliphatic hydrocarbon groups (cyclic groups). The cyclic group may be a monocyclic group or a polycyclic group, and can be appropriately selected from the many groups proposed for use in resins for resist compositions for ArF excimer lasers.

[0191] 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.

[0192] When the cyclic group is a polycyclic group, the number of carbon atoms of the polycyclic group is more preferably 7 to 30. Among them, a structural unit derived from an acrylic acid ester containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which a portion of the hydrogen atoms of the alkyl group is substituted with a fluorine atom is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from a bicycloalkane, a tricycloalkane, a tetracycloalkane, etc. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane are industrially preferred.

[0193] 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).

[0194] [ka] [In the formula, R is the same as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t' is an integer of 1 to 3, l is an integer of 0 to 5, and s is an integer of 1 to 3.]

[0195] 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.

[0196] In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5- or 6-position of the norbornyl group.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] Regarding the structural unit (a4): The component (A1) may further contain, in addition to the structural unit (a1), a structural unit (a4) that contains an acid non-dissociable aliphatic cyclic group. By including the structural unit (a4) in the component (A1), the dry etching resistance of the formed resist pattern is improved. In addition, the hydrophobicity of the component (A) is enhanced. The improved hydrophobicity contributes to improvements in the resolution, resist pattern shape, etc., particularly in the case of a solvent development process. The “acid non-dissociable cyclic group” within the structural unit (a4) is a cyclic group that, when acid is generated in the resist composition upon exposure (for example, when acid is generated from a structural unit that generates acid upon exposure or from the component (B)), does not dissociate even when acted upon by the acid, and remains as is within the structural unit.

[0201] The structural unit (a4) is preferably, for example, a structural unit derived from an acrylate ester containing an acid non-dissociable aliphatic cyclic group. The cyclic group can be any of a large number of conventionally known resin components for resist compositions for ArF excimer lasers, KrF excimer lasers (preferably KrF excimer lasers), etc. The cyclic group is preferably at least one selected from a cyclohexyl group, a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group, from the viewpoint of industrial availability, etc. These cyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent. Specific examples of the structural unit (a4) include the structural units represented by the following general formulas (a4-1) to (a4-8).

[0202] [ka] [In the formula, R α is the same as above.]

[0203] The structural unit (a4) contained in the component (A1) may be of one type, or two or more types. When the component (A1) contains the structural unit (a4), the proportion of the structural unit (a4) relative to the total (100 mol %) of all structural units constituting the component (A1) is preferably 20 to 80 mol %, more preferably 25 to 75 mol %, and even more preferably 30 to 70 mol %. By ensuring that the proportion of the structural unit (a4) is at least as large as the preferred lower limit, the effects of including the structural unit (a4) can be fully obtained, while by ensuring that the proportion is no more than the preferred upper limit, it becomes easier to achieve a balance with other structural units.

[0204] Regarding the structural unit (a11): The structural unit (a11) is a structural unit derived from a compound that contains an aromatic ring (excluding an aromatic ring having a hydroxy group bonded thereto) in the side chain. Suitable examples of the compound having an aromatic ring (excluding an aromatic ring having a hydroxy group bonded thereto) in the side chain include compounds represented by the following general formula (a11-1).

[0205] [ka] [In formula (a11-1), Ra x2 is a polymerizable group-containing group. x2 is (n ax2 +1)valent aromatic hydrocarbon group. x2 And Wa x2 and R may form a condensed ring structure. x02 Wa x2 It is a substituent that replaces the hydrogen atom that constitutes the (aromatic hydrocarbon group). ax2 is an integer from 0 to 3. ax2 If is 2 or more, multiple Ra x02 may be bonded to each other to form a ring structure.

[0206] In the formula (a11-1), Ra x2 is a polymerizable group-containing group. Ra x2 The "polymerizable group" in the above formula is a group that enables a compound having a polymerizable group to be polymerized by radical polymerization or the like, and refers to a group that contains a multiple bond between carbon atoms, such as an ethylenic double bond. Examples of the polymerizable group include a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a fluorovinyl group, a difluorovinyl group, a trifluorovinyl group, a difluorotrifluoromethylvinyl group, a trifluoroallyl group, a perfluoroallyl group, a trifluoromethylacryloyl group, a nonylfluorobutylacryloyl group, a vinyl ether group, a fluorine-containing vinyl ether group, an allyl ether group, a fluorine-containing allyl ether group, a styryl group, a vinyl naphthyl group, a fluorine-containing styryl group, a fluorine-containing vinyl naphthyl group, a norbornyl group, a fluorine-containing norbornyl group, and a silyl group. The polymerizable group-containing group may be a group composed only of a polymerizable group, or may be a group composed of a polymerizable group and a group other than the polymerizable group. Examples of the group other than the polymerizable group include a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

[0207] Ra x2 For example, the chemical formula: CH 2 =C(R)-Ya x0 In this chemical 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; x0 is a divalent linking group.

[0208] In the formula (a11-1), Wa x2 is (n ax2 +1)-valent aromatic hydrocarbon group, x1 The same can be mentioned.

[0209] However, Ra x2 And Wa x2may form a condensed ring structure. Ra x2 And Wa x2 When a condensed ring structure is formed with Wa, x2 The aromatic ring derived from Ra x2 The multiple bonds between the carbon atoms of the polymerizable group derived from are cleaved to form the main chain of the component (A1). That is, some of the carbon atoms constituting the fused ring constitute the main chain of the component (A1).

[0210] In the formula (a11-1), Ra x02 Wa x2 It is a substituent that replaces a hydrogen atom that constitutes (aromatic hydrocarbon group). Ra x02 Examples of the substituent in include an alkyl group, an alkoxy group, and an acyloxy group. Ra x02 The alkyl group as the substituent in 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. Ra x02 The alkoxy group as the substituent in 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 particularly preferably a methoxy group or an ethoxy group. Ra x02 The acyloxy group as a substituent in the formula (I) preferably has 2 to 6 carbon atoms, and CH 3 C(=O)-O-(acetoxy group), C 2 H 5 C(=O)-O- is more preferred, CH 3 C(=O)-O- (acetoxy group) is particularly preferred.

[0211] In the formula (a11-1), n ax2 represents an integer of 0 to 3, preferably 0, 1 or 2, and more preferably 0 or 1. n ax2 If is 2 or more, multiple Ra x02may be bonded to each other to form a ring structure. The ring structure formed here may be a hydrocarbon ring or a heterocyclic ring. For example, Wa x2 Two Ra bonds to the same aromatic ring in x02 And these two Ra x02 The aromatic ring (Wa x2 ) and one side (the bond between the carbon atoms) of

[0212] Suitable examples of the structural unit (a11) include the structural units represented by the following general formulas (a11-u1-1) to (a11-u1-6).

[0213] [ka] [In the formula, R α R is a hydrogen atom, a methyl group, or a trifluoromethyl group. β is an alkyl group, an alkoxy group, or an acyloxy group. ax2 is an integer from 0 to 3. ax2 If is 2 or more, multiple R β may be bonded to each other to form a ring structure. 21 , n 22 , n 24 and n 25 Each of n is independently 0 or 1. 23 and n 26 are each independently 1 or 2.

[0214] In the above formulae (a11-u1-1) to (a11-u1-6), R β The alkyl group, alkoxy group, and acyloxy group in the above formula (a11-1) are x02 The substituents are the same as the alkyl group, alkoxy group and acyloxy group exemplified in the above.

[0215] Specific examples of the structural unit (structural unit (a11)) derived from the compound represented by general formula (a11-1) above are shown below. In each of the following formulas, R αrepresents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[0216] [ka]

[0217] [ka]

[0218] [ka]

[0219] [ka]

[0220] [ka]

[0221] Among the above examples, the structural unit (a11) is preferably at least one type selected from the group consisting of structural units represented by general formulas (a11-u1-1) to (a11-u1-3), and the structural unit represented by general formula (a11-u1-1) is more preferable. Of these, the structural unit (a11) is preferably a structural unit represented by any one of chemical formulas (a11-u1-11), (a11-u1-21) or (a11-u1-31), and a structural unit represented by chemical formula (a11-u1-11) is more preferable.

[0222] The structural unit (a11) contained in the component (A1) may be of one type, or two or more types. When the component (A1) contains the structural unit (a11), the proportion of the structural unit (a11) in the component (A1) is preferably 1 to 30 mol %, more preferably 1 to 25 mol %, and even more preferably 1 to 20 mol %, based on the combined total (100 mol %) of all structural units constituting the component (A1). By ensuring that the proportion of the structural unit (a11) is at least as large as the lower limit of the present invention, lithography properties are likely to be improved, while by ensuring that the proportion is no more than the upper limit of the present invention, throughput during etching is likely to be improved and it is also easy to achieve a balance with other structural units.

[0223] In the resist composition of this embodiment, the component (A) contains a resin component (A1) (component (A1)) that contains the structural unit (a10). Preferred examples of the component (A1) include polymeric compounds having at least the structural unit (a10) and the structural unit (a1).Specific examples of suitable polymeric compounds include those having a repeating structure of the structural unit (a10), the structural unit (a1), and the structural unit (a4), and those having a repeating structure of the structural unit (a10), the structural unit (a1), and the structural unit (a11).

[0224] The weight average molecular weight (Mw) of the component (A1) (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, but is preferably 500 to 50,000, more preferably 1,000 to 30,000, and even more preferably 2,000 to 20,000. When the Mw of the component (A1) is no more than the preferred upper limit of this range, the compound has sufficient solubility in a resist solvent for use as a resist, and when it is no less than the preferred lower limit of this range, the dry etching resistance and cross-sectional shape of the resist pattern are improved.

[0225] The dispersity (Mw / Mn) of the component (A1) is not particularly limited, and is preferably from 1.0 to 4.0, more preferably from 1.0 to 3.0, and particularly preferably from 1.0 to 2.5, where Mn represents the number average molecular weight.

[0226] 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 (a10) and, if necessary, a monomer that derives a structural unit other than the structural unit (a10) in a polymerization solvent, adding the above-mentioned radical polymerization initiator to the resulting solution to polymerize, and then carrying out a deprotection reaction. In addition, during polymerization, for example, HS-CH 2 -CH 2 -CH 2 -C(CF 3 ) 2 By using a chain transfer agent such as -OH in combination, the chain can be terminated with -C(CF 3 ) 2 A -OH group may be introduced. In this way, a copolymer having a hydroxyalkyl group, in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms, is effective in reducing development defects and reducing LER (line edge roughness: non-uniform unevenness on the line sidewall). Additionally, the component (A1) can also be produced by anionic polymerization using an organic alkali metal such as n-butyllithium, s-butyllithium, t-butyllithium, ethyllithium, ethylsodium, 1,1-diphenylhexyllithium, or 1,1-diphenyl-3-methylpentyllithium as a polymerization initiator.

[0227] Regarding component (A2) The resist composition of this embodiment may use, in combination with the component (A), a base component (hereafter referred to as “component (A2)”) that does not fall under the category of the component (A1) above and whose solubility in a developer changes under the action of an acid. There are no particular restrictions on the component (A2), and it may be selected from the many conventional base components for chemically amplified resist compositions. The component (A2) may be a polymeric compound or a low molecular weight compound, and may be used either alone or in combination of two or more.

[0228] The proportion of the (A1) component in the (A) component is preferably 25% by mass or more, more preferably 50% by mass or more, and even more preferably 75% by mass or more, and may be 100% by mass, based on the total mass of the (A) component. When the proportion is 25% by mass or more, a resist pattern that is excellent in various lithography properties such as high sensitivity, resolution, and improved roughness is easily formed.

[0229] The amount of the component (A) in the resist composition of this embodiment may be adjusted depending on factors such as the thickness of the resist film to be formed. <(B) component> Regarding the (B0) component The component (B) is an acid generator component that generates an acid upon exposure. In the resist composition of this embodiment, the component (B) includes at least a compound (B0) represented by the following general formula (b0-1) (hereinafter also referred to as "component (B0)").

[0230] [ka] [In the formula, R b1 is a hydrocarbon group having 1 to 30 carbon atoms, b1 When the hydrocarbon group as the formula (I) contains one or more methylene groups, at least a part of the methylene groups is -O-, -S-, -CO-, -CO-O-, -SO-, -SO 2 -, -CR b4 R b5 - and -NR b6 -, wherein R b1 When the hydrocarbon group as R contains a hydrocarbon ring, at least one of the carbon atoms constituting the hydrocarbon ring may be substituted with a heteroatom selected from the group consisting of N, O, P, S, and Se, or an atomic group containing such a heteroatom; b4 and the above R b5 are each independently a hydrogen atom or a halogen atom, b4 and the above R b5 At least one of R is a halogen atom. b6 is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms; (Ra1 )n, (R a2 )m, where n and m are integers from 0 to 3; R a1 and R a2 are each independently a hydrogen atom or an organic group; Q 1 , and Q 2 are each independently a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms; L is an ester bond.]

[0231] In formula (b0-1), as the organic groups in R a1 and R a2 , specifically, there may be mentioned a cyclic group which may have a substituent, a linear alkyl group which may have a substituent, or a linear alkenyl group which may have a substituent, etc.

[0232] Cyclic group which may have a substituent: The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. Also, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

[0233] R a1 and R a2 The aromatic hydrocarbon group in is a hydrocarbon group having an aromatic ring. The number of carbon atoms of the aromatic hydrocarbon group is preferably 3 to 30, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. R a1 and R a2 Specific examples of the aromatic ring of the aromatic hydrocarbon group in include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which a part of the carbon atoms constituting these aromatic rings is substituted with a heteroatom. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, etc. Ra1 and R a2 Specific examples of the aromatic hydrocarbon group in the above include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), and a group in which one hydrogen atom of the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0234] R a1 and R a2 The cyclic aliphatic hydrocarbon group in the formula (I) is an aliphatic hydrocarbon group containing a ring in the structure. Examples of aliphatic hydrocarbon groups that contain a ring in their structure include alicyclic hydrocarbon groups (groups in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), groups in which an alicyclic hydrocarbon group is bonded to the end of a straight-chain or branched-chain aliphatic hydrocarbon group, and groups in which an alicyclic hydrocarbon group is present in the middle of a straight-chain or branched-chain aliphatic hydrocarbon group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, the polycycloalkane is more preferably a polycycloalkane having a polycyclic skeleton of a bridged ring system, such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; or a polycycloalkane having a polycyclic skeleton of a condensed ring system, such as a cyclic group having a steroid skeleton.

[0235] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has a carbon number of 1 to 10, 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 specifically, a methylene group [-CH 2 -], ethylene group [-(CH 2 ) 2 -], trimethylene group [-(CH 2 ) 3 -], tetramethylene group [-(CH 2 ) 4 -], pentamethylene group [-(CH 2 ) 5 -] etc. The branched aliphatic hydrocarbon group 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 specifically, -CH(CH 3 )-, -CH(CH 2 CH 3 )-, -C(CH 3 ) 2 -, -C(CH 3 )(CH 2 CH 3 )-, -C(CH 3 )(CH 2 CH 2 CH 3 )-, -C(CH 2 CH 3 ) 2 -, etc. alkylmethylene groups; -CH(CH 3 )CH 2 -, -CH(CH 3 )CH(CH 3 )-, -C(CH 3 ) 2 CH 2 -, -CH(CH 2 CH 3 )CH 2 -, -C(CH 2 CH 3 ) 2 -CH 2-, etc. alkyl ethylene groups; -CH(CH 3 )CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 -, etc.; -CH(CH 3 )CH 2 CH 2 CH 2 -, -CH 2 CH(CH 3 )CH 2 CH 2 The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

[0236] Also, R a1 and R a2 The cyclic hydrocarbon group in may contain a heteroatom, such as a heterocycle. Specifically, the lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) and the —SO 2 -containing cyclic groups, and other heterocyclic groups represented by the above chemical formulas (R-HR-1) to (R-HR-16), respectively. In the formula, * represents a bond bonded to the aromatic ring in formula (B0-1).

[0237] Optionally substituted chain alkyl groups: R a1 and R a2 The chain alkyl group may be either linear or branched. The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. 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 decanyl 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. The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

[0238] An optionally substituted chain alkenyl group: R a1 and R a2 The chain alkenyl group in may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, further preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Of the above chain alkenyl groups, linear alkenyl groups are preferred, vinyl groups and propenyl groups are more preferred, and vinyl groups are particularly preferred.

[0239] In formula (b0-1), R a1 and R a2When the aliphatic hydrocarbon group in the formula (I) contains one or more methylene groups, at least a part of the methylene groups is selected from the group consisting of -O-, -S-, -CO-, -CO-O-, -SO-, -SO 2 - and -NR a5 -, and may be substituted with a group selected from the group consisting of: R a5 R is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. a5 The hydrocarbon group having 1 to 6 carbon atoms as the alkyl group may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a combination thereof. The aliphatic hydrocarbon group may be linear, branched, or cyclic, or may be a combination of these structures. Examples of the aliphatic hydrocarbon group include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, and n-hexyl. An example of the aromatic hydrocarbon group is a phenyl group.

[0240] R a1 and R a2 The organic group in is -R a3 -R a4 The group may be represented by the following formula: R a3 is a methylene group, -O-, -CO-, -CO-O-, -SO-, -SO 2 - or -NR a6 -It is. R a6 is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. R a4 is a heteroarylalkyl group containing an aromatic group having from 5 to 20 ring atoms which may have a substituent, a perfluoroalkyl group having from 1 to 6 carbon atoms, an aralkyl group having from 7 to 20 carbon atoms which may have a substituent, or an aromatic heterocyclic group having from 5 to 20 ring atoms which may have a substituent. R a4 The aromatic group having 5 to 20 ring atoms which may have a substituent is R a1 and R a2The substituents are the same as those of the aromatic hydrocarbon group which may have a substituent described above. R a4 As the perfluoroalkyl group having 1 to 6 carbon atoms, CF 3 -, CF 3 CF 2 -, (CF 3 ) 2 CF-, CF 3 CF 2 CF 2 -, CF 3 CF 2 CF 2 CF 2 -, (CF 3 ) 2 CFCF 2 -, CF 3 CF 2 (CF 3 )CF-, (CF 3 ) 3 C-, etc. R a4 Specific examples of the aralkyl group having 7 to 20 carbon atoms, which may have a substituent, include a benzyl group, a phenethyl group, an α-naphthylmethyl group, a β-naphthylmethyl group, a 2-α-naphthylethyl group, and a 2-β-naphthylethyl group. In formula (b0-1), the heteroarylalkyl group is a group in which some of the carbon atoms constituting the aromatic hydrocarbon ring in the arylalkyl group are substituted with heteroatoms such as N, O, and S. a4 Specific examples of the heteroarylalkyl group containing an aromatic heterocyclic group having 5 to 20 ring-constituting atoms which may have a substituent as the heteroaryl group include a pyridin-2-ylmethyl group, a pyridin-3-ylmethyl group, and a pyridin-4-ylmethyl group. R a6 The hydrocarbon group having 1 to 6 carbon atoms in R a5 This is the same as the hydrocarbon group having 1 to 6 carbon atoms described above.

[0241] In formula (b0-1), R a1 and R a2Among the above, at least a part of the methylene groups is -O-, -S-, -CO-, -CO-O-, -SO-, -SO 2 - and -NR a5 - is preferably a linear alkyl group having 1 to 10 carbon atoms or -R a3 -R a4 A group represented by the following formula is more preferable, and a linear alkyl group having 1 to 5 carbon atoms is even more preferable.

[0242] In formula (b0-1), m and n each independently represent an integer of 0 to 3, preferably 0 or 1, and more preferably one of m and n is 0 and the other is 1.

[0243] In formula (b0-1), R b1 The hydrocarbon group having 1 to 30 carbon atoms in the formula (1) may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a combination thereof. The aliphatic hydrocarbon group may be linear, branched, or cyclic, or may be a combination of these structures. R b1 The hydrocarbon group having 1 to 30 carbon atoms in the formula (I) is R a1 and R a2 Examples of the hydrocarbon group include the same groups as those in the above. Specific examples of the aliphatic hydrocarbon group include chain aliphatic hydrocarbon groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group, and cyclic aliphatic hydrocarbon groups (hydrocarbon rings) such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, and a norbornyl group. Examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group. Examples of groups in which an aliphatic hydrocarbon group and an aromatic hydrocarbon group are combined include a benzyl group, a phenethyl group, and a furylmethyl group.

[0244] R b1When the hydrocarbon group as described above contains a hydrocarbon ring, examples of the atomic group containing a heteroatom substituting at least one of the carbon atoms constituting the hydrocarbon ring include -CO-, -CO-O-, -SO-, -SO 2 -, -SO 2 -O-, -P(=O)-(OR b7 ) 3 Examples include:

[0245] R b7 R is a hydrocarbon group having 1 to 6 carbon atoms. b7 The hydrocarbon group having 1 to 6 carbon atoms as the alkyl group may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a combination thereof. The aliphatic hydrocarbon group may be linear, branched, or cyclic, or may be a combination of these structures. Examples of the aliphatic hydrocarbon group include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, and n-hexyl. An example of the aromatic hydrocarbon group is a phenyl group.

[0246] In formula (b0-1), R b4 and R b5 Specific examples of the halogen atom as include a chlorine atom, a fluorine atom, a bromine atom, and an iodine atom.

[0247] In formula (b0-1), R b6 The hydrocarbon group having 1 to 6 carbon atoms as R b7 The same applies to the hydrocarbon groups having 1 to 6 carbon atoms in the above formula (1).

[0248] In formula (b0-1), R b1 Among the above, a linear or branched alkyl group, a group in which one or more hydrogen atoms have been removed from a monocycloalkane, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, -SO 2-containing cyclic groups are preferred, and examples thereof include linear or branched alkyl groups having 1 to 5 carbon atoms, cyclohexyl alkyl groups, adamantyl alkyl groups, and -SO 2 -containing cyclic groups are more preferred, and examples thereof include a methyl group, a cyclohexylethyl group, an adamantylethyl group, and the -SO 2 -containing cyclic groups are more preferred.

[0249] In formula (b0-1), Q 1 and Q 2 As the perfluoroalkyl group having 1 to 6 carbon atoms, CF 3 -, CF 3 CF 2 -, (CF 3 ) 2 CF-, CF 3 CF 2 CF 2 -, CF 3 CF 2 CF 2 CF 2 -, (CF 3 ) 2 CFCF 2 -, CF 3 CF 2 (CF 3 )CF-, (CF 3 ) 3 C-, etc.

[0250] In the compound represented by formula (b0-1), the orientation of the ester bond as L is not particularly limited, and may be either -CO-O- or -O-CO-.

[0251] The component (B0) is preferably a compound represented by the following formula (b0-1-1).

[0252] [ka] [In formula (b0-1-1), R b1 , R a1 , Q 1 , and Q2 R in the formula (b0-1) b1 , R a1 , Q 1 , and Q 2 is the same as:

[0253] The component (B0) can be produced by the following method for producing an N-organosulfonyloxy compound. The method for producing an N-organosulfonyloxy compound capable of producing the component (B0) comprises reacting an N-hydroxy compound (B0-A') with a sulfonic acid fluoride compound (B0-B') in the presence of a basic compound (B0-D'), and is characterized in that a silylating agent (B0-C') is present in the system when reacting the N-hydroxy compound (B0-A') with the sulfonic acid fluoride compound (B0-B'), the sulfonic acid fluoride compound (B') being represented by the following formula (B0-B'-1), and the silylating agent (B0-C') being capable of converting the hydroxy group on the nitrogen atom of the N-hydroxy compound (B0-A') into a silyloxy group represented by the following formula (B0-c1). -O-Si(R c1 ) 3 (B0-c1) (In formula (B0-c1), R c1 are each independently a hydrocarbon group having 1 to 10 carbon atoms. R b1 -L-CQ 1 Q 2 -SO 2 -F···(B0-B'-1) (In formula (B0-B'-1), R b1 , L, Q 1 , and Q 2 are R in the above formula (b0-1), b1 , L, Q 1 , and Q 2 is equivalent to

[0254] Furthermore, a method for producing an N-organosulfonyloxy compound capable of producing the component (B0) includes a silylation step of silylating an N-hydroxy compound (B0-A') with a silylating agent (B0-C'), and a condensation step of condensing the silylated product of the N-hydroxy compound (B0-A') produced in the silylation step with a sulfonic acid fluoride compound (B0-B') in the presence of a basic compound (B0-D'), wherein the sulfonic acid fluoride compound (B0-B') is represented by the above formula (B0-B'-1), and the silylating agent is capable of converting the hydroxy group on the nitrogen atom of the N-hydroxy compound (B0-A') into a silyloxy group represented by the above formula (B0-c1).

[0255] The N-hydroxy compound (B0-A') is a compound represented by the following formula (B0-A'-1).

[0256] [ka] [In formula (B0-A'-1), R b1 , R a1 m and n are R in the above formula (b0-1). b1 , R a1 Same as m and n.]

[0257] The N-hydroxy compound (B0-A') can be synthesized by a conventional method, for example, as disclosed in International Publication No. 2014 / 084269 and JP-A-2017-535595. For example, R represented by the formula (b0-1-1) a2 The compound in which R is a hydrogen atom can be obtained by converting the bromo group on naphthalic anhydride to R by the reaction shown in the following formula, starting from a commercially available bromide. a1 Then, the acid anhydride group is reacted with a hydroxylamine compound such as hydroxylamine hydrochloride to form an N-hydroxyimide. Alternatively, a commercially available product may be used as the N-hydroxy compound (B0-A').

[0258] [ka]

[0259] The sulfonic acid fluoride compound (B0-B') can be synthesized by a conventional method. For example, in (B0-B'-1), Q 1 and Q 2 The compound in which is a fluorine atom can be synthesized by the reaction represented by the following formula: Furthermore, a commercially available product may be used as the sulfonic acid fluoride compound (B0-B').

[0260] [ka]

[0261] In formula (B0-c1), R c1 The hydrocarbon group having 1 to 10 carbon atoms as the alkyl group may be an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a combination thereof. The aliphatic hydrocarbon group may be linear, branched, or cyclic, or may be a combination of these structures. Examples of the aliphatic hydrocarbon group include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl. Examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group.

[0262] Specific preferred examples of the component (B0) are listed below.

[0263] [ka]

[0264] [ka]

[0265] [ka]

[0266] [ka]

[0267] The component (B0) contained in the resist composition of this embodiment may use either a single type, or a combination of two or more types.

[0268] In the resist composition of this embodiment, the content of the component (B0) relative to 100 parts by mass of the component (A) is preferably 0.1 to 50 parts by mass, more preferably 0.1 to 40 parts by mass, even more preferably 0.1 to 30 parts by mass, and particularly preferably 0.1 to 20 parts by mass. By setting the content of the component (B0) within the above preferred range, sufficient pattern formation is achieved and lithography properties such as CDU tend to be good. 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 good, which is preferable.

[0269] Regarding component (B1) The resist composition of this embodiment may include, as the component (B), an acid generator other than the component (B0) (hereafter referred to as “component (B1)”). There are no particular limitations on the component (B1), 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, and disulfone-based acid generators.

[0270] Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as "component (b-1)"), a compound represented by general formula (b-2) (hereinafter also referred to as "component (b-2)"), or a compound represented by general formula (b-3) (hereinafter also referred to as "component (b-3)").

[0271] [ka] [In the formula, R 101 , R 104 ~R 108 R is 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. 104 , R 105 may be bonded to each other to form a ring. 102 and R 103 each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. nb is 0 or 1. Y 101 is a single bond or a divalent linking group containing an oxygen atom. 101 ~V 103 Each of L is independently a single bond, an alkylene group, or a fluorinated alkylene group. 101 ~L 102 Each of L is independently a single bond or an oxygen atom. 103 ~L 105 each independently represents a single bond, -CO- or -SO 2 m is an integer of 1 or more, and M' m+ is an onium cation with a valence of m.

[0272] In the formula (b-1), R 101is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, it is preferably a phenyl group, a naphthyl group, or a group obtained by removing one or more hydrogen atoms from a polycycloalkane; a group obtained by removing one or more hydrogen atoms from camphor; a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) and (a2-r-3) to (a2-r-7); 2 -containing cyclic groups and the like are preferred (all of which may have substituents).

[0273] In the formula (b-1), Y 101 is preferably a single bond, a divalent linking group containing an ester bond, or a divalent linking group containing an ether bond.

[0274] In the formula (b-1), V 101 is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms.

[0275] In the formula (b-1), R 102 is preferably a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 5 carbon atoms.

[0276] In the formula (b-2), R 104 , R 105 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, and each of them is represented by R 101 However, R 104 , R 105 may be bonded to each other to form a ring. R 104 , R 105 is preferably a chain alkyl group which may have a substituent, and more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. In formula (b-2), V 102 , V 103is, independently of each other, a single bond, an alkylene group, or a fluorinated alkylene group, and each is V in formula (b-1). 101 Examples thereof are the same as those in 101 . In formula (b-2), L 101 and L 102 are each independently a single bond or an oxygen atom.

[0277] In formula (b-3), R 106 to R 108 are each independently a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof are the same as those of R 101 in formula (b-1). L 103 to L 105 are each independently a single bond, -CO- or -SO 2 -.

[0278] In the above formulas (b-1), (b-2) and (b-3), m is an integer of 1 or more, and M’ m+ is an m-valent onium cation, and preferably a sulfonium cation or an iodonium cation.

[0279] In the resist composition of this embodiment, the component (B1) may be used alone or in combination of two or more. When the resist composition contains the component (B1), the content of the component (B1) in the resist composition is preferably 50 parts by mass or less, more preferably 0.1 to 40 parts by mass, still more preferably 0.1 to 30 parts by mass, and particularly preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the component (A).

[0280] <Optional component> ≪Component (D)≫ The resist composition in this embodiment may further contain an acid diffusion control agent component (hereinafter also referred to as “component (D)”) in addition to the component (A) and the component (B). The component (D) acts as a quencher (acid diffusion control agent) that traps the acid generated by exposure in the resist composition. Examples of the component (D) include a nitrogen-containing organic compound (D1) (hereinafter referred to as “component (D1)” and a photodecomposable base (D2) (hereinafter referred to as “component (D2)”) which does not fall under the category of component (D1) and which decomposes upon exposure to light and loses its acid diffusion controllability. 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.

[0281] Regarding component (D1) The component (D1) is a base component, and is a nitrogen-containing organic compound component that acts as an acid diffusion controller in the resist composition.

[0282] The component (D1) is not particularly limited as long as it acts as an acid diffusion controller, and examples thereof include aliphatic amines and aromatic amines.

[0283] Of the aliphatic amines, secondary aliphatic amines and tertiary aliphatic amines are preferred. An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms. The aliphatic amine is ammonia NH 3 Examples of the amine include amines in which at least one hydrogen atom is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkyl alcohol amines), and cyclic amines. Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 5 to 10 carbon atoms are more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

[0284] 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 preferably has 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.

[0285] 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.

[0286] Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, aniline compounds, N-tert-butoxycarbonylpyrrolidine, and the like.

[0287] The component (D1) may be used alone or in combination of two or more types. Among the above, the component (D1) is preferably an aromatic amine, and more preferably an aniline compound, such as 2,6-diisopropylaniline, N,N-dimethylaniline, N,N-dibutylaniline, or N,N-dihexylaniline.

[0288] When the resist composition contains the component (D1), the component (D1) is typically used in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the component (A). When the amount of the component (D1) is at least the preferred lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained, while when the amount is no more than the upper limit, a balance with other components can be achieved, resulting in various good lithography properties.

[0289] Regarding component (D2) The component (D2) 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 (d2-1) (hereinafter referred to as "component (d2-1)") and a compound represented by the following general formula (d2-2) (hereinafter referred to as "component (d2-2)"): The components (d2-1) and (d2-2) do not act as quenchers in the exposed areas of the resist film because they decompose and lose their acid diffusion control ability (basicity) in the exposed areas of the resist film, but act as quenchers in the unexposed areas of the resist film.

[0290] [ka] [In the formula, Rd 1 , Rd 3 and Rd 4 each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. 1 is a single bond or a divalent linking group; m is an integer of 1 or more; M' m+ are each independently an onium cation having a valence of m.

[0291] In formula (d2-1), Rd 1 As the alkyl group, an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkyl group which may have a substituent is preferable.

[0292] In formula (d2-2), Rd 3 is preferably a fluorine atom-containing cyclic group, a chain alkyl group, or a chain alkenyl group.

[0293] In formula (d2-2), Rd 4 is preferably an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group which may have a substituent.

[0294] In formula (d2-2), Yd 1is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof.

[0295] In formulas (d2-1) to (d2-2), m is an integer of 1 or more, and M' m+ is an onium cation having a valence of m, and preferred examples thereof include a sulfonium cation and an iodonium cation.

[0296] The component (D2) may be any one of the above components (d2-1) and (d2-2), or a combination of two or more of them. When the resist composition contains the component (D2), the amount of the component (D2) in the resist composition is preferably 0.5 to 35 parts by mass, more preferably 1 to 25 parts by mass, even more preferably 2 to 20 parts by mass, and particularly preferably 3 to 15 parts by mass, relative to 100 parts by mass of the component (A). When the content of the component (D2) is at least the preferred lower limit, particularly good lithography properties and resist pattern shape are likely to be obtained, while when it is at most the upper limit, a balance with other components can be achieved and various lithography properties are excellent.

[0297] Manufacturing method of component (D2): The method for producing the component (d2-1) is not particularly limited, and the component can be produced by a known method. The method for producing the component (d2-2) is not particularly limited, and it can be produced, for example, in a manner similar to that described in US2012-0149916.

[0298] <(Z) component> In addition to the components (A) and (B), the resist composition of this embodiment may further contain a polyether compound (hereinafter, also referred to as "component (Z)"). The component (Z) is not particularly limited as long as it is a polyether compound, and examples of the component (Z) include a compound having a partial structure represented by the following general formula (z-1).

[0299] [ka] [In the formula, Rz 11 is an alkylene group which may have a substituent. nz is an integer of 1 or more.

[0300] In the above general formula (z-1), Rz 11 represents an alkylene group which may have a substituent. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably 1 to 15, more preferably 2 to 8, and even more preferably 2 to 4. The substituent is not particularly limited, but is preferably an alkyl group (preferably having 1 to 10 carbon atoms). In the above general formula (z-1), * represents a bond. The compound represented by general formula (z-1) has a mass average molecular weight (Mw) (based on polystyrene conversion by gel permeation chromatography (GPC)) of preferably 200 to 25,000, more preferably Mw 250 to 24,000, and even more preferably Mw 300 to 23,000.

[0301] The component (Z) is preferably a compound represented by the following general formula (z-1-1).

[0302] [ka] [In the formula, Rz 11 Rz is an alkylene group which may have a substituent. 12 and Rz 13 are each independently a hydrogen atom or an alkyl group. nz is an integer of 1 or more.

[0303] Rz in the above general formula (z-1-1) 11 The definition, specific examples and preferred embodiments of Rz in the above general formula (1) are as follows: 11 is the same as: In the above general formula (z-1-1), Rz 12 and Rz 13 Each of Rz independently represents a hydrogen atom or an alkyl group. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 15. 12 and Rz13 is preferably a hydrogen atom. The compound represented by general formula (z-1-1) has a mass average molecular weight (Mw) (based on polystyrene conversion by gel permeation chromatography (GPC)) of preferably 200 to 25,000, more preferably Mw 250 to 24,000, and even more preferably Mw 300 to 23,000.

[0304] In particular, the component (Z) is more preferably at least one selected from the group consisting of a compound represented by the following general formula (z-1-11), a compound represented by the following general formula (z-1-12), and a compound represented by the following general formula (z-1-13).

[0305] [ka]

[0306] [ka]

[0307] [ka]

[0308] The mass average molecular weight (Mw) of (Z) (based on polystyrene conversion by gel permeation chromatography (GPC)) is preferably 200 to 25,000, more preferably 250 to 24,000, and further preferably 300 to 23,000. When the mass average molecular weight (Mw) of (Z) is equal to or greater than the lower limit of the above-mentioned preferred range, a pattern having good wet etching resistance is easily formed. On the other hand, when the mass average molecular weight (Mw) of (Z) is equal to or less than the upper limit of the above-mentioned preferred range, the solubility of the resist film in a developer is easily improved, and a pattern having good resolution is easily formed.

[0309] The component (Z) contained in the resist composition of this embodiment may use either a single type, or a combination of two or more types. In the resist composition of this embodiment, the content of the component (Z) relative to 100 parts by mass of the component (A1) is preferably less than 50 parts by mass, more preferably no more than 40 parts by mass, even more preferably no more than 35 parts by mass, even more preferably no more than 30 parts by mass, and particularly preferably less than 20 parts by mass. There is no particular lower limit for the amount of the (Z) component, but it is preferably at least 0.1 part by mass, more preferably at least 0.2 part by mass, and even more preferably at least 0.5 part by mass, per 100 parts by mass of the (A1) component. When the content of the component (Z) is at most the upper limit of the above preferred range, a pattern with better resolution is more easily formed. When the content of the component (Z) is at least as large as the lower limit of the above preferred range, a pattern with better throughput during etching is more likely to be formed.

[0310] <Component (E): at least one compound selected from the group consisting of organic carboxylic acids, phosphorus oxoacids, and derivatives thereof> The resist composition of this embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxoacids and derivatives thereof (hereafter referred to as "component (E)") for the purposes of preventing deterioration of sensitivity and improving the resist pattern shape and stability over time after exposure. Suitable organic carboxylic acids include, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic 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. In the resist composition of this embodiment, the component (E) may use either a single type, or a combination of two or more types. When the resist composition contains the component (E), the amount of the component (E) is typically within a range from 0.01 to 5 parts by mass per 100 parts by mass of the component (A).

[0311] <(S) component: organic solvent component> The resist composition of this embodiment can be produced by dissolving the resist materials in an organic solvent component (hereafter referred to as “component (S)”). The component (S) can be any solvent that is capable of dissolving the individual components used to form a homogeneous solution, and any solvent can be appropriately selected from those known in the art as a solvent for chemically amplified resist compositions. Examples of the (S) component include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate; and compounds having an ether bond such as monoalkyl ethers, monoethyl ethers, monopropyl ethers, and monobutyl ethers of the above-mentioned polyhydric alcohols or compounds having an ester bond, or monophenyl ethers. derivatives of polyhydric alcohols (among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred); cyclic ethers such as dioxane, esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO). In the resist composition of this embodiment, the component (S) may be used either as a single type alone, or as a mixed solvent of two or more types. Among these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferable. A mixed solvent obtained by mixing PGMEA and a polar solvent is also preferred. The mixing ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, and is preferably within a range of 1:9 to 9:1, and more preferably 2:8 to 8:2. More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. When PGME is blended as the polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferred. 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 is preferably 20 mass % or more, more preferably in the range of 20 to 50 mass %.

[0312] The resist composition of the present embodiment may further contain, if desired, compatible additives such as an additional resin for improving the performance of the resist film, an ionic or nonionic fluorine-based and / or silicon-based surfactant, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, or a dye.

[0313] In the resist composition of this embodiment, after dissolving the resist material in the component (S), impurities and the like may be removed using a polyimide porous film, a polyamideimide porous film, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous film, a filter made of a polyamideimide porous film, or a filter made of a polyimide porous film and a polyamideimide porous film. Examples of the polyimide porous film and the polyamideimide porous film include those described in JP 2016-155121 A.

[0314] The resist composition of this embodiment contains a resin component (A1) that has a structural unit (a10) represented by general formula (a10-1), and a compound (B0) represented by general formula (b0-1). In the resist composition of this embodiment, the proportion of the structural unit (a10) in the component (A1) is relatively low, greater than 5 mol % and less than 45 mol %, relative to the total (100 mol %) of all structural units constituting the component (A1), and this makes it possible to increase the Ohnishi parameter of the component (A1). Here, the Ohnishi parameter is expressed by the following formula. Onishi parameter = N total / (N carbon -N oxygen ) [In the formula, N total is the total number of atoms in the molecule, and N carbon is the number of carbon atoms in the molecule, and N oxygen is the number of oxygen atoms in the molecule. The Onishi parameter is proportional to the etching rate, so a larger Onishi parameter means a better throughput during etching. On the other hand, the (B0) component has a substituent R at the end of the sulfonyloxy group bonded to N. b1 As a result, the diffusion length of the acid generated by the component (B0) upon exposure is short, making it difficult for the acid to diffuse into unexposed areas. It is presumed that due to the combination of the above effects, the resist composition of this embodiment enables the formation of a resist pattern that has a good throughput during etching and a good CDU.

[0315] (Method of forming a resist pattern) A second aspect of the present invention is a method for forming a resist pattern, comprising: a step (i) of forming a resist film on a support using the resist composition related to the first aspect described above; a step (ii) of exposing the resist film to light; and a step (iii) of developing the exposed resist film to form a resist pattern. One embodiment of the resist pattern forming method is, for example, a resist pattern forming method carried out as follows.

[0316] Process (i): 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 160°C for 40 to 200 seconds, preferably 60 to 150 seconds, to form a resist film.

[0317] Step (ii): Next, the resist film is selectively exposed, for example, by exposure through a mask (mask pattern) having a predetermined pattern formed thereon, using an exposure device such as a KrF exposure device, and then baked (post-exposure bake (PEB)) at a temperature of, for example, 80 to 150° C. for 40 to 150 seconds, preferably 60 to 120 seconds.

[0318] Step (iii): 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.

[0319] After the development or rinsing process, drying is performed. In some cases, a baking process (post-baking) may be performed after the development process. The baking process (post-baking) is performed, for example, at a temperature of 80° C. or higher, preferably 90 to 120° C., for 10 to 120 seconds, preferably 300 to 90 seconds. In this manner, a resist pattern can be formed.

[0320] 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. The support may be a substrate as described above on which an inorganic and / or organic film is provided. Examples of inorganic films include inorganic anti-reflective coatings (inorganic BARC). Examples of organic films include organic anti-reflective coatings (organic BARC) and organic films such as lower organic films in a multi-layer resist method. Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the lower organic film is patterned using the resist pattern formed on the upper resist film as a mask, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, the required thickness can be secured by the lower organic film, so that the resist film can be made thin, and a fine pattern with a high aspect ratio can be formed. Multilayer resist methods are basically divided into a two-layer structure consisting of an upper resist film and a lower organic film (two-layer resist method), and a three-layer structure consisting of three or more layers with one or more intermediate layers (such as a thin metal film) provided between the upper resist film and the lower organic film (three-layer resist method).

[0321] The method for forming a resist pattern according to the embodiment is useful when forming a thick resist film. Even if the thickness of the resist film formed in the step (i) is, for example, 1 to 20 μm, preferably 3 μm or more, more preferably 3.5 μm or more, and even more preferably 5 μm or more, a resist pattern can be stably formed in a good shape.

[0322] The wavelength used for exposure is not particularly limited, and may be ultraviolet light such as g-line or i-line, ArF excimer laser light, KrF excimer laser light, F 2This can be carried out using radiation such as excimer laser light, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-rays, and soft X-rays. The resist composition according to the first aspect described above is highly useful for ultraviolet rays such as g-line and i-line, KrF excimer laser light, ArF excimer laser light, EB or EUV, is more useful for ultraviolet rays such as g-line and i-line, KrF excimer laser light, and ArF excimer laser light, and is particularly useful for ultraviolet rays such as g-line and i-line, and KrF excimer laser light. The method of forming a resist pattern according to the second aspect is a method particularly suitable for irradiating the resist film with ultraviolet rays such as g-line and i-line, or KrF excimer laser light in the step (ii).

[0323] The exposure method for the resist film may be a normal exposure method (dry exposure) performed in air or an inert gas such as nitrogen, or may be liquid immersion lithography. Immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure tool is filled with a solvent (immersion medium) that has a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state. The immersion medium is preferably a solvent having a refractive index 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 from the viewpoints of cost, safety, environmental issues, versatility, and the like.

[0324] 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 in their structure. Ester-based solvents are organic solvents that contain CC(=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.

[0325] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), etc. Among these, methyl amyl ketone (2-heptanone) is preferred as the ketone solvent.

[0326] Examples of ester-based solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol Licorice monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate Examples of the alkyl esters include butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, and propyl 3-methoxypropionate.Among these, butyl acetate is preferred as the ester solvent.

[0327] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0328] The organic developer may contain known additives as necessary. Examples of such additives include surfactants. The surfactant is not particularly limited, but may be, for example, an ionic or nonionic fluorine-based and / or silicon-based surfactant. The surfactant is preferably a nonionic surfactant, more preferably a nonionic fluorine-based surfactant or a nonionic silicon-based surfactant. When a surfactant is added, the amount added is usually from 0.001 to 5 mass %, preferably from 0.005 to 2 mass %, and more preferably from 0.01 to 0.5 mass %, based on the total amount of the organic developer.

[0329] 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).

[0330] The organic solvent contained in the rinse solution used in the rinse treatment after the development treatment in the solvent development process can be selected appropriately from the organic solvents listed as the organic solvents used in the organic developer, and can be used if it is difficult to dissolve the resist pattern.Usually, at least one solvent selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, and an ether solvent is used.Among these, at least one solvent selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, and an amide solvent is preferred, at least one solvent selected from an alcohol solvent and an ester solvent is more preferred, and an alcohol solvent is particularly preferred. The alcohol-based solvent used in the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be any of linear, branched, and cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferred, and 1-hexanol and 2-hexanol are more preferred. These organic solvents may be used alone or in combination of two or more. They may also be used in combination with other organic solvents or water. However, in consideration of development characteristics, the blending amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and particularly preferably 3% by mass or less, based on the total amount of the rinse solution. The rinse solution may contain known additives as necessary. Examples of such additives include surfactants. The surfactants include those similar to those described above, and nonionic surfactants are preferred, and nonionic fluorine-based surfactants or nonionic silicon-based surfactants are more preferred. When a surfactant is added, the amount of the surfactant added is usually 0.001 to 5 mass %, preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %, based on the total amount of the rinse liquid.

[0331] 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).

[0332] In the method of forming a resist pattern of the present embodiment described above, the resist composition related to the first aspect described above is used, and therefore it is presumed that a resist pattern with excellent throughput and CDU during etching can be obtained. EXAMPLES

[0333] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0334] <Production of polymer compounds> The polymer compounds (A-1) to (A-7), (A-11), and (A-12) used in this example were each obtained by radical polymerization using monomers that derive the structural units constituting each polymer compound in a predetermined molar ratio. The weight average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) of each of the obtained polymer compounds were determined by GPC measurement (converted into standard polystyrene). The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) of each obtained polymer compound was measured by carbon-13 nuclear magnetic resonance spectroscopy (600 MHz, 13 The carbonyl group was determined by C-NMR.

[0335] [ka]

[0336] Polymer compound (A-1): Weight average molecular weight (Mw) 10000, molecular weight dispersity (Mw / Mn) 1.24, l / m / n=25 / 50 / 25. Polymer compound (A-2): Weight average molecular weight (Mw) 10000, molecular weight dispersity (Mw / Mn) 1.20, l / m / n=10 / 65 / 25. Polymer compound (A-3): Weight average molecular weight (Mw) 10000, molecular weight dispersity (Mw / Mn) 1.22, l / m / n=40 / 35 / 25. Polymer compound (A-11): Weight average molecular weight (Mw) 10000, molecular weight dispersity (Mw / Mn) 1.22, l / m / n=5 / 70 / 25. Polymer compound (A-12): Weight average molecular weight (Mw) 10000, molecular weight dispersity (Mw / Mn) 1.22, l / m / n=45 / 30 / 25.

[0337] [ka]

[0338] Polymer compound (A-4): Weight average molecular weight (Mw) 10000, molecular weight dispersity (Mw / Mn) 1.35, l / m / n=25 / 50 / 25. Polymer compound (A-5): Weight average molecular weight (Mw) 10000, molecular weight dispersity (Mw / Mn) 1.21, l / m / n=25 / 50 / 25.

[0339] [ka]

[0340] Polymer compound (A-6): Weight average molecular weight (Mw) 10000, molecular weight dispersity (Mw / Mn) 1.35, l / m / n=25 / 50 / 25. Polymer compound (A-7): Weight average molecular weight (Mw) 10000, molecular weight dispersity (Mw / Mn) 1.46, l / m / n=25 / 15 / 60.

[0341] <Preparation of resist composition> (Examples 1 to 14, Comparative Examples 1 to 4) The components shown in Tables 1 to 3 were mixed and dissolved to prepare resist compositions of each example (solid content: 35%).

[0342] [Table 1]

[0343] [Table 2]

[0344] [Table 3]

[0345] In Tables 1 to 3, the abbreviations have the following meanings: The numbers in brackets [ ] are the blend amounts (parts by mass). (A)-1 to (A)-7, (A)-11, (A)-12: the above-mentioned polymer compounds (A-1) to (A-7), (A-11), (A-12). (B)-1 to (B)-4, (B)-11: Acid generators composed of compounds represented by the following chemical formulas (B-1) to (B-4), (B-11), respectively.

[0346] [ka]

[0347] (D)-1: A nitrogen-containing organic compound represented by the following chemical formula (D-1). (Z)-1: Polypropylene glycol represented by the following chemical formula (Z-1) and having a mass average molecular weight (Mw) of 1,000.

[0348] [ka]

[0349] [ka]

[0350] (S)-1: a mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether = 50 / 50 (mass ratio).

[0351] <Method of forming a resist pattern> Process (i): Each resist composition of the example was applied using a spinner onto a silicon substrate that had been treated with hexamethyldisilazane (HMDS), and the substrate was pre-baked (PAB) on a hot plate at 130°C for 90 seconds, and then dried to form a resist film with a thickness of 9 μm.

[0352] Step (ii): Next, the resist film was selectively irradiated with a high-pressure mercury lamp (365 nm) through a mask pattern using an i-line stepper (reduction projection exposure device: NSR-2205i14E (Nikon Corporation; NA (numerical aperture) = 0.54, σ = 0.59)). This was followed by a post-exposure bake (PEB) treatment at 110° C. for 90 seconds.

[0353] Step (iii): Next, alkaline development was carried out using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (product name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a developer at 23° C. for 60 seconds. Then, a baking process (post-baking) was performed at 100° C. for 60 seconds. As a result, an isolated line pattern (hereinafter referred to as an "IS pattern") with a space width of 4 μm and a pitch of 24 μm was formed.

[0354] [Evaluation of Pattern Dimension Uniformity (CDU)] The 400 holes in the CH pattern were observed from above the CH pattern using a length measuring SEM (scanning electron microscope, accelerating voltage 500V, product name: CG5000, manufactured by Hitachi High-Technologies Corporation), and the hole diameter (nm) of each hole was measured. Then, the triple value (3σ) of the standard deviation (σ) calculated from the measurement results was calculated. The results are shown in Tables 4 to 6 as "CDU (nm)". The smaller the value of 3σ thus determined, the higher the uniformity of the dimensions (CD) of the multiple holes formed in the resist film.

[0355] <Dry etching resistance evaluation> The resist film formed by the same operation as in step (i) of the above-mentioned <Method of forming a resist pattern> was subjected to dry etching under the following conditions using an etching apparatus manufactured by Tokyo Ohka Kogyo Co., Ltd. conditions: Etching gas type and flow rate: O 2 / CF 4 =87.5 / 12.5 mixed gas Pressure: 40Pa Output: 600w Time; 120 seconds The resist film thickness was measured before and after etching, and the etching rate was calculated from the reduced film thickness. [Reduced thickness (μm)] = [Thickness before etching (μm)] - [Thickness after etching (μm)] [Etching rate (μm / sec)] = [Reduced film thickness (μm)] / [Etching time (120 sec)] The etching rate of the resist film formed using the resist composition of Comparative Example 2 was taken as 100%, and the etching rates of the other examples were expressed as relative values. The results are shown in Tables 4 to 6 as "ER [%]".

[0356] [Table 4]

[0357] [Table 5]

[0358] [Table 6]

[0359] From the results shown in Tables 4 to 6, it was confirmed that the resist patterns formed using the resist compositions of Examples 1 to 14 had good CDU and also good throughput during etching.

Claims

1. A resist composition which generates an acid upon exposure and changes its solubility in a developer by the action of the acid, a resin component (A1) whose solubility in a developer changes under the action of an acid; and an acid generator component (B) that generates an acid upon exposure to light, The resin component (A1) has a structural unit (a10) represented by the following general formula (a10-1), a structural unit (a1) represented by the following general formula (a1-1-1), and a structural unit (a4) represented by any one of the following general formulas (a4-1) to (a4-8), or a structural unit (a11) represented by the following general formula (a11-u1-1) or (a11-u1-4), The acid generator component (B) contains a compound (B0) represented by the following general formula (b0-1): the proportion of the structural unit (a10) in the resin component (A1) is more than 5 mol % and less than 45 mol % with respect to the total (100 mol %) of all structural units constituting the resin component (A1); A resist composition having a solid content concentration of 20 to 50 mass %. 【Chemistry 1】 [In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. ｘ１ is a single bond, -C(=O)-O- or -O-C(=O)-. ｘ１ is a group in which (n ax1 +1) hydrogen atoms have been removed from benzene or naphthalene, and which has as a substituent an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogen atom, or a halogenated alkyl group having 1 to 5 carbon atoms. ａｘ１ is an integer of 1 or more. 【Chemistry 2】 [In the above general formula (a1-1-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 1 represents a divalent hydrocarbon group which may have an ether bond. n a1 represents an integer of 0 to 2. Ra 1 ″ is an acid dissociable group represented by general formula (a1-r2-1) or (a1-r2-4). In the general formula (a1-r2-1), Ra' 10 is an alkyl group having 1 to 5 carbon atoms. Ra' 11 is a group that forms a monocyclic aliphatic cyclic group together with the carbon atom to which Ra' 10 is bonded. In the general formula (a1-r2-4), a' 12 and Ra' 13 each independently are an alkyl group having 1 to 5 carbon atoms. Ra' 14 is a linear alkyl group having 1 to 5 carbon atoms or a branched alkyl group having 3 to 5 carbon atoms.] 【Chemistry 3】 [In the formula, R α is a hydrogen atom, a methyl group, or a trifluoromethyl group.] 【Chemistry 4】 [In the formula, R α is a hydrogen atom, a methyl group, or a trifluoromethyl group. R β is an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an acyloxy group having 1 to 5 carbon atoms. n ax2 is an integer from 0 to 3. When n ax2 is 2 or more, a plurality of R β may be bonded to each other to form a ring structure. n 21 and n 22 are each independently 0 or 1. n 23 is 1 or 2.] 【Chemistry 5】 [In the formula, R ｂ１ is a group in which one or more hydrogen atoms have been removed from a monocycloalkane, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, or an —SO 2 —-containing cyclic group represented by any of the general formulae (a5-r-1) to (a5-r-4), The R ｂ１ When the hydrocarbon group as the formula (I) contains one or more methylene groups, at least a part of the methylene groups is -O-, -S-, -CO-, -CO-O-, -SO-, -SO ２ -, -CR ｂ４ R ｂ５ - and -NR ｂ６ -, The R ｂ１ When the hydrocarbon group represented by the formula (I) contains a hydrocarbon ring, at least one of the carbon atoms constituting the hydrocarbon ring may be substituted with a heteroatom selected from the group consisting of N, O, P, S, and Se, or an atomic group containing such a heteroatom, The R ｂ４ and the R ｂ５ are each independently a hydrogen atom or a halogen atom, ｂ４ and the R ｂ５ At least one of R is a halogen atom. ｂ６ is a hydrogen atom or a hydrocarbon group having from 1 to 6 carbon atoms, (R a１ )n, (R a２ ) m, n and m are integers from 0 to 3, R ａ１ and R ａ２ each independently represents a hydrogen atom or an organic group, Q １ , and Q ２ each independently represents a fluorine atom or a perfluoroalkyl group having from 1 to 6 carbon atoms, L is an ester bond. 【Chemistry 6】 [In the formula, 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 an -SO 2 - containing cyclic group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n' is an integer of 0 to 2.]

2. The resist composition according to claim 1 , further comprising a polyether compound (Z).

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

4. 4. The method for forming a resist pattern according to claim 3, wherein the resist film has a thickness of 5 μm or more.

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