Resist composition and resist pattern forming method

Abstract

To provide a resist composition which achieves higher sensitivity and can form a resist pattern with good roughness reduction, and a resist pattern forming method using the resist composition.SOLUTION: A resist composition generates an acid upon exposure, changes its solubility in a developer by the action of an acid, and contains: a base component (A) which changes its solubility in a developer by the action of an acid; an acid generator component (B) which generates an acid upon exposure; a first acid diffusion control component (D1); and a second acid diffusion control component (D2). The acid generator component (B) contains a compound represented by a general formula (b1-1) described in the specification, the first acid diffusion control component (D1) contains a compound represented by a general formula (d1-1) or (d1-2) described in the specification, and the second acid diffusion control component (D2) contains a compound represented by a general formula (d2-1) described in the specification.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] In lithography technology, for example, a resist film made of a resist material is formed on a substrate, selective exposure is performed on the resist film, and a development process is performed to form a resist pattern having a predetermined shape on the resist film. A resist material whose property changes such that the exposed portion of the resist film dissolves in the developer is called a positive type, and a resist material whose property changes such that the exposed portion does not dissolve in the developer is called a negative type.

[0003] In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to the advancement of lithography technology. As a miniaturization technique, generally, the wavelength of the exposure light source is shortened (the energy is increased). Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using KrF excimer laser and ArF excimer laser has been started. In addition, EUV (extreme ultraviolet ray), EB (electron beam), X-ray, etc., which have a shorter wavelength (higher energy) than these excimer lasers, are also being studied.

[0004] For resist materials, lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions are required. As a resist material that satisfies such requirements, conventionally, a chemically amplified resist composition containing an acid generator component that generates an acid upon exposure and a base material component whose solubility in a developer changes by the action of the acid has been used.

[0005] However, there is a trade-off relationship between sensitivity and lithography characteristics such as roughness reduction. The base resin used as a substrate component in a chemically amplified resist composition generally has a plurality of constituent units in order to improve lithography characteristics and the like. For example, in Patent Document 1, a resist composition and a resist pattern forming method capable of achieving high sensitivity and forming a resist pattern with good roughness reduction have been studied. And in Patent Document 1, a resist composition using two types of photo-disintegrating bases having a specific structure is described.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] As lithography technology further progresses and the miniaturization of resist patterns advances more and more, the resist composition is required to have further higher sensitivity and a technology capable of forming a fine pattern in a good shape. However, in the conventional technology, the roughness reduction in resist pattern formation is not always sufficient, and a higher level of roughness reduction is required.

[0008] The present invention has been made in view of the above circumstances, and an object thereof is to provide a resist composition capable of achieving high sensitivity and forming a resist pattern with good roughness reduction, and a resist pattern forming method using the resist composition.

Means for Solving the Problems

[0009] As a result of intensive studies to solve the above problems, the present inventors have found that a resist composition capable of forming a resist pattern with reduced roughness can be obtained by the following configuration, and a resist pattern forming method using the resist composition, thus completing the present invention.

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

[0011] The resist composition according to an embodiment of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes by the action of the acid, including a base material component (A) whose solubility in a developer changes by the action of an acid, an acid generator component (B) that generates an acid upon exposure, a first acid diffusion control component (D1), and a second acid diffusion control component (D2), wherein the acid generator component (B) includes a compound represented by the following general formula (b1-1), the first acid diffusion control component (D1) includes a compound represented by the following general formula (d1-1) or (d1-2), and the second acid diffusion control component (D2) includes a compound represented by the following general formula (d2-1).

[0012] [Chemical formula]

[0013] [In general formula (b1-1), R1 to R3 are each independently an alkyl group or a cycloalkyl group that is at least partially fluorinated, or at least two of R1 to R3 may be bonded to form a fluorinated alkylene group. m is an integer of 1 or more, and M m+ is an m-valent organic cation. ]

[0014] [Chemical formula]

[0015] 〔In general formulas (d1-1) and (d1-2), Rd 11 and Rd 12 are each a linear or cyclic aliphatic hydrocarbon group which may have a substituent. X1 and X2 are each independently a heteroatom or a methylene group which may have a substituent. n1 and n2 are each independently an integer from 1 to 10. m is each independently an integer of 1 or more, and M m+ are each independently an m-valent organic cation.〕

[0016]

Chemical formula

[0017] 〔In formula (d2-1), Rd2 is a cyclic aliphatic hydrocarbon group having an oxygen atom (=O). m is an integer of 1 or more, and M m+ is an m-valent organic cation.〕

[0018] A resist pattern forming method according to another embodiment of the present invention includes a step of forming a resist film on a support using the resist composition according to the embodiment of the present invention, a step of exposing the resist film, and a step of developing the resist film to form a resist pattern.

Advantages of the Invention

[0019] The present invention can provide a resist composition and a resist pattern forming method using the resist composition, which can achieve high sensitivity and form a resist pattern with good roughness reduction.

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments for carrying out the present invention will be described in detail. Note that the present invention is not limited to the embodiments described below.

[0021] In this specification and the claims of this patent, "aliphatic" is a relative concept with respect to aromatic, and is defined to mean a group, compound, etc. that does not have aromaticity. Unless otherwise specified, the "alkyl group" shall include linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group. Unless otherwise specified, the "alkylene group" shall include linear, branched, and cyclic divalent saturated hydrocarbon groups. The "halogenated alkyl group" is a group in which some or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The "fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which some or all of the hydrogen atoms of the alkyl group or alkylene group are substituted with fluorine atoms. The "constitutional unit" means a monomer unit (monomeric unit) that constitutes a high molecular compound (resin, polymer, copolymer). When it is described as "optionally having a substituent", it includes both the case of substituting a hydrogen atom (-H) with a monovalent group and the case of substituting a methylene group (-CH2-) with a divalent group. "Exposure" is a concept that includes irradiation with radiation in general.

[0022] The "acid-decomposable group" is a group having acid-decomposability in which at least some of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid. Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group. Examples of the polar group include a carboxy group, a hydroxy group, an amino group, a sulfo group (-SO3H), etc. More specifically, examples of the acid-decomposable group include a group in which the polar group is protected by an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

[0023] The "acid-dissociable group" refers to both (i) a group having acid-dissociability such that the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved by the action of an acid, or (ii) a group such that after some bonds are cleaved by the action of an acid and then a decarboxylation reaction occurs, the bond between the acid-dissociable group and the atom adjacent to the acid-dissociable group can be cleaved. The acid-dissociable group constituting the acid-decomposable group needs to be a group with lower polarity than the polar group generated by the dissociation of the acid-dissociable group. Thereby, 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 and the polarity increases. As a result, the polarity of the entire component (A1) described later increases. By increasing the polarity, relatively, the solubility in the developer changes. When the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility decreases.

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

[0025] The "structural unit derived from an acrylate ester" means a structural unit formed by cleavage of the ethylenic double bond of an acrylate ester. An "acrylate ester" is a compound in which the hydrogen atom at the carboxy group terminal of acrylic acid (CH2=CH-COOH) is substituted with an organic group. The hydrogen atom bonded to the carbon atom at the α-position of the acrylate ester may be substituted with a substituent. The substituent (R α0 ) that substitutes the hydrogen atom bonded to the carbon atom at the α-position is an atom or group other than a hydrogen atom, and examples thereof include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and the like. Further, it is assumed to include itaconic acid diesters in which the substituent (R α0 ) is substituted with a substituent containing an ester bond, and α-hydroxyacrylate esters in which the substituent (R α0 ) is substituted with a hydroxyalkyl group or a group obtained by modifying the hydroxyl group thereof. Note that, unless otherwise specified, the carbon atom at the α-position of the acrylate ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded. Hereinafter, the acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylate ester. Further, the acrylate ester and the α-substituted acrylate ester may be collectively referred to as “(α-substituted) acrylate ester”.

[0026] The alkyl group as the substituent at the α-position is preferably a linear or branched alkyl group, and specifically, an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like can be mentioned. Further, the halogenated alkyl group as the substituent at the α-position specifically includes a group obtained by substituting part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α-position” with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is particularly preferable. Further, the hydroxyalkyl group as the substituent at the α-position specifically includes a group obtained by substituting part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α-position” with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

[0027] In the present disclosure, a numerical range represented using "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value. Furthermore, in the present disclosure, the amount of each component in the composition means the total amount of the corresponding plurality of substances present in the composition when there are a plurality of substances corresponding to each component in the composition, unless otherwise specified. In addition, the chemical structural formulas in the present disclosure may be described as simplified structural formulas omitting hydrogen atoms. In this specification and the claims of the present patent, depending on the structure represented by the chemical formula, there may be asymmetric carbons and enantiomers or diastereomers may exist. In that case, those isomers are represented by one chemical formula. Those isomers may be used alone or as a mixture. In the present disclosure, "mass %" and "weight %" are synonymous, and "parts by mass" and "parts by weight" are synonymous.

[0028] 〔Resist Composition〕 The resist composition according to an embodiment of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes by the action of the acid, a base material component (A) (hereinafter also referred to as "(A) component") whose solubility in a developer changes by the action of an acid, an acid generator component (B) (hereinafter also referred to as "(B) component") that generates an acid upon exposure, a first acid diffusion control component (D1) (hereinafter also referred to as "(D1) component"), and a second acid diffusion control component (D2) (hereinafter also referred to as "(D2) component"), wherein the acid generator component (B) includes a compound represented by the following general formula (b1-1), and the first acid diffusion control component (D1) includes a compound represented by the following general formula (d1-1) or (d1-2), The second acid diffusion control component (D2) includes a compound represented by the following general formula (d2-1).

[0029]

Chemical Formula

[0030] In general formula (b1-1), R1 to R3 are each independently an alkyl group or a cycloalkyl group that is at least partially fluorinated, or at least two of R1 to R3 may be bonded to form a fluorinated alkylene group. m is an integer of 1 or more, and M m+ is an m-valent organic cation.

[0031]

Chemical formula

[0032] In general formulas (d1-1) and (d1-2), Rd 11 and Rd 12 are a linear or cyclic aliphatic hydrocarbon group that may have a substituent. X1 and X2 are each independently a heteroatom or a methylene group that may have a substituent. n1 and n2 are each independently an integer from 1 to 10. m is each independently an integer of 1 or more, and M m+ are each independently an m-valent organic cation.

[0033]

Chemical formula

[0034] In formula (d2-1), Rd2 is a cyclic aliphatic hydrocarbon group having an oxygen atom (=O). m is an integer of 1 or more, and M m+ is an m-valent organic cation.

[0035] When a resist film is formed using the resist composition according to an embodiment of the present invention and selective exposure is performed on the resist film, acid is generated in the exposed portion of the resist film, and due to the action of the acid, the solubility of the component (A) in the developer changes, while in the unexposed portion of the resist film, the solubility of the component (A) in the developer does not change. Therefore, a difference in solubility in the developer occurs between the exposed portion and the unexposed portion of the resist film. Therefore, when the resist film is developed, when 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 when the resist composition is a negative type, the unexposed portion of the resist film is dissolved and removed to form a negative type resist pattern.

[0036] In this specification, a resist composition in which the exposed portion of the resist film is dissolved and removed to form a positive type resist pattern is referred to as a positive type resist composition, and a resist composition in which the unexposed portion of the resist film is dissolved and removed to form a negative type resist pattern is referred to as a negative type resist composition. The resist composition according to an embodiment of the present invention may be a positive type resist composition or a negative type resist composition. Further, the resist composition according to an embodiment of the present invention may be for an alkali development process using an alkali developer for the development treatment during resist pattern formation, or may be for a solvent development process using a developer containing an organic solvent (organic-based developer) for the development treatment.

[0037] The resist composition according to an embodiment of the present invention contains an acid generator component (B) that generates acid upon exposure, and the compound represented by the general formula (b1-1) having a specific structure, and since the first acid diffusion control component (D1) and the second acid diffusion control component (D2) each contain a compound having a specific structure, it is effective in improving the reducibility of the roughness of the resist film when used for the formation of the resist film. Further, in the alkali development process, the sensitivity of the resist film to the alkali developer increases during development. Compounds having a specific structure contained in the (B) component exhibit a high acid strength. Due to the synergistic effect achieved by using the (D1) component and the (D2) component containing the compound with the specific structure, the acid diffusion control ability is improved, so that the reaction contrast at the interface between the exposed portion and the unexposed portion can be further enhanced. Therefore, according to the resist composition according to the embodiment of the present invention, it is presumed that a resist pattern with high sensitivity and good roughness reduction property can be formed.

[0038] ≪Component (A)≫ In the resist composition of the present embodiment, the (A) component is a base material component whose solubility in a developer changes by the action of an acid. The (A) component preferably contains a resin component (A1) (hereinafter also referred to as the “(A1) component”) whose solubility in a developer changes by the action of an acid. The (A) component may be one whose solubility in a developer increases by the action of an acid, or may be one whose solubility in a developer decreases by the action of an acid. By using the (A1) component, the polarity of the base material component (A) changes before and after exposure, so that a good development contrast can be obtained not only in the alkali development process but also in the solvent development process. As the (A) component, at least the (A1) component is used, and other high molecular compounds and / or low molecular compounds may be used in combination with the (A1) component.

[0039] When applying an alkali development process, the base material component (A) containing the (A1) component is hardly soluble in an alkali developer before exposure. When an acid is generated from the (B) component by exposure, the polarity of the base material component (A) increases by the action of the acid, and the solubility in the alkali developer increases. Therefore, in the formation of a resist pattern, when the resist composition is selectively exposed to a resist film obtained by coating on a support, the exposed portion of the resist film changes from hardly soluble to soluble in an alkali developer, while the unexposed portion of the resist film remains alkali-insoluble and does not change. Therefore, a positive resist pattern is formed by alkali development.

[0040] On the one hand, when applying a solvent development process, the substrate component (A) containing the (A1) component has high solubility in an organic developer before exposure. When an acid is generated from the (B) component by exposure, the polarity of the substrate component (A) increases due to the action of the acid, and the solubility in the organic developer decreases. Therefore, in the formation of a resist pattern, when selectively exposing a resist film obtained by coating the resist composition on a support, the exposed portion of the resist film changes from being soluble to being hardly soluble in the organic developer, while the unexposed portion of the resist film remains soluble and does not change. Therefore, by developing with an organic developer, contrast can be created between the exposed portion and the unexposed portion, and a negative-type resist pattern is formed.

[0041] The substrate component (A) preferably contains a polymer compound (A1) having a structural unit (a1) represented by the following general formula (a-1). As the (A1) component, it is preferable to use a polymer compound having a structural unit (a1) represented by the general formula (a-1). In addition to the structural unit (a1), it is more preferable to use a polymer compound having a structural unit (a2) containing a lactone-containing cyclic group, a -SO2-containing cyclic group, or a carbonate-containing cyclic group.

[0042] In the resist composition according to an embodiment of the present invention, the (A1) component may be used alone or in combination of two or more.

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

[0044]

Chemical formula

[0045] 〔In the general formula (a-1), R 01 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 01 is a divalent hydrocarbon group that may have an ether bond. n a01is an integer from 0 to 2. Ra 01 is an acid dissociable group. ]]

[0046] In general formula (a-1), R 01 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. R 01 The alkyl group having 1 to 5 carbon atoms represented by is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, a methyl group, an ethyl group, a propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, a pentyl group, an iso-pentyl group, a neopentyl group, etc. can be mentioned. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable. R 01 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. From the viewpoint of easy availability in industry, a hydrogen atom or a methyl group is most preferable.

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

[0048] Va 01 The aliphatic hydrocarbon group as the divalent hydrocarbon group in may be saturated or unsaturated, and is usually preferably saturated. More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0049] The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, examples include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, and other alkylalkylene groups. The alkyl group in the alkylalkylene group preferably is a linear alkyl group having 1 to 5 carbon atoms.

[0050] Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms 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, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group are the same as those of the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group described above. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms. The alicyclic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically includes cyclopentane, cyclohexane, etc. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from polycycloalkane is preferable, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically includes adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc.

[0051] Va 01 The aromatic hydrocarbon group as the divalent hydrocarbon group in 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 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring of the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which a part of the carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group in which one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0052] n a01 is an integer from 0 to 2, with 0 being preferred.

[0053] Ra 01 is an acid-dissociable group. In the constitutional unit (a1), Ra 01 Examples of the acid-dissociable group represented by Ra include those that have been proposed as the acid-dissociable group of the base resin for chemically amplified resists. Specific examples of those proposed as the acid-dissociable group of the base resin for chemically amplified resist compositions include "acetal-type acid-dissociable groups", "tertiary alkyl ester-type acid-dissociable groups", and "tertiary alkyloxycarbonyl acid-dissociable groups".

[0054] Acetal-type acid-dissociable group: Examples of the acid-dissociable group that protects the carboxy group or the hydroxy group among the polar groups include, for example, the acid-dissociable group represented by the following formula (a1-r-1) (hereinafter sometimes referred to as "acetal-type acid-dissociable group").

[0055] [Chemical formula]

[0056] [In formula (a1-r-1), Ra' 1 , Ra' 2 is a hydrogen atom or an alkyl group. Ra' 3 is a hydrocarbon group, and Ra' 3 may combine with either Ra' 1 , Ra' 2 to form a ring.]

[0057] In formula (a1-r-1), it is preferable that at least one of Ra' 1 and Ra' 2 is a hydrogen atom, and it is more preferable that both are hydrogen atoms. Ra' 1 or Ra' 2When it is an alkyl group, examples of the alkyl group include the same ones as the alkyl groups listed as substituents that may be bonded to the carbon atom at the α-position in the description of the above α-substituted acrylic acid ester, and an alkyl group having 1 to 5 carbon atoms is preferred. Specifically, a linear or branched alkyl group is preferably mentioned. 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, etc. are mentioned, a methyl group or an ethyl group is more preferred, and a methyl group is particularly preferred.

[0058] In the formula (a1-r-1), Ra’ 3 As the hydrocarbon group of, an aliphatic hydrocarbon group is preferred, and it may be a polycyclic group or a monocyclic group, and a monocyclic group is preferred.

[0059] As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from monocycloalkane is preferred. As the monocycloalkane, those having 3 to 6 carbon atoms are preferred, and specifically, cyclopentane, cyclohexane, etc. are mentioned. As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from polycycloalkane is preferred, and as the polycycloalkane, those having 7 to 12 carbon atoms are preferred, and specifically, adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc. are mentioned.

[0060] Ra’ 3 The alicyclic hydrocarbon group in may have a substituent. Examples of this substituent include, for example, -R P1 , -R P2 -O-R P1 , -R P2 -CO-R P1 , -R P2 -CO-O-R 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 "). Examples thereof include etc. Here, R P1 is a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Also, R P2 is a single bond, a divalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, a part or all of the hydrogen atoms of the linear saturated hydrocarbon group, aliphatic cyclic saturated hydrocarbon group, and aromatic hydrocarbon group of R P1 and R P2 may be substituted with fluorine atoms. The above alicyclic hydrocarbon group may have one or more of the above substituents alone, or may have one or more of a plurality of types of the above substituents.

[0061] Examples of the monovalent linear 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, a decyl group, etc. 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, a cyclododecyl group, etc. Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include groups obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene, etc.

[0062] Ra' 3 is Ra' 1 , Ra' 2When combined with any of them to form a ring, the cyclic group is preferably a 4- to 7-membered ring, more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group, a tetrahydrofuranyl group, and the like.

[0063] Tertiary alkyl ester type acid dissociable group: Among the above polar groups, examples of the acid dissociable group for protecting a carboxy group include an acid dissociable group represented by the following general formula (a1-r-2). Among the acid dissociable groups represented by the following formula (a1-r-2), Ra’ 4 ~Ra’ 6 which are each an alkyl group, may be referred to as “tertiary alkyl ester type acid dissociable group” for convenience.

[0064]

Chemical formula

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

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

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

[0068] The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, etc., and an isopropyl group is preferred.

[0069] Ra’ 4 ~Ra’ 6 When any of Ra’~Ra’ becomes a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the aliphatic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, examples include cyclopentane, cyclohexane, etc.

[0070] Ra’ 4 ~Ra’ 6 When any of Ra’~Ra’ becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This 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 of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, even more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.

[0071] Specific examples of the aromatic hydrocarbon group include a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); a group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings (for example, biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms of the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

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

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

[0074] [Chemical formula]

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

[0076] In the above formula (a1-r2-1), the alkyl group having 1 to 10 carbon atoms in Ra 031 includes a linear or branched alkyl group. The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, etc. Among them, a methyl group or an ethyl group is preferred. The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, etc. An isopropyl group is preferred.

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

[0078] In formula (a1-r2-1), Xab 0 (An aliphatic cyclic group that forms an alicyclic hydrocarbon together with Yab 0 ) is preferably a monocyclic alicyclic hydrocarbon group. For example, a group obtained by removing two or more hydrogen atoms from a monocycloalkane can be mentioned. The monocycloalkane preferably has 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, and even more preferably 3 to 6 carbon atoms. Specifically, cyclopentane and cyclohexane are preferably mentioned.

[0079] In formula (a1-r2-2), the alicyclic hydrocarbon group formed by Xa and Ya together is preferably a monocyclic alicyclic hydrocarbon group, which is the same as the content described for Xab in the above formula (a1-r2-1) 0 above. In formula (a1-r2-2), Ra 101 ~Ra 103 As the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, for example, 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 decyl group, etc. can be mentioned. Ra101 ~Ra 103 In ~Ra, examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, cyclododecyl group, and the like. Ra 101 ~Ra 103 Among them, from the viewpoint of ease of synthesis of the monomer compound, ~Ra is preferably a hydrogen atom or a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms. Among these, a hydrogen atom, a methyl group, and an ethyl group are more preferable, and a hydrogen atom is particularly preferable.

[0080] The above Ra 101 ~Ra 103 Examples of the substituent of the linear saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by ~Ra include the same groups as the above-mentioned Ra 05 and the like.

[0081] Ra 101 ~Ra 103 Examples of the group containing a carbon-carbon double bond formed by two or more of ~Ra bonding to each other to form a cyclic structure include cyclopentenyl group, cyclohexenyl group, methylcyclopentenyl group, methylcyclohexenyl group, cyclopentylideneethenyl group, cyclohexylideneethenyl group, and the like. Among these, from the viewpoint of ease of synthesis of the monomer compound, cyclopentenyl group, cyclohexenyl group, and cyclopentylideneethenyl group are preferable.

[0082] In formula (a1-r2-3), the alicyclic hydrocarbon group formed by Xaa together with Yaa is preferably a monocyclic alicyclic hydrocarbon group, which is the same as the content described for Ra' in the above formula (a1-r-2). 4 and the like. In formula (a1-r2-3), examples of the aromatic hydrocarbon group in Ra 104 include groups obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among them, Ra 104is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group obtained by removing one or more hydrogen atoms from benzene, naphthalene or anthracene, particularly preferably a group obtained by removing one or more hydrogen atoms from benzene, and most preferably a group obtained by removing one or more hydrogen atoms from benzene.

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

[0084] In formula (a1-r2-4), Ra' 12 and Ra' 13 are each independently a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms. Examples of the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in Ra' 12 and Ra' 13 include the same ones as the monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms in the above Ra 101 ~Ra 103 Some or all of the hydrogen atoms of this linear saturated hydrocarbon group may be substituted. Ra' 12 and Ra' 13 Among them, an alkyl group having 1 to 5 carbon atoms is preferable, a methyl group and an ethyl group are more preferable, and a methyl group is still more preferable. When the linear saturated hydrocarbon group represented by the above Ra' 12 and Ra' 13 is substituted, examples of the substituent include the same groups as those of the above Ra 05 for example.

[0085] In formula (a1-r2-4), Ra' 14is an alicyclic hydrocarbon group, preferably a monocyclic alicyclic hydrocarbon group which may have a substituent. Ra’ 14 Examples of the alicyclic hydrocarbon group in 14 include groups obtained by removing one or more hydrogen atoms from monocycloalkanes. The monocycloalkanes preferably have 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, and even more preferably 3 to 6 carbon atoms. Specific examples thereof preferably include cyclopentane and cyclohexane.

[0086] Ra’ 14 Examples of the substituent that Ra’ 104 may have include the same substituents as those that Ra

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

[0088]

Chemical formula

[0089]

Chemical formula

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

[0091]

Chemical formula

[0092]

Chemical formula

[0093]

Chemical formula

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

[0095]

Chemical formula

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

[0097]

Chemical formula

[0098] Tertiary alkyloxycarbonyl acid dissociable group: Among the polar groups, examples of the acid dissociable group for protecting a hydroxyl group include, for example, an acid dissociable group represented by the following formula (a-r-3) (hereinafter sometimes referred to as a "tertiary alkyloxycarbonyl acid dissociable group" for convenience).

[0099]

Chemical formula

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

[0101] In the formula (a-r-3), Ra’ 7 ~Ra’ 9 are each preferably an alkyl group having 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms. Also, the total number of carbon atoms of each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

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

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

[0104] [Chemical formula]

[0105] (In the general formula (a1-2), R 01 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va 01 is a divalent hydrocarbon group which may have an ether bond. na3 represents an integer of 0 to 2. Ra 031 represents an alkyl group, Yab 0 represents a carbon atom. Xab 0 is a group that forms an alicyclic hydrocarbon group together with Yab 0 and some or all of the hydrogen atoms of this alicyclic hydrocarbon group may be substituted.)

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

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

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

[0109] In the general formula (a1-2), Ra 031Among them, a chain alkyl group is preferable, and a monovalent chain alkyl group having 1 to 3 carbon atoms is more preferable. Specifically, a methyl group, an ethyl group, a propyl group or an iso-propyl group is more preferable.

[0110] In the general formula (a1-2), Yab 0 and Xab 0 are the same as Yab 0 and Xab 0 in the formula (a1-r2-1), respectively.

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

[0112]

Chemical formula

[0113]

Chemical formula

[0114]

Chemical formula

[0115]

Chemical formula

[0116]

Chemical formula

[0117]

Chemical formula

[0118]

Chemical formula

[0119] [Chemical formula]

[0120] [Chemical formula]

[0121] [Chemical formula]

[0122] (A1) component may have a structural unit (a1), which may be one kind or two or more kinds. In the (A1) component, the proportion of the structural unit (a1) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol% with respect to the total (100 mol%) of all the structural units constituting the (A1) component. By setting the proportion of the structural unit (a1) to be equal to or higher than the lower limit value of the above preferred range, lithography characteristics such as high sensitivity, resolution, and roughness improvement are improved. Further, by setting it to be equal to or lower than the upper limit value, a balance with other structural units can be achieved, and various lithography characteristics become good.

[0123] <Structural unit (a2)> The structural unit (a2) is a structural unit represented by the following general formula (a-2). The polymer compound (A1) preferably further contains a structural unit (a2) represented by the following general formula (a-2).

[0124] [Chemical formula]

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

[0126] In the formula (a-2), R 02 is the same as R 01 in the general formula (a-1). R 02 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 particularly preferably a hydrogen atom or a methyl group from the viewpoint of easy availability in industry.

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

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

[0129] ··Va 02 The aliphatic hydrocarbon group 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 a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

[0130] ···Linear or branched aliphatic hydrocarbon group The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferred. Specifically, examples include a methylene group [-CH2-], an ethylene group [-(CH2)2-], a trimethylene group [-(CH2)3-], a tetramethylene group [-(CH2)4-], a pentamethylene group [-(CH2)5-], and the like. The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred. Specifically, examples include alkylmethylene groups such as -CH(CH3)-, -CH(CH2CH3)-, -C(CH3)2-, -C(CH3)(CH2CH3)-, -C(CH3)(CH2CH2CH3)-, -C(CH2CH3)2-; alkylethylene groups such as -CH(CH3)CH2-, -CH(CH3)CH(CH3)-, -C(CH3)2CH2-, -CH(CH2CH3)CH2-, -C(CH2CH3)2-CH2-; alkyltrimethylene groups such as -CH(CH3)CH2CH2-, -CH2CH(CH3)CH2-; alkyltetramethylene groups such as -CH(CH3)CH2CH2CH2-, -CH2CH(CH3)CH2CH2-, and other alkylalkylene groups. The alkyl group in the alkylalkylene group preferably has 1 to 5 carbon atoms and is a linear alkyl group.

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

[0132] ···an aliphatic hydrocarbon group containing a ring in the structure Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring) which may contain a substituent containing a hetero atom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the terminal 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 are the same as those described above. The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms. The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferred. The monocycloalkane preferably has 3 to 6 carbon atoms, and specifically, cyclopentane, cyclohexane, etc. are included. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferred, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically, adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc. are included.

[0133] The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, etc. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferred, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferred. As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferred, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group is more preferred, and a methoxy group or an ethoxy group is even more preferred. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferred. Examples of the halogenated alkyl group as the substituent include a group in which some or all of the hydrogen atoms of the alkyl group are substituted with the halogen atoms. In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. Preferred examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, -S(=O)2-, -S(=O)2-O-.

[0134] ··Va 02 The aromatic hydrocarbon group in The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring. This 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, still more preferably 6 to 15, and particularly preferably 6 to 12. However, the number of carbon atoms does not include the number of carbon atoms in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with hetero atoms. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, a nitrogen atom, etc. Specific examples of the aromatic heterocyclic ring include a pyridine ring, a thiophene ring, etc. Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (such as biphenyl, fluorene, etc.); a group in which one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group) is substituted with an alkylene group (for example, a group obtained by further removing one hydrogen atom from the aryl group in an arylalkyl group such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The number of carbon atoms of the alkylene group bonded to the aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

[0135] In the aromatic hydrocarbon group, the hydrogen atoms of the aromatic hydrocarbon group may be substituted with substituents. For example, the hydrogen atoms bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with substituents. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, etc. As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable. Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0136] Va 02 is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, further preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group.

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

[0138] The lactone-containing cyclic group, -SO2-containing cyclic group, or carbonate-containing cyclic group in the constituent unit (a2) is effective in enhancing the adhesion of the resist film to the substrate when the (A1) component is used for forming the resist film. Further, by having the constituent unit (a2), lithography characteristics and the like become good due to effects such as appropriately adjusting the acid diffusion length, enhancing the adhesion of the resist film to the substrate, and appropriately adjusting the solubility during development.

[0139] The "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -O-C(=O)- in its ring skeleton. Counting the lactone ring as the first ring, in the case of only the lactone ring, it is a monocyclic group, and in the case of having another ring structure, regardless of the structure, it is called a polycyclic group. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group. As the lactone-containing cyclic group in the constituent unit (a2), any group can be used without particular limitation. Specifically, groups represented by any of the following general formulas (a2-r-1) to (a2-r-7) can be mentioned.

[0140]

Chemical formula

[0141] 〔In formulas (a2-r-1) to (a2-r-7), Ra’ 21 is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR”, -OC(=O)R”, a hydroxyalkyl group, or a cyano group; R” is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2-containing cyclic group; A” is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom, n’ is an integer of 0 to 2, and m’ is 0 or 1. * indicates a bond.〕

[0142] In the formulas (a2-r-1) to (a2-r-7), Ra’ 21 As the alkyl group in, an alkyl group having 1 to 6 carbon atoms is preferable. The alkyl group is preferably linear or branched. Specifically, a methyl group, an ethyl group, a propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, a pentyl group, an iso-pentyl group, a neopentyl group, a hexyl group, etc. are mentioned. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable. Ra’ 21 As the alkoxy group in, an alkoxy group having 1 to 6 carbon atoms is preferable. The alkoxy group is preferably linear or branched. Specifically, a group in which the alkyl group mentioned as the alkyl group in the above Ra’ 21 is linked to an oxygen atom (-O-) is mentioned. Ra’ 21 As the halogen atom in, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, and a fluorine atom is preferable. Ra’ 21 As the halogenated alkyl group in, a group in which some or all of the hydrogen atoms of the alkyl group in the above Ra’ 21 are substituted with the above halogen atom is mentioned. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

[0143] Ra’ 21 In -COOR” and -OC(=O)R” in, each of R” is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2-containing cyclic group. As the alkyl group in R”, any of linear, branched, and cyclic may be used, and the number of carbon atoms is preferably 1 to 15.

[0144] When R” is a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 10, more preferably 1 to 5, and particularly preferably a methyl group or an ethyl group. When “R” is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, it may or may not be substituted with a fluorine atom or a fluorinated alkyl group, and examples thereof include a group obtained by removing one or more hydrogen atoms from a monocycloalkane; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane. More specifically, examples include a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane; a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, or tetracyclododecane.

[0145] Examples of the lactone-containing cyclic group in “R” include the same groups as those represented by any of the general formulas (a2-r-1) to (a2-r-7). Examples of the carbonate-containing cyclic group in “R” are the same as the carbonate-containing cyclic groups described later, and specifically include groups represented by any of the general formulas (ax3-r-1) to (ax3-r-3). Examples of the -SO2-containing cyclic group in “R” are the same as the -SO2-containing cyclic groups described later, and specifically include groups represented by any of the general formulas (a5-r-1) to (a5-r-4).

[0146] Ra’ 21 The hydroxyalkyl group in preferably has 1 to 6 carbon atoms, and specifically, examples include a group in which at least one hydrogen atom of the alkyl group in the above Ra’ 21 is substituted with a hydroxyl group.

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

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

[0149] [Chemical formula]

[0150] [Chemical formula]

[0151] The “-SO2-containing cyclic group” means a cyclic group containing a ring containing -SO2- in its ring skeleton, specifically, a cyclic group in which the sulfur atom (S) in -SO2- forms part of the ring skeleton of the cyclic group. The ring containing -SO2- in its ring skeleton is counted as the first ring. In the case of only this ring, it is a monocyclic group, and when it has another ring structure, regardless of the structure, it is called a polycyclic group. The -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2-containing cyclic group is particularly preferably a cyclic group containing a sultone ring in which -O-S- in -O-SO2- forms part of the ring skeleton, that is, a cyclic group containing -O-SO2- in its ring skeleton. As the -SO2-containing cyclic group, more specifically, groups represented by any of the following general formulas (a5-r-1) to (a5-r-4) can be mentioned.

[0152]

Chemical formula

[0153] [In formulas (a5-r-1) to (a5-r-4), Ra’ 51 is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR”, -OC(=O)R”, a hydroxyalkyl group or a cyano group; R” is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2-containing cyclic group; A” is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n’ is an integer of 0 to 2. * indicates a bond.]

[0154] In the above formulas (a5-r-1) to (a5-r-2), A” is the same as A” in the above formulas (a2-r-2), (a2-r-3), (a2-r-5). Ra’ 51 Examples of the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR”, -OC(=O)R”, and hydroxyalkyl group in 21 are the same as those mentioned in the description of Ra’ in the above general formulas (a2-r-1) to (a2-r-7). Specific examples of the group represented by any of the following formulas (a5-r-1) to (a5-r-4) are given below. “Ac” in the formula indicates an acetyl group.

[0155]

Chemical formula

[0156]

Chemical formula

[0157] [Chem.]

[0158] The "carbonate-containing cyclic group" refers to a cyclic group containing a ring (carbonate ring) containing -O-C(=O)-O- in its ring skeleton. Counting the carbonate ring as the first ring, if it is only a carbonate ring, it is a monocyclic group, and if it has other ring structures, regardless of the structure, it is called a polycyclic group. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group. As the carbonate-containing cyclic group, any group can be used without particular limitation. Specifically, groups represented by any of the following general formulas (ax3-r-1) to (ax3-r-3) can be mentioned.

[0159] [Chem.]

[0160] [In the formula, Ra’ x31 are each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO2-containing cyclic group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, p’ is an integer of 0 to 3, and q’ is 0 or 1. * represents a bond.]

[0161] In the general formulas (ax3-r-2) to (ax3-r-3), A" is the same as A" in the general formulas (a2-r-2), (a2-r-3), and (a2-r-5). Ra’ X31As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR”, -OC(=O)R”, and hydroxyalkyl group in the formula, those exemplified in the description of Ra’ in the general formulas (a2-r-1) to (a2-r-7) are the same respectively. 21 Those similar to those exemplified in the description of 21 can be mentioned. Specific examples of the group represented by any of the following general formulas (ax3-r-1) to (ax3-r-3) are given below.

[0162]

Chemical formula

[0163] Ra 02 As the lactone-containing cyclic group, -SO2-containing cyclic group, and carbonate-containing cyclic group in Ra, groups represented by any of the aforementioned general formulas (a2-r-1) to (a2-r-7), groups represented by any of the general formulas (a5-r-1) to (a5-r-4), and groups represented by any of the general formulas (ax3-r-1) to (ax3-r-3) are preferably exemplified.

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

[0165] (A1) The constituent unit (a2) it has may be one kind or two or more kinds. (A1) When the component has the constituent unit (a2), the proportion of the constituent unit (a2) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, particularly preferably 40 to 60 mol% with respect to the total (100 mol%) of all the constituent units constituting the (A1) component. When the proportion of the constituent unit (a2) is at least the preferable lower limit value, the effect of containing the constituent unit (a2) can be sufficiently obtained by the above-described effect. When it is at most the upper limit value, the balance with other constituent units can be achieved and various lithography characteristics become good.

[0166] ≪Other constituent units≫ (A1) The component may further have other constituent units in addition to the above-described constituent unit (a1) and constituent unit (a2). Examples of the other constituent units include a constituent unit (a3) containing a polar group-containing aliphatic hydrocarbon group; a constituent unit (a4) containing an acid non-dissociable aliphatic cyclic group, etc. The constituent unit (a3) and the constituent unit (a4) exclude those corresponding to the constituent unit (a1) or the constituent unit (a2), and a number of those conventionally known as those used for the resin component of the resist composition can be used.

[0167] Such (A1) component can be produced by dissolving the monomers that induce each constituent unit in a polymerization solvent, and adding a radical polymerization initiator such as azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (for example, V-601, etc.) thereto and carrying out polymerization. Alternatively, such (A1) component can be produced by dissolving the monomer that induces the constituent unit (a1) and the monomer that induces the constituent unit (a2) in a polymerization solvent, and adding the radical polymerization initiator as described above thereto and carrying out polymerization.

[0168] In addition, during polymerization, for example, by using a chain transfer agent such as HS-CH2-CH2-CH2-C(CF3)2-OH in combination, a -C(CF3)2-OH group may be introduced at the terminal. Thus, a copolymer into which a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms is introduced is effective in reducing development defects and LER (Line Edge Roughness: non-uniform unevenness on the sidewall of the line).

[0169] (A1) component's weight average molecular weight (Mw) (polystyrene conversion basis by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 2000 to 30000, and even more preferably 3000 to 20000. When the Mw of the (A1) component is below the preferred upper limit of this range, there is sufficient solubility in the resist solvent for use as a resist, and when it is above the preferred lower limit of this range, the dry etching resistance and the cross-sectional shape of the resist pattern are good.

[0170] (A1) component's dispersity (Mw / Mn) is not particularly limited, preferably 1.0 or more, preferably 4.0 or less, more preferably 3.0 or less, and particularly preferably 2.0 or less. (A1) component's dispersity (Mw / Mn) is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. Here, Mn indicates the number average molecular weight.

[0171] ·Regarding the base material component other than the (A1) component The resist composition according to the embodiment of the present invention may use, as the (A) component, a base material component (hereinafter referred to as the "(A2) component") that does not correspond to the (A1) component and whose solubility in a developer changes by the action of an acid in combination. (A2) component is not particularly limited, and may be arbitrarily selected from a number of those conventionally known as base material components for chemically amplified resist compositions and used. (A2) component may be used alone as one kind of high molecular compound or low molecular compound, or may be used in combination of two or more kinds.

[0172] (A) component, the proportion of (A1) component is preferably 25% by mass or more, more preferably 50% by mass or more, still 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 excellent in various lithography characteristics such as high sensitivity, resolution, and roughness improvement is likely to be formed. The proportion of the (A1) component in the (A) component is not particularly limited, but can be, for example, 100% by mass or less.

[0173] In the resist composition according to an embodiment of the present invention, the content of the (A) component may be adjusted according to the resist film thickness to be formed or the like, and is not particularly limited. However, it is preferably 2% by mass or more, more preferably 3% by mass or more, based on the total mass (100% by mass) of the resist composition. The upper limit of the content of the (A) component is not particularly limited as long as it is a concentration at which a resist film can be formed. For example, it is preferably 10% by mass or less, more preferably 5% by mass or less.

[0174] ≪Acid generator component (B)≫ The resist composition according to an embodiment of the present invention further contains an acid generator component (B) (hereinafter also referred to as "(B) component") that generates an acid upon exposure, in addition to the above-mentioned (A) component and the (D) component described later. The acid generator component (B) includes a compound represented by the following general formula (b1-1).

[0175]

Chemical formula

[0176] 〔In general formula (b1-1), R1 to R3 are each independently an alkyl group or a cycloalkyl group that is at least partially fluorinated, or at least two of R1 to R3 may be bonded to form a fluorinated alkylene group. m is an integer of 1 or more, and M m+ is an m-valent organic cation.〕

[0177] [Anion part] In general formula (b1-1), R1 to R3 are each independently an alkyl group (preferably having 1 to 8 carbon atoms) or a cycloalkyl group (preferably having 3 to 8 carbon atoms) that is at least partially fluorinated, or at least two of R1 to R3 are bonded to represent a fluorinated alkylene group. Preferably, R1 to R3 each independently represent a fluorinated alkyl group (preferably having 1 to 8 carbon atoms) or a fluorinated cycloalkyl group (preferably having 3 to 8 carbon atoms).

[0178] Examples of the fluorinated alkyl group represented by R1 to R3 include a perfluoro or partially fluorinated alkyl group, such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoro-n-butyl group, a heptafluoro-n-propyl group, a heptafluoro-i-propyl group, a nonafluoro-n-butyl group, a nonafluoro-2-methylpropyl group, a nonafluoro-1-methylpropyl group, a nonafluoro-t-butyl group, a perfluoro-n-pentyl group, a perfluoroneopentyl group, a perfluoro-n-hexyl group, a perfluoro-n-heptyl group, a perfluoro-n-octyl group, and the like.

[0179] Examples of the fluorinated cycloalkyl group represented by R1 to R3 include a group in which at least one hydrogen atom of the cycloalkyl group is substituted with a fluorine atom (fluorocycloalkyl group), such as a monofluorocyclopentyl group, a difluorocyclopentyl group, a nonafluorocyclopentyl group, a monofluorocyclohexyl group, a difluorocyclohexyl group, an undecafluorocyclohexyl group, and other fluorocycloalkyl groups having 3 to 20 members. The fluorocycloalkyl group preferably has 5 to 20 members, and more preferably 5 to 15 members.

[0180] Examples of the fluorinated alkylene group in which at least two of R1 to R3 are bonded include perfluoro- or partially fluorinated alkylene groups, such as difluoromethylene group, tetrafluoroethylene group, hexafluoro-n-propylene group, hexafluoro-i-propylene group, octafluoro-n-butylene group, octafluoro-2-methylpropylene group, octafluoro-1-methylpropylene group, octafluoro-t-butylene group, perfluoro-n-pentylene group, perfluoroneopentylene group, perfluoro-n-hexylene group, perfluoro-n-heptylene group, perfluoro-n-octylene group, and the like.

[0181] Preferred examples of the anion moiety of the compound represented by the general formula (b1-1) include the following compounds.

[0182] [Chemical formula]

[0183] [Cation part: (M m+ ) 1 / m ) In the general formula (b1-1), M m+ represents an m-valent organic cation. As the organic cation in M m+ , an onium cation is preferred, a sulfonium cation, an iodonium cation, and an ammonium cation are more preferred, and a sulfonium cation and an iodonium cation are even more preferred. m is an integer of 1 or more.

[0184] Preferred cation parts ((M m+ ) 1 / m ) include organic cations represented by any of the following general formulas (ca-1) to (ca-3).

[0185] [Chemical formula]

[0186] In general formulas (ca-1) to (ca-3), R 201 ~R 207 each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent, and R 201 ~R 203 , R 206 ~R 207 may be bonded to each other to form a ring together with the sulfur atom in the formula. R 208 ~R 209 each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R 210 is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO2-containing cyclic group which may have a substituent, and L 201 represents -C(=O)- or -C(=O)-O-.]

[0187] Examples of the aryl group in R 201 ~R 207 include unsubstituted aryl groups having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferred. Examples of the alkyl group in R 201 ~R 207 include linear or cyclic alkyl groups, preferably those having 1 to 30 carbon atoms. Examples of the alkenyl group in R 201 ~R 207 preferably have 2 to 10 carbon atoms. Examples of the substituent which R 201 ~R 207 may have include, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, an arylthio group, and a group represented by any of the following formulas (ca-r-1) to (ca-r-7). Examples of the aryl group in the arylthio group as the substituent include aryl groups having 6 to 20 carbon atoms, and a phenyl group, a naphthyl group, and a biphenyl group are preferred. Examples of the arylthio group include a phenylthio group, a naphthylthio group, and a biphenylthio group.

[0188]

Chem.

[0189] [wherein, R’ 201 is each independently a hydrogen atom, 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.]

[0190] R’ 201 The cyclic group which may have a substituent represented by R’ is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Examples of the aromatic hydrocarbon group include an aryl group obtained by removing one hydrogen atom from an aromatic hydrocarbon ring or an aromatic compound containing two or more aromatic rings, and a phenyl group and a naphthyl group are preferable. Examples of the aliphatic hydrocarbon group include a group obtained by removing one hydrogen atom from a monocycloalkane or a polycycloalkane, and an adamantyl group and a norbornyl group are preferable.

[0191] R’ 201 The linear or branched-chain alkyl group which may have a substituent represented by R’ 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. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicicosyl group, docosyl group, etc. may be mentioned.

[0192] R’ 201The chain alkenyl group which may have a substituent represented by may be linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5, even more preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), a butenyl group and the like. Examples of the branched alkenyl group include a 1-methylpropenyl group, a 2-methylpropenyl group and the like. Among the above, the propenyl group is particularly preferable as the chain alkenyl group.

[0193] R’ 201 Examples of the cyclic group which may have a substituent or the chain alkyl group which may have a substituent represented by include the same as those of the above acid dissociable group.

[0194] R’ 201 Examples of the substituent in the cyclic group, the chain alkyl group, or the chain alkenyl group represented by include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group and the like. The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and most preferably a methoxy group or an ethoxy group. Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like, and a fluorine atom is preferable. Examples of the halogenated alkyl group as the substituent include a group in which a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group, are substituted with the above halogen atom.

[0195] R 201 ~R203 , R 206 ~R 207 When they are bonded to each other to form a ring together with the sulfur atom in the formula, they are not included in the heteroatom such as a sulfur atom, an oxygen atom, a nitrogen atom, a carbonyl group, -SO-, -SO2-, -SO3-, -COO-, -CONH- or -N(R N )-(applicable R N is an alkyl group having 1 to 5 carbon atoms.) The ring formed is preferably a 3- to 10-membered ring, including the sulfur atom, and particularly preferably a 5- to 7-membered ring, inclusive of the sulfur atom. Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, and a thioxanium ring.

[0196] R 208 ~R 209 R each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. 208 ~R 209 When each of these is independently an alkyl group, they may be bonded to each other to form a ring.

[0197] R 210 is an optionally substituted aryl group, an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted -SO2- containing cyclic group. R 210 The aryl group in the formula (I) may be an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferred. R 210 The alkyl group in is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms. R 210 The alkenyl group in the formula (I) preferably has 2 to 10 carbon atoms. R 210 In the optionally substituted -SO2-containing cyclic group in R, the "-SO2-containing cyclic group" refers to a cyclic group containing a ring containing -SO2 in its ring skeleton. Specifically, it is a cyclic group in which the sulfur atom (S) in -SO2 forms part of the ring skeleton of the cyclic group. The ring containing -SO2 in its ring skeleton is counted as the first ring. If it is only this ring, it is a monocyclic group, and if it has another ring structure, it is called a polycyclic group regardless of its structure. The -SO2-containing cyclic group may be a monocyclic group or a polycyclic group. The -SO2-containing cyclic group is particularly preferably a cyclic group containing a sultone ring in which -O-S in -O-SO2 forms part of the ring skeleton, that is, a cyclic group containing -O-SO2 in its ring skeleton. R 210 As the optionally substituted -SO2-containing cyclic group in R, the group represented by the above formula (a5-r-1) is preferred.

[0198] The cation represented by the formula (ca-1) is preferably a cation represented by the following general formula (b-2). That is, M in the general formula (b1-1) m+ is preferably a cation represented by the following general formula (b-2).

[0199]

Chemical formula

[0200] 〔In the general formula (b-2), Rb 201 ~Rb 203 are each independently an aryl group which may have a substituent, an alkyl group which may have a substituent or an alkenyl group which may have a substituent. Rb 201 ~Rb 203 may be bonded to each other to form a ring together with the sulfur atom in the general formula (b-2).〕

[0201] Rb 201 ~Rb 203The aryl group which may have a substituent represented by may, as the alkyl group which may have a substituent and the alkenyl group which may have a substituent, each be the above R 201 ~R 207 It is synonymous with the aryl group which may have a substituent, the alkyl group which may have a substituent, and the alkenyl group which may have a substituent as, and the preferred examples are the same.

[0202] Specific examples of the suitable cation represented by the formula (ca-1) include cations represented by any of the following formulas (ca-1-1) to (ca-1-70).

[0203] [Chemical formula]

[0204] [Chemical formula]

[0205] [Chemical formula]

[0206] [In the formula, g1, g2, and g3 represent the number of repetitions, g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.]

[0207] [Chemical formula]

[0208] [In the formula, R” 201 is a hydrogen atom or a substituent, and the substituents are the above R 201 ~R 207 , and R 210 are the same as those listed as the substituents which may be possessed.]

[0209] [Chemical formula]

[0210] Specific examples of the preferred cation represented by the formula (ca-3) include cations represented by any of the following formulas (ca-3-1) to (ca-3-6).

[0211]

Chemical formula

[0212] As the compound represented by the general formula (b1-1), all combinations of the above cation moiety and anion moiety can be preferably used. Further, the compound represented by the general formula (b1-1) is preferably, for example, a sulfonium salt represented by the following formula.

[0213]

Chemical formula

[0214]

Chemical formula

[0215]

Chemical formula

[0216]

Chemical formula

[0217]

Chemical formula

[0218] Among the above, preferred sulfonium salts are B1-1 to B1-4, B1-9 to B1-13, and particularly preferred sulfonium salts are B1-1 to B1-4.

[0219] Further, the component (B) may be used alone or in combination of a plurality thereof. In the resist composition of the present embodiment, the content of the component (B) is preferably 1 to 60 parts by mass, more preferably 2.5 to 50 parts by mass, and particularly preferably 5 to 20 parts by mass with respect to 100 parts by mass of the component (A).

[0220] ≪Acid diffusion control component (D)≫ The resist composition according to an embodiment of the present invention further includes a first acid diffusion control component (D1) and a second acid diffusion control component (D2) in addition to the component (A) and the component (B). The first acid diffusion control component (D1) includes a compound represented by the following general formula (d1-1) or (d1-2), and the second acid diffusion control component (D2) includes a compound represented by the following general formula (d2-1). The first acid diffusion control component (D1) (hereinafter referred to as the component (D1)) and the second acid diffusion control component (D2) (hereinafter referred to as the component (D2)) act as quenchers (acid diffusion control agents) that trap the acid generated by exposure in the resist composition. By using a resist composition containing the component (D1) and the component (D2), the contrast between the exposed portion and the unexposed portion of the resist film can be further improved when forming a resist pattern. The component (D1) and the component (D2) may be used as acid generators in addition to or instead of the component (B). Further, the component (D1) and the component (D2) may be, for example, photodegradable bases that decompose upon exposure and lose acid diffusion controllability.

[0221] <First acid diffusion control component (D1)> The resist composition of the present embodiment further includes a first acid diffusion control component (D1) and a second acid diffusion control component (D2) that control the diffusion of the acid generated by exposure from the component (B) in addition to the component (A) and the component (B). The (D1) component contains a compound represented by the following general formula (d1-1) (hereinafter also referred to as "compound (d1-1)") or a compound represented by the following general formula (d1-2) (hereinafter also referred to as "compound (d1-2)").

[0222] ≪Compound (d1-1))≫ Compound (d1-1) is a compound represented by the following general formula (d1-1).

[0223] [Chemical formula]

[0224] [In general formula (d1-1), Rd 11 is an optionally substituted linear or cyclic aliphatic hydrocarbon group. X1 is a heteroatom or a methylene group which may have a substituent. n1 is an integer of 1 to 10. m is an integer of 1 or more, and M m+ is an m-valent organic cation.]

[0225] [Anion part] In the above general formula (d1-1), Rd 11 is an optionally substituted linear or cyclic aliphatic hydrocarbon group. The linear aliphatic hydrocarbon group is specifically a linear or branched aliphatic hydrocarbon group.

[0226] Rd 11 The aliphatic hydrocarbon group in may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group, but is preferably a saturated aliphatic hydrocarbon group.

[0227] Rd 11 Specific examples of the linear or branched aliphatic hydrocarbon group in include a linear or branched saturated hydrocarbon group (alkyl group) or a linear or branched unsaturated hydrocarbon group.

[0228] The linear or branched alkyl group is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms. Specific examples of the linear or branched alkyl group include methyl group, ethyl group, propyl group, isopropyl group, linear or branched butyl group, linear or branched pentyl group, linear or branched hexyl group, linear or branched heptyl group, linear or branched octyl group, linear or branched nonyl group, linear or branched decyl group, and the like. Among the above, the linear or branched alkyl group is preferably a linear alkyl group having 1 to 10 carbon atoms, more preferably a linear alkyl group having 5 to 10 carbon atoms.

[0229] A part of the carbon atoms constituting the chain-like aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom. Preferred examples of the substituent containing a hetero atom include -O-, -C(=O)-O-, -S-, -S(=O)2-, -S(=O)2-O-.

[0230] More specifically, the unsaturated hydrocarbon group in the linear or branched unsaturated hydrocarbon group includes unsaturated hydrocarbon groups having a double bond such as alkenyl group, alkadienyl group, alkatrieneyl group; unsaturated hydrocarbon groups having a triple bond such as alkynyl group, a group obtained by removing one hydrogen atom from dialkyne, a group obtained by removing one hydrogen atom from trialkyne, and the like.

[0231] Specific examples of the linear or branched alkenyl group include linear alkenyl groups such as vinyl group, propenyl group (allyl group), 2-butenyl group; branched alkenyl groups such as 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group, and the like.

[0232] Specific examples of the alkadienyl group include propadienyl group and butadienyl group, and the like. Specific examples of the alkatrieneyl group include butatrieneyl group, and the like.

[0233] Specific examples of the linear or branched alkynyl group include linear alkynyl groups such as ethynyl group, propargyl group, 3-pentynyl group; branched alkynyl groups such as 1-methylpropargyl group, etc.

[0234] Specific examples of the group obtained by removing one hydrogen atom from the dialkyne include the group obtained by removing one hydrogen atom from diacetylene, etc. Specific examples of the group obtained by removing one hydrogen atom from the trialkyne include the group obtained by removing one hydrogen atom from hexa-1,3,5-triyne, etc.

[0235] Rd 11 Specific examples of the cyclic aliphatic hydrocarbon group in Rd include monocyclic alicyclic groups and polycyclic alicyclic groups.

[0236] As the monocyclic alicyclic group, a group obtained by removing one hydrogen atom from monocycloalkane or monocycloalkene is preferable. As the monocycloalkane, those having 3 to 6 carbon atoms are preferable, and specifically, cyclopentane, cyclohexane, etc. may be mentioned. As the monocycloalkene, those having 3 to 6 carbon atoms are preferable, and specifically, cyclopentene, cyclohexene, etc. may be mentioned. As the polycyclic alicyclic group, a group obtained by removing one or more hydrogen atoms from polycycloalkane is preferable, and as the polycycloalkane, those having 7 to 30 carbon atoms are preferable. Among them, as the polycycloalkane, polycycloalkanes having a crosslinked ring system polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane; polycycloalkanes having a condensed ring system polycyclic skeleton such as a cyclic group having a steroid skeleton are more preferable.

[0237] Rd 11As the cyclic aliphatic hydrocarbon group in [general formula], it may contain a heteroatom such as a heterocyclic ring. Specifically, lactone-containing cyclic groups represented by any of the general formulas (a2-r-1) to (a2-r-7), -SO2-containing cyclic groups represented by any of the general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by any of the above-described chemical formulas (r-hr-7) to (r-hr-16) can be mentioned. * in each formula represents a bond that binds to the carbon atom of the carbonyl group in the above general formula (d1-1).

[0238] Rd 11 Examples of the substituent that the chain or cyclic aliphatic hydrocarbon group in [general formula] may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a nitro group, an oxygen atom (=O), and the like. As the alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable. As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group are more preferable, and a methoxy group and an ethoxy group are most preferable. Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable. Examples of the halogenated alkyl group as a substituent include a group in which some or all of the hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group, are substituted with the halogen atom. "Having an oxygen atom (=O) as a substituent" means that two hydrogen atoms bonded to one carbon atom constituting the aliphatic hydrocarbon group are substituted with an oxygen atom (=O). It can also be said that the methylene group (-CH2-) constituting the aliphatic hydrocarbon group is substituted with a carbonyl group.

[0239] In the above general formula (d1-1), Rd 11is preferably a cyclic aliphatic hydrocarbon group which may have a substituent, more preferably a cyclic aliphatic hydrocarbon group having an oxygen atom (=O), and even more preferably a polycyclic alicyclic group having an oxygen atom (=O).

[0240] In the general formula (d1-1) above, X1 is a heteroatom or a methylene group which may have a substituent, and is preferably a heteroatom. Examples of the heteroatom include an oxygen atom, a sulfur atom, a nitrogen atom, etc., and an oxygen atom (-O-) is preferred. Examples of the substituent when the methylene group has a substituent include the same substituents as those which the linear or cyclic aliphatic hydrocarbon group in Rd 11 may have.

[0241] In the general formula (d1-1) above, n1 is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, and even more preferably an integer of 2 to 4.

[0242] Preferred specific examples of the anion part in the compound (d1-1) are shown below.

[0243]

Chemical formula

[0244] The anion part in the compound (d1-1) is preferably an anion represented by any of the above chemical formulas (an-d01-1) to (an-d01-5), and more preferably an anion represented by any of the above chemical formulas (an-d01-1) to (an-d01-3).

[0245] [Cation part] In the general formula (d1-1) above, m is an integer of 1 or more, and M m+ is an m-valent organic cation. M m+As the organic cation, those similar to the cations represented by any of the general formulas (ca-1) to (ca-3) are preferably mentioned. The cation represented by the general formula (ca-1) is more preferable, and the cation represented by any of the formulas (ca-1-1) to (ca-1-70) is even more preferable.

[0246] Among them, the compound (d1-1) is preferably the compound (d1-1-1) represented by the following general formula (d1-1-1).

[0247]

Chemical Formula

[0248] [In the formula (d1-1-1), Rd 11 is a linear or cyclic aliphatic hydrocarbon group which may have a substituent. X1 is a heteroatom or a methylene group which may have a substituent. n1 is an integer of 1 to 10. R 201 ~R 203 each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent or an alkenyl group which may have a substituent. R 201 ~R 203 may be bonded to each other to form a ring together with the sulfur atom in the formula. ]

[0249] In the compound (d1-1-1), the anion part of the compound (d1-1-1) is the same as the anion part of the compound (d1-1), and the cation part of the compound (d1-1-1) is the same as the cation represented by the general formula (ca-1).

[0250] In the resist composition of this embodiment, the compound (d1-1) may be used alone or in combination of two or more. In the resist composition of this embodiment, the content of the compound (d1-1) is preferably 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 3 to 15 parts by mass with respect to 100 parts by mass of the component (A). By setting the content of the compound (d1-1) to be not less than the above-mentioned preferable lower limit value, better lithography characteristics can be easily obtained. On the other hand, when it is not more than the above-mentioned preferable upper limit value, the sensitivity can be maintained better and the throughput can also be better.

[0251] ≪Compound (d1-2))≫ Compound (d1-2) is a compound represented by the following general formula (d1-2).

[0252]

Chemical formula

[0253] 〔In the general formula (d1-2), Rd 12 is a linear or cyclic aliphatic hydrocarbon group which may have a substituent. X2 is a heteroatom or a methylene group which may have a substituent. n2 is an integer from 1 to 10. m is an integer of 1 or more, and M m+ is an m-valent organic cation.〕

[0254] [Anion part] In the general formula (d1-2), Rd 12 is a linear or cyclic aliphatic hydrocarbon group which may have a substituent, and is the same as the linear or cyclic aliphatic hydrocarbon group which may have a substituent in Rd 11 in the general formula (d1-1).

[0255] In the above general formula (d1-2), X2 is a heteroatom or a methylene group which may have a substituent, and is preferably a heteroatom, and more preferably an oxygen atom (-O-).

[0256] In the above general formula (d1-2), n2 is an integer from 1 to 10, preferably an integer from 1 to 8, more preferably an integer from 1 to 5, and even more preferably an integer from 1 to 3.

[0257] The following shows preferable specific examples of the anion part in the compound (d1-2).

[0258] [Chemical formula]

[0259] [Cation part] In the general formula (d1-2) above, m is an integer of 1 or more, and M m+ is an m-valent organic cation. M m+ As the organic cation of, cations similar to those represented by any of the general formulas (ca-1) to (ca-3) above are preferably exemplified, the cation represented by the general formula (ca-1) is more preferable, and the cation represented by any of the formulas (ca-1-1) to (ca-1-70) is even more preferable.

[0260] Among the above, the compound (d1-2) is preferably the compound (d1-2-1) represented by the following general formula (d1-2-1).

[0261] [Chemical formula]

[0262] [In the formula (d1-2-1), Rd 12 is an optionally substituted linear or cyclic aliphatic hydrocarbon group. X2 is a heteroatom or a methylene group which may have a substituent. n2 is an integer from 1 to 10. R 201 ~R 203 each independently represents an optionally substituted aryl group, an optionally substituted alkyl group or an optionally substituted alkenyl group. R 201 ~R 203 may be bonded to each other to form a ring together with the sulfur atom in the formula. ]

[0263] In the compound (d1-2-1), the anion part of the compound (d1-2-1) is the same as the anion part of the compound (d1-2), and the cation part of the compound (d1-2-1) is the same as the cation represented by the general formula (ca-1) above.

[0264] In the resist composition of the present embodiment, the compound (d1-2) may be used alone or in combination of two or more. In the resist composition of the present embodiment, the content of the compound (d1-2) is preferably 0.5 to 30 parts by mass, more preferably 1 to 20 parts by mass, and still more preferably 2 to 15 parts by mass with respect to 100 parts by mass of the component (A). By setting the content of the compound (d1-2) to be equal to or higher than the above-mentioned preferable lower limit value, better lithography characteristics can be easily obtained. On the other hand, when it is equal to or lower than the above-mentioned preferable upper limit value, the sensitivity can be maintained better and the throughput can also be better.

[0265] ≪Compound (d2-1)≫ The compound (d2-1) is a compound represented by the following general formula (d2-1).

[0266] [Chemical formula]

[0267] [In formula (d2-1), Rd2 is a cyclic aliphatic hydrocarbon group having an oxygen atom (=O). m is an integer of 1 or more, and M m+ is an m-valent organic cation.]

[0268] [Anion part] In the above general formula (d2-1), Rd2 is a cyclic aliphatic hydrocarbon group having an oxygen atom (=O). Here, "having an oxygen atom (=O)" means that two hydrogen atoms bonded to one carbon atom constituting the cyclic aliphatic hydrocarbon group are substituted with an oxygen atom (=O).

[0269] The cyclic aliphatic hydrocarbon group is preferably a cyclic aliphatic hydrocarbon group having 4 to 20 carbon atoms. Specific examples of the cyclic aliphatic hydrocarbon group include a monocyclic alicyclic group and a polycyclic alicyclic group.

[0270] As the monocyclic alicyclic group, a group obtained by removing one or more hydrogen atoms from monocycloalkane or monocycloalkene is preferred. As the monocycloalkane, those having 3 to 6 carbon atoms are preferred, and specific examples include cyclopentane, cyclohexane, etc. As the monocycloalkene, those having 3 to 6 carbon atoms are preferred, and specific examples include cyclopentene, cyclohexene, etc.

[0271] As the polycyclic alicyclic group, a group obtained by removing one or more hydrogen atoms from polycycloalkane is preferred, and as the polycycloalkane, those having 7 to 20 carbon atoms are preferred. Among them, as the polycycloalkane, polycycloalkanes having a crosslinked ring system polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclo[5.2.1.02,6]decane, tetracyclododecane, etc. are preferred.

[0272] Rd2 may have a substituent other than an oxygen atom (=O). Examples of the substituent include the same substituents as those that the linear or cyclic aliphatic hydrocarbon group in Rd 11 may optionally have, and among them, an alkyl group is preferred.

[0273] Preferred specific examples of Rd2 are shown below. In the following formulae, * indicates a bond that binds to the methylene group in the above general formula (d2-1).

[0274]

Chemical formula

[0275] Preferred specific examples of the anion part in the compound (d2-1) are shown below.

[0276]

Chemical formula

[0277] [Cation part] In the above general formula (d2-1), m is an integer of 1 or more, and Mm+ is an m-valent organic cation. M m+ As the organic cation of M, those similar to the cations represented by any of the general formulas (ca-1) to (ca-3) are preferably mentioned, the cation represented by the general formula (ca-1) is more preferable, and the cations represented by any of the formulas (ca-1-1) to (ca-1-70) are even more preferable.

[0278] Among the above, the compound (d2-1) is preferably a compound (d2-1-1) represented by the following general formula (d2-1-1) (hereinafter, also referred to as "compound (d2-1-1)").

[0279] [Chemical formula]

[0280] [In the formula (d2-1-1), Rd2 is a cyclic aliphatic hydrocarbon group having an oxygen atom (=O). R 201 ~R 203 each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent. R 201 ~R 203 may be bonded to each other to form a ring together with the sulfur atom in the formula.]

[0281] In the compound (d2-1-1), the anion part of the compound (d2-1-1) is the same as the anion part of the compound (d2-1), and the cation part of the compound (d2-1-1) is the same as the cation represented by the general formula (ca-1).

[0282] In the resist composition of the present embodiment, the compound (d2-1) may be used alone or in combination of two or more. In the resist composition of the present embodiment, the content of the compound (d2-1) is preferably 0.1 to 15 parts by mass, more preferably 1 to 12 parts by mass, and even more preferably 2 to 10 parts by mass with respect to 100 parts by mass of the component (A). By setting the content of the compound (d2-1) to be not less than the above-mentioned preferable lower limit value, better lithography characteristics can be easily obtained. On the other hand, when it is not more than the above-mentioned preferable upper limit value, the sensitivity can be maintained better and the throughput can also be better.

[0283] In the resist composition of the present embodiment, the total content of the component (D1) and the component (D2) is preferably 1 to 40 parts by mass, more preferably 3 to 30 parts by mass, and even more preferably 5 to 25 parts by mass with respect to 100 parts by mass of the component (A). (D1) component and (D2) component By setting the total content to be not less than the above-mentioned preferable lower limit value, better lithography characteristics can be easily obtained. On the other hand, when it is not more than the above-mentioned preferable upper limit value, the sensitivity can be maintained better and the throughput can also be better.

[0284] In the resist composition of the present embodiment, the mass ratio of the content of the component (D1) to the content of the component (D2) ((D1) component: (D2) component) is preferably 1:3 to 3:1, and more preferably 1:2 to 2:1.

[0285] In the resist composition of the present embodiment, from the viewpoint of improving sensitivity, it is preferable that the content of the component (D1) is more than the content of the component (D2). On the other hand, from the viewpoint of improving roughness reduction property, it is preferable that the content of the component (D2) is more than the content of the component (D1). More specifically, from the viewpoint of improving sensitivity, it is preferably 1 < (D1) component / (D2) component < 4, and more preferably 1 < (D1) component / (D2) component < 3. On the other hand, from the viewpoint of improving roughness reduction property, it is preferably 1 < ((D2) component / (D1) component < 4, and more preferably 1 < (D2) component / (D1) component < 3.

[0286] <Other components> The resist composition of the present embodiment may further contain other components in addition to the above-mentioned components (A), (B), (D1), and (D2). Examples of the other components include the following component (E), component (F), component (S), etc.

[0287] <<(E) component: at least one compound selected from the group consisting of organic carboxylic acids, oxoacids of phosphorus and their derivatives>> In the resist composition according to an embodiment of the present invention, for the purpose of preventing sensitivity deterioration and improving resist pattern shape, stability over time in standing, etc., as an optional component, at least one compound (E) (hereinafter referred to as "(E) component") selected from the group consisting of organic carboxylic acids, oxoacids of phosphorus and their derivatives can be contained. Examples of the organic carboxylic acid include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, isophthalic acid, etc., which are preferable. Examples of the oxoacid of phosphorus include phosphoric acid, phosphonic acid, phosphinic acid, etc., and among these, phosphonic acid is particularly preferable. Examples of the derivative of the oxoacid of phosphorus include esters in which the hydrogen atom of the above oxoacid is substituted with a hydrocarbon group, and examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 15 carbon atoms, etc. Examples of the derivative of phosphoric acid include phosphate esters such as di-n-butyl phosphate, diphenyl phosphate, etc. Examples of the derivative of phosphonic acid include phosphonate esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, dibenzyl phosphonate, etc. Examples of the derivative of phosphinic acid include phosphinate esters, phenylphosphinic acid, etc.

[0288] Among the above, the (E) component is preferably an organic carboxylic acid, and more preferably an aromatic carboxylic acid. Specifically, benzoic acid, hydroxybenzoic acid, salicylic acid, phthalic acid, terephthalic acid, isophthalic acid are preferable, and salicylic acid is more preferable.

[0289] In the resist composition according to an embodiment of the present invention, the component (E) may be used alone or in combination of two or more. When the resist composition contains the component (E), the content of the component (E) is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and still more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the component (A).

[0290] ≪Component (F): Fluorine additive component≫ The resist composition in the present embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") as a hydrophobic resin. The component (F) is used to impart water repellency to the resist film, and the lithography characteristics are improved by using it as a resin different from the component (A). As the component (F), for example, fluorine-containing polymer compounds described in JP-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226 can be used. More specifically, as the component (F), polymers having a structural unit (f11) represented by the following general formula (f1-1) can be mentioned.

[0291] As the polymer having a structural unit (f11) represented by the following general formula (f1-1), a polymer (homopolymer) consisting only of the structural unit (f11) represented by the following formula (f1-1); a copolymer of the structural unit (f11) and the structural unit (a1); a copolymer of the structural unit (f11), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a3) are preferred. Here, as the structural unit (a1) copolymerized with the structural unit (f11), a structural unit containing an acid dissociable group represented by the formula (a1-r2-1) is preferred.

[0292]

Chemical formula

[0293] [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. Rf 102 and Rf 103 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf 102 and Rf 103 may be the same or different. nf 1 is an integer from 0 to 5, and Rf 101 is an organic group containing a fluorine atom.]

[0294] In the general formula (f1-1), R bonded to the carbon atom at the α-position is the same as R 01 in the general formula (a-1). As R, a hydrogen atom or a methyl group is preferable. In the general formula (f1-1), Rf 102 and Rf 103 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is particularly preferable. Rf 102 and Rf 103 Examples of the alkyl group having 1 to 5 carbon atoms of Rf 102 and Rf 103 are the same as those of the alkyl group having 1 to 5 carbon atoms of the above R, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms of Rf 102 and Rf 103 include a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is particularly preferable. Among them, Rf 102 and Rf 103 are preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group. In the general formula (f1-1), n f1 is an integer from 1 to 5, preferably an integer from 1 to 3, and more preferably 1 or 2.

[0295] In the general formula (f1-1), Rf 101is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom. The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, preferably having 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms. Further, in the hydrocarbon group containing a fluorine atom, preferably 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and particularly preferably 60% or more are fluorinated because the hydrophobicity of the resist film during immersion exposure is increased. Among them, Rf 101 is more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms, and trifluoromethyl group, -CH2-CF3, -CH2-CF2-CF3, -CH(CF3)2, -CH2-CH2-CF3, -CH2-CH2-CF2-CF2-CF2-CF3 are even more preferably, and -CH2-CF3 is particularly preferably.

[0296] (F) The weight average molecular weight (Mw) (based on polystyrene conversion by gel permeation chromatography) of the component is preferably 1000 to 50000, more preferably 5000 to 40000, and most preferably 10000 to 30000. When the weight average molecular weight is below the upper limit of this range, the resist composition in this embodiment has sufficient solubility in the resist solvent for use as a resist, and when the weight average molecular weight is above the lower limit of this range, the resist composition in this embodiment has good dry etching resistance and resist pattern cross-sectional shape. (F) The dispersity (Mw / Mn) of the component is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

[0297] In the resist composition in this embodiment, the (F) component may be used alone or in combination of two or more. When the resist composition contains the component (F), the content of the component (F) is usually used in a proportion of 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A).

[0298] ≪Organic solvent component (S)≫ The resist composition according to the embodiment of the present invention can be produced by dissolving a resist material in an organic solvent component (hereinafter referred to as “component (S)”). As the component (S), any one can be appropriately selected from those known as solvents for chemically amplified resist compositions as long as it can dissolve each component to be used and form a uniform solution. In the resist composition according to the embodiment of the present invention, the component (S) may be used alone or as a mixed solvent of two or more kinds. Among them, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), γ-butyrolactone, ethyl lactate (EL), and cyclohexanone are preferable.

[0299] Further, as the component (S), a mixed solvent obtained by mixing PGMEA and a polar solvent is also preferable. The mixing ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent. In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio is preferably such that the mass ratio of the former to the latter is 70:30 to 95:5. The amount of the component (S) used is not particularly limited and is appropriately set according to the coating film thickness at a concentration that can be applied to a substrate or the like. Generally, the component (S) is used so that the solid content concentration of the resist composition is in the range of 0.1 to 20% by mass, preferably 0.2 to 15% by mass.

[0300] In the resist composition of the present embodiment, additives having miscibility as desired, for example, additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, etc. can be appropriately contained.

[0301] The resist composition according to an embodiment of the present invention contains the above-described component (A), component (B), component (D1), and component (D2), and, if necessary, the above-described optional components. For example, a resist composition containing component (A), component (B), component (D1), component (D2), component (E), component (F), and component (S) is preferably mentioned.

[0302] As described above, the resist composition according to an embodiment of the present invention contains the above-described component (A), component (B), component (D1), and component (D2). It is presumed that the component (B), component (D1), and component (D2) in the resist composition each contain a compound having a specific structure, thereby achieving high sensitivity and forming a resist pattern with good roughness reduction properties.

[0303] 〔Resist pattern forming method〕 The resist pattern forming method according to the second aspect of the present invention is a method having a step of forming a resist film on a support using the resist composition of the above-described embodiment, a step of exposing the resist film, and a step of developing the resist film to form a resist pattern. As an embodiment of such a resist pattern forming method, for example, a resist pattern forming method performed as follows can be mentioned.

[0304] First, the resist composition of the above-described embodiment is applied onto a support with a spinner or the like, and a baking (post-apply bake (PAB)) treatment is performed at a temperature condition of, for example, 80 to 150°C for 40 to 120 seconds, preferably 50 to 90 seconds, to form a resist film. Next, selective exposure is performed on the resist film by exposure through a mask (mask pattern) with a predetermined pattern formed thereon or by direct irradiation with an electron beam without using a mask pattern, using an exposure apparatus such as an electron beam lithography apparatus or an EUV exposure apparatus. Thereafter, a baking (post-exposure baking (PEB)) treatment is performed, for example, at a temperature condition of 80 to 150°C for 40 to 120 seconds, preferably 50 to 90 seconds. Next, the resist film is developed. In the case of an alkali development process, an alkali developer is used, and in the case of a solvent development process, a developer containing an organic solvent (organic-based developer) is used. After the development process, preferably a rinsing process is performed. In the case of an alkali development process, water rinsing using pure water is preferable, and in the case of a solvent development process, it is preferable to use a rinsing liquid containing an organic solvent. In the case of a solvent development process, after the development process or the rinsing process, a process of removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid may be performed. After the development process or the rinsing process, drying is performed. Also, in some cases, a baking process (post-bake) may be performed after the above development process.

[0305] The support is not particularly limited, and conventionally known ones can be used. For example, a substrate for electronic components and those with a predetermined wiring pattern formed thereon can be mentioned. More specifically, substrates made of metals such as silicon wafers, copper, chromium, iron, and aluminum, and glass substrates can be mentioned. As the material for the wiring pattern, for example, copper, aluminum, nickel, gold, etc. can be used.

[0306] The wavelength used for exposure is not particularly limited, and it can be performed using radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc.

[0307] The exposure method of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be liquid immersion exposure (Liquid Immersion Lithography), but liquid immersion exposure is preferred. Liquid immersion exposure is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is filled with a solvent (liquid immersion medium) having a refractive index greater than that of air in advance, and exposure (immersion exposure) is performed in this state. As the liquid immersion medium, a solvent having a refractive index greater than that of air and smaller than that of the resist film to be exposed is preferred. The refractive index of such a solvent is not particularly limited as long as it is within the above range. Examples of the solvent having a refractive index greater than that of air and smaller than that of the resist film include water, fluorine-based inert liquids, silicon-based solvents, hydrocarbon-based solvents, and the like. Water is preferably used as the liquid immersion medium.

[0308] Examples of the alkaline developer used for development in the alkaline development process include an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH). The organic solvent contained in the organic developer used for development in the solvent development process may be any one that can dissolve the component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specifically, polar solvents such as ketone-based solvents, ester-based solvents, alcohol-based solvents, nitrile-based solvents, amide-based solvents, ether-based solvents, and hydrocarbon-based solvents can be mentioned.

[0309] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl 3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butyrate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0310] Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, butyronitrile, and the like.

[0311] Known additives can be blended into the organic developer as needed. Examples of such additives include surfactants. The surfactant is not particularly limited, and for example, ionic or non-ionic fluorine-based and / or silicon-based surfactants can be used.

[0312] The development process can be carried out by known development methods. For example, a method of immersing the support in the developer for a certain period of time (dip method), a method of raising the developer on the surface of the support by surface tension and allowing it to stand still for a certain period of time (paddle method), a method of spraying the developer on the surface of the support (spray method), a method of continuously discharging the developer while scanning a developer discharge nozzle at a constant speed on a support rotating at a constant speed (dynamic dispense method), and the like.

[0313] The rinsing process (cleaning process) using a rinsing solution can be carried out by a known rinsing method. Examples of the method of the rinsing process include a method of continuously discharging the rinsing solution onto a support rotating at a constant speed (spin coating method), a method of immersing the support in the rinsing solution for a certain period of time (dip method), a method of spraying the rinsing solution onto the surface of the support (spray method), and the like.

[0314] The resist composition of the above-described embodiment and various materials used in the pattern forming method of the above-described embodiment (for example, resist solvents, developers, rinsing solutions, compositions for forming an antireflection film, compositions for forming a top coat, etc.) preferably do not contain impurities such as metals, metal salts containing halogens, acids, alkalis, components containing sulfur atoms or phosphorus atoms. Here, examples of impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The content of impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, still more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially not contained (below the detection limit of the measuring device).

[0315] In the resist pattern forming method of the present embodiment described above, since the resist composition according to the above-described embodiment of the present invention is used, when forming a resist pattern, high sensitivity can be achieved, and the lithography characteristics are excellent, and a resist pattern with a good shape can be formed.

Examples

[0316] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0317] Monomers for inducing the structural units constituting the following polymer compounds (A)-1 to (A)-8 were used in a predetermined molar ratio to synthesize each polymer compound. Regarding the obtained polymer compound, 13The copolymerization composition ratio of the polymer compound determined by 13C-NMR (the ratio of each structural unit in the polymer compound (molar ratio)), the weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement, and the molecular weight dispersity (PDI) (Mw / Mn) were shown together.

[0318] [Chemical formula]

[0319] [Chemical formula]

[0320] <Preparation of resist composition> (Examples 1 to 21, Comparative Examples 1 to 5) Each component shown in Table 1 or 2 below was mixed and dissolved in a solvent: S-1, and the resist compositions of each example were prepared respectively. S-1: A mixed solvent of 1650 parts by mass of propylene glycol monomethyl ether acetate (PEGMEA), 600 parts by mass of propylene glycol monomethyl ether (PGME), and 750 parts by mass of cyclohexanone The mixing ratio of PEGMEA, PGME, and cyclohexanone in S-1 (PEGMEA:PGME:cyclohexanone) is 55:20:25.

[0321] [Table 1]

[0322] [Table 2]

[0323] In Tables 1 and 2, each abbreviation has the following meaning respectively. The numerical values in [ ] are the blending amounts (parts by mass). (A)-1 to (A)-8: The above polymer compounds (A)-1 to (A)-8. (B1)-1 to (B1)-5: An acid generator composed of compounds represented by the following chemical formulas (B1)-1 to (B1)-5. (B2)-1: An acid generator composed of a compound represented by the following chemical formula (B2)-1. (D1)-1 to (D1)-8: An acid diffusion controller composed of compounds represented by the following chemical formulas (D1)-1 to (D1)-8. (D2)-1 to (D2)-3: An acid diffusion controller composed of compounds represented by the following chemical formulas (D2)-1 to (D2)-3. (D3)-1 to (D3)-2: An acid diffusion controller composed of compounds represented by the following chemical formulas (D3)-1 to (D3)-2. (E)-1: A compound represented by the following chemical formula (E)-1. (F)-1: A hydrophobic resin (F)-1 containing the following structural unit (composition ratio (molar ratio): l / m = 80 / 20, Mw: 20,000, Mw / Mn: 1.70).

[0324]

Chemical formula

[0325]

Chemical formula

[0326]

Chemical formula

[0327]

Chemical formula

[0328]

Chemical formula

[0329]

Chemical formula

[0330] <Formation of Resist Pattern> An organic antireflective film composition "ARC29" (manufactured by Brewer Science) was applied onto a 12-inch silicon wafer using a spinner, and dried by baking on a hot plate at 205 °C for 60 seconds, thereby forming an organic antireflective film with a film thickness of 98 nm. A resist composition was applied onto the above-mentioned organic antireflective film using a spinner, and prebaked (PAB) at 100 °C for 60 seconds on a hot plate and dried, thereby forming a resist film with a film thickness of 100 nm.

[0331] Using an immersion ArF exposure apparatus XT-1900Gi [manufactured by ASML; NA (numerical aperture) = 1.35, Dipole (in / out = 0.78 / 0.97) with TE Polarization, immersion medium: water], an ArF excimer laser (193 nm) was selectively irradiated through a photomask (6% halftone). Thereafter, a PEB treatment was performed at 90 °C for 60 seconds.

[0332] Subsequently, alkali development was carried out at 23 °C for 10 seconds with a 2.38 mass% TMAH aqueous solution (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.), and then, water rinsing was carried out for 30 seconds using pure water, followed by spin drying. As a result, 1:1 line and space (LS) patterns with a line width of 45 nm and a pitch of 90 nm were formed in each example.

[0333] [Evaluation of Optimum Exposure Dose (Eop)] The line size in the above <Formation of Resist Pattern> was observed, and the exposure dose at which an LS pattern with a line width of 45 nm and a pitch of 90 nm was formed was defined as the optimum exposure dose (Eop) (mJ / cm 2 ) and shown in Tables 1 and 2.

[0334] [Evaluation of LWR (Line Width Roughness)] For the LS pattern formed in the above <Formation of Resist Pattern>, 3σ, which is a measure indicating LWR, was determined and shown in Tables 1 and 2. "3σ" represents three times the standard deviation (σ) (unit: nm) obtained from measuring the line positions at 400 locations in the longitudinal direction of the line using a scanning electron microscope (acceleration voltage: 800 V, product name: CG-6300, manufactured by Hitachi High-Technologies Corporation). The smaller the value of 3σ, the smaller the roughness of the line sidewall, meaning that an LS pattern with a more uniform width was obtained.

[0335] From the results shown in Tables 1 and 2, it was confirmed that the resist compositions of the examples had better roughness reduction properties than those of the comparative examples, and it was possible to achieve both high sensitivity and roughness reduction.

[0336] In the resist composition of Comparative Example 1, since a compound (B2)-1 having no specific structure was used instead of the component (B) having a specific structure as the acid generator, the sensitivity and roughness reduction properties were inferior to those of the resist composition of the example. In the resist composition of Comparative Example 2, only the component (D2) having a specific structure was used as the acid diffusion controller, and the component (D1) having a specific structure was not used. Therefore, the sensitivity and roughness reduction properties were inferior to those of the resist composition of the example.

[0337] In the resist composition of Comparative Example 3, only the component (D1) having a specific structure was used as the acid diffusion controller, and the component (D2) having a specific structure was not used. Therefore, the roughness reduction property was inferior to that of the resist composition of the example, and it was not possible to achieve both high sensitivity and roughness reduction. In the resist compositions of Comparative Examples 4 and 5, since compounds (D3)-1 and (D3)-2 having no specific structure were used instead of the component (D2) having a specific structure as the acid diffusion controller, the sensitivity and roughness reduction properties were inferior to those of the resist composition of the example.

Industrial Applicability

[0338] According to the present invention, it is possible to provide a resist composition capable of achieving high sensitivity and forming a resist pattern with good reduction of roughness, and a method for forming a resist pattern using the resist composition.

Claims

1. A resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, comprising a base material component (A) whose solubility in a developer changes due to the action of an acid, an acid generator component (B) that generates an acid upon exposure, a first acid diffusion control component (D1), and a second acid diffusion control component (D2), wherein the acid generator component (B) contains a compound represented by the following general formula (b1-1), the first acid diffusion control component (D1) contains a compound represented by the following general formula (d1-1) or (d1-2), and the second acid diffusion control component (D2) contains a compound represented by the following general formula (d2-1). A resist composition. [Chemical Formula 1] [In general formula (b1-1), R １ ~R ３ are each independently an alkyl group or a cycloalkyl group that is at least partially fluorinated, or at least two of R １ ~R ３ may be bonded to form a fluorinated alkylene group. m is an integer of 1 or more, and M ｍ＋ is an m-valent organic cation. ] [Chemical Formula 2] [In general formulas (d1-1) and (d1-2), Rd １１ and Rd １２ are a linear or cyclic aliphatic hydrocarbon group that may have a substituent. X １ and X ２ are each independently a heteroatom or a methylene group that may have a substituent. n １ and n ２ are each independently an integer from 1 to 10. m is each independently an integer of 1 or more, and M ｍ＋ are each independently an m-valent organic cation. ] [Chemical Formula 3] [In formula (d2-1), Rd ２is a cyclic aliphatic hydrocarbon group having an oxygen atom (=O). m is an integer of 1 or more, and M ｍ＋ is an m-valent organic cation. ]

2. M in the general formula (b1-1) ｍ＋ is a cation represented by the following general formula (b-2), and the resist composition according to claim 1. 【Chemical Formula 4】 〔In the general formula (b-2), Rb ２０１ to Rb ２０３ are each independently an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. Rb ２０１ to Rb ２０３ may be bonded to each other to form a ring together with the sulfur atom in the general formula (b-2). ]

3. The base material component (A) contains a polymer compound (A1) having a structural unit (a1) represented by the following general formula (a-1), and the resist composition according to claim 1 or 2. 【Chemical Formula 5】 〔In the general formula (a-1), R ０１ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ０１ is a divalent hydrocarbon group which may have an ether bond. n ａ０１ is an integer of 0 to 2. Ra ０１ is an acid dissociable group. ]

4. The polymer compound (A1) further contains a structural unit (a2) represented by the following general formula (a-2), and the resist composition according to claim 3. 【Chemical Formula 6】 〔In the general formula (a-2), R ０２ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ０２ is a divalent hydrocarbon group which may have an ether bond. n ａ０２ is an integer of 0 to 2. Ra ０２ is a lactone-containing cyclic group, -SO ２ -containing cyclic group, or a carbonate-containing cyclic group. ] Claim 5 A method for forming a resist pattern, comprising: forming a resist film on a support using the resist composition according to claim 1 or 2; exposing the resist film; and developing the resist film to form a resist pattern.

Images